International Journal of Water (13 papers in press)
Evaluation of a pumping test with skin effect and wellbore storage on confined aquifer in the Bela Crkva, Serbia
by Jiri Holub, Pavel Pech, Michal Kuraz, Petr Maca, Daniel Kahuda
Abstract: Pumping test is a fundamental method to determinate aquifer hydraulic parameters, such as the transmissivity and the aquifer storage coefficient. These main indicators define the basic physical properties of the aquifer. For estimation of these parameters, a semi-logarithmic straight line method is commonly used, which is based on the assumptions of the Theis mathematical model. Nevertheless, there are other parameters corresponding to real conditions during the pumping test, such as the skin effect and the wellbore storage. Both can occur in a large-diameter pumping well. The skin effect and the wellbore storage are neglected in the Theis solution. The evaluation of pumping test data is usually carried out by estimation through curve matching a straight line to drawdown data plotted on a semi-log graph. These methods are derived from the Theis solution for the non-leaky confined aquifers where the skin effect and the wellbore storage is not included. However, neglecting the skin effect and the wellbore storage can lead to false analysis of the time-drawdown variation in the pumping well. In this paper we develop an evaluation method for the transmissivity, the aquifer storage coefficient, skin effect and wellbore storage from the pumping test data.
Keywords: pumping test; skin effect; wellbore storage; pumping test analysis.
Efficiency of the groundwater artificial recharge from dam water release in arid area
by Zouheira Ibn Ali, Asma Ahmed Gharbi, Amjad Kallel, Lamia Laajili Ghzelb, Moncef Zairi
Abstract: This paper describes a methodology to estimate the groundwater artificial recharge efficiency. The Water Table Fluctuation method (WTF), Stream-Flow estimation method (SF) and Hydrus-1D model are used to estimate the effective water quantity reaching the aquifer. The efficiency of the stream flooding on groundwater level trend was discussed based on groundwater table fluctuation. The comparison between the three methods is found to be valuable for determining the range of plausible recharge amounts and for highlighting the uncertainty of the estimates. The SF method yields the largest recharge estimate whereas the WTF method provides actual recharge reaching the aquifer. The SF method and the Hydrus-1D model show the best fit between estimated recharge volume and water volume released, with a coefficient-of-determination (R2) of 0.9 and 0.8, respectively. The combination of the SF with water-table fluctuations methods is recommended to increase the constancy of recharge estimates and preliminary assessment.
Keywords: artificial recharge; assessment; stream infiltration; groundwater; water level.
Soil moisture dynamics and response to rainfall under two typical vegetation covers based on HYDRUS-3D
by Jing Zhang, Zhan Liang
Abstract: In this study, based on the continuous measurement of soil water content and meteorological parameters, the HYDRUS-3D model was used to simulate the dynamic changes of soil moisture in different soil layers (1050 cm soil depth) under two typical vegetation covers [alluvial wetland forest (AWF) and ungrazed Bahia grassland (UBG)] in wet and dry seasons in the Alafia River Basin, Florida. Model performance was evaluated using several statistical criteria. Water balance and parameter sensitivity were analysed to indicate the adaptability of the model to the study area. Furthermore, soil moisture variation was assessed under different rainfall levels, and its relationships with vegetation type, root biomass, and soil physical characteristics were quantitatively and qualitatively analysed. Results showed that the correlation degree between the measured and simulated values of soil water content in the wet and dry period was higher in the AWF than in the UBG. The water reserves of the UBG were relatively stable. The most sensitive parameters of the model to simulate soil moisture were saturated water content and pore size index. There were significant differences in soil water variation between the two vegetation types. The effect of precipitation on soil moisture was higher under AWF than under UBG.
Keywords: soil moisture dynamics; HYDRUS-3D; precipitation; water balance; sensitivity analysis; soil layer.
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.
Hydrochemical characteristics of inland rivers in Khorasan Razavi Province, North-Eastern Iran
by Mojtaba Heydarizad
Abstract: This study is the first comprehensive hydrochemical investigation of 25 rivers in Khorasan Razavi, the second most populated province in Iran. Surface water provides the dominant part of agricultural water in this province. The results of this study demonstrated that rock weathering is the dominant factor controlling water quality in river samples. Stable isotopes (δ 18O and δ 2H) also demonstrated that river samples were mainly plotted below Mashahd Meteoric Water Line (MMWL), with negligible deviation due to low evaporation effect. However, dam reservoir samples showed notable deviation from MMWL due to huge surface evaporation. River water in all stations is considered appropriate for agricultural purposes based on Wilcox diagram, residual carbonate index and also potable usages (except for a few stations) according to World Health Organization protocols. The results of this study can be used by the scientists in Iran Ministry of Agriculture for the future agricultural management programs.
Keywords: cluster analyses; hydro chemistry; Iran; Khorasan Razavi; rivers; stable isotopes.
Rainfall and air temperature projections for Sharjah City, United Arab Emirates
by Abdullah Yilmaz, Ahmad Shabib
Abstract: Climate change has significant effects on hydrological cycles and water resources. Sharjah City in the United Arab Emirates (UAE) is located in one of the most water scarce regions of the world. Despite the importance of climate change projection and impact studies, those studies specifically for Sharjah City are rare. In this study, first, monthly rainfall and temperature projections were generated for near and far future. Then, trend analysis was conducted to detect trends in future rainfall and temperature projections for Sharjah City. Findings of this study showed that mean air temperature in Sharjah City is expected to rise up to 12-17% for near and far future respectively, whereas average annual rainfall is projected to decrease in the range of 1-53%. Trend analysis showed significant increasing air temperature trends and non-significant decreasing rainfall trends. This study will contribute to climate change impact and policy making studies in Sharjah City.
Keywords: climate change; temperature; rainfall; projections; water; hydrological cycle; global climate models; coupled model intercomparison project phase 5; UAE; Sharjah.
A hybrid approach for water resources management in Tunisia
by Mohamed Ali Elleuch, Lobna Elleuch, Ahmed Frikha
Abstract: Optimal water resources management is often related to the desirability of achieving equitable distribution of water among the users based on economic, social, availability, reliability and environmental procedures. In Tunisia, the main issues of water resources management are addressed with specific reference to the available water resources and water demand from domestic, agricultural, tourism, municipal and industry sectors. Usually, there is increasing competition for water among the various water use sectors in several regions of Tunisia. Water policy and legal frameworks are some of the feasible measures that provide opportunities to evolve a systematic approach to water resources management. For that, this paper describes the development of a hybrid approach for the evaluation and allocation of potential water resources management for many sectors according to several criteria. A hybrid approach between the reciprocal weights method (RR) based on the results of the Delphi method, the Analytic Hierarchical Process (AHP) and the Hurwicz Criterion Method (HCM) has been developed to evaluate and select the best water resources management for Sfax (Tunisia) based on sensitivity analysis.
Keywords: water resources management; sensitivity analysis; water use sectors; Tunisia.
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.