Evaluation of spatial stability of Varamin aquifer in three dimensions of quantity, quality and environment

To protect aquifers, it is necessary to assess their current and future stresses. For this purpose, in this paper, the indicators of groundwater resources sustainability in three dimensions of quantity, quality, and environment in the Varamin aquifer have been used to evaluate the spatial sustainability of different parts of this aquifer. In this study, a quantitative hydrogeological index; two qualitative hydrogeological indicators and two environmental indicators, and a total of 5 sustainability indicators have been used to study the spatial sustainability of the Varamin aquifer. The overall sustainability of the aquifer has been evaluated by AHP weight averaging and entropy methods from different dimensions of sustainability assessment indicators with the opinions of experts. The final results of the spatial sustainability assessment of the Varamin aquifer show that the eastern part of the aquifer is more stable than the western part of the aquifer. The low stability of the aquifer in the western parts between zero and 25 indicates the urgent need to implement aquifer sustainability management plans. The hydrogeological and hydrogeochemical status of the aquifer confirms the results obtained from the spatial sustainability of the aquifer. Hydrogeologically, the northern and eastern parts of the aquifer are very thick and have high transmissivity, while in the west the thickness decreases sharply and the alluvium is granular with low transmissivity. Also, the presence of the saline river in the western part of the aquifer, which is the passage of sewage, has reduced the quality stability and increased the vulnerability of the aquifer in the western part of the aquifer.