Exploring Potable Groundwater Sources Surrounding Manchar Lake

Abstract

This study was carried out to explore the groundwater quality in Manchar Lake's surroundings, (one of Asia's largest lakes in Sindh Province of Pakistan), to discover sites where potable groundwater is available. To achieve this objective, Vertical Electrical Sounding (VES) was employed at 21 sites in shallow depths by adopting Schlumberger electrode array alignment. The maximum distance chosen between current electrodes (A and B) was 300 m, and 20 m was between potential electrodes (M and N). ABEM terrameter SAS 4000 and IX1D resistivity software was used for data collection and interpretation, respectively. The results revealed that except for two sites (13 and 19), all other sites do not have potable groundwater at any depth. At site 13, one out of three layers lies under a high resistivity zone, while at site 19, two out of four layers lie under a high resistivity zone, which indicates the presence of potable water. To verify VES findings, water samples from 5 trial bores made by hand percussion method were collected and analyzed for Electrical Conductivity (EC) and Total Dissolved Solids (TDS), which revealed saline water from all trial bores. To sum up, potable groundwater is not available in the vicinity of Manchar Lake at shallow depths.