International Journal of Hydrology Science and Technology (57 papers in press)
Comparison of solutions of Saint-Venant equations by characteristics and finite difference methods for unsteady flow analysing in open channel
by Kaveh Ostad-Ali-Askari, Mohammad Shayannejad, Saeid Eslamian, Bahareh Navabpour
Abstract: The unsteady flow can be analyzed by Saint-Venant equations. These equations can be solved by characteristics and finite difference methods. The Saint-Venant equations are changed into four complete differential equations in characteristics method and these equation are solved by drawing two characteristics lines. The Saint-Venant equations are changed into a set non-linear equations and are solved using Preissman scheme in finite difference method. This set equation are changed into linear equation using Newton-Rafson method and can be solved using Sparce method. In this research, the results of the two method were compared and this was shown that 1) these two methods can draw the surface profiles and flow hydrograph as well, 2) the finite difference method is more accurate than that one, 3) the mesh size in finite difference method can be larger than that one, and 4) the difference between two methods are increased by increasing the time and distance.
Keywords: flood routing; dynamic wave; characteristics lines; finite difference; Saint-Venant equations; characteristics method ; Newton-Rafson method; Sparce method.
The Performance of Fuzzy Regression Method for Estimating of Reference Evapotranspiration under Controlled Environment
by Mohammad Javad Amiri, Jahangir Abedi-Koupai, Saeid Eslamian
Abstract: With the objective of evaluating the performance of Fuzzy regression method for estimating the reference evapotranspiration in greenhouse, a lysimeter study was conducted to determine the evapotranspiration (ET) rates for grass crop. Daily outputs from model have been tested against reference evapotranspiration data computed by the lysimeter to assess the accuracy of the model. The estimated ETо values from a fuzzy regression model using five input parameters, including maximum and minimum temperature, mean relative humidity, wind speed and solar radiation were obtained with RMSE=0.68 mm/day, R2 =0.98. The accuracy of fuzzy 1 was the best but the accuracy of the Fuzzy 3 was the worse for estimating daily evapotranspiration. The RMSE values of fuzzy 1, fuzzy 2, Fuzzy 3 were 0.68, 0.99 and 1.307, respectively. Thus, Fuzzy 1 approaches work well for the data set used in greenhouse condition.
Keywords: Evapotranspiration; Fuzzy regression; Lysimeter; Meteorological variable.
Suspended sediment estimation using regression and artificial neural network models: Kebir watershed, northeast of Algeria, North Africa
by Amina Amamra, Kamel Khanchoul, Saeid Eslamian, Soraya Hadj Zobir
Abstract: The focus of this research was to identify potential equivalences between artificial neural networks and statistical regression and to verify these equivalences when applied to modelling sediment loads in the Kebir river. The use of feed-forward backpropagation neural networks such as MLP and LM were studied by applying relationship stream flow-sediment discharge data and geomorphology watershed parameters. Daily based water and sediment discharge were used as inputs for sediment rating curve and ANNs. In the present study the models were adopted by changing numbers of neuron in hidden layers and epoch. Results have shown that the ANN models were superior in reproducing sediment discharge compared to SRC. The findings further have suggested that LM could provide the most accurate estimates of sediment discharge, (R
Keywords: Sediment discharge; geomorphology; Neural network; sediment rating curve; Kebir river.
Evaluation of Clark IUH in Rainfall-Runoff Modeling (Case Study: Amameh Basin)
by Meysam Salarijazi, Mohammad Abdolhosseini, Khalil Ghorbani, Saeid Eslamian, Iman Ahmadianfar
Abstract: The application of Clark IUH in Amameh basin, Iran is investigated in this study. Six recorded rainfall-runoff events were selected. Calibration results showed great changes in the calibrated parameters, percentage error in peaks and volumes (PEP and PEV), and the model efficiency (EFF) while percentage error in time to peak (PTEP) had always low values. Furthermore, the simulations of falling limbs of runoff hydrographs were better than rising limbs. Validation results indicated that time to peaks, runoff volumes, and falling limbs of runoff hydrographs were much better predicted than peak discharges, rising limbs, and total shapes of runoff hydrograph. One way sensitivity analysis revealed that the storage coefficient was more sensitive than time of concentration and EFF, PEP, PETP, and PEV had highest to lowest sensitivity. It can be concluded that the estimation of time to peak and runoff volume had higher performance than runoff hydrograph shape and peak discharge.
Keywords: Clark IUH; Rainfall-Runoff Model; Sensitivity Analysis; Model Efficiency.
Determination of the height of vertical filter in heterogeneous earth dams with vertical clay core
by Mohammad Shayannejad, Saeid Salehi-Hafshejani, Hossein Samadi Boroujeni, Ali-Reza Zarraty, Bahareh Soltani, Kaveh Ostad-Ali-Askari
Abstract: In order to determine the height of the filter in heterogeneousearthdam, three embankment models were provided in a flume laboratory, with the length of 4.2 m at the base of dam, the width of 60 cm and the height of 1 m and bodyslope1H: 2V. For embankment of model,two types of fineand coarsegrained soils were used. The texture of the soil was made using hydrometer method. In the first model,the fine-grained and coarse-grained soils were used in downstream and upstream of the dam crest respectively. In Models2and3 with cutting fine grained soil from the toe of the dam to the dam crest,vertical clay core was replaced.Index of a / L (athickness of clay core and L is the length of base dam) was 1.7 and 1.10 in the second and third models respectively.Seepage experiments in 3 water height of 80and55and30 were performed.The phreatic surface was determined using wells and 30 embedded Piezometer in the models. Then rate of falling head due to clay core was measured and it compared with software PLAXIS V8.5 results.The clay core of height of filterwith safety factor 1.2 (Encounter Line Leak with 20% of the bottom filter)was introduced.The hydraulic conductivity of theclay were affected decline of water level.
Keywords: Model of heterogeneous earth dam; HeightofFilter; thickness ofthe clay core; software PLAXIS V8.5.
Monitoring and prediction of drought by Marcov chain Model based on SPI and new index (SPEI) in Isfahan
by Saeid Eslamian, Mahsa Jahadi
Abstract: Abstract: Drought evaluation and associated prediction are essential for water resource management. Most of previous studies analyzed and predicted drought pattern in Isfahan based on the standardized precipitation index (SPI). Due to the high evapotranspiration in Isfahan, the SPI index which is based on precipitation alone may not be sufficient to monitor and estimate drought pattern. So it is vital to analyze and predict drought phenomenon at this region based on the new index (SPEI) that considers potential evapotranspiration in addition to the precipitation. Hence drought analysis is performed based on SPI and SPEI (standardized precipitation- evaporation index) in Isfahan. The results indicate that there is some difference between two indices. Finally SPEI and the Marcov Chain model are applied to predict the drought patterns in a 30 years period in the long term future. It is predicted that the percentage of aridity state will increase comparison with the past decade.
Keywords: Keywords: Drought monitoring; Drought prediction; Isfahan; Iran; Markov chain model; SPEI index; SPI index.
Modeling hydraulics of flow-path cuts through dense vegetation in a northern Everglades wetland
by Kyle Douglas-Mankin, Donatto Surratt
Abstract: Flow-path cuts through dense marsh vegetation can dominate wetland hydraulics. The friction equation, including Mannings, provides simple, effective modeling of flow velocity, but this was the first study to apply the friction equation to wetland flow-cut hydraulics. Side-facing acoustic Doppler velocity and channel geomorphologic data were collected at seven locations on three shallow airboat flow-cuts and one deeper canoe trail in the Everglades. Data were fitted to the friction equation using friction (a), water depth (b), and water surface slope (c) parameters. Mannings form of the friction equation (b = 1.67, c = 0.5) was inappropriate to simulate shallow, low-gradient flow-cuts. The best overall statistical performance for describing flow-cut hydraulics was a = 3.18 x 10^7 m^ 0.72 d^-1, b = 1.28, c = 1.00 for airboat trails and a = 1.39 x 10^7 m^0.72 d^-1 for the canoe trail. Two applications are presented to demonstrate use of these models to quantify impacts of flow-cuts.
Keywords: Acoustic Doppler velocity meter; friction equation; Manning’s equation; marsh vegetation; wetland hydraulics; wetland hydrology.
Influence of calibration data on hydrological model prediction
by Shailesh Kumar Singh, Jiaying Liang, Alejandro Chamorro
Abstract: The quality and information content of data has a great influence on the calibration and validation of hydrological models. A model calibrated with data from a given time period can perform well or poorly when evaluated on prediction time period. This depends on the information content and hydrological variability of the calibration data, in relation to the validation period data. The hypothesis for this study was that a priori predictability of the model performance can be made based on knowledge about the data used for calibration of the model. If the validation time period has similar hydrological variability to the calibration period where the model is expected to perform better and it is termed as the interpolation case, otherwise it is extrapolation, where a better performance cannot be expected. In this study a geometrical property of data was used to discriminate between the cases of interpolation or extrapolation. To see the geometry of the input data, a data depth function was used. A case of interpolation and extrapolation was defined based on the location of data in relation to the convex hull of the calibration data set. The results show that the data available for calibration has great influence on the prediction performance of the model. It was found that the relative residual is very high at extrapolation case as compare to the interpolation case. The methodology was demonstrated using WaSiM-ETH model in Rems (right tributary of the Neckar River in eastern Baden-W
Keywords: Hydrological model; Interpolation; Extrapolation; Data depth function; WaSiM-ETH.
Urban water consumption in water-stressed areas of the developed world: An examination of multiple interrelated variables
by Alvaro-Francisco Morote, María Hernández, Saeid Eslamian
Abstract: The developed world has witnessed significant land changes since the second half of the twentieth century. These include a process of intensive urban development, which is also accompanied by the growth in the urban population and housing. One of the outcomes of this process has been an increase in the consumption of resources, including water. The aim of this paper is to identify and analyse the factors affecting water consumption and the areas studied in water-stressed regions of the developed world. A literature review of territorial studies examining the factors that affect urban water consumption in these areas was conducted methodologically. The results reveal that: a) a significant number of papers have been written on water consumption factors in areas where there is substantial urban growth; and b) North America and Australia, have been compared to the rest of the developed world (especially Southern Europe), recently (since 2000s) due to the expansion of the low-density urbanism in the last few years.
Keywords: water; urban; factors; consumption; water-stressed areas; developed world.
Changing climate and glacio-hydrology: A case study of Shaune Garang basin, Himachal Pradesh
by Shaktiman Singh, Rajesh Kumar, Anshuman Bhardwaj, Ramesh Kumar, Atar Singh
Abstract: The rise in temperature is already evident in Himalaya with rate of
increase varying seasonally and spatially. Changes in precipitation are also
evident with no clear trend. Several studies in different parts of Himalayas
suggest that the glaciers are retreating in general with few exceptions as
response to changes in temperature and precipitation. The stream flow in river
basins in Indian Himalayan region (IHR) is already showing changes in studies
undertaken in last few decades. Use of glacio-hydrological models gives
opportunity to estimate stream flow in glaciated river basins and understand the
changes. Present study deals with estimation of discharge in Shaune Garang
Basin, Himachal Pradesh using a glacio-hydrological model based on degree
day factors. The model was used to estimate long term average of melt season
discharge (19852007) in the basin. The modelled discharge shows good
correlation with measured discharge for simulation period except for first year
Keywords: climate change; snow melt; glacier melt; glacio-hydrological modelling; degree day factor.
Spatio-Temporal prediction of water quality parameters of a reservoir using Genetic Programming and Least Square Support Vector Machine.
by Mrunalini Jadhav, Kanchan Khare, Arundhati Warke
Abstract: In water quality Spatio temporal modelling is used for classification or pattern recognition by using multivariate statistical techniques. Sometimes due to extreme environmental conditions or limited or insufficient water quality testing locations, it is difficult to find water quality parameters of previous time series. In the present study an attempt has been made to develop Spatio- temporal prediction model using Genetic Programming (GP) and Least Square Support vector Machines(LS-SVM). Water quality parameters such as, BOD (Biochemical Oxygen Demand), COD(Chemical Oxygen Demand), DO(Dissolved Oxygen), and P-total(Phosphorous) from Gangapur, Kadwa and NandurMadmeshwar reservoirs are used for the prediction of the same parameters respectively for the next time step of NandurMadmeshwar reservoir. Data from single sampling point station from July 2007 to Jan 2015 is used for the study, as input data being small and only from three locations, it is a great challenge for the prediction. Performance of models is assessed by COD (Coefficient of Determination), RMSE (Root Mean Square Error) and CC (Correlation Coefficient).Models are also evaluated by using Band error, to know the upper limits of the water quality parameters or the number of months for which the water quality standards has been violated.
Keywords: Genetic Programming; Least square support vector machines; Water quality parameters; Coefficient of determination; Root mean square error; Correlation coefficient; Band error.
Efficacy of slope-adjusted curve number models with varying initial abstraction coefficient for runoff estimation
by Sangeeta Verma, Anju Singh, Surendra Kumar Mishra, Pushpendra Kumar Singh, Ravindra Kumar Verma
Abstract: The present study evaluated the efficacy of three slope adjusted CN2 models as well as original SCS-CN method using LISS-III and ASTER DEM data. The Performance of these models were also evaluated for four different values of initial abstraction coefficient (λ) i.e., 0.05, 0.1, 0.2 and 0.3 for the Kalu watershed in Maharashtra, India using R2 and RMSE. The results show that slope adjusted CN formulation given by the Sharpley and Williams (1990) (Model 2) for λ = 0.3 performed the best with lowest RMSE (10.88) and highest R2 (0.8757) in comparison to the other models. On the contrary, original SCS-CN model performed the worst. Results also show that watershed slope is an important factor affecting runoff generation and hence due consideration should be given to it in planning of soil and water conservation structures. This study also revealed that RS and GIS techniques are useful for estimating as SCS-CN model input data to predict runoff more accurately.
Keywords: SCS-CN method; runoff; slope adjustment; initial abstraction coefficient; RS and GIS.
Relationship between precipitation and soil water chemistry in an intensively managed clayey soil environment in southwest England: A preliminary study
by Adebayo Eludoyin
Abstract: This study investigated the temporal characteristics of precipitation chemistry, and precipitation-soil water chemistry relationship at an intensively managed farm in the United Kingdom. Data investigated were the Environment Change Network (ECN) Terrestrial observation data for the Rothamsted Research Farm Platform at North Wyke in Devon. Results showed that temporal variability exists in the precipitation chemistry but did not show that either the soil or the precipitation was chemically impaired. Temporal variations in the precipitation chemistry were attributed to climatic effects and anthropogenic sources as informed by the trends and results of the comparison to the seawater ion ratio. Strong relationships that existed in the investigated chemical variables (except Cl- and PO43-) between the top (above 10 cm) and lower (below 10 cm) soil layers indicated significant mixing of the soil water at this profile. The study indicated significant precipitation-soil water chemistry in the clayey-rich area.
Keywords: Precipitation; Soil chemistry; Runoff processes; Clayey-rich soils.
Modelling of hydrological processes in snowmelt-governed permafrost-free catchments of the Western Siberian Lowlands
by Jens Kiesel, Matthias Pfannerstill, Britta Schmalz, Vitaliy Khoroshavin, Artyom Sheludkov, Tatyana Veshkurseva, Nicola Fohrer
Abstract: To date, no examples of small- to meso-scale hydrological simulations exist in the southern part of the Western Siberian Lowlands, despite intensive agriculture and high vulnerability to climate change. We propose a first simulation approach in which we assess the importance of surface and groundwater processes on hydrological model performance. Therefore, we simulated three catchments, using four different model setups incorporating different landscape characteristics and processes. An objective calibration and comparison framework was applied to assess the different setups which reached very diverse performance: The setups where physically based surface retention is considered, showed slightly more realistic surface runoff driven peak flows and the setups with a more complex groundwater concept improved the depiction of surface runoff, the recession phase and the contributing baseflow significantly. The best performing, most complex setup was used to assess the prevailing hydrological processes of the lowland with its cold, continental climate in more detail.
Keywords: groundwater; surface water retention; flow duration curve; hydrological process evaluation; SWAT3S.
Potential Impacts of Climate Change on Precipitation Patterns over Iran (An Arid/Semi-Arid Climate)
by Jaber Rahimi, Ali Khalili
Abstract: In this study, two objectives were paramount. One is to assess the spatio-temporal patterns of precipitation in Iran and the other is to investigate the projected changes in these patterns for the period 20712100 as compared to 19652010. These were achieved by using monthly precipitation data from 256 rain gauge stations and the outputs of the HadCM3 global circulation model (under the A2 and B2 scenarios). The statistical (Delta Method) and dynamical (PRECIS) downscaling techniques were compared in terms of their results for projecting annual isohyets, annual march of monthly precipitation and the precipitation homogeneity. The results showed that, by HadCM3_Delta Method_A2, HadCM3_Delta Method_B2, HadCM3_PRECIS_A2 and HadCM3_PRECIS_B2 projections, the annual mean precipitation over the country (which is already 254 mm) would be 208.6, 187.1, 174.1 and 175.0 mm, respectively. Also, the corresponding values for the average of precipitation homogeneity index would change from 57% in the current conditions to 53, 54, 59 and 61 % in climate change conditions, respectively. Although temporal and spatial monthly precipitation was envisaged, there was no impressive impact of climate change on precipitation pattern, but it's effect on time of maximum precipitation was subtle.
Keywords: Intra-Annual Precipitation Regimes; Climate Change; Downscaling; Iran.
A Simplification of the Einstein Equation for the Calculation of Suspended Sediment Transport in Rivers
by Hydar ALI, Thamer Mohammed, Badronnisa Yusuf, Azlan Aziz
Abstract: In this study, a simplified equation for estimating suspended sediment load is proposed, based on regression analysis and the concept presented by Einstein, Ackers and White, and Shields. Field data for 11 rivers located at different parts of the world were used for the calibration and validation of the proposed equation. The results show that the equation gives a good performance compared with Einsteins and Bagnolds equations when tested using field data for the Atchafalaya, Red, South American, Rio Grande and Al-Garraf Rivers. The minimum and maximum values of Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) between the output of the proposed equation and field records were 0.005 to 0.007 and 0.09 to 0.289, respectively. For the above rivers, graphical comparisons show that the predicted values of suspended sediment load had a range of D50<0.14 and 0.140.2 gave a good prediction compared with the measured sediment load. The main advantages of the proposed equation are that it is easy to apply and the results obtained from its application have reasonable accuracy.
Keywords: Equation; Suspended Sediment; Natural Rivers; Validation; Testing.
ANFIS Based PCA to Predict the Longitudinal Dispersion Coefficient in Rivers
by Abbas Parsaie, Samad Emamgholizadeh, Hazi Mohammad Azamathulla, Amir Hamzeh Haghiabi
Abstract: Study on the river water quality is the main part of environmental engineering. Longitudinal dispersion coefficient () is one of the main important parameters in the river water quality studies. The is proportional to the flow velocity, channel width, depth of flow, and shear velocity. The results of Principal component analysis (PCA) indicate that the width of the river, flow depth, and flow velocity are the most important parameters on the . In this paper with aim of the PCA results, the adaptive neuro fuzzy inference system (ANFIS) model was developed to predict the . The performance of developed ANFIS model based on PCA with error indices (and RSME=0.055) is suitable to predict the . During the development of ANFIS model, five neurons to the width channel, four neurons to the flow depth, four neurons to the velocity and two neurons to the shear velocity were assigned. The hyperbolic tangent sigmoid (tansig) function was considered as membership function for the neurons.
Keywords: River Mixing; Water Quality; River Pollution; ANFIS; PCA.
Reducing Water Shortage Crisis Through Rainwater Reuse: Lessons Learned from Ancient Toward Integrated Technology
by Saeid Okhravi, Saeid Eslamian, Nicolas R. Dalezios
Abstract: The quantity of freshwater available per person in the world has been proceeded to decrease due to a combination of factors, including population increase, water pollution, inadequate planning and management of transboundary water, and inefficient operation of water supply and distribution systems. There is a direct water source to cease increasing potential for water scarcity, crisis and associated conflicts around the world in the future called rainwater harvesting that is an ancient technique enjoying a revival in popularity due to the inherent quality of rainwater and interest in reducing consumption of treated water. Rainwater harvesting is included as an innovative site design strategy to minimize runoff based on LID practices. The present study on literature attempts to offer a comprehensive account of the above issues and also some important guidelines for advancing research in this direction. Assessments of past, present and future statuses of the worlds water are reviewed.
Keywords: Climate change; LID; Rainwater harvesting; Stormwater management; Water crisis.
Cost-Effective Smart Irrigation Controller Using Automatic Weather Stations
by Hema Nagaraja
Abstract: Water has become increasingly scarce and valuable resource due to the increasing population and misuse of the same. Agriculture is the largest sector using scarce water resource with low efficiency and low-cost. Traditional irrigation methodology uses qualitative or feel approach to schedule irrigation which does not measure actual environmental condition. The quantitative approach requires additional setup for measuring climate condition for scheduling the irrigation. Low cost innovative water-saving technology is the need of the hour. The presented work proposes the cost-effective smart irrigation controller using automatic weather stations. The proposed smart controller makes real-time irrigation decision by gathering climatic data from nearby automatic weather stations. Automatic weather stations data are available on an hourly basis from Indian meteorological department. The primary challenge in designing irrigation controller is to acquire real-time data, to validate and to reconstruct the missing data. These problems are addressed in the presented paper. Evapotranspiration computed from nearby automatic weather stations are comparable with evapotranspiration provided by Indian agricultural research institute.
Keywords: Smart Irrigation Controllers; Automatic Weather Station; Real-Time Climatic Data; Validation; Reconstruction.
An Introduction to the Hyperspace of Penman-Monteith Reference Evapotranspiration
by Naim Haie, Rui Pereira, Gaspar Machado, Shakib Shahidian
Abstract: Evapotranspiration is crucial and very relevant to hydrology, particularly under global warming and the growing water scarcity. The FAO Penman-Monteith is the highly used method to calculate the daily standardized reference evapotranspiration (ETo). It utilizes seven variables, mostly climatic, and produces a complex n-dimensional domain (or hyperspace). No study has presented the internal structure of this 8D space which forms the objective of the present work. To this end, a computer program called HyperET is developed to facilitate the advancement of two intertwined processes: creating windows into the hyperspace and understanding the resulting regions of the domain. The former gives 2D figures for partial analysis and the latter presents significant infeasible regions which are subspaces composed of ETo values outside its chosen minimum and maximum (or thresholds). HyperET is expensive computationally and presents an ETo domain that resembles Swiss holey cheese with three types of infeasible regions and emerging non-linearity.
Keywords: Penman-Monteith evapotranspiration (ETo); hydrology; irrigation;
water management and design; infeasible regions of ETo; climate change;
water scarcity; hyperspace; HyperET; domain discretisation; n-dimensional
Maximum Total Rainfall and Intensity by using Hershfield Isohyet Maps and Weiss Equation
by Mahbub Hasan, Aschalew Kassu, Srinivasa Rao Mentreddy
Abstract: Southern region of the United States does not show a regular or uniform pattern of rainfall. A study done by Hasan et al. in 2008 stated that there is an uncertainty in distribution of rainfall has never been a favorable water resource for crop production. Accurate information on total rainfall and rainfall intensity is necessary for calculating the amount of rainfall needed for crop water use, storage and for designing flood control and water conveyance structures. Models developed based on weather data can help forecast potential total rainfall, supplemental irrigation, water storage, and water losses. Total rainfall and intensity were calculated by linearizing method based on isohyet (lines of equal rainfall) maps developed by Hershfield (1963), and by using the Weiss equation (1962). The calculated values of the maximum total rainfall and intensity were 50.80 and 119.38 mm and 101.60 and 19.90 mm/h, respectively for 0.33 and 6.0-hour storm durations. These results showed a very good agreement with the actual data collected from the National Oceanic and Atmospheric Administration (NOAA) climate station in Gadsden, Alabama. Hence, this method of calculating the maximum rainfall and its intensity can be a valuable tool to determine rainwater harvesting, rainwater storage, irrigation scheduling and designing of flood control structures.
Keywords: Total rainfall; Rainfall intensity; Rainfall duration; Linearization; Hershfield Isohyets; Weiss equation.
Hydrological study and suspended sediment transport in the MACTA:
Mekerra watershed (NW Algerian)
by Saleh MOKADMI, El-Amine CHERIF
Abstract: The aim of this work is hydrological study and quantification of solid suspended transport in Mekerra basin whichi is located in the northwest of Algeria, in order to understand and explain the mechanisms of sediment, their causes and their consequences.
The quantitative and qualitative analysis of the liquid flows and solid flows measured at this representative basin over a period from 1988-2009 (Station: Sidi Bel Abb
Keywords: hydrological study; quantification of solid suspended transport; classes of evolution; sediment; Sidi Bel Abbes; Algeria.
A Bootstrap Regional Model for Assessing the Long-Term Impacts of Climate Change on River Discharge
by Chi-Yu Li, Shiu-Shin Lin, Yi-Fong Lin, Ping-Shiuan Kan
Abstract: Water resources in Taiwan come predominantly from rivers. Hence, it is important to understand the impact of future climate scenarios for policy-making. To investigate the impact of accelerating climate change on river flow in Taiwan, a Regional Flow Impact Model (RFIM) was developed. The RFIM is based on the Radial Basis Function Neural Network. It adapts the genetic algorithm for parameter optimisation, and the bootstrap method for quantifying uncertainties in the model and its results. The study area is the Taiwan Island, divided into four water resource management regions: North, Middle, South, and East. After the RFIMs were developed for different regions, various future weather scenarios predicted from global circulation models were applied. The results suggest that the average discharge increases at a higher rate in the Middle and the East, and the uncertainty of future discharge is higher in the Middle and the South of Taiwan Island.
Keywords: climate change; genetic algorithm; neural network; regional river model; bootstrap.
GROUNDWATER FLOW PATTERNS IN THE OBAGI OIL FIELDS OF SOUTH-SOUTH NIGERIA
by Ifeanyichukwu Ezekwe, Chukwuma Oji
Abstract: This study was an attempt to decipher groundwater flow patterns and the factors that affect it in the Obagi Oil Fields of South-South Nigeria. In this study, head, position and geological data were obtained from 13 hand dug wells tapping the water table and the Sombreiro and the Orashi Rivers, while water quality data was generated through groundwater sampling and analysis using standard methods. This study discovered a hidden channel system, a reversed recharge system for the Sombreiro River system with serious local groundwater quality implications. Groundwater flow in the study area has components of regional, intermediate and local flow systems, while movement is controlled by topography; recharge; a groundwater channel system running NW-SE through the middle of the study area and a system of wetlands in the Omoku and Erema areas. These wetlands which are used as sinks are also major recharge areas for the groundwater system in the study area thereby posing public health dangers. Also the dumping of industrial and domestic wastes in the wetlands may be limiting the capacity of these wetlands as sinks and purification plants for the natural hydro-geopollution cycle.
Keywords: Water Quality; Groundwater Channels; Groundwater controls; Tothian flow; Orashi; Sombreiro.
Dynamic parameter estimation for hydrological model
by Shailesh Kumar Singh
Abstract: Hydrological models are frequently used for forecasting, water management and decision making in watershed development. Due to simplification of complex natural processes in a hydrological model and the limited availability of observations, parameters of these models cannot be identified precisely during model calibration. Parameters of models are commonly assumed to be time independent even though some catchment properties are not stationary. The flexibility of hydrological models can be increased by introducing dynamic variation in the parameters of a hydrological model. In turn, this will improve the representation of natural processes. The purpose of this paper is to develop a methodology to investigate the dynamic nature of model parameter. A Robust Dynamic Parameter Estimation (RDPE) algorithm is developed which can be used for model diagnosis as well as for improving model predictions by allowing for parameter time dependence. After identification of the range of time varying parameters, a moving window approach and simulated annealing are used to optimize the parameters of the HBV (Hydrologiska Byrans Vattenavdelning) hydrological model for the each window size. The resulting time series of parameters are used for defining sensitive and insensitive periods in parameter time series and for understanding the reasons for parameter variation in time. To improve predictions a predictive parameter model is developed and applied using HBV model on meso-scale catchments in the Neckar basin in South-West Germany using HBV model. Finally, it is shown that the new methodology leads to more realistic confidence intervals for model simulations and model structure identification.
Keywords: Time varying parameters; RDPE algorithm; HBV; Parameter estimation.
Contribution of the multivariate analysis and origin for groundwater quality of mixed aquifer in the Msila plain (Algeria)
by Mostefa Dougha, Mahmoud Hasbaia
Abstract: The change of climate and intensive exploitation of groundwater
resources in the plain of Msila has influenced the hydrochemical functioning
of the complex aquifer. This resulted in a decrease in the piezometric level of
groundwater. The multivariate statistical techniques were used to determine the
main factors and regrouping parameters/wells and to understand the origin of
groundwater chemistry. Multivariate analysis (principal component analysis
and cluster analysis) was performed to identify a common source for sampling
data of a semi-arid aquifer. Physicochemical analyses were conducted on the
waters of 17 wells. The chemical water classification shows the dominance of a
chlorinated calcium and magnesium sulphate type facies, which has a very
remarkable tendency towards the salinisation. Cluster analysis based on major
parameters contents defined four main chemical water groups with increased
water-rock interaction. Some parameters presented the highest concentrations
of the total of dissolved salts provoking a poor quality of water.
Keywords: multivariate analysis; PCA technique; HCA technique; piper;
hydrochemical facies; water quality; origin of groundwater; salinity; mixed
aquifer; M’sila plain.
Optimal Control Applied to an Irrigation Planning Problem : a real case study in Portugal
by Sofia O. Lopes, Rui M.S. Pereira, Paulo A. Pereira, Amélia C. Caldeira, Victor Francisco Fonte
Abstract: In this paper, a daily plan model to the irrigation of a crop field using
optimal control was developed. This daily plan model have in consideration:
weather data (temperatures, rainfall, wind speed), the type of crop, the location,
humidity in the soil at the initial time, the type of soil and the type of irrigation.
The aim is to minimise the water used in the irrigation systems ensuring that
the field crop is kept in a good state of preservation. MATLAB was used to
develop our mathematical model and obtain its output. Its results were
compared with experimental ones obtained from a real farm field of grass in
Portugal. This comparison not only allowed us to validate our model, but also
allowed us to conclude that, using optimal control considerable savings in
water resources, while keeping the crop safe are obtained. Some real test cases
were simulated and the comparison between the optimised water to be used by
the irrigation system (calculated by software) and the real amount of water used
in irrigation site (on-off control system for irrigation) produced water savings
Keywords: optimal control; irrigation systems; real data; water resources;
INVESTIGATION ON WATER CONTENT OF SELECTED AGRICULTURAL PRODUCTS OF EAST AZARBAIJAN AND WEST AZARBAIJAN
by Marzieh Momeni, Zahra Zakeri, Sina Zahedi, Vahid Razavi
Abstract: According to a numerous environmental sustainability indicators, Iran is considered to be in an undesirable situation. Meanwhile "critical water crisis" is one of the most fundamental problems that decision and policy makers are facing. Thus, analyzing and coming up with solutions for the current water crisis is of outmost importance. The current study intends to focus on East and West Azarbaijan, in which Lake Urmia basin covers main part of this area. According to the sustainable development index of The United Nations Educational, Scientific and Cultural Organization (UNESCO) for water resources, this basin is exposed to extremely high risks of drought (High Risk Category> 40 %). Statistics indicate that the total amount of water consumption for selected agricultural products, in these provinces, is approximately 9.52 Billion Cubic Meters (BCM). In other words, agriculture sector consumes almost 91.8 % of allocated water in this area. For a better understanding of the current situation, this research focused on the water consumption in agriculture sector. Furthermore, by using partial equilibrium method, real virtual water content, calculated by amount of allocated water, was compared to that calculated based on water requirement of selected products. The results show that for production of one unit per kilogram, real water consumption is more than water requirement indicating that averaged value of water efficiency for producing most of the agricultural products in East/West Azarbaijan is almost 21%. Due to the water crisis, appropriate policies should be made to improve efficiency of water consumption in this area.
Keywords: Real Virtual Water Content; Water Consumption Efficiency; Partial Equilibrium; East Azarbaijan; West Azarbaijan.
An assessment of Water Resources at Halayib and Shelatine Sub regions, Southeastern Desert, Egypt, Using Conventional and Isotopic Approaches
by Samir Al-Gamal
Abstract: Surface water resources are expressed as potential surface runoff of ten watersheds in Halayib and Shelatine sub regions. Hydrologic response of the studied watersheds subjected to single storm event is tested. Base flow source areas and major recharge areas were delineated by infiltration using conventional infiltrometer and the water isotopes of O-18 and H-2. Aerial and linear aspects of each watershed were defined and due to paucity of runoff data, potential runoff was determined according to Snyders equation (1938). Groundwater resources are represented by two main aquifers; those pertaining to wadi fill and alluvial deposits of Quaternary aquifers resting unconformably over fluviatile sandstone of Um-Barmil Formation of Upper Cretaceous age. The Quaternary aquifer is receiving direct recharge from the present day precipitation as a consequence of infiltration from runoff water; particularly for soil of high infiltration capacity (7 mm/h).This represents the first pole of water while paleowater derived from the fluviatile sandstones of the tectonically dissected Um-Barmil Formation of Upper Cretaceous age represents the 2nd pole of water. Stable isotopes of O-18 and H-2 have proven the hydraulic connection between those two main aquifers. The foregoing situation has resulted in mixing of the two water types. The δ18O and δ2H values suggest a local meteoric line (whose slope of 5), characterizing low intensity, short duration rainfall, which partially were being evaporated during their precipitation.
Keywords: groundwater; surface water; infiltration;environmental isotopes; d-excess; aquifer;watershed.
Climate modeling using ANN
by Mehnaza Akhter, Manzoor Ahanger
Abstract: In the present study artificial neural network (ANN) model was applied to monthly temperature and precipitation data for base time (19792009) at four different metrological stations viz.Srinagar, Pahalgam, Qazigund and Gulmarg of river Jhelum basin in the State of Jammu & Kashmir, India and the future average annual temperature and precipitation predicted up to 2100. The large scale GCM predictors were related to observed precipitation and temperature and future projections of climate were made under A1B and A2 scenario upto 21st century. At the end of the 21st century the mean annual temperature of the Jhelum river basin is predicted to increase by 1.43
Keywords: Artificial Neural Network; Srinagar; Pahalgam; Qazigund ; Gulmarg; Scenario; Temperature; Precipitation.
Constructing Depth-Area-Duration Curves using Public Domain Satellite-Based Precipitation Data
by MARINA PATRICK, Yau Seng Mah, Frederik Josep Putuhena, Yin Chai Wang, Onni Suhaiza Selaman
Abstract: Dense network of rain gauges are used to accurately characterize the variation of rainfall over a less than ideal region such as Sarawak, Malaysia. This research aims to develop depth-area-duration (DAD) relationships of selected rainstorm event over Sungai Sarawak Basin by using public domain satellite-based precipitation data from Tropical Rainfall Measuring Mission (TRMM) product. Geographic Information System (GIS) was used to manipulate the 3-hourly accumulated precipitation dataset from TRMM and subsequently used to investigate spatial and temporal pattern of rainstorm. The findings suggested that rainfall depth decreases with increasing area for a given duration. This also implies that the remotely sensed information from TRMM product can be used as an alternative source of dataset to envelop rainfall DAD curves. Future work suggested would be to use the plotted DAD curves to estimate the probable maximum precipitation for the purpose of hydraulic structure designs.
Keywords: Areal rainfall; depth-area-duration; extreme rainstorm event; Geographic Information System; isohyets; Kriging; North-East Monsoon; Sungai Sarawak Basin; Thiessen Polygon; Tropical Rainfall Measuring Mission.
Comparison of perturbation methods for rainfall and temperature data: case of a Belgian catchment
by Yann Peltier, Benjamin Dewals, Sebastien Erpicum, Michel Pirotton, Pierre Archambeau
Abstract: Analyses of hydrological impacts of climate change require appropriate methods for perturbing the rainfall and temperature (or evapotranspiration) time-series to represent future climate conditions. In this paper, two readily available tools for perturbing rainfalls and temperatures are compared: CCI-HYDR and KNMI-ADC. CCI-HYDR provides three scenarios, tailored for Belgium, for every decade until 2100. In contrast, KNMI-ADC provides 191 scenarios, at a regional level and for two time horizons (near and far future). The suitability and practical applicability of CCI-HYDR and KNMI-ADC tools is particularly examined for a medium-sized catchment in Belgium. Since these two perturbation tools deliver stationary time-series, the pros and cons of such an approach are compared to an alternate one which produces transient time-series. The CCI-HYDR tool is found suitable for forcing computationally intensive detailed hydrological models, as it provides a limited number of contrasting scenarios representing the range of possible future climate conditions. The KNMI-ADC tool enables scanning a broader spectrum of climate scenarios (although less extreme than in the CCI-HYDR tool), which makes it suitable for forcing multiple runs of fast conceptual hydrological models. The approach based on the transient stochastic tool is particularly computationally demanding due to its stochastic nature and is therefore also not optimal for use in combination with a detailed distributed hydrological model.
Keywords: rainfall perturbation; climate change scenarios; hydrological modelling.
Laboratory Investigation for development of local scour depth model for varying shapes of obstruction
by Mir Bintul Huda, Mohd Akbar Lone, Javaid Ahmad Bhat
Abstract: This paper reports the effect of the shape of obstruction on local scour depth. Laboratory experiments were conducted on a tilting glass flume to study scour phenomenon around five obstructions of different shapes. Obstructions studied were chosen keeping in view not only the bridge piers but also some other structures, like obstructions in the flow channels e.g. a jetty, big boulder, any building in the coastal area, etc. Maximum local equilibrium scour, a dependent parameter, was studied as a function of flow parameters and shape parameters of the obstruction. A model was developed for the maximum local scour depth estimation in which maximum local scour depth (ds) is a function of Froude number (Fr), flow depth (y) and shape factor (Sf). The experimental findings depict a considerable effect of the shape of obstruction on the local scour depth.
Keywords: discharge; flow depth; Froude number; scour; local scour; obstructions; shapes.
Mining Industry Impacts on Surface Water Quality in South Part of Armenia
by Marine Nalbandyan
Abstract: This paper deals with the quality of water of one of the tributaries of the river Araks- River Voghchi and its watershed basin. This article covers an investigation of common ions (Ca, Mg, Na, Cl, K, SO4, HCO3) and HMs (Cu, Mo, Cr, Ni, Mn, Zn, Co, Cd, Pb, Ag, Hg, As ) in waters of the River Voghchi and its tributaries. The performed river water research was underpinned by monthly monitoring data for 2003-2011. The impact of pollution sources and water quality formation factors were indicated. Assessment of the river water pollution with common ions and HMs were carried out, and dominating elements were indicated. The paper is highlight pollution level of the river water for the period of unstable economy and period of their stabilization, giving the comparative analysis of river water pollution.
Keywords: mining industry; river water pollution; heavy metals; common ions; statistics; correlation analysis; River Voghchi; Armenia.
Application of non-parametric regression in estimating missing daily rainfall data
by Rachel Makungo, John Odiyo
Abstract: Most daily rainfall time series data are too short and/or possess missing records hindering them to perform reliable and meaningful analyses. Robust locally weighted scatter smoother non-parametric regression approach (NPR), with tricube weighting function was used to estimate missing daily rainfall data in the upper reaches of Nzhelele and Luvuvhu River Catchments in Limpopo Province of South Africa. Though a number of methods have been developed and tested, the approach proposed in this study has not yet been widely applied for estimating missing rainfall data. Model performance was evaluated using mean bias error, correlation coefficient, coefficient of determination, root mean square error and Nash Sutcliffe coefficient of efficiency. Model performance ranged from acceptable to excellent. Graphical fits of observed and estimated rainfall data showed a general agreement. Scatter plots indicated that there was no definite pattern of underestimation and overestimation of peak rainfall events in both calibration and validation runs. Scatter points for low rainfall values (mostly between 0-25 mm) were closer to the best fit line showing good agreement between observed and simulated rainfall values for most of the stations. The study showed that NPR effectively estimated missing rainfall data.
Keywords: catchment; missing rainfall data; model performance; non-parametric; regression; time series; tricube weighting function.
Farm dam siltation and sediment source tracing in the Zeerust - Swartruggens area in the North-West of South Africa
by Samuel Che Nde, Munyaradzi Manjoro, Manny Mathuthu
Abstract: Soil erosion and dam siltation are two serious environmental problems facing farmers in South Africa. The study aimed to assess farmers perceptions on dam siltation and strategies employed to address it, and to assess the potential of sediment source tracing in a farming area in the North-West region of South Africa. Most of the dams in the study area were severely affected by siltation and the most important strategy used to address the problem was regular mechanical removal of the accumulated sediment. In relation to sediment tracing, lead-210 (210Pb) was found to be a more effective tracer than caesium-137 (137Cs) for distinguishing between surface and subsurface sediment sources. On the other hand, magnetic susceptibility offered better distinction of the sediment sources than magnetic remanance. Mass balance modeling indicated that 100 % of the sampled sediment Dam 1 originated from surface sources. The results reflect the complexity of sediment mobilization processes influenced by the nature and spatial distribution of rainfall and runoff connectivity in the catchments.
Keywords: Farm dam siltation; environmental radionuclides; environmental magnetism; sediment source tracing; mass balance modelling.
Assessment of Future Groundwater Quality Using GIS for Bhimrad Area of Surat City (India)
by Manisha Desai, Jayantilal Patel
Abstract: Declination of water quality has become a global issue of concern as with the growth of human population, industrial and agricultural activities expand. Climate change threatens to cause major alterations in the hydrological cycle. The Bhimrad area of Surat city (Gujarat) is highly affected by ground water pollution because of its location in the vicinity of the industrial zone. There exists a creek adjoining Arabian Sea, in which all the wastewater of the city, including that of the industrial area is discharged, thus polluting land and other sources of water in the surrounding areas. The research paper shows the assessment of the groundwater quality degraded in the Bhimrad area of the Surat city on the basis of collection of past few year data of groundwater quality. Water quality has been assessed in term of the groundwater quality index (GWQI) by determining pH, Electric Conductivity, Total Dissolved Solids, Chlorine, Total Hardness, and Alkalinity in the premonsoon (May-June) and post monsoon (November-December) period for the years 2004, 2006, 2008, 2011, 2012, 2013, 2015. This research paper aims to analyze groundwater dilution used under the threat of pollution by identifying the prospects for improving the quality through artificial recharging that may impact groundwater quality. Calculation of percentage reduction in the groundwater quality parameters after recharging was carried out through which estimated improvement in GWQI using GIS, GWQI after recharging is analyzed for the years 2015 to 2050.
Keywords: Sustainable Resources; Groundwater Quality; Water Conservation; GIS; Geological Information System.
Hydrological impacts of Climate Change on the Future Streamflow of Three Unregulated Catchments of the Australian Hydrologic Reference Stations
by Hashim Alsafi, Ranjan Sarukkalige
Abstract: A physically-based distributed hydrological model, the Block-wise use of the original TOPMODEL with the Muskingum-Cunge routing method (BTOPMC), is adopted to assess the impacts of future climate changes on the hydrological behaviour of three different sized contributing catchments of the Australian Hydrologic Reference Stations (HRSs); including Harvey River at Dingo-Road in Western Australia, Beardy River at Haystack and Goulburn River at Coggan in New South Wales. In this study, both historical and future modelled streamflow trends are compared and discussed. Firstly, the BTOPMC-model was calibrated and validated based on the observed hydro-meteorological data from the three contributing catchments. Then, the downscaled future climate signals from a multi-model ensemble of eight-GCMs of the CMIP5 under the RCP4.5 and RCP8.5 scenarios were used to force the calibrated BTOPMC-model to simulate the future daily streamflow at the three HRSs for the mid (2046-2065) and late (2080-2099) of the 21st-century. Nearly all GCMs predict a reduction tendencies in mean annual rainfall and an increase in temperature and potential evapotranspiration across the studied catchments. The mean annual streamflow measured at the three HRSs also shows reduction tendencies during the future periods under the two climate scenarios ranged between 26-53% at Dingo-Road HRS, 10-25% at Haystack-HRS and 6-33% at Coggan-HRS relative to the control run. The outcomes of this study are used to deliver valuable water management strategies to overcome the expected problem of water scarcity in the studied catchments.
Keywords: Climate change; Hydrologic Reference Stations; physically-based simulation modelling; BTOPMC model; CMIP5; Australia.
Recent Approach in Producing Transparent Conductive Films (TCFs)
by Siavash Hosseinpour Chermahini, Kaveh Ostad-Ali-Askari
Abstract: Transparent conductive films (TCFs) are well known for their use in improving the efficiency of solar cell devices. The properties of transparent conductive materials are highly important due to their specifications and their influence on the performance of various devices. On the other hands, waste disposal is creating a global crisis which threaten the well-being of humans. Cheap electronic is one of the urgent current environmental problem. To this regards, different types of transparent conductive films have emerged, but indium tin oxide (ITO) and fluorine tin oxide (FTO) have been used in TCF sheets due to their optical transparency and electrical conductivity. However, some weaknesses, such a slow quality in the infrared region, the high cost of the elements, and their activity at low temperatures without the flexibility of transparency, have led to the search for a substitute. Moreover, TCFs need to be viable on a large scale for the next generation of optoelectronic devices as there is a lack of study in this area. Among all the candidates, a transparent hybrid of graphene and single-wall carbon nanotubes (SWCNTs) is a new trend in this area. Stable and homogeneous suspensions of GO sheets with strong hydrophilic and electrostatic repulsion properties are being used to produce TCFs. This trend has led to the creation of nanomaterials that exhibit better properties than their solo applications. Some techniques are able to increase the opt electrical properties with an additional transparency of more than 90%. Therefore, a comprehensive review was conducted for a new approach for the improvement of photovoltaic devices by means of a hybrid GP and SWCNT transparent conductive film.
Keywords: Transparent conductive films (TCFs); single wall carbon nanotubes (SWCNTs); graphene oxide (GO); nanomaterial.
Estimating root zone soil moisture using multilayer feedforward neural networks based on Levenberg-Maquardt and scaled conjugate gradient algorithms
by John Odiyo, Rachel Makungo
Abstract: This paper presents the use of multilayer feedforward neural networks for root zone soil moisture estimation based on Levenberg-Maquardt (LM) and scaled conjugate gradient (SCG) algorithms. Data driven approaches such as artificial neural networks overcome some limitations of remote sensing, conceptual and semi-analytical models in root zone soil moisture estimation. This creates the need to compare neural networks training algorithms to determine those with best estimation accuracy. Observed volumetric soil moisture at 80 cm depth, rainfall and evaporation data were used to estimate soil moisture at 120 and 180 cm depths, within MATLAB. SCG trained network underestimated and/or overestimated soil moisture as compared to LM trained network. LM trained network has better performance and estimation accuracy. Estimated soil moisture is useful for irrigation scheduling, hydrological modelling, and groundwater recharge estimation in the study area.
Keywords: algorithm; estimation accuracy; Levenberg-Maquardt; multilayer feedforward; neural networks; root zone; scaled conjugate gradient; soil moisture.
Prediction of discharge coefficient of combined weir-gate using ANN, ANFIS and SVM
by Abbas Parsaie, AmirHamzeh Haghiabi, Samad Emamgholizadeh, Hazi Mohammad Azamathulla
Abstract: Flow measurement is an important issue for developing the water conservation projects and evaluating the performance of irrigation and drainage networks. Weirs and gates are the most common structures which have been widely used for flow measurement. The main defects related them are deposition of suspended matter behind the weirs and accumulation of floating matter on water behind the gates, respectively. therefore, the weir-gate structure has been proposed to solve them infirmities. In this study, predicting the discharge coefficient of Weir-Gate was considered using the artificial neural network (ANN), support vector machine (SVM) and adaptive neuro-fuzzy inference systems (ANFIS). For this purpose, the related dataset were collected from the literature. Assessing the performance of three models show that all of them have suitable accuracy, however, the SVM model with a coefficient of determination (R2=0.94) and root mean square of error (RMSE=0.008) has the best performance in comparison with others. During the preparation of SVM it was found that the radial basic function as kernel function has best performance among the tested kernel functions. Sensitivity analysis of applied models showed that the ANN is the most sensitive model in comparison with others.
Keywords: Flow Measurement; Hydraulic Efficiency; Irrigation and Drainage Networks; ANFIS.
DETERMINATION OF HYDRAULIC FEATURES IN COLOMBIAN RIVERS BY TRACER ANALYSIS
by Alfredo Constain, Carlos Peña, Duvan Mesa
Abstract: The importance of hydraulic, geomorphological and hydrodynamic conditions in rivers on watershed management cannot be overstated. However, in developing countries, sometimes the infrastructure is poor and these conditions are not managed properly. Therefore, this paper proposes a methodology to calculate flow, slope, Chezys C, Mannings n and hydrodynamic conditions in rivers with a tracer. This methodology allows the calculation of these hydraulic and hydrodynamic characteristics for rivers that have velocity from 0.108 m / s to 1.93 m/s.
Keywords: Hydraulica features; hydrodynamic; rivers; tracer.
Selection of the Most Adequate Frequency Model to Estimate the Flood Extreme Values in the North west of Algeria
by Hebal Aziz
Abstract: This work is intended to determine the most appropriate model to estimate the extreme values of flood in the North West of Algeria. The study is conducted in two steps. The first one consists on the determination of the type of laws which may represents better the data series using the log-log plot. The second step extends on the establishment of a ranking of the laws of the selected type. This has become possible with the application of different choice criteria: the Bayesian Information Criterion, the Aka
Keywords: Frequency model; North-west of Algeria; flood extreme values; Bayesian approach.
The application of Conceptual Modelling Approach to Evaluate the Impacts of Climate Change on the Future Streamflow in Three Unregulated Catchments of the Australian Hydrologic Reference Stations
by Hashim Alsafi, Ranjan Sarukkalige
Abstract: The future climate change impacts on streamflow variability at three selected contributing catchments of the Australian Hydrologic Reference Stations (HRSs), Harvey, Beardy and Goulburn catchments, are presented in this study. The HRSs network represents living gauges that enable the long-term streamflow monitoring and climate change adaptation. Observed hydro-meteorological data from the contributing catchments were used to calibrate and validate the Hydrologiska Byrans Vattenbalansavdelning (HBV) hydrological model before the streamflow prediction. The downscaled future rainfall and temperature from a multi-model ensemble of eight-Global Climate Models of the Coupled Model Inter-comparison Project phase 5 (CMIP5) under two Representative Concentration Pathways RCP4.5 and RCP8.5 were used to run the calibrated HBV model to simulate the future daily streamflow at the three HRSs. Nearly all GCMs predict reduction tendencies in mean annual rainfall and an increase in temperature and potential evaporation across the studied catchments during the mid (2046-2065) and late (2080-2099) of the 21st -century. The mean annual streamflow across the three catchments also tend to decrease during the future periods under the two climate scenarios and ranged between 31-60% for the Harvey catchment, 1- 24% for the Beardy catchment and 18-42% for the Goulburn catchment relative to the control run. The outcomes of this study could deliver valuable water management strategies to overcome the expected problem of water deficiency in the studied catchments.
Keywords: Climate change; Hydrologic Reference Stations; conceptual modelling; HBV model; CMIP5; Australia.
Water Balance Study of a High Altitude Catchment in Indus Basin of Himalayas: Application of physics based distributed hydrologic model-MIKE SHE.
by Yasir Altaf, Manzoor Ahangar, Mohammad Fahimuddin
Abstract: The water balance of the Lidder basin was done by re-enacting all components of the hydrological cycle. MIKE SHE model was utilized to simulate all components of hydrological cycle of the Lidder basin. Water balance components were estimated at three sub-catchments Aru, Sheeshnag and at Akura and the model results show that ET losses at Aru, Sheeshnag, and Akura (total catchment) were to be 19.23 , 19.65 and 24.61 % of the total rainfall while runoff at Aru, Sheeshnag and Akura (total catchment) of Lidder basin were 34%, 40% and 57.02% of the total rainfall. Snowmelt contribution to the total streamflow in the Lidder River at Aru, Sheeshnag, and Akura (total catchment) was found to be 58.54, 54.19 and 41.75 %. The base flow contribution to the discharge in Lidder River at Aru, Sheeshnag, and Akura (total catchment) were estimated to be 22 %, 35 % and 43 % respectively. rnrn
Keywords: Distributed Hydrological Model; Water Balance; Coupled Model.
Quantifying Soil Erodibility Parameters Due to Wastewater Chemicals
by Mohammed Abbas, Abdul-Sahib Al-Madhhachi, Sarah Esmael
Abstract: Many factories and hospitals dumped their wastewater into Tigris River without any treatment in Baghdad city. Rather than the wastewater chemicals and substances influenced on river water quality, this could influence on soil erodibility on Tigris Riverbanks. Phenol, Sodium Nitrate (as a source of NO3), and Dipotassium hydrogen Phosphate (as a source of PO4) were considered as huge concentrations in wastewater chemicals. The main objectives of this research were 1) to investigate the influence of three wastewater chemicals (Phenol, Nitrate, and Phosphate) on erodibility parameters of cohesive soils using Blaisdells solution and Scour Depth solution techniques from Jet Erosion Tests (JETs), and 2) to develop relationship between soil erodibility parameters and soil hardness. An excess shear stress model was utilized to measure soil erodibility based on two empirical soil parameters: critical shear stress (τc) and erodibility coefficient (kd) using two solution methods: Blaisdells solution and Scour Depth solution. A new miniature version of the JET device (mini JET) was laboratory performed on soil samples which were acquired from riverbank site to measure the soil erodibility parameters due to fluvial erosion. Subsequently, different concentrations of wastewater chemicals (Phenol, Nitrate, and Phosphate) at different polluted times (1, 3, and 7 days) were conducted on soil samples to observe the influence of these chemicals on soil erodibility parameters (τc and kd). The results showed a constantly increased in kd for all three wastewater chemical even with increasing in both concentrations of wastewater chemical and polluted time, while τc values were decreased. An inverse relationship was developed between τc and kd for both Blaisdells solution and Scour Depth solution techniques. Parallel inverse relationships of the kd with soil hardness were reported between Blaisdells solution and Scour Depth solution techniques, while parallel direct correlation relationships of the τc with soil hardness were investigated.
Keywords: Wastewater chemicals; Soil erodibility parameters; Polluted soils; JET.
The map-correlation method for ungauged catchments streamflow prediction in the Ufa River, Russian Federation
by Elena Belozerova, Nataliya Krasnogorskaya, Antonia Longobardi, Elvira Nafikova
Abstract: The paper investigates the problem of streamflow prediction at ungauged catchments by the use of the map correlation method and focuses on the selection of reference stream gauges to estimate the average daily streamflow for ungauged catchments. Daily streamflow data are indeed crucial for several fields such as water management, sustainable water resource management, hydropower energy production, but the number of ungauged watersheds is still big and reliable large scale regional approaches are indeed needed as a practical response to the ungauged catchment problem. In the following, results of an application to the catchments of the rivers Ufa and main tributaries for a total of 25 catchments, is presented. The map correlation method has been performed, where differences is made between the nearest stream gauge and the best correlated stream gauge criterion for reference station selection. It was found that, on average, for the case study the best performing method for the selection of reference station is the best correlated.
Keywords: map correlation method; kriging; ungauged catchment prediction; reference stream gauge; Russian Federation.
Calibration of a Hydrological Model and Sensitivity Analysis of its Parameters: A Case Study of Seonath River Basin
by Mani Kant Verma, Mukesh Kumar Verma
Abstract: The objective of this paper is surface runoff estimation of the Seonath river basin using a semi-distributed hydrological model, i.e., SWAT (soil and water assessment tool). In this paper, the study on calibration and sensitivity is carried out using SWAT-CUP (calibration and uncertainty program) along with SUFI-2 (sequential uncertainty fitting algorithm). The performance of SWAT model is evaluated by various statistical measures; such as Nash-Sutcliffe coefficient (NS), coefficient of determination (R2), percent bias (Pbias), p factor, r factor and ratio of the root-mean-square error (RMSE) to the standard deviation of the observation (RSR). In the current work, 31 years (1980-2010) of weather data was used. The time slice for model calibration was 15 years, i.e., 1987 2001 with seven years of warming period 1980 1986 and validation period was comprised of 9 years (2002 2010). In the study, the calibration of the model was done for the two stations which is a major step for carrying out further study related to climate and land use change impact assessment. The study yielded satisfactory results in terms of model performance.
Keywords: Hydrological modelling; Calibration; Sensitivity analysis; SWAT-CUP; SUFI-2.
Groundwater vulnerability Mapping of Jordanian phosphate mining area based on Phosphate concentration and GIS: Al-Abiad mine as a case study
by Adnan Al-Harahsheh, Majed Ibrahim, Noureddine Elboughdri, Mohammad Al-harahsheh, Salah Aljbour
Abstract: Groundwater constitutes the main water supply in Jordan. Therefore, various steps are taken to monitor groundwater quality and vulnerability for a sustainable groundwater development. The present study uses DRASTIC model on a national rate and assess the groundwater contamination by phosphate concentration released from the mining activities in south of Jordan (Al-Abiad area) using GIS environment. The DRASTIC index was used with seven parameters to describe physical characteristics of the aquifers. It is concluded that about 58.6% of the area was considered to be of moderate vulnerability, while high and low vulnerability were found to be at 0.6% and 42.8% respectively of the total area. On the other hand, investigation of infiltration process of selected pollutants (Soluble phosphate and chloride ions) through the surface layer of study area is concluded the vulnerability of the groundwater quality toward such as pollutants. These pollutants are detected in washing water effluent of phosphate beneficiation process. Chemical Analysis of the used washing water shows high concentration of P2O5(TCP) , Cl- and SiO2 comparing with initial feed water. To get rid of waste water streams, the current practice in at Al-Abiad and other Jordanian phosphate mining industry is to send it to desert without any attempt to treat and recycle this water. Therefore, urgent pollution prevention measures should be considered for such mining activities within the whole of Jordanian phosphate mining area .
Keywords: Vulnerability; Waste water; Groundwater; DRASTIC; Phosphate; GIS.
Hydrochemistry and water quality index (WQI)application in the assessment of groundwater quality in Oyo State, Nigeria.
by Timothy O. Ogunbode, Omowumi T. Akinola
Abstract: An investigation into spatial water quality and the application of WQI groundwater quality assessment in the rural suburbs of Oyo State, Nigeria was carried out. Twenty five out of the 33 LGAs in the State were selected for while five rural communities were randomly selected from each for the purpose of this research. Groundwater samples were collected from each of the communities and were analysed following standard laboratory procedure. The results revealed that the groundwater in the study area is generally fit for human consumption by World Health Organisation standard. The results of weighted average water quality index (WAWQI) showed that the groundwater in the 24 LGAs (96%) fell in the excellent water category while Oyo East LGA only (4%) fell in the good water category indicating its potability. Water Quality Index (WQI) mapping using paint software revealed the spatial spread of WQI in the study area while multivariate analysis showed that four pairs of water quality variables (namely EC and TDS, EC and NO3, TDS and NO3, Na+ and K+) have positive correlations. Also, EC and TDS correlate positively with WQI indicating that the results of WQ analysis were positively influenced by the composition of EC and TDS in the water. Though, WQI and its mapping afford quick knowledge of water quality status for temporal and spatial intervention in water quality management, regular quality investigation is essentially recommended to guaranty human safety.
Keywords: WQI; groundwater; Oyo State; Correlation; hydrochemistry; WQI mapping.
The long-term trends in hydro-climatology of the Dinder and Rahad basins, Blue Nile, Ethiopia/Sudan
by Khalid Hassaballah, Yasir Mohamed, Stefan Uhlenbrook
Abstract: This paper examines the long-term trends of streamflow, rainfall, and temperature over the Dinder and Rahad River basins. Streamflow of the Rahad River showed significant increasing trends in both the annual and seasonal flows. There was no detectable change in the mean annual and seasonal flow patterns of the Dinder. However, the analysis of seasonal maxima suggested a shift towards decreased flows during the high flow period (August) and increased flows during the low flow period (November). The Dinder maxima of August decreased from 517 m3/s over the early part of the record (1972-1991) to 396 m3/s over the latest years (1992-2011). The mean annual temperature showed significant increasing trends at the rate of 0.24 and 0.30 oC/decade in the examined stations. Rainfall showed no significant change. The result of this study suggests other factors than climate variability (e.g. land use land cover changes) to be responsible for streamflow alterations.
Keywords: Time series analysis; Hydro-climatic trend; Dinder and Rahad basin; Mann–Kendall; Pettitt test; IHA; non-parametric analysis.
Assessment of heavy metals in surface water of Vishwamitri river
by Pranavkumar Bhangaonkar, Jayeshkumar Patel
Abstract: Heavy metal analysis of the surface waters from Vishwamitri river was conducted in pre-monsoon, monsoon and post-monsoon seasons during year 2015-16. Samples were collected and analyzed from various sampling stations along the Vishwamitri with a view to assess and analyze the concentration of various metals i.e. Cd, Cu, Fe, Pb, Mn, Hg, Ni and Zn. The concentration of Cd, Cu, Mn in all samples has been found within safe limit described by Bureau of Indian Standards (BIS, 2012) for drinking water. Fe concentration is found maximum at Munjamahuda, Karali and Thikaria bridges during pre-monsoon, monsoon and post-monsoon respectively. Pb concentration is observed maximum at Baska bridge. Concentration of Zn at Munjamahuda bridge (during 2015) is observed 5.410 mg/L. Concentrations of majority of the heavy metals were observed high in downstream sampling stations. Suitability of Vishwamitri water is to be assessed for drinking purposes. Assessment regarding the biotoxic effects of heavy metals concentration in river water of Vishwamitri is essential. Adoption of appropriate treatment and controlling measures to reduce metallurgical effluent load deposited into the river through various point and non-point sources of pollution is need of the hour.
Keywords: heavy metals; monsoon; post-monsoon; pre-monsoon; Vishwamitri; water quality.
ASSESSMENT OF MODIFIED CURVE NUMBER METHOD BY EVALUATION OF RUNOFF DEPTH IN SULAK BASIN-IRAQ
by GHASSAN AL-DULAIMI
Abstract: Traditional hydrological analysis used maps and ground survey as tools to obtain the basic parameters of the watershed. However, for large catchment area the above criteria are both costly and time consuming. In this research a hydrological model modified natural resources conservation service curve number (NRCS-CN) & Geographical Information System GIS technique are used together to obtain the runoff depth for Sulak catchment area that located in the northern western part of Iraq. The basin divided into three sub-basins, runoff has been estimate for each sub-basin by three approaches. The research detect that the slope parameter affects runoff estimation significantly also its found that for each sub-watershed runoff varies drastically from sub-watershed to sub-watershed of Sulak basin. The analysis of variance test showed that there was significant difference between each curve number value for each sub-watershed, accordingly runoff calculated by Williams method gives valves above the average comparing with other methods . Total runoff estimated by three approaches for entire catchment area which shows that around 51% of total runoff is generated in months January and February, That because of heavy rainfall and high soil moisture content (Antecedent Moisture Content AMC-III) during that period.
Keywords: Sulak Catchment area; Runoff,Modified Curve Number Method; GIS Technique.
Impact of Potential Evapotranspiration on Maize yields in Northern Cameroon using Aquacrop Model
by Brice B.S. Wandjie, Andre LENOUO, David Monkam
Abstract: This work presents impact of potential evapotranspiration (PET) on the agricultural yield of maize in Northern Cameroon using the AquaCrop model. Weather variables, rainfall, temperature, wind, solar radiation, water vapor pressure, relative humidity in three (03) towns in Northern Cameroon, located in Central Africa are used as independent variables in estimating five (05) PET models from 1985 to 2004 in two of these towns and from 1985 to 1995 in the other. After comparing different PET models, AquaCrop model, which is a crop, culture simulation software developed by the Food and Agriculture Organization (FAO) has been calibrated to simulate maize yields during the period of June 15 to October 24. The results indicated that maize yields increased with PET methods values in the whole study zones for each year. In fact, this study revealed that, compared to the results given using reference PET (FAO Penman-Monteith) values, maize yields raised until up to 60% for the PET values greater than reference PET in the different towns.
Keywords: Potential evapotranspiration; AquaCrop; Central Africa; Maize yields.
A SIMPLE AND EFFICIENT NUMERICAL MODEL FOR SIMULATING ONE DIMENSIONAL DAM BREAK FLOWS
by Hriday Mani Kalita
Abstract: A semi implicit finite difference scheme is presented in this paper for simulation of dam break flow over undulated bed. For this purpose, the one dimensional (1D) governing equations of shallow water flow, in a deviatoric version is solved here. One of the main important features of the present model is that, no special treatment is required here to deal with the offending friction slope source term for very less water depth. Regarding the bed slope term also, simple central difference approximation is sufficient to handle undulated channel bed. To investigate the performance of the present model in diverse situations, it is used to replicate different dam break test problems including one of known analytical solution and two experimental dam break cases. A detail analysis of the results show that the model capable is of producing good quality results for varied conditions. A sensitivity analysis is carried out for the damping parameter and an optimal range is proposed for it.
Keywords: Shallow water equations; dam break flow; wetting and drying; irregular topography.
Hydrological model parameters space during calibration
by Shailesh Kumar Singh
Abstract: Hydrological models are widely used for different water resource problems. Hence, the same model can have different purpose. Depending on the purpose of the model, it need to be calibrated differently. There are several objective functions which can be use to calibrate a model, but there is not a single objective function which can describe all the components of a hydrograph simultaneously. In this study, an attempt has been made to analysis the parameter space mapped by different objective functions during calibration of a hydrological model. A conceptual hydrological model HYMOD was calibrated using Robust Parameter Estimation (ROPE) algorithm with different objective functions, namely Nash-Sutcliff coefficient, root mean square error, volume error and peak error. Also with log Nash-Sutcliff coefficient, log root mean square error, log volume error and log peak error. It has been found that the different objective function have mapped parameter spaces differently. Details diagnosis of parameter space reveal that there is no common intersection of parameter space obtained by different objective functions. The volume shrinkage of parameter space by different objective functions during parameter searching iteration are different. Which indicate optimal parameter set obtained by different objective functions are at different rate. The diagnosis of parameter space has lead us to develop a Hierarchical Optimization (HOP) calibration technique. In HOP calibration, firstly the search domain are constrain using one objective function which is general in nature and gives importance to over all characteristics of hydrograph. In second iteration it further constrain the space using another function. This process is repeated until dynamics of the hydrograph are well represented. HOP based calibration outperformed any calibration based on single objective function calibration. The result of this study will be helpful for robust parameterization of hydrological model and to obtain a global parameter which can be better represent ion of all component of hydrograph.
Keywords: ROPE algorithm; conceptual hydrological model; objective function; HYMOD.
Evaluation of multiple satellite-derived rainfall products over Morocco
by FOUAD GADOUALI, MOHAMED MESSOULI
Abstract: The focus of this study is to assess the accuracy of four satellite-based rainfall estimations in Morocco. Tropical Rainfall Measuring Mission, version 7 (TRMM3B42V7), African Rainfall Climatology, version 2 (ARC2), African Rainfall Estimation Algorithm, version 2 (RFE2.0) and Precipitation Estimation From Remote Sensing Information using Artificial Neural Network-Climate Data Center (PERSIANN-CDR) are evaluated with observations from 19 meteorological stations over Morocco, at daily and monthly time steps for the period 2001-2014. In order to study the performance dependency of these satellite products on topography and climate types, evaluation is carried out at different seasons as well as different classes of topography. Results show that, all the satellite datasets reasonably reproduce the mean annual rainfall and the seasonal cycle over all the studied area. In terms of rainfall day statistics, ARC2 and RFE2.0 have performed the best while PERSIANN-CDR exhibited the worst performance. Categorical statistical indices obtained for different seasons and elevation classes showed that the TRMM3B42V7 product outperforms others in both the boreal summer (JJA) and the rain shadow areas. For the total precipitation, all the products underestimate rainfall amount in low and mid elevation, whereas a marked overestimation is observed over the rain shadow areas. Comparison between monthly and daily scores confirmed the improvement of the satellite products performance when using the monthly step. In terms of rainfall intensity, TRMM3B42V7 exhibits good performance to reproduce high rainfall intensities, which makes this product suitable on the monitoring of floods that are mainly caused by heavy rainfall. However, the shortcomings presented by all the satellite rainfall products, especially at the daily step, could be useful for their improvements and point out to the need for applying bias adjustments before using them.
Keywords: TRMM; ARC2; RFE2.0; PERSIANN; Satellite rainfall; Morocco; Precipitation.