Role of Hydrogeological Factors on Aquifer Storage and Recovery Performance in Saline Groundwater Regions

Abstract

Aquifer storage and recovery (ASR) is a potential solution to growing global freshwater insecurity. However, the performance of ASR in saline regions depends on regional hydrogeology and groundwater salinity level. Hydrogeological factors, e.g., hydraulic conductivity, hydraulic gradient, aquifer thickness, aquifer heterogeneity, and hydrodynamic dispersivity, affect freshwater recovery efficiency (RE) prominently along with the groundwater salinity. Therefore, a site feasibility analysis for ASR based on the prevailing hydrogeological conditions is required for its successful operation. This study investigates the influence of these hydrogeological parameters and groundwater salinity level on the performance of ASR. Findings from previous field studies were reviewed, grouped, and analyzed systematically for each hydrogeological factor independently and in combination to understand their influence on RE. The interdependency of the effects caused by each factor is also analyzed. The results show that higher freshwater recovery can be achieved at sites offering moderate hydraulic conductivity, low hydraulic gradient, low hydrodynamic dispersivity, thinner aquifers, and low groundwater salinity. The overall findings of this meta-analysis will help in synthesizing information for site hydrogeological conditions to aid in the decision-making process for ASR application in saline groundwater regions.