International Journal of Water (13 papers in press)
Investigating the effect of climate change on inflow into Karun-4 dam based on IPCC's fourth and fifth reports
by Afshin Mansouri, Babak Aminnejad, Hassan Ahmadi
Abstract: In the present paper, fluctuations of inflow into Karun-4 dam under different climate change scenarios for the future period of 2021-2050 have been investigated. For this purpose, the outputs of HadCM3 model under the scenarios of B1 (optimistic) and A2 (pessimistic) were used for the IPCC fourth assessment report. Additionally, the outputs of the ensemble model under RCP 2.6 (optimistic) and RCP 8.5 (pessimistic) scenarios were used for the IPCC fifth assessment report. Furthermore, to estimate discharge in the future period, artificial neural network (ANN) was considered as a rainfall-runoff model. Results indicated that the average annual precipitation in the five study stations under B1 and RCP 2.6 scenarios increased by 15% and 5%, respectively, and showed a decrease equal to 8% and 6%, respectively, under A2 and RCP 8.5 scenarios. Moreover, the average annual temperature in all scenarios showed increases, which were at least 1.06 oC under B1 scenario and 1.89 oC under RCP 8.5 scenario. Examining the inflow into the Karun-4 dam showed that under both B1 and RCP 2.6 scenarios, the annual inflow would increase by 1.8% and 1.5%, respectively, and under the two scenarios A2 and RCP 8.5, the annual inflow would decrease by 10.4% and 9.8%, respectively.
Keywords: HadCM3 model; ensemble model; optimistic scenarios; pessimistic scenarios.
Impacts of lands and land cover detection on climate variability of Gumara watershed, Ethiopia
by Afera Halefom, Asirat Teshome, Ermias Sisay
Abstract: This study uses a combination analysis of land use and land cover (LULC) impacts on climate variability which is conducted by using remote sensing data and weather data. The detection of LULC is examined using satellite images and climate variability using Mann-Kendall used to identify the trends of the temperature and rainfall data and give alarm how to handle LULC and climate variability. Four satellite images (Landsat 8 OLI, Landsat 7 ETH+, Landsat 5 &7 TM) were acquired and supervisory classification was used to categorise land cover types. The major categories used for the classification were built-up area, forest, waterbody, agriculture and grasslands. The LULC results tell that the built-up area development has changed substantially during the period from 1997 to 2017. Analysis of the temperature data from the period of 1997 to 2016, using the Mann-Kendalls tau and Sens slope estimator test of average annual maximum temperature and annual mean temperature, shows a significant positive trend and average annual minimum temperature shows decreasing trends. Trend analysis of rainfall conducted as shows positive trends in the bega season and decrement trends in annual rainfall, belg season rainfall and kiremt season rainfall. Percentage changes of average annual minimum temperature, average annual maximum temperature and average annual temperatures were observed as 0.4%, 2.4% and 2.6% respectively and percentage changes of average annual rainfall, bega season, belg season and kiremt seasons were -1.7%, 3.5%, 6.5% and -6.4% respectively. Hence, this percentage changes indicates how land use land cover change affects climate.
Keywords: climate change; grassland; temperature; rainfall; Ethiopia; built-up area.
Factors influencing farmers knowledge about sustainable groundwater management
by Azade Bakhshi, Lucio Cecchini, Bahman Khosravi Pour, Mansour Ghanian, Fabio Maria Santucci
Abstract: This paper analyses the influence of socioeconomic and structural factors on the knowledge about sustainable groundwater management (SGWM) among farmers in Iran. 189 wheat producers have been interviewed during summer 2017 in the South Khorasan province. The dependent variable (TK, Total Knowledge) has been constructed through the answers to 18 questions, defined as pk, partial knowledge. The model includes ten independent variables (age, education, income, knowledge about drought, relationship with the local advisory service, water rights, irrigation method, area with wheat, wheat total production, and fragmentation). There is a correlation, sometimes positive and sometimes negative, between all independent variables and SGWM. Participation in extension meetings, total wheat production, and family income show the strongest positive correlations. A multiple linear regression estimates the influence of the variables on the TK regarding SGWM; 45.0% of the TK variance is determined by the independent variables used in the model.
Keywords: irrigation; drought; knowledge; advisory services; South Khorasan; Iran.
Identification of flood vulnerable zones in Mahanadi Delta based on post-Hirakud historical data
by Anil Kar, Krishna Gupta, Joygopal Jena, Dipti Ranjan Jena
Abstract: The Mahanadi basin with a big catchment of 141,569 sq. km occupies a major geographical area of two states Chhattisgarh and Orissa. A lot of hydroclimate variation is seen in the basin owing to its large size. The basin lies in the south-west monsoon tract. Besides regular monsoon rains, three or four cyclonic storms occur in the basin during the monsoon period. The Hirakud reservoir is controlling the floods of upstream 83,000 sq. km, and the rest of the catchment remains unregulated since 1958. Although floods are natural in the delta owing to its poor drainage capacity and low lying area, the recent alarming part is its increasing frequency. The deltaic channels are capable of draining a safe discharge of 28,000 m3/s. Any discharge beyond this can lead to devastating flood at the delta. It is seen that 19 floods so far have occurred beyond this magnitude after 1958 and up to 2008. Out of this, most floods occurred owing to the contribution of downstream catchments rather than Hirakud dam release. In this study, the entire catchment of Mahanadi is divided into 10 X 10 grids. The grids with at least 25% of basin area are taken into consideration. The gridwise rainfall data are analysed for each flood between 1958 and 2004. At least 15 day daily rainfall of all the grids prior to a particular flood is considered to find the vulnerable grid for that particular flood. These grids are further analysed statistically to find the possible reasons for occurrence of floods. No increasing trend in rainfall is found over the grids. It is also observed that the decrease in rainy days and more rainfalls in a short period of time remain the reason for formation of peak floods at the delta. Besides that, higher 1-day maximum rainfall also makes a concern for floods.
Keywords: gridded rainfall; Mahanadi; Hirakud; vulnerable; trend.
Modelling the impacts of blue-green infrastructure on rainfall runoff: a case study of Eastern Victoria, Australia
by Zahra Ghofrani, Victor Sposito, Robert Faggian
Abstract: In Australia, flood risk mitigation and response has followed an ad hoc development trajectory starting largely with structural measures, such as levees, and later non-structural approaches, such as planning and regulation. These have proved largely ineffective in reducing the exposure of towns and rural populations to flood risk and damage over time. This paper explores the possible implementation of Blue-Green Infrastructure (BGI) approaches as a new, alternative method to reduce flood volume and rainfall runoff in regional Australia. It outlines a case study example in rural Victoria that is subject to regular and damaging floods where the possible introduction of BGI has been modelled. Different types of BGI components - bio-retention cell, rain barrel, infiltration trench, and vegetative swale - were examined, and the results indicate that developing BGI systems in a regional Australian context provides multi-functional and cost-effective solutions to flooding that will support adaptation to future climate changes.
Keywords: sustainable development; blue-green infrastructure; rainfall runoff; climate change; flood mitigation.
Short-term forecasting of hourly water demands: a Portuguese case study
by Bernardete Coelho, Antonio Andrade-Campos
Abstract: Predicting future water demands is becoming essential for the efficient management of Water Supply Systems (WSS). To improve the operations of a Portuguese network, short-term water demand forecasting models are applied to a number of datasets collected from distinct locations in the network. Traditional forecasting models, such as exponential smoothing and na
Keywords: water demand forecasting; artificial neural networks; data analysis; exponential smoothing; naïve methods; Portuguese water network.
Discharge prediction in meandering compound channels
by Arpan Pradhan, Kishanjit Kumar Khatua
Abstract: Reliable prediction of discharge is the foremost requirement for the safety of river work and flood management. The striking feature of a meandering channel makes its distinguishably unique for analysis; hence in this paper a concern on discharge prediction methods is presented. Parameters related to channel geometry and flow characteristics, including effects of secondary current produced along the flow, momentum transfer across the main channel and floodplain, and formation of shear layer due to flow of water from flood plain into main channel, are discussed briefly. In total seven datasets from a large scale channel facility (FCF phase B) at Wallingford (1991), higher sinuous channel data of Willetts and Hardwick at University of Aberdeen (1993) and the data observed at NIT Rourkela by Khatua (2008) and Mohanty (2013) are taken for analysis. The experimental collected discharge data are used to compare the discharge predicted by three well known existing methods, i.e. channel division methods by Greenhill and Sellin (1993), theoretical and empirical methods by James and Wark (1992) and the dimensional analysis method by Shiono and Knight (1999). Relative error is calculated to check the degree of exactness given by each method and is used as a utility tool to decide the effectiveness of the mentioned methods. The adequacy of each method is known by going through its applicability and limitations. Hence the paper provides a comparative study and error analysis of the different discharge methodologies over a wide variety of datasets.
Keywords: meandering channel; discharge prediction; secondary current; momentum transfer; error analysis.
An urban flood inundation model based on cellular automata
by Saman Armal, Rafea Al-Suhili
Abstract: This study develops a modified Cellular Automata (CA) model to simulate the flash flood inundation extent on a case study of an urban sub-catchment, in New York City. Based on the soil composition, the Horton equation is modified with threshold infiltration rates applied to different land cover types. Further, the orifice equation is updated with a time-variant parameter to account for partial/full blockage in the inlets. We propose a slope-weighted flow transfer function to adjust the CA model and address the problem of depth positivity and flow regime changes, occurring due to the partial submergence. Seven ponding points with different levels of inundation are detected in the survey of the area and accordingly compared with the output of the simulation. The results prove the applicability of developed CA model to reproduce the evolution of water depth.
Keywords: urban flooding; flash flood; cellular automata.
Proposing the minimum and maximum probable WQI indices for better water quality management in poor and underdeveloped countries (case study: Bilghan intake)
by Ali Dehnavi, Pardis Goudarzian
Abstract: Increasing the measurements cost for surface water quality assessment besides the need for continuous measurements will be cause a dilemma in poor countries. Therefore, a new method was proposed to identify and predict minimum probable WQI (MIP-WQI) and maximum probable WQI (MAP-WQI) values instead of the traditional ones by combining available WQI data and Taguchi method. For this purpose, the water quality data of Bilghan station on the Karaj River were used for prediction and comparison of the MIP-WQI and the MAP-WQI. According to the surveys and based on the proposed method, the MIP-WQI and the MAP-WQI values based on 2008s data were estimated 61.6 and 87.4, respectively. Whereas, from 2008 to 2010, actual minimum WQI values were 65.9, 69.8 and 69.3, respectively. In addition, actual maximum WQI values were 83.1, 77.2 and 75.6, respectively. Moreover, these probable indices could be more suitable to use for water management, especially in poor and underdeveloped countries.
Keywords: water quality index; surface water quality; water quality management; catchment area; empirical index; Bilghan intake; Taguchi method; minimum probable WQI; maximum probable WQI.
Sustainable urban development through a blue and green network approach focusing the protection of water resources: the case of the Belo Horizonte Metropolitan Region, in Brazil
by Nilo Nascimento, Julian Eleuterio, Heloisa Costa, Brigitte Vinçon-Leite, Ana Mourao, Diomira Faria, Roberto Monte-Mor
Abstract: This paper explores the potentialities offered by blue-green approaches to promote protection of water resources at the metropolitan scale and to contribute to structuring territorial development. An ongoing experience of regional planning and land use regulation in the Belo Horizonte Metropolitan Region (BHMR), in Brazil, is here a reference. With a population of 5.8 million inhabitants and territory of 10,000 km2, the BHMR offers a rich example of land use diversity that highlights the complexity of metropolitan territorial planning and management. In the first part of the paper, blue-green concepts are developed emphasising their role for the protection of water resources. This is followed by the methods and results of applying these concepts to the BHMR. We then evaluate whether blue-green approaches are sufficient to protect water resources and discuss the potentialities of additional tools such as the payment for environmental services with the same objectives.
Keywords: metropolitan areas; water resource protection; metropolitan development planning; blue-green approach; metropolitan zoning; participatory process; participatory planning; drinking water supply; sources of drinking water; green corridors.
Development of prediction model for forecasting rainfall in Western Australia using lagged climate indices
by Farhana Islam, Monzur Imteaz
Abstract: The main aim of the study was to develop a model to forecast autumn rainfall several months in advance for the south-west division (SWD) of Western Australia (WA). For any rainfall forecasting approach, it is necessary to have a wide understanding of the behaviour of potential climate indices with rainfall variability. This study identifies and incorporates the relationship among major climate indices such as Dipole Mode Index (DMI), Southern Oscillation Index (SOI), ENSO Modoki Index (EMI) and autumn rainfall in SWD of WA. Significant correlations among lagged climate indices with autumn rainfall were evaluated. Eight rainfall stations from two separate regions of SWD were considered for this study. From statistical analysis, it was found that DMI, SOI, Nino3.4, Nino3 and Nino4 have shown significant correlations with autumn rainfall for all the stations. On the other hand, EMI showed significant correlations only for the stations on the north coast. DMI effect has been found stronger for all the stations compared with other climate indices. Several multiple regression analyses were conducted using lagged ENSO-DMI, lagged SOI-DMI and lagged EMI-DMI indices. Results showed that multiple regression has significantly increased the correlations between autumn rainfall and climate indices. Finally, developed models were tested without the sample dataset and statistically significant models were suggested.
Keywords: climate indices; dipole mode index; El Nino southern oscillation; southern oscillation index; ENSO Modoki index.
Hydrogeochemical assessment of groundwater quality: a case study from Adamawa in northeastern Nigeria
by Ahmed B. Seli, Buba Apagu Ankidawa, Jackson M. Ishaku, Mohammed D. Aminu
Abstract: This research is aimed at assessing the hydrogeochemistry of groundwater in Ganye (northeastern Nigeria) and environs using multivariate statistical analysis. A total of 30 water samples, 14 from boreholes and 16 from hand-dug wells, were collected from the research area. The abundance of the cation concentrations is in the order of Ca2+>Mg2+>K+ Cl- CO32-. The sodium absorption ratio values range from 0.077 to 1 meq/l with an average of 0.423 meq/l. The residual sodium carbonate values range from -1.392 to 3.332 meq/l with an average of 0.106 meq/l. The soluble sodium percentage ranges from 3.965% to 249.5% with an average of 17.7%. The magnesium ratio ranges from 34.51 to 67.03% with an average of 53.19%. About 70% of the water sources are unsuitable for agricultural use as they have magnesium ratios >50%. Total hardness ranges from 60 to 89 mg/l with an average of 73.18 mg/l. Electrical conductivity ranges from 149 to 431
Keywords: Ganye Nigeria; groundwater; hydrogeochemistry; multivariate statistical analysis; water quality index.
Frictional head loss relation between Hazen-Williams and Darcy-Weisbach equations for various water supply pipe materials
by Rehan Jamil
Abstract: This research presents the analytical relationship between the frictional head loss obtained by two of the most common equations, Darcy-Weisbach and Hazen-Williams, considering plastic and metallic pipe materials as major categories. A wide range of hydraulic situations have been covered for the water supply system for buildings through five models for each pipe material category, based on water temperatures ranging from 20 oC to 60 oC, pipe diameters from 15 mm to 50 mm and volume flow-rates from 0.25l ps to 2l ps. The head loss values obtained by both equations were used to establish the correlation between them by using statistical techniques. The analysis showed reliable results with a combined correlation coefficient of 0.981 between the two equations for plastic and metallic pipes, while the R2 value for the trend line of head loss values obtained by these equations was found to be 0.9978. This relationship will prove to be very useful for the water supply pipe manufacturers and designers for the mutual conversion of frictional head loss values obtained by these equations.
Keywords: Darcy-Weisbach; Hazen-Williams; analytical relation; water supply; pipe materials; fluid dynamics; regression analysis.