ASSESSMENT OF HYDRAULIC PARAMETERS OF THE QUATERNARY AQUIFER USING PUMPING TEST, JIFARAH PLAIN, NORTHWEST LIBYA

Abstract

Groundwater conditions (GWCs) of an area depend on aquifer hydraulic parameters such as transmissivity (T), storativity (S), hydraulic conductivity (k), and specific capacity (Sc). These parameters play a key role in groundwater flow modeling, well performance, solute and contaminant transport assessment, and the identification of areas for additional hydrologic testing. The present work aims to estimate the hydraulic parameters (T, k, and Sc) of the Quaternary aquifer in the study area and to create an integrated geographical database and map spatial distributions through geographic information systems (GIS) programs. The results indicate that the average value of transmissivity (T) of this aquifer differs from one locality to another, ranging between 6.36 m²/day and 7150 m²/day, calculated based on Cooper-Jacob and Theis recovery solutions. The hydraulic conductivity values (k) ranged from 0.04 m/day to 47.66 m/day. The specific capacity (Sc) of wells ranged from 7.29 to 642.86 m³/d/m. Spatially, transmissivity and hydraulic conductivity values increase in the north and northeast directions, while they gradually decrease in the western and southern parts of the study area. Great variation in the values of the hydraulic parameters is recognized and attributed to the variation in the lithological properties, either laterally or vertically.