Mapping Of Sea Water Intrusion in the Western Libyan Coast Using Geo-electrical Method: Case Study

Abstract

As most of the Libyan population live in the north side of the country; mainly in the western coastal zone; the sea water intrusion is a vital phenomena that need to be studied to locate, measure its diffusion rate, and take a remediation actions [1]. Conventionally, water sampling of ground water wells is used to evaluate sea water intrusion in coastal areas [2]. Nevertheless, excessive use and cost of drilling should be avoided by relaying on advanced technologies [2]. Geo-electrical methods such as electrical resistivity and electromagnetic can be used for studying sub surface geophysics from the earth surface with no need for drilling, and can give a trusted results [3]. The huge contrast in resistivity between saline and fresh water makes measurement of the resistivity in the ground a useful technique for detecting and delineate the saline interface, consequently, using the electrical resistivity method is a successful technology for studying sea water intrusion [3]. Mapping sea water intrusion in a selected area located in the western coast of Libya is reported by this study, it covers about 120 Km² from Algrabouli to Elallus by 16 profiles perpendicular to shoreline with total number of 53 vertical electric sounding (VES). This study is considered as a case study to insure the need to cover the whole Libyan coast with more detailed studies, furthermore, it concluded that the sea water intrusion in Libya is truly a serious issue that will lead to pollute the groundwater in the coastal areas with salt and costal contaminated water in the case of not correcting the situation.