International Journal of Hydrology Science and Technology (68 papers in press)
The Analysis of the Most Important Climatic Parameters Affecting Performance of Crop Variability in a Changing Climate
by Safieh Javadinejad, Saeid Eslamian, Kaveh Ostad-Ali-Askari
Abstract: Projecting crop yield, under future climate plays a vital role in planning for supply and demand, especially in arid and semi-arid regions. The rice and potato are sensitive to variations in temperature and rainfall patterns, the present study was undertaken to assess the impact of climate change on these crop yields. Historical climate data from 19712005 were used as input to CROPWAT model to analyse the potential and actual evapotranspiration that affects crop yields. Furthermore, the generated local climatic data of future years (20062040), (20412075) and (20762100) under the severest scenario (RCP 8.5) from CMIP5 climate model are selected. Then the data were downscaled statistically and were inputted to the CROPWAT to determine the changes in ETo, Eta and crop yield from the baseline period for Zayandeh Rud river basin. The results indicate that all crops show increasing water
requirement in the future period and enable us to generate the appropriate adaptation measures.
Keywords: climate change; evapotranspiration; CROPWAT; crop yield; Zayandeh Rud.
LANDUSE CHANGE AND SEDIMENT YIELD IN AN URBANIZED TROPICAL DELTAIC CATCHMENT IN PORT HARCOURT, SOUTH-SOUTH OF NIGERIA
by IFEANYICHUKWU EZEKWE, Michael Ulu Kalu ANYA
Abstract: River channel blockage due to high siltation is common in most urbanized catchments, leading to frequent flooding experiences. This is the case in the Woji River Basin. This study set out to investigate the changing landuse characteristics in the Woji River basin and its effect on the river channel dynamics and sediment yield. Channel morphometry was determined from remotely sensed data and correlationship was measured using the Spearman Ranks and Pearsons Product Moment co relational statistics. The result showed high influence of urban processes / landuse change on the River sediment yield, channel discharge regimes and channel morphometry characteristics. Other secondary effects of urbanization on the river dynamics found include; urban encroachment into the floodplains, deposition of wastes into the river course and high runoff occasioned by increasing basin surface imperviousness culminating in downstream flooding events. Treatment of river channel and headstream wetlands protection was among recommendations.
Keywords: Channel dynamics; Landuse; Sediment Yield; Urbanization; Woji River.
Determination of distance advanced by the waterfront in a border strip land using Laplace transformation
by Mahbub Hasan, Aschalew Kassu
Abstract: Among various methods of surface irrigation, border method is widely applicable to cultivate most cereal crops like wheat, maize etcetera and rice (Amiri et al., 2016). The waterfront advance data has to be synchronised with the infiltration depth, especially at the head end along with the consideration of sufficiency of infiltrated depth of water at the tail end. With that point of view, this study was undertaken to calculate the waterfront advance distance from the head end using Laplace transformation. Values for the constants for infiltration equation were collected and used in the Laplace transformation equations and found to match the calculated and actual waterfront advance data with a very reasonable discrepancy. The actual
waterfront distance was only 0.51 m shorter than that was calculated by Laplace transformation. This might have caused due to soil cover, irregular tillage operation, huge potholes, and discontinuation of the uniformity of slope of the border strip. Application of this method will help to increase the water application efficiency with respect to flow size, border strip slope, depth of water requirement infiltrated in certain time to meet the crop water requirement.
Keywords: border irrigation; Laplace transformation; infiltration; border strip; waterfront advance; optimum irrigation water.
GIS based impact analysis of revitalization of dried rivulets in Pampa River basin, Kerala, India
by MAYAJA NA, SRINIVASA CV
Abstract: Inundation models play significant role in flood disaster management. Pampa River is a tropical, monsoon fed river in Kerala, India. Its basin experiences severe recurring floods owing to excessive human interference. Some of the streams in this river, which effectively did hydraulic-balancing, dried up due to indiscriminate human intervention. In this paper,utilizing HEC-RAS model, flood plain inundation map of Pampa River Basin evolved. Scenario of rejuvenating two prominent dried streams simulated and effects of rejuvenation in reducing flood havoc analyzed.Study revealed that by revitalizing dried rivulets, about 20% reduction in flood inundation can be achieved, improving flood situation considerably.
Keywords: Pampa river basin; rejuvenation of rivulets; flood plain inundation mapping.
Runoff Volume by SCS Method for the Alabama A&M University Agricultural Research Station
by Mahbub Hasan, Aschalew Kassu
Abstract: This study was undertaken to determine and have the information on runoff volume that could be available for water reuse in cultivating crops. This information might help in decision making for water budgeting and achieving the best water management in crop cultivation practices. This research was conducted in the agricultural research station of Alabama A&M University in Hazel Green, Alabama. A part of the total research station, an area of 40.82 ha belongs to the Agronomy and Crop Science was selected with the hydrologic soil group of C and B of 24.49 and 16.33 ha, with land use pattern of straight row and small grain straight row, respectively. Both the land areas were in good conditions. Runoff volume was calculated by the SCS method and found to be 1.40 ha-m. Rainfall information as reported in earlier works and other
related information and their applications were found to be suitable.
Keywords: runoff; SCS method; hydrological soil group; rainfall.
Assessment of climate variability and short term land use land cover change effects on water quality of Cahaba river basin
by Pooja Preetha, Ashraf Al-Hamdan, Michael Anderson
Abstract: This study examines the short term impacts of land use land cover (LULC) changes as well as climate variability on the water quality of the Cahaba river watershed in Alabama. The Soil and Water Assessment Tool (SWAT), in combination with spatial-temporal analysis were applied for evaluating contributions of dominant LULC patterns on changes in the sediment yields and nutrient loads. Optimized hot spot analysis with LULC change alone showed decreases in sediment yield and nutrient loads in the upper Cahaba watershed where forests and agricultural lands were replaced by urban development. Climate and LULC raised annual sediment yield and phosphorus load by 2.8% and 61% respectively and lowered nitrogen load by 17%. The combined changes in climate and land use posed a stronger impact on water quality in future. The findings of this study will provide useful information for future water and land management in the Cahaba river basin.
Keywords: Water quality; Land cover change; Climate change; SWAT model; Cahaba river basin.
Damaging hydrological events during the exiting of the Little Ice Age in a highland area of Southern Italy
by Nazzareno Diodato, Giuseppe Santoni, Andrea Cevasco, Francesco Fiorillo, Gianni Bellocchi
Abstract: Historical documentary sources reflect a myriad of social, cultural, political, and scientific narratives about weather, climate and hydrological effectiveness. Their use in climate research provides an important contribution to current debates about climate and related damaging hydrological events. In Europe, the end of the Little Ice Age (LIA, 18401920) was characterized by an unusual mixture of storms, floods and landslides. They have marked profoundly the regional landscape of the highlands of the Tammaro area (Campano Apennines, Southern Italy). In this way, we found that episodes of climate variability and its extremes have often disrupted ecosystems during stormy wintertimes (SeptemberMarch) by injuring plant development phases,
and causing sometimes disruption, while also creating new interactions with the
agricultural and social environment. The results indicated that the end of the
19th century was the stormiest period of the series 18002000, in conjunction
with landscape deforestation started in 1850.
Keywords: climate variability; deforestation; documentary sources; extreme precipitation events; floods; hydrological hazards; landslides; Tammaro basin; Southern Italy; storms.
Application of web enabled open source geospatial technologies in generation of water resource development plan
by Arati Paul, Vemuri Chowdary
Abstract: Sustainable planning and management of water resources is necessary, as water is essential for food security, industrial production and sustaining ecosystems as well as socio-development of a country. Geospatial technologies are successfully employed in the field of hydrology for planning and management. However, the implementation of these technologies is restricted because of non-availability of necessary data, processing knowledge as well as software and hardware infrastructures in time. Hence, in this study, a web enabled customised geographic information system (GIS) is developed using open source geospatial tools to generate water resource development
(WRD) plans for non-GIS professionals. The application was demonstrated by
considering the spatial layers pertaining to three districts of Jharkhand state, India. The tool takes the area of interest as an input from the user and analyses the data to produce WRD action plans. Plans include identifying suitable zones for artificial recharge that makes watershed management simpler and more effective.
Keywords: water resource development plan; geospatial; web GIS; open source; multi criteria analysis.
Effect of Roughness Coefficient on Discharge and Flow Depth by Using Hydraulic Model for Nethravathi River Basin, India
by Pramodkumar Kappadi, Nagaraj M. K.
Abstract: The river stage and discharge are dynamic due to various factors affecting the flow characteristics in a natural channel. The channel roughness plays an important role since it is not a constant parameter and varies along the length of the river. Estimation of discharge and depth of flow is contingent upon accurate representation of the roughness coefficient value. The objective of the present study is to assess the variation of Mannings roughness coefficient on flow characteristics of Nethravathi river. The study is carried out between the two gauging stations of Uppinangadi and Bantwal for a length of 28 km river reach. In the study, 1D SaintVenant equation based HEC-RAS hydraulic model was used to simulate the effect of roughness coefficient (Mannings Coefficient n) on discharge and stage of river flow. The model is calibrated using flow hydrograph from June 2008 to December 2008 and validated for the flow duration from June 2009 to December 2009. The model result showed good consensus between model computed flow discharge values and observed flow discharge measured at Bantwal gauging station. The study results indicated that the computed stage values are increased and the associated peak discharges are decreased with the increase in Mannings roughness coefficient. In addition, the stage-discharge rating curves revealed that Mannings n value is relatively more sensitive at higher discharge values. The computed results are useful to predict flood stage and discharge values for the Nethravathi river basin.
Keywords: Hydraulic model; Roughness coefficient; HEC-RAS; Discharge and Stage.
A Hybrid model to assess the hydropower potential for rivers
by Anas Mahmood Al-Juboori, Aytac Guven
Abstract: A computer program called hydropower plant site assessment program (HPSAP) was developed by using Visual Basic programming to assess the hydropower potential in river basins. A methodology to select the best site to install the hydropower plant was developed according to meteorological, hydrological and economical design criteria. HPSAP has several options to analyse watersheds for different head or power criteria. HPSAP estimates the locations coordinate and upstream drainage area for powerhouse and weir locations, elevation of powerhouse and weir, the distance between weir site and powerhouse site, penstock length, design head and power for proposed plants. The design discharge is estimated by using a flow duration curve
regression equation developed by group method of data handling (GMDH) based on rainfall-runoff model outputs. The hydrological engineering centre-hydrological modelling system (HEC-HMS) model was used as the hydrological rainfall-runoff model in this study. The results have proven the ability of the program to assess the hydropower potential in river basins.
Keywords: run-of-river hydropower plant; flow duration curve; FDC;
Visual Basic programming; hydropower program; hydrological engineering centre-hydrological modelling system; HEC-HMS; group method of data handling; GMDH.
Assessment of Factors Affecting Bromate Formation in Drinking Water Bottles
by Maruf Mortula, Serter Atabay, Haifa Ismail, Nour Aljafari
Abstract: This paper presents the results of experimental study conducted to investigate the effects of different parameters on bromate formation in bottles of drinking water. The effects of various temperatures, storage times, pH and some water quality parameters including bromide, total organic carbon (TOC) and total dissolved solids (TDS) were investigated. Three different regional and international water bottles brands available in the United Arab Emirates (UAE) were selected. For each brand 36 polyethylene terephthalate (PET) bottles of water were used for the experimental study. It is concluded that the effects of storage time and temperature was negligible for all brands and that the effects of pH levels on bromate formation was noticeable. Increasing pH level increases the bromate formation for brands X and Y but decreases the bromate formation for brand Z. It is also concluded the effect of TDS, TOC and turbidity on bromate formation was not significant.
Keywords: polyethylene terephthalate; PET; bottle water; bromate; total organic carbon; TOC; total dissolved solids; TDS.
Using Two-Dimensional Numerical Model for Hydrodynamic Modeling of a Western Himalayan Alluvial River Reach
by Abdul Qayoom Dar, Aqleem Shah
Abstract: The era of numerical modeling has become an integral part of the decision making process and design for water resource engineers especially in data deficient water bodies. A study has been carried out to assess the variability and magnitude of flow regimes at ungauged sites of an alluvial river reach, i.e. River Jhelum in Jammu and Kashmir, India. A finite element numerical model. (TELEMAC 2-D) was used to simulate the river hydrodynamics of the domain from Sangam (33
Keywords: Numerical modeling; Hydrodynamic analysis; Ungauged sites; Flood map; Alluvial River course; Statistical analysis.
Impact of Climate Change on Water Sector in Gumbasa Watershed, Central Sulawesi, Indonesia
by I. Wayan Sutapa, Saiful Darman, Djayani Nurdin, Fathurrahman -
Abstract: Global climate change resulting in increased or decreased rainfall volume, rising temperatures, may also be associated with changes in season patterns, wind patterns, air humidity, and solar irradiance. This study aims to determine the potential hazards arising in the water sector due to climate change. This research was conducted in Gumbasa watershed, Central Sulawesi, Indonesia. Primary data used in this research are characteristic of land, while secondary data include rain data, climatology data and earth map. The data of rain used by the nearest station are Bora Station, Kulawi, Palolo, Bangga Down, and Wuasa, whereas climatology data is used Bora Station. Some analyzes performed include: 1). Regional rainfall; 2). Evapotranspiration; 3). Water availability; 4). CDF Statistical Analysis; 5). Climate change projections; 6). Potential hazards. The conclusions of this study are: 1). There is no danger of decreasing water availability for all periods (1993-2052); 2). There is a high flood hazard in the period 2013-2022, while the other periods do not occur due to flood hazard; 3). Low drought hazards occur in the period 2003-2012, while for other periods there is no drought hazard
Keywords: Climate Change; Gumbasa Watershed; MockWyn-UB Model; Water Sector; Hazard.
SwinOSD: a computer tool for designing Onsite Detention (OSD) Basin
by Monzur Imteaz, Iqbal Hossain, Amimul Ahsan, Abdallah Shanableh
Abstract: A computer tool was developed to calculate sizing requirements of onsite detention (OSD) basins. Tool reads design rainfall and temporal pattern from pre-populated spreadsheets, which are linked with the tool. Tool calculates OSD storage required from the calculated runoff time-series (for a particular time period) and user-provided permissible site discharge (PSD). The tool calculates maximum storage required considering worst temporal pattern of rainfall for a conservative design. It also calculates average storage volume required taking averages of calculated storages based on all the temporal patterns. Eventually, for a selected water height, tool calculates required orifice diameter to maintain a given PSD. The tool calculated storage requirements were compared with the widely used urban drainage model, DRAINS. For all the selected scenarios, the DRAINS simulated storage-depth curves show that the developed tool calculated results are compatible with DRAINS calculations under same scenario.
Keywords: ARR; OSD; PSD; design rainfall; DRAINS.
ASSESSING THE EFFECTIVENESS OF ANALYTICAL AND NUMERICAL INVERSE MODELING APPROACH FOR SLUG TESTS INTERPRETATION
by Francesco Chidichimo, Michele De Biase, Carmine Fallico, Samuele De Bartolo, Mario Ianchello, Salvatore Straface
Abstract: Groundwater management or remediation requires the knowledge of the main hydrodynamic parameters of the hydrological system. The aim of the study focused on the investigation of the reliability of the methods used for the estimation of these important parameters. Several pumping and slug tests were performed in the Hydraulics Laboratory of University of Calabria, where a high controlled experimental apparatus was designed and constructed. The data collected during the experiments have been used to estimate the hydraulic conductivity and the storage coefficient of the porous medium. The analysis was carried out both through classical analytical methods and by the development of an ad hoc three-dimensional finite element model of the apparatus working in transient conditions. An extreme variability in the results was observed but the estimates obtained by the inverse numerical modelling were the ones returning, on average, the best outcomes among all the characterisation methods
Keywords: slug tests interpretation; analytical solutions; numerical inverse modelling; groundwater; laboratory experiments; hydrodynamic properties; hydraulic conductivity estimation; storage coefficient estimation; characterisation techniques.
The Effect of Urban Development on Runoff Volumes in the London Borough of Barking and Dagenham
by Shahrokh Soltaninia, Lobat Taghavi, Saeid Eslamian
Abstract: Estuarine and coastal areas have always had an issue with regard to an increased level of flood hazards. In addition, since urban developments have an impact on water runoff, future house building plans and new decisions to prevent flooding are essential. The peak rate of runoff is greater for a developed site than it was for the pre-development sit and flood recovery of developed sites requires more time. Therefore, it is crucial to ensure that future developments do not worsen flooding problems. The London Borough of Barking and Dagenham (LBBD) is an example of an area in the north-east corner of London, on the north bank of the River Thames which is currently undergoing major developments. The runoff coefficient as calculated by the Wallingford modified rational method, the geographic information system, and the core strategy in the LBBD illustrated that there was an increase in the peak runoff discharge by about 29.4% following developments. The use of sustainable urban drainage systems and other feasible mitigations such as drainage systems could reduce the risk of flooding as a result of surface water runoff.
Keywords: Runoff volume; Urban development; Wallingford modified rational method.
Assessment of groundwater quality of the Karst aquifer of Cherea, Tebessa (Northeast of Algeria)
by Yasser Mehidi, Ismail Nouioua, Ines Kahoul
Abstract: This article is indicated for the assessment of the groundwater quality of the karst aquifer of Cherea, Northeast of Algeria by the use of the Water Quality Index (WQI). Ten samples are taken from different areas of the basin depending on the geological variation of the soil. The analyses are carried out for 12 physico-chemical parameters, in which 10 parameters used for the determination of WQI. The analyses results show that most of the samples have acceptable contents of these parameters, according to the standards of the Algerian Ministry of Water Resources (2011) and WHO (2016). The WQI results indicate 40% of checked points have a good quality, 40% have a fair quality and 20% have a poor quality. This poor quality is equivalent to the high levels of Nitrates that exceed the standards. In general, the WQI for the collected samples varies between 32.16 and 91.4.
Keywords: Groundwater quality; Water Quality Index; Cherea plain; Physico chemical analysis; ground water; Karst aquifer.
Conjunctive Use Modeling and Application of Jaya Algorithm for Optimization in Multi Crop Irrigation
by Pawan Bhavsar, Jayantilal Patel
Abstract: A linear conjunctive use mathematical model is developed for an effective irrigation purpose. Objective of the model is to maximize the net benefit from the available land and available crops without changing the cropping pattern. Great potential of groundwater is being identified in the study area and it is shown that if farmer uses groundwater in addition to the canal water how they can help the improving economy of the nation. The developed conjunctive use model was subjected to various constraints such as maximum groundwater extraction constraint, maximum canal water availability constraint, gross irrigation requirement constraint and minimum and maximum area constraint. The developed model is being solved by JAYA algorithm. The results obtained by JAYA area validated by widely used optimization tool LINGO. From both the algorithm it has been found that sugarcane cultivation has to be increased so as to obtain more net return. Increased potential can be 5-15% of CCA. In almost all season except sugarcane all other crops have shown less potential to increase in an area. Wheat and all other crops cultivation have to be decreased by 2 - 5% of the total area of cultivation. Optimization results shows that, to maximize the net benefit all other cultivable area (except sugarcane) has to be reduced by 7- 15%. Overall net benefit is increased to 5-10% in any given area. From the results it has been concluded that, by utilizing both canal water and ground water, canal water can be saved up to 40% which can be used for the other purposes or it can be shared with the neighboring state.
Keywords: Irrigation; conjunctive use; crop water requirement; linear programming; JAYA algorithm; LINGO software package.
Evaluation of the impact of climate change on reference crop evapotranspiration in Hamedan-Bahar plain
by Hossein Talebmorad, Jahangir Abedi-Koupai, Saeid Eslamian, Sayed-Farhad Mousavi, Samira Akhavan, Kaveh Ostad-Ali-Askari, Vijay P. Singh
Abstract: Abstract: Evapotranspiration (ET) is one of the important components of the hydrologic cycle that can be affected by climate change and it is important to determine its correct value for water resource management and agricultural programming. In addition, evapotranspiration (ET) should be evaluated in arid and semi arid areas which are more vulnerable in water crisis. Considering the fact that calculation of reference crop evapotranspiration (ETo) is prerequisites for other plants evapotranspiration calculation and using this parameter the trend of evapotranspiration could be studied, this research assessed the impact of climate change on reference crop evapotranspiration (ETo). Climate change was simulated using the HADCM3 general circulation model (GCM) and was downscaled using the LARS-WG downscaling model. After downscaling and uncertainty analysis, climatic parameters were generated until year 2090, assuming three emission scenarios A1, B1 and A1B. After fitting an equation for ETo, its future values were calculated for the simulation period. Results indicated an increase in the mean annual ETo under all three scenarios. The highest increase occurred under the A2 scenario and the lowest increase occurred under the B1 scenario. Comparison of monthly ETo values showed that although greenhouse gas emissions in the next 30-year period did not lead to a perceptible increase in ETo but severe long-term increase was predictable. According to predictions, the mean monthly ETo in the [cold months] in different scenarios did not change significantly and much of the increase occurring in the mean annual ETo was due to a significant increase in the monthly ETo in [hot months] of the year. Therefor a review and revise in crop pattern and water resource management is needed in study area.
Keywords: Climate change; ETo; Greenhouse gas emission scenarios; LARS-WG; GCM.
Performance Evaluation of Flow Routing Algorithms in Different Topographic Characteristics
by Swarna Bintay Kadir
Abstract: It is a complicated process to estimate the direction of water flow above the earth's surface. Several algorithms exist to calculate the flow direction, which may yield different results for a particular place with specific topographic characteristics. The complicacy lies in the choice of algorithm to get more accurate results. The selection of algorithms should be made considering their suitability in different topographic situations. In this research, eight existing commonly used algorithms have been used to extract the streamlines of a study area with a distinct topographic condition. This study tends to analyze and compare the resulted streamlines from these algorithms with a reference streamline. Evaluation has been done based on variation in stream orders, variation in contributing cells and spatial changes. Spatial differences have also been measured considering three topographic characteristics: elevation, slope, and roughness of study areas. Lastly, this study attempts to suggest the usability of these algorithms in different terrain characteristics.
Keywords: Flow Routing; Digital Elevation Model; Spatial Change; Geographic Information System; Stream Extraction; Topographic Characteristics; Elevation; Slope; Roughness.
Effect of First Flush Diversion on the Reliability of Urban Rainwater Harvesting Systems in Dhaka
by Tanvir Ahmed, Mushfiqur Rahman Khan
Abstract: First-flush diversion, which involves discarding the initial, dirtiest flush of runoff from a rainfall event, is one of the most commonly adopted and effective means of improving stored water quality in rainwater harvesting (RWH) systems. Discarding a certain fraction of the runoff can diminish the amount of water available for use and may affect the reliability of the RWH systems. We developed Storage-Reliability-Yield (SRY) relationships within practical ranges of daily demand and storage volumes and analyzed the reduction of reliability of RWH system for Dhaka city resulting from different first-flush diversion schemes recommended in national and international guidelines. It is found that a maximum 5% reduction in reliability can occur if various strategies of run-off diversion are applied. While analyzing the operational performance of four RWH systems in Dhaka city, it was found that the baseline reliabilities of three out of the four RWH systems were very poor although first-flush diversion will not significantly reduce their performance any further. The study highlights that SRY relationship can be effectively applied to determine the reliability of existing RWH systems and to assess the effect of first-flush diversion schemes on its performance.
Keywords: First flush; Rainwater harvesting; Reliability; Storage.
Lysimeter water balance for estimation of water requirement and crop coefficient of rice in temperate climate
by Owais Ahmad Bhat
Abstract: The field study on lysimeter water balance presented here pertains to the estimation of evapo-transpiration and the crop coefficient of the main crop of rice being grown in the temperate region of the State of Jammu and Kashmir, India. No such study was carried out for the region earlier, which adversely affects the water use and the crop growth and its yield. Two different locations of the Kashmir Valley were selected for the experimental study (Shalimar and Khudwani). The experimental studies were carried out during the crop season, at these two locations with the help of two non -weighing type lysimeters (drainage type) of 1m
Keywords: Water requirement; Crop coefficient; Rice; Growth stages; reference ET model,lysimeter.
Unique Lightning Signatures Observed from sub-tropical, Mountainous country, Nepal
by Pitri Bhakta Adhikari
Abstract: Unique lightning signatures have been observed from sub-tropical, mountainous country, Nepal. These signature were observed by measuring the electric field using a simple circuit and antenna system. Theunique unusual signatures analyzed are assumed them to be positive ground flashes. These lightning signatures were each characterized by a relatively slow, negative electric field events preceded by a pronounced opposite-polarity pulse. The average durations of the main waveform was 523.84
Keywords: Unique waveforms; Unusual lightning; Himalaya’s thunderstorm; Opposite polarity-pulses.rn rn.
Estimating probable maximum precipitation for Bangladesh
by Sheikh Hefzul Bari
Abstract: One day probable maximum precipitation (PMP) is estimated for 29 meteorological stations of Bangladesh. Widely recognized statistical method viz. Hershfield method is used for PMP estimation. Afterward, the spatial prediction map of PMP is generated based on Geostatistical analysis. It is found that Hershfields frequency factor (km) for estimating PMP varies from 2.03 to 8.03 while most are around 3 to 4. Results indicate that higher values of PMP are found in the eastern part of the country whereas lower at the western part. However, maximum PMP (811mm) is found in Bhola which is located in the coastal region. The second highest is also found in the coastal region. Results from the Geostatistical analysis shows that EBK (Empirical Bayesian Kriging) performs slightly better in the spatial prediction map generation.
Keywords: Probable maximum precipitation; Bangladesh; Hershfield method; Empirical Bayesian Kriging.
Uncertainty and Sensitivity Analysis in Developing Surrogate Model of Flood Control Channel Design in an Urban Area
by Masoume Behrouz, Saeed Alimohammadi
Abstract: The main purpose of uncertainty analysis is deriving the model output statistical properties and/or its cumulative distribution function (CDF). In this paper, uncertainty and sensitivity analysis of a flood control design problem have been implemented in an urban area using Monte Carlo simulation via Latin hypercube sampling method as well as response surface methodology (RSM) for global sensitivity analysis (GSA). Probability theory along with evidence theory which is a more modern theory especially for epistemic uncertainty analysis has been used here. Several results have been achieved after uncertainty propagation such as the model output CDFs and quantiles. Also, a GSA has been implemented and sensitive parameters determined. Then using RSM, a regression model has been defined as surrogate of the main model. The training and testing of the surrogate model reveals its efficiency that means it's accurate enough for further analysis without any need to the main model.
Keywords: Uncertainty analysis; Global sensitivity analysis; Aleatory; Epistemic; Evidence theory; Flood control; Latin hypercube sampling; Monte Carlo simulation.
An efficient and robust algorithm for estimating parameters in a horizontal subsurface flow of a constructed wetland treating greywater
by Ihsane Mouaouia, Abderrahim Charkaoui, Nour Eddine Alaa
Abstract: We establish a new method for estimating parameters in reaction-adsorption-diffusion systems modeling the greywater treatment through a horizontal subsurface flow of a constructed wetland. Two cost functions are presented to estimate the permeability coefficients, the initial concentration and the degradation of the phosphor in the considered model. A Lagrangian method is considered to compute the derivative of the cost functions with respect to the state variable.
An iterative algorithm is illustrated with the reaction-adsorption-diffusion systems using optimization techniques and the adjoint state model. We were able to estimate our parameters and our initial data. In addition, the performance of our algorithm is evaluated by perturbing the data with various levels of additive noise.
Keywords: Horizontal Sub-Surface Flow Constructed Wetland; Mathematical Modeling; Advection-Dispersion-Reaction Equation; Inverse Problem; Lagrangian Method; Optimization Algorithm.
Determination of water requirement and crop coefficients for green gram in temperate region using lysimeter water balance
by Owais Ahmad Bhat, Mohd Akbar Lone, Rohitashw Kumar
Abstract: The field study was done on Lysimeter by employing soil water balance method to compute the irrigation requirement and Crop Evapotranspiration of green gram crop in temperate climatic zone of Kashmir, India. Reference evapotranspiration along with the crop coefficient values enables to generate crop coefficient curves of water utilization ,to manage irrigation requirement of a particular crop. The experimental study was carried out during the crop season, at Shalimar with the help of a non -weighing type lysimeter (drainage type) of 1m
Keywords: Lysimeter; Reference Evapotranspiration; leaf area index;crop coefficients;temperate:soil water balance.
Urban flood vulnerability mapping using integral value ranked fuzzy AHP and GIS.
by Abimbola Atijosan, Ibrahim Isa, Abayomi Alaga
Abstract: An integral value ranked fuzzy Analytical Hierarch Process (AHP) and Geographic Information System (GIS) based Multi-Criteria Decision Making (MCDM) system for urban flood vulnerability mapping of Ile-Ife is presented. Flood vulnerability mapping is required and critical for realistic preparedness, planning and mitigation of flood. Flooding causative factors like elevation, slope, soil, rainfall, drainage density, geology and land use land cover information were used as input to the fuzzy-AHP MCDM system. The integral value method was used in prioritizing and assigning weights to each causative factor in the MCDM process due to its ability to represent the relative importance of two or more triangular fuzzy networks (TFNs) rather than just an index for showing to what degree a TFN is greater than all the others. Vulnerability maps were created using GIS techniques based on the aggregation of the input factor and their derived weights in the fuzzy AHP MCDM system. This was done on a pixel by pixel level to yield the flood vulnerability map. The result showed that 4.41% of the study area was identified as very high vulnerability, with 30.90% identified as high vulnerability, 37.38% identified as moderate vulnerability, 18.28% identified as low vulnerability and 9.03% identified as very low vulnerability. Validation of the methodology was carried out by simulating flooding across the study area. The proposed approach can be applied in other urban towns to estimate and produce flood vulnerability maps. The flood vulnerability maps will help identify vulnerable areas and provide needed information to help mitigate the disaster risk posed by floods. This will further enable the development of effective flood risk management plans.
Keywords: Flood vulnerability mapping; G.I.S; fuzzy AHP; TFN.
DELINEATION OF GROUNDWATER VULNERABILITY TO POLLUTION AROUND DUMPSITES IN SAPELE, NIGERIA
by Ochuko Anomohanran, Bright Utieyin, Merrious Ofomola
Abstract: Fifteen vertical electrical soundings and six dipole-dipole profiles were conducted to determine the subsurface structure and groundwater vulnerability to pollution around dumpsites in Sapele, Nigeria. The result of the study showed that the subsurface consist of four geo-electric layers composed of topsoil, lateritic sand, fine sand and medium to coarse grain sand. The third and fourth layers were identified as the aquifer layers located at a depth ranging from 4.5 - 10 m. The analysis of the results obtained for the various geo-electric layers revealed that the resistivity values of the aquifer layers below the two dumpsites are lower than those of the control. This fact when compared with the values of the physico-chemical study of the groundwater, showed that the aquifer under the dumpsite is already been impacted. This is due to the inability of the first and second layers to protect the underlying aquifers. It is suggested that the dumpsites be relocated with special attention to the groundwater flow direction to avoid continuous contamination of the groundwater.
Keywords: Groundwater; vulnerability; dumpsites; geoelectric method; protective capacity; Sapele.
Prediction of stage-discharge relationship in two-stage channels
by Mahsa Hashemi, Serter Atabay, Abdullah Yilmaz, Maruf Mortula
Abstract: Predicting the stage-discharge relationship in two-stage channels is a significant factor, as it determines the discharge and the degree of flood accurately. There are conventional methods, in which they either do not meet the required accuracy or simplicity. In this paper, a new simple model is developed for symmetric compound channels to predict the stage-discharge relationship accurately. The method is proposed by improving the weighted divided channel method (WDCM), which includes the apparent shear force (ASF), wetted perimeters and B/b ratio. It was concluded that the improved weighted divided channel method (IWDCM) is limited to all rigid symmetric compound channels with B/b ratios greater than or equal to 3. The IWDCM led to an absolute percentage error always less than 10% for total discharges for all smooth and rough cases. The proposed IWDCM method will therefore be very helpful to hydraulic engineers to predict the stage-discharge relationship precisely due to its simplicity.
Keywords: Stage-discharge; symmetric compound channel; Weighted divided channel method; Apparent shear force.
Temporal Dynamics of Hydraulic Fracturing and Water Use: A Case Study from Northwestern Alberta, Canada
by Gopal Saha, Michael Quinn, Connie Van Der Byl
Abstract: The practice of hydraulic fracturing, an unconventional oil and gas extraction method, has increased significantly in North America. Hydraulic fracturing requires a large volume of water to fracture the source formations. This water is often withdrawn from nearby surface water or groundwater sources. Thus, there is the potential for negative effects on water sources, especially during low flow periods. This study presents the temporal dynamics of hydraulically fractured wells and water use in hydraulic fracturing by using a case study in a shale gas and oil play area in northwestern Alberta, Canada. Data from 432 wells during 2013-2014 were collected from a publicly available source (Frac Focus Chemical Disclosure Registry). The results showed the number of hydraulically fractured wells in the study area was greater in all but two months in 2014 compared to 2013. Water consumption (i.e., use) in hydraulic fracturing not only depended on the number of wells, but also on the type of rock formation, how deep and how many stages were required to fracture the targeted formation. The majority (52%) of total water consumption was conducted during low flow periods in 2013-2014. We recommend monitoring nearby water sources by respective authorities during low flow periods in order to protect aquatic ecosystems. The results obtained from this study provide useful information to the oil and gas industry for developing sustainable water resources management plans for hydraulic fracturing to minimize substantial negative impacts on water sources during low flow periods.
Keywords: Hydraulic fracturing; temporal dynamics; water use; northwestern Alberta.
Microbial Fuel Cells for Soil Based Green Energy Conversion System
by Anand Kumar K.S., Sachin Kumar, R.K. Saket, R. Rajendran, S. Eslamian
Abstract: This paper presents technological aspects, operating principle and scientific applications of MFCs for soil based green energy conversion system. The cell uses bacteria as biocatalysts to generate electricity by digesting biodegradable organics present in the organic waste material, through a catalytic reaction of microorganisms under an anaerobic condition. An investigation has intensified in this field in the last few years due to the promotion of sustainable energy production from organic wastes. Some researchers are uncovering that the importance of MFC technology is not only the production of electricity but the ability of electrode associated microbes to degrade wastes and toxic chemicals. This paper provides a platform to explore the possibilities of generating renewable power using biomass and the working principle of MFC technology with its applications. The soil microbial fuel cell technology has been implemented in the soil for green electricity generation.
Keywords: Biocatalyst; biomass; green energy; microbial fuel cell; organic waste; remote sensors; soil; wastewater.
Numerical study of shallow-water equations using three explicit schemes -Application to dam break flood wave-
by Tahar IKNI, Ali BERREKSI, Mohamed BELHOCINE
Abstract: The numerical method to solve dam break problem on regular bathymetry was developed. Two cases of dam break wave propagation on wet and dry bottoms were selected to verify the numerical model elaborated. Three numerical schemes of Lax-Friedrichs, Adams-Bashforth and Adams-Bashforth-Adams-Moulton are applied to simulate this phenomenon using the 1D Saint-Venant equations. An artificial viscosity is added to these numerical schemes to provide stability and reduce numerical diffusion. This viscosity makes the numerical scheme robust (very powerful) for the simulation of this phenomenon. The results obtained show that these developed models are able to simulate dam break wave propagation process. The relative error in the L1 norm between the computed results and analytical solutions is calculated. The L1 norm indicates that the Adams-Bashforth-Adams-Moulton scheme is better accuracy than the other two schemes. It is shown that the technique used is simple, accurate, robust and stable for the simulation of the dam break wave propagation on wet and dry bed conditions.
Keywords: dam break; explicit schemes; artificial viscosity; Lax-Friedrichs; Adams-Bashforth; Adams-Moulton.
Modelling the hydrological processes of Koupendri catchment northwest, Benin.
by Chukwuebuka Vincent Azuka, Attanda Muinou Igué
Abstract: This study calibrated and validated rainfall-runoff model (WaSiM) to aid decisions on sustainable management of scarce water resources in Koupendri catchment. The model was successfully calibrated (NSE= 0.61; R2=0.61, RMSE= 0.63) and validated (NSE=0.68; R2=0.78; RMSE=0.57) using optimized soil and land use parameters. Though, the model under predicted some of the peak flows, the overall calibration result could be adjudged satisfactory with a p-factor of 0.94 and an r-factor of 0.93 which were all within the acceptable range of uncertainty. Evapotranspiration and discharge constituted 98-99% of the total water balance of the catchment while the change in soil moisture storage constituted only <2%. Surface runoff was the predominant stream flow component (86-90%), suggesting infiltration excess overland flow as the main runoff generation mechanism for the catchment. The water balance reflected the hydro climatic conditions of the catchment with actual evapotranspiration ranging between 68% and 75% of the total annual rainfall.
Keywords: surface runoff; rainfall-runoff; water resources; hydroclimate; hydrological.
The Implication of Tectonic Structures Compartment in the Hydrochemical Distribution in the Merapi Unconfined Aquifer System
by Herry Riswandi, Emi Sukiyah, Boy Yoseph C.S.S. Syah Alam, Mohamad Sapari Dwi Hadian
Abstract: This study focuses on the tectonic structures compartment. Furthermore, it controls the hydrochemical and piezometric groundwater distribution in the Merapi unconfined aquifer system. The investigation methods are proposing morphotectonic, statistical, and a hierarchical cluster of hydrochemical analysis. Thus methods are to characterize the multi-element of the structures spatial pattern on the structural compartment. And to aims the cross-correlation of the hydrochemical population on the compartment. The morphotectonic studies showed structures lineament created by active tectonics, and it controls the groundwater flow system. The statistical analysis represents a relation between structure lineament controlling flow pattern and groundwater piezometric. It is related to the hydrochemical characteristics in the concentration of the ion analysis and the value of total dissolved solids. The analysis results are depicted on the digitized map for each compartment compares with the groundwater distribution flow and trends of piezometric. From there, the hydrogeochemical spatial distribution allowed us to characterize the unconfined aquifer system.
Keywords: Hydrochemical; morphotectonic; hierarchical cluster; piezometric; groundwater; tectonic.
Assessing Impacts of Climate Change on Hydrology in Data-Scarce Volta River Basin using Downscaled Reanalysis Data
by Sulemana Abubakari
Abstract: This study uses high resolution (0.3o~3km) Climate Forecast System Reanalysis (CFSR), SWAT and statistically downscaled A1B emission scenario to assess impacts of climate change on hydrology in data scarce Volta River basin of West Africa. SWAT was calibrated to simulate runoff at six gauging stations within the basin. Using 1979-2008 as baseline, there is average increase in rainfall of 3.0 to 5.0%. Average rainfall in 2071-2100 is higher than 2041-2070 and 2011-2040 by 0.9 and 2.0% respectively. Monthly runoff is projected to increase from February to August and decrease from September to January. Overall the simulation reveals increased variability and increase of 12.0% in average annual runoff. The results give more insight into future water availability and provide quantitative data for incorporation into climate change adaptation policies for effective water resources management in the basin.
Keywords: Volta River Basin; Climate Change; SWAT;IPCC; scenario; NCEP Climate Forecast System Reanalysis (CFSR).
Hydrological models: A review
by Dinagarapandi Pandi
Abstract: Hydrological modelling is carried out for understanding the earth environmental system and it improves a decision making in water resource planning, flood prediction, irrigation practices, groundwater development etc. So, different kind of hydrological parameters that are implemented in the soft computing models, mathematical models and systematic model. These combined models perform complex hydrological models. It is simply classified as physical based, conceptual, empirical and hybrid hydrological models and it releases the suitable models for the global or particular national. Every hydrological model is ad hoc with the several hydrological parameters as input. But it provides the results as hydrological components, especially runoff. At this moment, the runoff parameter is used for understanding the hydrological model efficiency, which depends upon the model requirements. Moreover, runoff parameter is mandatory performs the model calibration and validation using monitored runoff to follow the model efficiency at the present scenario. In this paper, model classification is reviewed to understand the model requirement and efficiency over the watershed. From the limited sources of hydrological data is to choose in the hydrological modelling for a real-time world.
Keywords: Hydrological; Empirical; Conceptual; Physical-based; Hybrid; Model validation and Model uncertainty.
Evaluation of the efficiency of the Ouargla wastewater treatment plant - (South- East Algeria)
by Sedrati Nassima, Majour Habiba
Abstract: The study relates to the quality of raw water treated at the wastewater treatment station WTSof Ouargla (Algeria). This study made it possible to highlight the importance of the physicochemical characteristics of wastewater within the WTS. The results we have obtained clearly show the effectiveness of such a system of urban wastewater treatment of a medium agglomeration. Pollution abatement achieves organic pollutants (COD , BOD5, NO3 and NO2). Despite the efficient treatment of these waters remain of bad quality to very bad. They are rich in nitrates and phosphorus, which avoided the purchase of fertilizers, so they can be used for irrigating non-productive trees and palms according to FWO parameters.
Keywords: quality; characteristics; pollution; efficiency; urban wastewater; Ouargla.
Cloud Classification: Principles and Applications
by Seema Mahajan, Bhavin Fataniya
Abstract: Clouds classification is essentially required in weather forecasting and climate related study. Optical remote sensing satellite images are widely used for analyzing coastal, rural, urban, forest area etc. Detection, removal and classification of cloud are the major challenge to deal with satellite based images. In this paper literature survey on cloud classification techniques published during 2000 to 2018 is presented. In recent years various approaches are applied for cloud classification such as threshold based, Machine learning, clustering, K-Means, K-NN (k-nearest-neighbor) algorithm and hybrid approach. Threshold based is the easiest approach but it fails to classify cloud in complex sky conditions. It is also unable to classify cloud at night time. Machine learning based approach gives highest accuracy but it depends on various parameters like day/night time, weather season, types of satellite and geographical region of the cloud. It is recommended to have hybrid model with the use of machine learning, threshold values and physical parameters
Keywords: Cloud Detection; Classification; Classifier; Machine learning.
Analysis of drought, its impact on landuse / landcover and duration-severity analysis for the Sone River Catchment, Bihar
by Suraj Kumar, Thendiyath Roshni
Abstract: Drought is a natural hazard, which poses significant threat on water and food security. Drought indices are calculated for the Sone river catchment, Bihar utilizing DrinC (Drought Indices Calculator) software for the period 1991-2014. Standard Precipitation Index, Deciles, Reconnaissance Drought Index and Streamflow Drought Index are the indices calculated by the DrinC software. Results of correlation analysis between SPI and RDI showed a R2 value of 0.99 for both monthly and annual time scale. The drought conditions were found to be severe in the year 2010. The study was also extended to assess the impact of drought on land use / land cover which depicted a decrease of agriculture land from 89% to 84%, water body increases from 1% to 2% and increase of built-up land from 8% to 12%. The joint probability distribution of drought characteristics was also studied through bivariate modelling of droughts and found that Frank Copula is suitable for the catchment area.
Keywords: Copula; DrinC; Drought; Land use / Land cover.
Groundwater Deterioration in Arid Agricultural Area Under the Pressure of Climate Change and High Refugee Inflow
Case Study: Jordan
by Osama Gazal
Abstract: Protecting groundwater from pollution and depletion is a high priority in Jordan as one of the poorest water countries in the world. Climate change and rapid population growth due to natural and unexpected growth over the last decades and associated anthropogenic activities have exacerbated many environmental problems, such as nitrate contamination and groundwater depletion. The influx of a large number of refugees escaping the Syrian crisis poses serious stress on the natural water and land resources, especially in North Jordan. This study assesses the deterioration of renewable groundwater aquifers through a comprehensive analysis, using all available hydrogeological and climatological data with the groundwater level and quality records from several production wells in the shallow aquifer. In this study, the online version of Microsoft Excel 365, the GIS (Geographical Information Systems) tools, RS (Remote Sensing), and FAO irrigation programming software were used. The research demonstrated the fragility of the scarce water resources situation in the area under study, their high vulnerability to degradation in quality and quantity due to lack of precipitation, a succession of droughts, unsustainable use of water sources, exposure to contamination from agricultural activities, and the natural susceptibility of these resources to the contamination that has been approved by groundwater vulnerability maps, the description of the hydrogeological setting and high groundwater nitrate contamination associated with heavy use of fertilizer in agricultural areas and waste from dairy and poultry farms. The study showed the importance of reliable groundwater vulnerability maps and the need to avoid intensive agricultural activity in highly vulnerable areas and suggested viable alternatives.
Keywords: Groundwater Vulnerability; Climate Change; Water scarcity; Agriculture; Drought; Refugees; Contamination;.
Developing model for forecasting rainfall intensity-duration-frequency curves using artificial neural network in Al-Najaf Region, Iraq
by Ayad K. Hussein, Hayder H. Kareem, Hussien A. Almadani
Abstract: The surface and subterranean water sources are greatly affected by the precipitations intensity (I), sustainability (Duration-D) as well as its return
period (Frequency-F). Therefore, attention is directed to identify the relationship between these elements, especially in present time which suffers from recession of rain. The research focuses on establishing the relationship (IDF) in Al-Najaf Governorate, Iraq. Using the artificial neural network (ANN) and MATLAB, a new and rapid method is developed to link these parts. The model is calibrated using multiple methods and the results matched the collected data. In addition, the accuracy of the results obtained from the developed program/model is compared to programs of other researchers and its accuracy is greater and striking. The ruling curve IDF of Al-Najaf Governorate is derived which will help in extracting these components easily. The developed program/model can be interesting for various locations with only changing its inputs.
Keywords: intensity-duration-frequency curves; artificial neural network; ANN; Al-Najaf Region; statistical distributions; mean squared error.
Utilizing ammonium sulfate by-product, recovered from liquid manure with an ammonia recovery gas-permeable system, as a plant nutrient
by Amir Masoud Samani Majd, Gerald L. Riskowski, Saqib Mukhtar, Sam E. Feagleyd
Abstract: Ammonium sulfate by-product (ASB) was recovered from liquid dairy manure by using an acid-filled tubular gas-permeable membrane and evaluated as a plant fertilizer in comparison with synthetic ammonium sulfate (AS), and Control treatments. Two rounds of experiments with and without limestone (CaCO3) were also conducted to evaluate the impact of soil pH. In each round of experiments, wheat was grown in 12 pots (4 replications/treatment) and the required nitrogen (N) was calculated and added to the soil by using ASB and AS. The results of both rounds of experiments showed that the ASB treatment produced significantly higher wheat germination, biomass, dry mass, biomass per plant and dry mass per plant relative to the AS and Control treatments. ASB had greater availability of N and S which improved the plant growth parameters. The applied CaCO3 in the second round of experiments increased seed germination and other plant parameters.
Keywords: ammonia; gas-permeable membrane; ammonium sulfate; nitrogen (N); lime stone; sulfate (S); soil fertilizer; plant nutrient; macronutrient; biomass; dry mass,.
Loss Methods in HEC-HMS Model for Streamflow Projection under Climate Change: A Review
by Habibu Ismail, Md Rowshon Kamal, Md Abdul Mojid, Ahmad Fikri Bin Abdullah, Lai Sai Hin
Abstract: Hydrologic models are tools used extensively for simulation of various processes of the hydrological cycle, depending majorly on their characteristics. These models are classified as event-based, simulating a short-term hydrological event and continuous, which simulate hydrological processes for long-term. Among the various factors that characterize the models is the loss method that accounts for the volume of precipitation that falls in the watershed. Thus, certain loss methods are limited only to event-based while others can simulate event and continuous hydrological processes. Appropriate selection of these methods require knowledge of the watershed, goals of the hydrologic study and engineering judgment. The aim of this paper is to review loss methods in HEC-HMS model for streamflow simulation under climate change, with a view to highlighting their advantages, weaknesses and suitability in watershed development and climate change study. The result of the review showed that despite simplicity and accuracy of deficit and constant loss method of HEC-HMS, studies on climate change impacts using the method are still very few and has not yet been studied in Malaysia
Keywords: Hydrologic model; HEC-HMS; loss methods; climate change.
Land use/land cover change detection and validation of SWAT model on VISHOW subbasin using remote sensing and GIS techniques
by MOHAMMAD ASIF NAIKOO, MANZOOR AHANGAR
Abstract: Land use/Land cover (LU/LC) change has a direct impact on land management, watershed management practices, and economic health at regional, national and global levels. It also affects the various hydrological processes including the stream flow. The VISHOW river basin a sub-basin of Jhelum basin situated in the state of Jammu and Kashmir, India, has undergone tremendous land use/ land cover changes over the past few decades resulting in unprecedented hydrological response of the sub-basin to rainfall inputs. In this study the LU/LC of the study area for the years of 2000, 2008 and 2015 was determined using remote sensing and GIS techniques. Land use/ Land cover of the area is continuously changing with shift from agricultural crops to horticulture, increase in built-up area, reduction in forest cover and snow cover, increase in barren area being the major changes. From the year 2000 to 2008, the shrinkage in area has been detected under the land uses of agriculture (6.08%), snow(1.03%), forest (0.328%) and pastures(0.3478%); whereas the increase in area has been detected under the land uses of horticulture(5.88%), built up(0.444%), and barren (1.386%). For the period 2008 to 2015 the shrinkage in area has been detected under the land uses of agriculture (4.57%), snow(2.19%) and pastures(0.045%); whereas the increase in area has been detected under the land uses of horticulture(3.803%), built up(0.89%),, forest (0.067%) and barren(2.03%).The results of the SWAT model were found to be satisfactory with R2 of 0.789 and 0.82 during the calibration period for the monthly and yearly time steps respectively and R2 of 0.882 and 0.912 during the validation period for monthly and yearly time steps respectively. The runoff coefficients for the years 2000, 2008 and 2015 were found to be 0.1678, 0.1876 and 0.2445 respectively. The increase in runoff coefficient can be attributed mainly to the increase in built up area.
Keywords: Land use/ Land cover; SWAT model; stream flow; ArcGIS; Remote Sensing.
Risk assessment of flash flood potential in the humid tropics Indonesia: a case study in Tamiang river basin
by Cut Azizah, Hidayat Pawitan, Bambang Dwi Dasanto, Iwan Ridwansyah, Muh Taufik
Abstract: Flash flood is a one of catastrophic natural disasters, causing significant economic and human losses. Assessment of areas prone to flash flood is a major challenge especially in limited data basin. The objective of the study is to assess the areas vulnerable to flash flood in the Tamiang basin, Indonesia by computing the Flash-Flash flood is a one of catastrophic natural disasters, causing significant economic and human losses. Assessment of areas prone to flash flood is a major challenge especially in limited data basin. The objective of the study is to assess the areas vulnerable to flash flood in the Tamiang basin, Indonesia by computing the Flash Flood Potential Index (FFPI). The use of FFPI depends on the physiographic influencing factors. Here, we improved the index by integrating Antecedent Precipitation Index (API) and Curve Number (CN) into the index as influencing factors and using an analytical hierarchy process (AHP) to determine the weighted factor. A database containing historical flash flood location was used to verify the index. The index was computed in GIS environment, thus resulting the flash-flood vulnerability maps. The results show that the highest flash flood prone occurs in the northwestern upstream, where the soil shows the lowest infiltration rate and high curve number, and high API. Our findings were consistent with the historical flash flood events in the basin, therefore the use of weighted factor based on AHP is reliable. Flash flood hazard has affected 70% of villages within the basin, where they are relatively close to water bodies and high-density population. Moreover, our findings provide policymakers with the guidance and information needed to choose an appropriate management strategy to tackle possible future flash flood events that considers safety.
Keywords: Disaster; Curve Number; Antecedent Precipitation Index; Hazard; analytical hierarchy process.
An application of transfer function noise models for predicting groundwater level signals using rainfall signals in Adyar basin, India
by Mohanasundaram Shanmugam
Abstract: The effect of rainfall on groundwater level fluctuation was analyzed using autoregressive moving average exogeneous (ARMAX) transfer function noise (TFN) modeling approach on four selected observation wells in Adyar basin, Tamil Nadu, India. Evaluation of spatial average rainfall representation in the rainfall-groundwater level rise regression analysis was compared with three different methods namely simple arithmetic average (SAA), Thiessen polygon (TP), and Thiessen zone wise rainfall (TZR). Linear regression analysis on rainfall-groundwater level rise datasets revealed that the TZR method of inputting spatial average rainfall improved the rainfall-groundwater level rise correlation over SAA and TP methods. The four selected wells groundwater level fluctuation data from Adyar basin was further modeled using ARMAX-TFN modeling approach and MLR methods. The study results show that the ARMAX-TFN model prediction performance was superior over MLR methods at all four locations. The validation results of the ARMAX-TFN model show that the predicted and observed groundwater levels at the corresponding well locations were strongly correlated with the correlation coefficient values of 0.85-0.93.
Keywords: Transfer function noise models; ARMAX models; India; groundwater level; groundwater level rise; rainfall; time series modelling.
SWAT-Based Runoff and Sediment Simulation in a Small Watershed of Nepalese River: A Case Study of Jhimruk Watershed
by Madhab Rijal, Hari Prasad Pandit, Binaya Kumar Mishra
Abstract: Watershed models represent a scientific understanding of various processes involved within a watershed or simulate natural processes of the flow of water, sediment etc. This study presents the methodology of evaluating Soil and Water Assessment Tool (SWAT) and test the applicability of SWAT on runoff and sediment load simulation in the Jhimruk watershed located in hilly region of Nepal. Daily runoff and sediment event data of 1995-1998 period were used in this study. The evaluation statistics (NSE=0.768 and 0.689 for flow and NSE = 0.648 and 0.582 for sediment calibration and validation; coefficient of determination R2 = 0.774 and 0.689 for flow and R2 = 0.656 and 0.636 for sediment calibration and validation respectively) for the daily runoff simulation indicate that the model results were acceptable and the model performed well in capturing trend of runoff and sediment. The results indicate that the SWAT model can simulate the runoff and sediment yield with good performance. The study indicates that SWAT can be efficiently used in hilly region of Nepal.
Keywords: SWAT; Watershed; Sediment load; runoff; Simulation.
Hydrogeology and chemo-isotopic characteristics of the deepest Qanat in the World, Qasabeh Qanat, East of Iran
by Hojat Mirani Moghadam, Gholam Hossein Karami, Rahim Bagheri
Abstract: Qanats have a long history of supporting human life in arid regions and are a sustainable technology for harvesting groundwater. Qanats have been used in the hyper-arid Gonabad desert (east of Iran) for more than a thousand years. These environmentally-friendly water supplying structures are found only in a few other places on earth. Qasabeh Qanat is the oldest and deepest qanat of the world, has two major branches including Kalat Branch and Kakhk Branch. The water types of Kakhk and Kalat Branches are Mg2+-HCO3- and Na+-Cl -respectively which after mixing change to Na+-Cl-. Due to the direct cation exchange, the amount of calcium and magnesium deficit in the samples is proportional to their excess sodium. The equation of ?2H=6.3
Keywords: Qanat; Hydrograph; Cation exchange; Stable isotope.
DETERMINATION OF HYDRAULIC PROPERTIES OF SHALLOW AQUIFER FROM ELECTRICAL RESISTIVITY AND PUMPING TEST DATA IN ARAGBA-OKPE DELTA STATE NIGERIA
by Merrious Ofomola
Abstract: The hydraulic properties of shallow Coastal Plain Sands, which outline the main aquifer in the Niger Delta, were investigated around Aragba-okpe area of Delta State employing the vertical electrical sounding (VES) and conventional pumping test techniques. The intention was to find out the aquifer transmitting capacity to meet up with the required groundwater withdrawal for both domestic and industrial purpose and identify the distribution of hydraulic characteristics in the area. Fifteen VES stations using the Schlumberger array were occupied to study the subsurface geoelectric properties. Two wells were drilled for pumping test analysis. The interpreted resistivity result was compared with the borehole log data from the drilled well for lithologic identification, and the results showed that the preferred aquifer to source for water is encountered at the fourth layer with resistivity ranging from 1448 - 4935 ?m and a depth which varies from 16.0 32.0 m. The Pumping test data were analyzed in AQTESOLV software to determine transmissivity, storage coefficient and hydraulic conductivity using Cooper-Jacobs recovery methods. The pumping test results further revealed that the transmissivity, Storage coefficient and hydraulic conductivity of the aquifer are 0.3078 m2/min (443.23 m2/day), 0.002824 and 0.01539 m/min (22.16 m/day) respectively with an average maximum aquifer saturated thickness of about 20 m. These results closely approximate the distribution of hydraulic characteristics from Da-zarrouk parameters in the area. It is inferred from this study that the a combination of conventional pumping test and Da-zarrouk parameters will give a more reliable estimates for subsurface hydraulic properties determination, and that the aquifer in the area is prolific and capable of yielding good water for domestic and industrial use in the area.
Keywords: Pumping test; hydraulic characteristics; AQTESOLV; Storage coefficient; Aragba-okpe.
Flood Modelling for a Data-Scarce Semi-Arid Region by Using a Synthetic Unit Hydrograph and 1D or 2D Hydrodynamic Model
by M.P. Shaikh, S.M. Yadav, V.L. Manekar, B.K. Samtani
Abstract: In this study, the semi-arid Rel River Basin was divided into three sub-basins (SW1, SW2, and SW3). For first sub-basin (SW1), a unit hydrograph (UH) was developed using rain gauge data. Snyders method was used to develop a synthetic UH (SUH) for the remaining two ungauged sub-basins (SW2 and SW3). A storm hydrograph was developed from the UH for SW1 and from the SUH for SW2 and SW3. The storm hydrograph was used to create a one-dimensional (1D) steady hydraulic model and two-dimensional (2D) unsteady hydraulic model. The created models were calibrated and validated using field survey data collected immediately after an extreme precipitation event. (1) Critical cross-sections were identified using the 1D hydraulic model, (2) The flood inundation area was identified using the 2D hydraulic model and geographic information system techniques, (3) Remedial measures suggested on the basis of the observed depth, damages, probable reasons for flooding, field survey and modelling results (4) The observed flood depths were high in rural areas because the villagers had encroached the floodplains to conduct farming. In the urban areas, natural streams and nullahs had been plugged, which resulted in an increase in the flood depth and flood recession time.
Keywords: Rain gauge station; Snyder’s method; Inundation; Damages; Levees; Hydrograph.
Comparising and evaluating reaction factor and drainage water quality respect to direction of surface irrigation
by Zeinab Mirzaie, Rouhallah Fatahi, Azarakhsh Azizi
Abstract: This research was carried out to compare the performance of subsurface drainage laterals along and perpendicular to irrigation direction. For this purpose, research data was used that previously was carried out at the site of the drainage project in the Mianab, Khuzestan province, Iran. Four units including two laterals parallel to irrigation direction which are called LP and two laterals perpendicular to irrigation direction which are called LV were selected. The data analyzed were the water table level which was registered daily until the outflow was stopped. Volumetric lateral drains outflow from the open drain was measured during the growing season with a 24-hour alternation, and samples for quality analysis were also provided from this place. In order to study and compare the behavior of LP(laterals parallel to irrigation direction ) and LV(laterals perpendicular to irrigation direction) , the reaction factor in both laterals were calculated. The reaction factor were 0.49 and 0.41 in LP and 1.07 and 1.1 in LV. The average value of drainage water salinity was equal to 6.8 dS/m in LP and 19.4 ds/m in LV . Also maximum discharge rate occurred in LV, which was 4.5 mm/day and this parameter was 3.5 mm/day in LP. The reaction factor in LV was greater than LP which is implies that the system works properly, and has a quick response to rainfall inputs in LV. In this study, Duncan test was used to examine the changes. The results of test showed that there is not a significant difference between different levels of treatment of reaction factor, but there are significant difference between the different treatment levels of outflow and drainage water salinity, and these are dependent on irrigation direction.
Keywords: Subsurface Drainage; Irrigation Direction; Reaction Factor; Drainage water Salinity; Water Quality.
Most efficient channel section with multiple slender obstructions in flow path
by Sabita Madhvi Singh, Pabitra Ranjan Maiti
Abstract: An open channel is to be considered most efficient when it can passes maximum discharge for a given cross-sectional area, bottom slope and resistance of flow in the side walls. In the present work, the efficiency of channel section is determined analytically for rectangular and trapezoidal cross-section with slender structure equally spaced along the width of channel cross-section. The economic depth of flow and hydraulic radius is found for a given discharge with multiple barriers in flow path. The energy of flow is determined with slender structure in rectangular channel section. The proposed analytical solution will be helpful to optimum design of the lined rectangular and trapezoidal channel section with number of barriers that may be pier like structures.
Keywords: slender structure; multiple barriers; flow path; economic depth.
Water quality evaluation analysis of an urban river based on Self-Organizing maps: Annaba city (Eastern Algeria)
by Radia Hafsi, Hamouda Boutaghane
Abstract: The critical state of Oued Boudjemaa waters (hydrography network of Annaba city, in Algeria) remains in question. Despite the collection of wastewaters, the river remains polluted. Self-Organizing Map (SOM) was used to explore the spatiotemporal characteristics of the urban river in order to investigate the pollution sources. Thirty water quality variables were collected from April 2013 to March 2014 at five sampling points covering the study area. Filling gaps by using the k-nearest neighbors algorithm (K-NN), and transforming the original data by the Min-Max normalization were carried out as a preprocessing step for the application of the SOM. Patterns of water quality variables were visualized by the Self-organizing map, and similar planes were observed to the variables that correlated with each other and had the same origins. The SOM neural network grouped the water quality data into five clusters. It was found that the wet season is the main source of water pollution in Oued Boudjemaa; more than 90% of the parameters used in the study were correlated with the wet season, while just 10% were correlated with both the dry and wet season. Spatiotemporal variation on water quality and variables correlation are mainly a result of the impacts of anthropogenic sources such as stormwaters runoff, agricultural effluents, domestic and industrial discharges, in addition to natural processes, especially water interactions with geological formation and/or deposits on the riverbed.
Keywords: Self-Organizing Map (SOM); preprocessed data; water quality; Oued Boudjemaa; Clustering; spatio-temporal assessment; physicochemical parameters; correlation to dry and wet season; natural source of pollution; anthropogenic source of pollution.
Comparison of infiltration model parameter estimation techniques under different land use/land covers
by Tabasum Rasool, Abdul Qayoom Dar, Mushtaq Ahmad Wani
Abstract: Quantification of infiltration rate of the soil is a complex problem because of its variability, selection of suitable infiltration model, and determination of infiltration model parameters which depend on various soil characteristics and land use/land cover. This study compares three parameter-estimation techniques viz. conventional graphical method, generalised reduced gradient (GRG) optimisation and Levenberg-Marquardt algorithm (LMA) for estimation of infiltration model parameters of Horton, Kostiakov, modified Kostiakov and Philip, and select the best fit method.
Infiltration experiments were conducted to measure infiltration rate on three different land covers viz. farmland, built-up and shrubland under the soil textures of clay and sandy clay in an urban sub-basin of lesser Himalayas, India. The performance was assessed by computing different statistical indicators, and an overall performance index was computed to rank the techniques. From the comparative analysis, it was observed that LMA is the most suitable technique to ascertain the parameters of selected infiltration models.
Keywords: infiltration models; optimisation; geographic information system; multiple linear regression; Levenberg-Marquardt algorithm; LMA.
Assessment of Rainfall-Runoff Time Series Data Using Transfer Function Modelling with Exogenous Variable
by Homa Jalaeian Taghadomi, Xixi Wang, Mujde Erten-Unal, Turaj Vazifedan
Abstract: This study assesses the rainfall-runoff time series data using a transform function approach. Modelling rainfall-runoff data is crucial in the hydrology and water resource management. However, the characteristics of serial and cross-correlation between runoff and rainfall sequences have not been discussed widely in the literature. This study evaluates the performance of the transfer function method in modelling monthly rainfall-runoff data in the Blackwater River watershed located in coastal Virginia. Maximum likelihood estimation was employed for estimating the models parameters. Different performance evaluation criteria (AIC, AICC, BIC, RMSE, MASE) were employed for model selection. The adequacy of the final transfer function model was evaluated by Dickey-Fuller, KPSS, Ljung-Box, and Box-Cox transformation. Moreover, the performance of the final model was compared with the simplest time series models to justify the complexity of the model. This study is the first achievement of the hydrological response to precipitation and temperature over the Blackwater River watershed.
Keywords: Rainfall; Runoff; Temperature; Transfer function model; Exogenous variable; ARIMAX; Forecast; Seasonal; Dickey-Fuller; KPSS; Ljung-Box; Box-Cox Transformation; Blackwater River.
Statistical and trend analyses of long-term rainfall data: a case study for Mauritius
by Reena Hansa Seebocus, Michel Roddy Lollchund, Miloud Bessafi
Abstract: This paper focuses on the analysis of monthly rainfall data for the period 1950-2016 for Mauritius using statistical techniques and decomposition method. For the statistical analysis, the data are fitted to commonly used probability distribution function for which parameters are estimated using the method of maximum likelihood estimation (MLE). The Anderson-Darling (A-D), Kolmogorov-Smirnov (K-S) and chi-square (C-S) tests are then employed to determine which PDF best fits the data. The results obtained indicate that the log-normal, GEV and inverse Gaussian PDFs best fit the rainfall data at less than 5% significance level. The ensemble empirical mode decomposition (EEMD) method is employed to study the trends in the data. Results obtained are in terms of intrinsic mode functions (IMFs) and the trendline. The analysis reveals that there is a general linear decrease of 1 mm/year in the amount of rainfall.
Keywords: rainfall; statistical techniques; probability distribution function; goodness-of-fit tests; ensemble empirical mode decomposition; EEMD; Mauritius.
Assessment of meteorological and hydrological drought; a case study in Kirindi Oya river basin in Sri Lanka
by N.S. Abeysingha, M.G. Wickramasuriya, T.J. Meegastenna
Abstract: A desk study was conducted to detect the changes in drought, their frequencies and trends in the Kirindi Oya river basin in Sri Lanka using standardised precipitation index (SPI) and streamflow drought index (SDI). The frequency of drought events was assessed using SPI and trend of SPI was also determined using Mann-Kendall and Sen's slope. The results based on SPI analysis indicated that hydrological years 1989-1990, 1991-1992, 2000-2001 and 2013-2014 were drought years and the year 1991-1992 was identified as a severe drought year in the Kirindi Oya river basin. The significant negative trend of SPI (−0.055) during July to September time scale indicates the increasing drying tendency of the entire basin. However, frequency of being dry of the basin in annual and April to September period is only 16% for the entire basin. Based on SDI, 2000-2001 and 2003-2004 were identified as hydrological drought years especially for the October to December period both at Thanamalwila and Wellawaya gauge stations in the basin.
Keywords: drought analysis; Kirindi Oya river basin; SPI index; SDI index; Sri Lanka.
Rainwater harvesting in urban areas of developed countries. The state of the art (1980-2017)
by Alvaro-Francisco Morote, María Hernández, Saeid Eslamian
Abstract: Many urban areas suffer from water scarcity although paradoxically, a local source such as rainwater is mostly treated as a risk rather than a valuable resource. This change of paradigm is included in the 'integrated water resources management' and 'demand management' approach. The aim of this research is to identify and analyse studies that explore subject matters concerning rainwater in the integrated management systems of water resources into developed countries. The research methodology consisted in a literature review (from the 1980s to 2017) of territorial studies that examine rainwater harvesting in urban areas of the developed countries. To this end, a bibliometric analysis has been carried out in different databases according to the definition of keywords. The results reveal five thematic areas were identified and temporal and spatial differences between some subject matters.
Keywords: rainwater; harvesting; integrated water resources; management; developed countries.
Daily discharge simulation: combining semi-distributed GIS-based and artificial intelligence models
by Ali H. Ahmed Suliman, Ayob Katimon, Intan Zaurah Mat Darus
Abstract: Developing highly accurate semi-distributed rainfall runoff models are still a big challenge in streamflow simulation. In this paper, a new technique using ANN to improve the accuracy of TOPMODEL is presented. TOPMODEL contains three sub-models, which are root storage, gravity storage and saturated storage. The proposed scheme is to replace one of the sub-models by artificial neural networks (ANN) model. A medium catchment located in tropical Malaysia known as Rantau Panjang catchment (RPC) is used. Two years, 1998-1999, are used for calibration, and 2000-2001 are used for validation process using daily data sets. Model results are evaluated by Nash-Sutcliffe model (NS), relative volume error (RVE) and correlation coefficient (CoC) which have been improved from 0.63 to 0.86, 0.92 to 0.93 and 40.91 to 14.12 respectively demonstrate the ability of ANN to improve the accuracy of TOPMODEL. It is concluded that the scheme can improve performance in terms of streamflow simulation.
Keywords: TOPMODEL-Simulink; Johor River Basin; hybrid; artificial neural networks; ANN; MLP; artificial intelligence; tropical catchment; Rantau Panjang; rainfall runoff models; Malaysia.
Rainfall trends and intensity-frequency-duration relationships in Sharjah City, UAE
by Abdullah Gokhan Yilmaz, Abdallah Shanableh, Tarek Merabtene, Serter Atabay, Naseraldin Kayemah
Abstract: Trend analysis is important to understand effects of climate change and variability on rainfalls. In this study, rainfall and heavy rainfall trend analysis were performed for Sharjah City, UAE. Moreover, rainfall intensity-frequency duration (IFD) relationship was studied by fitting heavy rainfall data to extreme value distributions. Mostly decreasing rainfall trends were detected for short storm durations, whereas statistically non-significant rainfall trends were detected for long storm durations. Also, statistically non-significant increasing trends were detected in heavy rainfalls in Sharjah City. Heavy rainfall data sets were fit successfully to extreme value distributions, and rainfall IFD relationship was created for Sharjah City. Despite the availability of limited data for study area, this study contributed to better understanding of variations in rainfall and heavy rainfalls in Sharjah City. Moreover, derived rainfall IFD relationships by frequency analysis of generated heavy rainfalls provide significant input for water infrastructure projects in Sharjah City.
Keywords: rainfall trends; rainfall IFD curves; heavy rainfalls; Sharjah City; United Arab Emirates.
An empirical method for estimating the soil hydraulic conductivity using particle size distribution curve, case study: Isfahan City
by Farid Fazileh, Gholam H. Karami, Rassoul Ajalloeian
Abstract: Various equations have been developed for assessing the hydraulic conductivity (K) based on particle size distribution. Since the percentages of fine and coarse particles in a sediment significantly influence its permeability, values of K obtained using these empirical equations are erroneous. In this research, a new and applicable equation has been advised which is based on the percentages of fine and large particles in the sample. The following relationship obtained from multiple linear regressions between values of K and corresponding particle size data: K = 0.0419 (Fk)2 − 0.1478 (Fk) + 1.5629, Fk = 30Pg(2) − 3PS(0.1) + 3.2. The validity of this new presented equation has been controlled with eight new samples. Calculated values of K using this equation yield relative errors of 5% to 10% which fall in range of allowable errors.
Keywords: hydraulic conductivity; Iran; Isfahan; grain size distribution; sieve analysis.
Derivation of digital terrain models and morphological parameters from very high resolution satellite images
by Nawras Shatnawi, Mohammed Matouq, Awni Khasawneh, Saeid Eslamian
Abstract: Jordan is considered among the poorest countries in water resources in the world; therefore, many projects were introduced to the area to deal with this issue. The presented work focuses on two specific aspects - that could help in water resources management projects - the accuracy potential of these data in such areas and the benefit for hydrological models and applications using these data. We present methodology, ground truth validation and assessment for digital terrain model (DTM) generation by Pleiades data as well as for the derivation of drainage networks and morphometric parameters. The results were compared with DTM generated from laser scanning from airborne platforms (LiDar) data, which showed the ability of Pleiades data to generate DTMs in mountainous regions, and steep areas. The drainage density and morphometric parameters were also tested and compared. The absolute mean difference in elevation for the generated DTM from Pleiades data was 0.444 m (less than 1 pixel) with 0.509 standard deviation and root mean square error (RMSE) of 0.503, where the computed drainage density from both LiDar Pleiades data showed no significant difference.
Keywords: digital elevation models; DEMs; morphometric parameters; high resolution satellite images; Pleiades; laser scanning from airborne platforms; LiDar; ground control point; GCPs; filtering; refinement.
Estimation of extreme floods by regional methods in Trois Rivières watershed - North West Algeria
by Amel Talia, Mohamed Meddi
Abstract: The objective of this study is to estimate the extreme floods corresponding to different recurrence intervals in Trois Rivières watershed, a large sub-basin of the Macta basin (NW-Algeria). Two regional models are used flow-duration-frequency (Qdf) modelling and gradex method. A methodology for modelling QdF curves based on the so-called continuous converging model has been applied. The second model is gradex method which is a rainfall-runoff probability approach to computing extreme flood discharges in a river. The QdF model gives a complete description of the flood dynamics of Trois Rivières basin. Nevertheless, it is recommended to use this method with vigilance for the predetermination of severe floods for important return periods. However, the gradex method overestimates the extreme floods for different recurrence intervals. This study highlights that diverse methods should be employed for the regional analysis of extreme hydrological events.
Keywords: floods; QdF modelling; gradex method; Trois Rivières watershed; Algeria.
Characteristics and return period of hydrological drought base on reservoir capacity reliability: case study of Mamak Dam in Sumbawa Island, West Nusa Tenggara, Indonesia
by I. Wayan Yasa, Mohammad Bisri, Moch Sholichin, Ussy Andawayanti
Abstract: The analysis of hydrological drought indices by using the reservoir will obtain an actual and real drought indefinite and have a clear physical meaning. In this research, we use daily data of the water level of reservoir, inflow and outflow. The research method used to obtain the hydrological drought index (HDI) is the water balance method in the reservoir. Based on selected distribution, for the estimation of drought in a certain return period using the log Pearson type III. The results showed that the extreme drought on Sumbawa Island took place on average for 265 days with a maximum deficit of 35,378 × 103 m3 from the effective storage. The hydrological drought index (HDI) ranges from −1.31 to −0.01 with very severe drought criteria to weak drought. The hydrologic drought in the return period of 1, 2, 5, 10, 25, 50, 100 and 200 years, i.e., respectively −0.01, −0.54, −0.90, −1.04 and −1.12.
Keywords: drought; reservoir; El Niño; inflow; outflow; reliability; Indonesia.
Dam break analysis of Old Aswan Dam on Nile River using HEC-RAS
by Amira M. Helwa, Mohamed H. Elgamal, Ashraf H. Ghanem
Abstract: The Egyptian segment of the Nile River is controlled from its upstream end by two dams: the High Aswan Dam (HAD) and the Old Aswan Dam (OAD). Nowadays, questions are being raised about the efficiency and safety of the Old Aswan Dam and what will happen if the dam fails? For this regard, a 1D hydraulic model using HEC-RAS package was developed to investigate a number of dam break scenarios, to estimate the outlet hydrograph from the dam site and to route the produced flood wave throughout the first river reach from the dam site up to Esna barrage. A numerical sensitivity analysis was performed to select the relevant values of the implicit weighting factor θ, Δx and Δt. Eight dam break scenarios were developed to investigate the effect of initial water level, inlet flow and dam breach width on the expected inundated area. Results showed that there would not be catastrophic consequences from the Old Aswan Dam failure. The main concern is when large flow values are released deliberately (Q = 605 mm3/sec) from the Aswan Dam.
Keywords: Old Aswan Dam; OAD; dam breaching; dam break analysis; HEC-RAS; breaching parameters.
Hydrological drought frequency analysis - a case study in South Kerala
by G.S. Deepa Varghese, M.B. Joisy
Abstract: Hydrological droughts refer to the shortfalls on surface or subsurface water supply like streamflow, reservoir, groundwater etc. Many people consider droughts to be a rare event, when in fact they are a normal and recurrent feature in the cycle of climatic events. Droughts in Indian peninsula seem to be primarily associated with the failure of monsoon. With climate change studies predicting even more hydrological extremes for the future, already competing demand for water resources may further aggravate. Thus, the importance of water resources aspect of drought is being increasingly recognised. In this paper, the severity of droughts in terms of the cumulative water deficiency is studied by two methods by proper identification of the threshold levels in two major basins of Kerala in the south. The streamflow for the basins are generated for a period of over two decades using the 'Thomas Fiering model'. An application of the drought frequency analysis by Yevjevich and Dracup methods is performed and presented.
Keywords: hydrological droughts; streamflow generation; Dracup; Yevjevich; Thomas Fiering model; severity.
Assessing the efficiency of WRASTIC method in determining the vulnerability of surface water resources in semi-arid region using the NSFWQI
by Reza Ghazavi, Rasool Imani, Rohallah Mirzai, Babak Khayatrostami
Abstract: In this study, the WRASTIC method was used to assess the surface water vulnerability in sub-catchments of Kivi Dam's watershed which is located in the north-east of Iran using remote sensing and GIS techniques. Monthly change of the FC, pH, T, PO4, NO3, Tur and TS water quality parameters of the samples were measured in a one-year period. The NSFWQI of those sub-catchments were calculated based on average value of water quality parameters. Comparing the priorities of vulnerability and overall quality of surface water in studied sub-catchments showed the acceptable efficiency of WRASTIC method in assessing the vulnerability of surface water resources in semi-arid regions. Also, the results showed that among studies sub-catchments, the surface water in sub-catchment no. 1 has the most vulnerability (WRASTIC index = 56) and the worst overall quality (NSFWQI = 51).
Keywords: surface water; vulnerability; water quality; overlay and index; WRASTIC; NSFWQI; semi-arid; watershed; Kivi Dam; Ardabil.