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Determination of Groundwater Recharge Variation in Sylhet Sadar Upazila Using Water Table Fluctuation Method

Corresponding Author : Md. Shamim Ahmed (saiwm07@gmail.com)

Authors : Md. Shamim Ahmed

Keywords : Groundwater recharge, Recharge rate, Sylhet Sadar, Water table fluctuation, Specific yield

Abstract :

This study efforts to determine the variation of groundwater recharge and recharge rate with rainfall in Sylhet Sadar Upazila by water table fluctuation method. Rainfall and groundwater level data of the period 1990-2014 were collected and analyzed. The annual recharge varied from 56.35 mm to 225.19 mm with average of 110.31 mm. The annual groundwater recharge rate for the study period varied from only 1.68% to 5.13% with an average of 2.89% due to lower specific yield. In case of seasonal recharge, it is observed that the recharge was almost twice in monsoon (average 66.64 mm) than the pre-monsoon (average 31.69 mm). In contrast, the recharge rate in comparison with rainfall during the study period showed a higher recharge percentage in pre-monsoon (average 3.20%) than that of the monsoon (average 2.45%). This indicates that there are other factors that influence reasonably on groundwater recharge apart from rainfall.

Published on December 31st, 2020 in Volume 30, Issue 2, Applied Sciences and Technology