Assessment of rainfall variability and its impact on groundnut yield in Bundelkhand region of India

Bundelkhand region, one of the vulnerable areas in central India, is prone to frequent drought and crop failure due to annual rainfall variability. In this study, long-term (113 years) fine resolution (0.25 degrees x 0.25 degrees) daily gridded rainfall data has been analysed to depict a spatial variation of annual rainfall over Bundelkhand. An increase in annual rainfall has been observed from north to south of the study area. A declining trend varying from 0.49 to 2.16 mm per year is observed in annual rainfall time series in most parts of the study area. Trend analysis of monsoon rainfall shows overall declining trend over the study area. Rainfall events are categorized in various classes and their spatial trends over Bundelkhand are depicted. Kharif crop calendar (July-September) as well as its yield in India, including Bundelkhand, is primarily based on monsoonal rainfall parameters. A study on the relationship between groundnut yield and monsoonal rainfall parameters for Jhansi district in Bundelkhand shows highest correlation (0.46) between groundnut yield and rainfall class 3 events (16 <= rainfall intensity, mm day(-1) < 32) occurred in a year followed by cumulative rainfall amount precipitated during June-July (JJ). The frequency of rainfall class 5 type (64 <= rainfall intensity, mm day(-1) < 128) as well as a delay in onset of monsoonal rainfall have shown a negative correlation with groundnut yield. This study depicts rainfall pattern over the study area and identifies the vulnerable areas that are likely to experience more water stress due to rainfall variability.