Ground water year book, Bihar (2021-2022)

Monitoring of ground water levels from 768 (745+23) Hydrograph Network Stations (HNS) were carried out in the year 2021-2022 with an objective to assess ground water regime of phreatic aquifer. The water level monitoring was carried out manually in the months of May’19, August’19, November’19, and January’20. The ground water samples from the HNS were collected in the month of May’21 for chemical analysis. The water level in the HNS represented phreatic aquifer. During the year 2021-2022, water level monitoring has been badly affected by Covid-19 pandamic. The observed water level data had been grouped into four categories viz. 0-2 m, 2-5 m, 5-10 m and >10 m. Thematic maps depicting ground water levels measured in different periods, has been prepared. The water levels has been further analysed for study of its change with respect to measurement of pre-monsoon period of the same year, previous year water level data of the same period and decadal mean water level data of the same period. The fluctuation had been grouped under rise and fall categories. In each category there are three groups viz. 0-2 m, 2-4 m and >4 m. Thematic maps had been prepared for each category of fluctuation.