Impact of rainfall variability on groundwater resources and opportunities of artificial recharge structure to reduce its exploitation in fresh groundwater zones of Haryana

摘要

Climate change likely to impact rainfall patterns leading to higher uncertainty and difficulties in management of both water scarcity and flood events. Temporal trends of rainfall and its variability of Karnal district, representing fresh groundwater zones of Haryana, were analysed by non-parametric Mann Kendall (MK) test and Sen's slope approaches. Analysis of long-term rainfall data (1972-2010) indicated that Karnal receives a mean annual rainfall of 757.6 mm with a high degree of variation (CV = 34.3%). Categorization of monsoon rainfall based on long-period average (LPA) and its CV indicates that during the last decade (2001-2010) Karnal received deficit rainfall in 6 years (18-57% lower than LPA), normal rainfall in 2 years and excess rainfall (9-70% higher than LPA) also for 2 years. The rainfall and rainy days during the last decade (2000-2010) decreased by 13% and 20% respectively, over long-term (1972-2010) averages. The MK and Sen's slope approach applied to pre- and post-monsoon groundwater levels indicated significant declining trend emphasizing the need to augment groundwater by artificial groundwater recharge (AGR) system. AGR through recharge wells installed by CSSRI at village Nabiabad in Karnal districts resulted in 2.32 m and 3.16 m, rise in water table during 2009 and 2010 respectively. Installation of artificial groundwater recharge in low lying areas has proven highly effective in enhancing groundwater and improve its quality.