Trend Analyses in Groundwater Levels of the Bikaner District, Rajasthan

Groundwater (GW) is the essential part of the worldwide freshwater resources. Over-exploitation and insufficiency of GW resources are unfortunately widespread in several parts of the India. As per Central Groundwater Board (2016), groundwater level (GWL) fall of greater than 4 m was found in parts/patches of the Bikaner district, Rajasthan by comparison of depth to water level corresponding to year 2015 (2016 for January) with decennium average over the period 2005–2014 (for January, 2006–2015 is the decadal period) corresponding to January, August, November and May. Thus, in the current study, trend analyses of GWLs of six blocks of the Bikaner district, Rajasthan is carried out for monsoon, post-monsoon kharif, post-monsoon rabi and pre-monsoon temporal scales for the time period (1994–2018). For trend analyses, Mann Kendall (MK)/MK test with correction factor-2, Sen’s slope test, innovative trend analysis plot and smoothing curve are used. The results showed presence of statistically significant decreasing trends in GWL time series of the Khajuwal and Dungargarh blocks corresponding to monsoon and pre-monsoon temporal scales, respectively. All statistically significant trends are decreasing, thus it shows improvement in GWLs in given blocks.