Spatiotemporal trend characteristics of rainfall and drought jeopardy over Bundelkhand Region, India

Bundelkhand region is highly susceptible to meteorological and hydrological droughts, because of the reduced rainfall due to climate change and higher water demand for agriculture. The temporal and spatial drought characteristics of the Bundelkhand region were estimated by the standardized precipitation index (SPI) for the period 1961–2016. Non-parametric statistical tests including, the Mann-Kendall (MK) and Spearman’s rho (SR) have been used in precipitation and SPI series to detect monotonic trends. Statistical tests showed a significant decreasing trend for annual rainfall data with ZMK statistic ranges from −3.93 to −5.54 and ZSR statistics from −4.42 to −7.17 at 5% significant level. Additionally, the magnitude of trend was estimated by using Sen’s slope estimator and the Mi values range from −9.72 to −17.33 which define the extreme condition of drought. Linear regression analysis for monsoon months and annual precipitation also shows the negative slope value, indicating a considerably decreasing trend. Variable-sized cluster analysis (VSCA) provides a visible picture of the irregular rainfall pattern and has been employed for 3-D characterization of rainfall trends and their change point. Trend analysis of SPI on different timescale revealed a negative trend and that negative trend increases with increasing timescale. The highest ranges of drought index indicate the severe to extreme drought category for the study area. The significant drought event with high intensity occurred in 1966, 1987–1990, 1993–1995, 2002, 2007, 2011, and 2015.