Spatio-Temporal Analysis of Rainfall Variability and Long-Term Precipitation Trends in Tikamgarh District, Central India

Abstract

Variability in rainfall and the trend in precipitation have profound effects on rain-fed agriculture and water resources management in the drought prone Bundelkhand region of Central India. In this study, 40 years (1986–2025) monthly rainfall data set of Tikamgarh rain gauge station in Tikamgarh district of Madhya Pradesh was analyzed to understand the nature of rainfall variability and precipitation trend in the area. The monthly data were quality controlled and summarized into seasonal and annual time-series. Rainfall variability was analyzed using coefficient of variation (CV), precipitation concentration index (PCI) and IMD departure classes, while rainfall trend analysis was done using Mann-Kendall test, Sen’s Slope Estimator and Pettitt Test, assisted by decade-wise comparison and five year moving average plot. The annual mean rainfall was 986.25 mm (CV = 34.91%) varying between 348.00 mm in 2007 and 2,207.00 mm in 1999. South-West Monsoon season (June – September) contributed to 88.64% of total annual rainfall, annual mean PCI being 31.99 and post-monsoon seasons showing very high relative variability (post-monsoon CV = 268.24%). Eleven years were classified as excess, 17 years as normal, 11 years as deficient and one year as scanty. An insignificant increasing trend in annual rainfall (+6.31 mm yr⁻¹, p = 0.177) and SW monsoon rainfall was noted, but a significant increase (+0.64 mm yr⁻¹, p < 0.001) in pre-monsoon rainfall was noted, particularly during March – May period. No significant change point in annual rainfall could be detected (Pettitt test, p = 0.787). Results suggest considerable inter-annual variability coupled with trend in particular season and no long-term trend in annual rainfall. There is a need for rain water harvesting and in situ moisture conservation in the area.