Groundwater monitoring network design using vulnerability analysis and well preservation zone
Monitoring the quantity and quality of groundwater is a non-separable part of the environmental information system. There are several ways to design a groundwater monitoring network. In the present study, we attempted to develop a new method for flexible design. Flexible means that the results of this study allow the decision maker to select a limited number of high-priority wells, taking into account the budget level allocated to the project. It is also possible to use this method easily for wells under study or construction. Also, in this design method, monitoring is not limited to just one parameter (in the present study, EC concentration) and one or more parameters can be easily replaced. The DRASTIC model was used to calculate the aquifer vulnerability, which consists of seven layers of aquifer, including groundwater depth, net recharge, aquifer media, soil type, topography, impact of vadose zone, and the hydraulic conductivity of aquifers. The layers were optimized using differential evolutionary algorithm (DE) to find the highest correlation between the vulnerable points and the points with the highest concentration of EC. As a result of this optimization, the amount net recharge (the actual infiltration of water into the aquifer) had the highest correlation, which was confirmed by comparing net recharge and EC maps. With the help of WhAEM2000, 10-year capture zone of existing wells was calculated. The final priority of the wells was calculated by linking of these models.