A Preliminary Investigation of Wadi-Aquifer Interaction in Semi-Arid Regions: the Case of Faria Catchment, Palestine

List of Abbreviations Symbol The meaning OTIS One-Dimensional Transport with Inflow and Storage WESI Water and Environmental Studies Institute UNESCO-IHE Institute for Water Education/ Netherlands UWIRA Impact of Untreated Wastewater on Natural Water Bodies: Integrated Risk Assessment UPaRF UNESCO-IHE Partnership Research Fund PWA Palestinian Water Authority MCM Million cubic meters P Average annual precipitation PET Average annual potential evapotranspiration KL Longitudinal dispersion coefficient V Stream velocity Sm Mass flux per unit volume EXACT Executive Action Team K Typical hydraulic conductivity i Hydraulic gradient ne Effective porosity L Distance between the wadi and the well under study q Darcy flux B Aquifer thickness Q Well pumping rate XL The location of stagnation point YL Maximum width of well’s capture zone UC-T Upper Cretaceous – Tertiary N-E North – Eastern PL Quaternary – Pleistocene NO3- Nitrate Cl- Chloride MCL Maximum contamination level M Mass of tracer injected F The area under the tracer concentration curve MP Monitoring point IP Injection point c Tracer concentration I Integer C Character D Double precision Conc. Concentration Min. Minute PPb Part per billion List of Tables Table # Description Page 1 The hydrological classification of Faria catchment 16 2 The layers existed above the saturated zone in Faria catchment 21 3 General characteristics of the wells under study 42 4 Different delay times estimated between the rainfall peak time and the change in the water table peak time for the well 18/18/027 46 5 Typical features of various conductance categories for wadi-aquifer systems 47 6 Parameters used in determining of the capture zone of well 18/18/027 49 7 Artificial tracer types 66 8 The pros and cons of the environmental and artificial tracers 67 9 Model application features of case study 73 10 Experiment-relevant information, data, and calculations for each monitoring point at each section 83 11 The slope of each section in the selected reach 86 List of Figures Figure # Description Page 1 The distribution of the wells and springs along the main wadi in the Faria catchment 5 2 Research methodology 7 3 Location map of Faria catchment 10 4 Topography of Faria catchment 10 5 Location of Faria catchment with reference to the eastern aquifer basin 12 6 Water resources in Faria catchment 12 7 The agricultural land surrounding the main wadi of Faria at An-Nasariah area upstream the agricultural wells in the region 13 8 Percentages of landuse classes in Faria catchment 14 9 landuse map in Faria catchment 14 10 (a) All potential pollution sources to a selected reach located at An-Nasariyah area in Faria catchment 17 10 (b) The wadi segment at An-Nasariah area that describes the pollutants contributing to the wadi upstream the agricultural wells in the region 18 11 Asection in the main wadi of Faria at An-Nasariah area in summer 19 12 A segment in the main wadi of Faria at An-Nasariah area in winter 19 13 Geologic map of Faria catchment 20 14 Types of losing wadis 24 15 Types of aquifers and confining beds 26 16 Forms of interactions between surface water and groundwater 28 17 Wadi-aquifer interactions in the two directions 29 18 Wadi-aquifer interaction in arid and semi-arid regions 29 19 Turbulent diffusion of tracer particles in uniform flow 31 20 Al-Badan flood on the 9th of February 2006 43 21 The locations of the wells under consideration and Al-Badan flume at Jiser Al-Malaqi 43 22 Change in water table-rainfall relationship of well 18/18/027 (February, 2006) 44 23 Change in water table-rainfall relationship of well 18/18/027 (December, 2005) 45 24 Change in water table-rainfall relationship of well 18/18/027 (January, 2006) 45 25 Change in water table-rainfall relationship of well 18/18/027 (March, 2006) 46 26 A pictorial sketch of the interaction processes between the wadi and the upper aquifer and the arrival of contaminants to the well’s capture zone 49 27 Change in wadi flow-water table relationship of well 18/18/027 (February, 2006) 50 28 The depth to water table for well 18/18/027 and the depth of sediment in the reach under study 51 29 Variation in the fecal coliform bacteria concentration found in groundwater from well 18/18/034 with time and the trend of pollution 53 30 Variation in the nitrate concentration found in groundwater from well 18/18/034 with time and the trend of contamination 54 31 Variation in the chloride concentration found in groundwater from well 18/18/034 with time and the trend of contamination 54 32 A simple sketch that shows the different pollutants that may reach the upper aquifer 56 33 Calibration the fluorometer device and analyzing the samples 59 34 General scheme of the tracer field experiment 60 35 The selected reach along the main wadi at An-Nasariah area in Faria catchment to conduct a tracer field experiment 61 36 A satellite image that shows the selected reach 62 37 A longitudinal profile of the selected reach of the main wadi at An-Nasariah area in Faria catchment 63 38 Photo and cross-section of MP1 64 39 Photo and cross-section of MP2 64 40 Photo and cross-section of MP3 64 41 Photo and cross-section of MP4 65 42 Dissolving and mixing of uranine solution 69 43 Pouring of uranine solution into the wadi 70 44 Sampling process at section 4 (600 m from the injection point) 70 45 The wadi outlook before the injection process 71 46 The wadi outlook after the injection process 71 47 The observed concentration curve for the first monitoring point 76 48 The observed concentration curve for the first monitoring point after the manual extension 77 49 The observed concentration curve for the second monitoring point 77 50 The observed and simulated concentration curves for the second monitoring point 78 51 The observed concentration curve for the third monitoring point 79 52 The observed and simulated concentration curves for the third monitoring point 80 53 The observed concentration curve for the fourth monitoring point 80 54 The observed and simulated concentration curves for the fourth monitoring point 81 55 All concentration curves at the different monitoring points 82 A Preliminary Investigation of Wadi-Aquifer Interaction in Semi-Arid Regions: the Case of Faria Catchment, Palestine By Atta MohyiEddin Hamdan Abboushi Supervisors Dr. Mohammad N. Almasri Dr. Sameer M. Shadeed Abstract This thesis aims to investigate the potential existence of wadi-aquifer interaction in the semi-arid Faria catchment. Faria catchment, located in the northeastern part of the West Bank is considered as one of the most important catchments in the region due to the intense agricultural activities. Surface runoff in the catchment consists mainly from springs, runoff generated from winter storms, untreated wastewater effluent from the eastern part of Nablus City and Al-Faria Refugee Camp, and the return flow from the adjacent agricultural land. The groundwater in the catchment is the only water source for the agricultural and domestic uses. As such, wadi-aquifer interaction would be an important issue to investigate when considering the importance of groundwater in the catchment. Many analysis methods were considered to highlight the potential existence of wadi-aquifer interaction. Analysis of the variability of water table elevation with both the variability of rainfall and wadi flows was carried out. In addition, the quality of groundwater was assessed through chemical and microbiological tests.Also,a tracer field experiment was implemented to quantify the proposed interaction. The analyses show that the water table level in a selected groundwater well next to the main wadi significantly changed and spiked as a result of increasing rainfall and corresponding runoff in the wadi. This in turn provides a good evidence that the hydrogeology allows wadi-aquifer interaction to take place in the catchment. Also, the quantitative analyses revealed that the delay time in the area was relatively small and was estimated at 10 hours. This value of delay time also reflected in the value of the horizontal hydraulic conductivity of the formations at the vicinity of the well under consideration, which was calculated as 89 m/d using Darcy flux equation. And so, these formations have high conductance to transmit the water from the wadi to the aquifer. Whereas, the quality analyses show that some chemical and microbial pollutants were found in the sampled well. This can be mainly attributed to untreated wastewater flows in the wadi, which provide another potential evidence of wadi-aquifer interaction in the catchment. As well as the trends of contaminations in the different seasons were plotted. They showed that the pollutants concentrations had higher trends in summer than in winter. The tracer field experiment was conducted at An-Nasariah area in the middle part of Faria catchment using Uranine as a conservative tracer material. A representative reach of 600 m was chosen, and divided into four equally long distances. A concentration curve was plotted at each section (monitoring point) with the help of OTIS, a solute transport model for streams and rivers. Then, each concentration curve was converted to an average value of flowrate in the section. Finally, each two successive flowrates were subtracted to quantify the interaction. The tracer field experiment proved that transmission losses took place and infiltrated through the wadi bed (they became a potential recharge to groundwater). The percent loss in the flowrates values in the different sections ranged from 4.8% to 68.3%. As well as the hot spot area along the selected reach was located by determining the section, which has the largest loss in the flowrates between its monitoring points.