A STUDY ON GROUND WATER LEVEL FLUCTUATION IN SELECTED AREA O F CHITTAGONG CITY

Abstract

Southern part of Bangladesh is now facing water scarcity problems in both agriculture and secured livelihood. Ground water forms the major portion of earth’s fresh water source and it is almost safe to drink. Depletion of ground water table due to continuous pumping is causing scarcity of water in the city area of Bangladesh. So, information about ground water table is required for future recommendation of ground water supply to general people. For the investigation purpose, depth of water table has been determined in one season with respect to mean sea level. 41 wards of Chittagong City Corporation along north-south direction of 91˚47´ longitude and east-west direction of 22˚20´ latitude have been selected for this purpose where depth of water table has been measured from the shallow and deep tube well. The present investigation includes field investigation with the aim of measuring water level from ground surface. From this investigation, it has been established that, water table with respect to mean sea level is different at different wards. During field investigation, 82 shallow tube wells and 82 deep tube wells in 41 wards were found. The overall view shows that, in almost every ward, deep tube well is must to find fresh water as shallow tube well can’t frequently pump water. From the investigation, it is also clear that ground water table is lowering day by day. At the beginning of rainy season when it started to rain the water table comes up. Ground water through shallow tube well is not sufficient to fulfill the required demand for the general people as it is becoming out of reach through shallow well day by day. Depth of water table with respect to mean sea level is quite lower in ward 37& depth of water table with respect to mean sea level is quite higher in ward 13. The study was also carried out to assess groundwater table of Chittagong city. From this analysis, it is found that the GW level is lowering in almost all the region of the study. So, alternative water source should be ensured to mitigate the problem.