Spatiotemporal Analysis of Drought Characteristics in the Bundelkhand Region of Central India using the Standardized Precipitation Index

摘要

The spatiotemporal variations of the drought scenario over the Bundelkhand region in central India have been studied using the standardized precipitation index (SPI) for the time scales of 3, 6, and 12 months. The space-time variability of the drought characteristics has been analyzed using the SPI, which is based only on long-term monthly rainfall data. From this analysis, it is determined that the frequency and severity of droughts have increased over the last decade in the Bundelkhand region and varied between once in 3 years and once in 5 years. The nonparametric Mann-Kendall test for trend analysis of climatic variables has been applied to investigate the regular occurrences of drought during the last few decades. The sign test indicates that there is a falling trend in the seasonal rainfall and number of rainy days in a few blocks. However, statistically significant falling trends at a 95% confidence level have been observed with the 3-month SPI for many blocks in the region, indicative of the increasing severity of drought during the principal rainy months (July, August, and September). The spatiotemporal analysis, which included progression and withdrawal of drought over the region, indicates that every drought event has its own unique characteristics, including its onset, severity, frequency, duration, area of influence and the magnitude of the losses caused by it. The severity of recent drought events shows a more widespread aerial extent in the region. It is observed that the area under the influence of drought in the Bundelkhand during the year 2007 varied between 79.5% (July) and 100% (August). The comprehensive analysis does not indicate any climate change signal and study recommends that effective use of water resources may be the key to address the drought in Bundelkhand region.