Assessment of Specific Yield and Storage Capacity of Groundwater using Borehole Log

Abstract

The study aimed at evaluating the specific yield and storage capacity of groundwater in Chapai Nawabganj District of Bangladesh using borehole log data. The boring log samples from different layers were collected from each Upazila (administrative area) of the District. The specific yield of each Upazila was determined by the Cooper-Jacob method using Math lab software and storage of groundwater was then ascertained by a mathematical formula. The specific yield of the five Upazilas was determined and the values were found around 10 (%) which indicates good permeability of the areas, except Bholahat Upazila. The results illustrate that Nachole Upazila has a large storage volume, i.e., 49,305 Hec-m, but the other Upazilas have a storage capacity between 8000 to 18000 Hec-m. The storage capacity of the five Upazilas followed the order: Nachole>Nawabganj>Shibganj>Gomastapur> Bholahat. The highest number of DTWs at Nachole Upazila extracted 8848 Hec-m indicating excessive extraction concerning sustainable water management. A well-planned water resource management would have to be taken to achieve sustainable use of groundwater for irrigation aiming to achieve food security as well as an ecologically friendly environment. Keywords: Borehole, groundwater, storage, specific yield, storage capacity DOI: 10.7176/JEES/10-8-02 Publication date: August 31 st 2020