Determination of the Locations of Ground Water Table Anomalies by the Ring and Central Point Method Study of Three Areas in Iraq

Abstract

The groundwater table is observed in three areas in Iraq. Many wells are used to construct the ground water table maps in these areas. These maps are reflecting the irregularity in the water table. The observed values of groundwater table are converted to a regular grid of water table points, with different spacing interval from area to another. The regional groundwater table is calculated, using the ring and central point method, in each observation point. The residual (local) anomalies in the ground water table values for the grid points are obtained by the subtracting of the regional (average values) of ground water table from the observed values. The griding of water table and the calculations of regional and residual anomalies are done using QBASIC computer program build for this purpose. The regional ground water table and residual anomaly of groundwater table are mapped, the regional maps show the main water table level in the studied areas. The residual maps show many positive and negative anomalies of groundwater table. These maps reflect that the positive anomalies related to the leakage of water from the subsurface pipelines and drainage channels in the studied areas, while the negative anomaly related to the high pumping or discharge rate. This method can be used to determine the locations of leakage from pipelines and drainage channels