A comparison of Calculated Fixed Radius and Numerical Model Methods to delineate drinking water wellheads protection area in Yaft Abad district, Tehran
Subject Areas :
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Keywords: Wellhead protection area time of travel Calculated Fixed Radius Numerical model effectiveness,
Abstract :
Delineation of wellhead protection area is an important component of groundwater protection strategies to prevent probable environmental and health hazards. In this study, besides describing the calculated fixed radius (CFR) and the numerical model methods to determine the wellhead protection area, in order to compare of the methods, were used from data of eight number of drinking water wells in Yaft Abad district of Tehran. For this purpose, overlapping rate of CFR and numerical model protection areas in GIS environment were analyzed. The overlapping results show increasing distance from the wells, the effectiveness and accuracy of CFR method decreases rapidly. In the 50 days time of travel overlay, 88 percent of the numerical model areas are captured by the CFR areas. While in the 10 years overlay, only 41 percent of the numerical model areas are captured by the CFR areas. When time, money and data are limited, the Calculated Fixed Radius method is an acceptable method only to delineate the 50 days time of travel protection areas.