Determination of Quantitave and Qualitative Capture Zone of Drinking Water Wells to Nitrate Case Study: Aspas Plane, Eghlid City, Fars Province

Authors

1 Department of earth sciences, Shiraz University, Shiraz, Iran

2 Faculty of applied geology, kharazmi university, Tehran. Iran

Abstract

This study focused on determination of qualitatively and quantitatively of capture zone factors in Aspas aquifer water wells. Based on the hydrographs of 43 piezometers in the area, the aquifer of Aspas plain is divided into three zones in terms of hydrogeological behavior. In the processes of modeling, the conceptual model of the aquifer is first constructed based on geological and hydrogeological data. Then the MODFLOW is calibrated for the steady and unsteady state flow conditions.  As a result the distribution maps of hydraulic conductivity and storage coefficient are generated. In the second stage the capture zone of the drinking water wells in the area is delineated by the MODPATH model and the areal distribution of nitrate in the aquifer is plotted. Finally by superposition of wells capture zone and the iso-nitrate contour map the qualitative capture zone of well are determined. We have demonstrated that the capture zone of wells is controlled by the hydraulic gradient and the hydrogeological (in-flow and no-flow) boundaries and the increase in pumping rate increases the width of capture zone slightly. 
 

Keywords


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