Transmissivity Estimation and Mapping of the Dammam Karst Aquifer in Central Iraq

Abstract

The most reliable method to determine an aquifer's transmissivity is pumping tests; however, these studies are time-consuming and costly. An alternative approach to estimating transmissivity is to use the well's specific capacity. The aim of this research is to improve our knowledge of the transmissivity of the Dammam karst aquifer in central Iraq to support sustainable management strategies. The specific capacity and transmissivity data of 39 wells were collected. The normality tests showed that transmissivity and specific capacity are log-normally distributed. A simple linear regression with R2 = 0.84 relates transmissivity to the specific capacity. Subsequently, the resulting relationship was used to estimate transmissivity from the 135 specific capacities. The measured and estimated transmissivity data (174 data points) were used for geostatistical analysis. Using the kriging technique, an interpolated distribution map of transmissivity was developed. The cross-validation reveals that the geostatistical method gives a good estimate of the transmissivity of the Dammam aquifer.