Hydraulic Characterization of the Quaternary Aquifer in Eastern Maysan, Southern Iraq: Insights from Pumping Tests and Geostatistical Analysis

Abstract

This study determines the hydraulic characteristics of the Quaternary aquifer in the eastern part of the Missan Governorate, southern Iraq. As a result of the increasing demand for water supplies, especially for agricultural purposes, in addition to droughts, groundwater abstraction has intensified, leading to declining groundwater levels. This requires determining the hydraulic characteristics of the aquifer and assessing its development potential. To obtain the hydraulic characteristics of the aquifer, pumping tests were carried out on nine selected wells. The results of the single and multi-well tests were interpreted using the Theis (1935) method and Cooper-Jacob (1946) analytical methods to obtain the hydraulic characteristics: Transmissivity, hydraulic conductivity, and Storativity. The pumping test data analysis revealed that the Quaternary aquifer is unconfined, with storativity values ranging from 0.006 to 0.1, indicating moderate to high storage potential. Spatial data analysis shows that hydraulic conductivity and transmissivity are highest in the eastern and northeastern parts of the area, where coarse gravel and sand of the alluvial fan are found predominate. Specifically, well W8 recorded the highest values, with transmissivity of about 556.65 m²/day and hydraulic conductivity of 11.05 m/day. Mapping of the spatial distribution of hydraulic characteristics of the aquifer (transmissivity,  hydraulic conductivity , and  storativity) highlights the northeastern part of the study area has the greatest groundwater potential. Overall, the aquifer is characterized by moderate to high hydraulic conductivity, underscoring its importance as a strategic water resource.