Estimation of Transmissivity and Storage Coefficients in a Dual-Aquifer System Using Combined Field and Analytical Methods

This study investigates the hydrodynamic coefficients of the Kouhpayeh-Segzi (KSA) aquifer, a vital groundwater resource in Isfahan province in central Iran, located in an arid to semi-arid climate, where surface water is unreliable. The research addresses the increasing dependence on groundwater in the region, driven by population growth, agricultural expansion, and industrial development, which has led to over-extraction, groundwater table depletion, reduced well yields, and land subsidence. The main objective is to accurately estimate the parameters of hydrodynamic coefficients—transmissivity coefficient and storage —essential for sustainable groundwater management. Traditional pumping tests, although standard, are costly and limited by practical constraints, especially in deep or data-poor environments. To overcome these challenges, this study integrates multiple data sources, including grain-size distribution analysis, well drilling logs, geophysical surveys, and exploratory and observational well data. The approach involves re-analyzing pumping test data, determining alluvium thickness, bedrock elevation, and consequently preparing maps of the transmissivity and storage for the aquifer. The studied aquifer has two types of aquifers: confined and unconfined. The results show that the average values of hydrodynamic coefficients such as the transmissivity and storage of the KSA unconfined aquifer are estimated to be ۹۶۰ m۲/day and ۳.۹% and the transmissivity unconfined aquifer is estimated to be ۹۱۴ m۲/day, respectively. The findings emphasize the necessity of continuous monitoring, adaptive management, and the use of advanced analytical and geophysical techniques to ensure the long-term sustainability of groundwater resources in the KSA region.

کلیدواژه ها:

Aquifer ، Groundwater ، Transmissivity ، Storage