Review of Effective Factors on Drinking Wellhead Protection Area Using Numerical Mathematical Model (Case Study: Yaftabad District, City of Tehran)

Delineation of the wellhead protection area for drinking water wells is an effective method to manage and protect water supply resources. The current study focused on the effects of the aquifer's hydraulic features on the shape of each well's protecting area and the capture zone. A mathematical simulation is performed for YaftAbad district in Tehran metropolitan area using the data for 24 drinking water wells. Based on the results, the hydraulic gradient around each well and the hydraulic conductivity of the aquifer, among other parameters, have a direct correlation with the length of each well's upstream length. Also, both the aquifer's effective porosity and thickness, has an inverse correlation with the size of each protection area. The study showed that the convergence of groundwater flow lines around each well causes the well to receive same amounts of water from around itself that leads to a symmetric shape of wellhead protection area.