STUDY OF DROUGHT CHARACTERISTICS IN KEN RIVER BASIN OF BUNDELKHAND REGION IN INDIA

Abstract

Drought is a creeping phenomenon, which starts slowly and may prolong for months, seasons and years due to moisture deficiency. Characterization of drought an important aspect of inventing past drought events, their frequency and severity for an area. Bundelkhand region of India has a long-standing history of droughts and starvations. The Present research aims to study the drought characteristics of Ken River basin in Bundelkhand region compassing eight districts namely Banda, Hamirpur, Mahoba, Chhatarpur, Damoh, Katni, Panna and Sagar. The primary goal of the study was to investigate annual, seasonal and monthly meteorological drought events, hydrological drought event and analysis of critical dry spells in Ken river basin for provision of supplemental irrigation during critical dry spell period. Analysis of rainfall data of above 8-districts between the period of 1980-2016 (37 years), on an average there had been 8 drought years with an average frequency of every 5 years in the Ken basin. The maximum annual and seasonal rainfall deficiency have been recorded – 60% and -64% respectively. Among these districts, the Sagar district experienced more frequent droughts. The probability distribution analysis indicated the variation of annual rainfall equivalent to 75% of normal have the probability of occurrence of annual rainfall from 66% to 86%. The average length of effective monsoon period in the study area is around 89 days between the period June 22 to September 19. Thus, under the rainfed condition, the paddy varieties with 85 to 95 days crop duration may be cultivated in this area. Also, the area has medium black and black soils. Therefore, cultivation of soybean and maize crops may be preferred for rainfed cultivation in this basin. The analysis of intervening dry spells during monsoon season revealed that one to two critical spells (period of >12 consecutive non-rainy) have occurred in some years and have caused serious crop loss in the region. The crop water requirement for maize, paddy and soybean have been estimated as 322.73, 417.09 and 357.09mm respectively for the Ken basin. In order to prevent the crops from moisture stress and to ensure the success of at least one season crops, it is desirable to have provisions for supplemental irrigation for critical dry spell period. The SPI analysis using multiple time-scales reveal that selection of time-scale for SPI estimation plays a significant role in analysing the meteorological drought events in a given basin. The SPI analysis showed that duration and severity of drought were increased considerably with increasing SPI time scale value. The meteorological drought characteristics based on EDI, specify the Page | iv maximum drought severity of -28.34 occurred at Hamirpur station with maximum intensity -2.18 happened between June 1993 to June 1994. However, the drought having longest duration (16 months) occurred in Panna station during June 2007 to September 2009. The study also analysis the hydrological drought and its characteristics with the help of streamflow drought index and groundwater drought index. The monthly streamflow data for Banda station on Ken river for the period of 30 years (1981-2010) has been used in the analysis. It revealed that the stream flow drought duration varies from 61 days to 365 days with single extreme drought condition during April 2007 to March 2008. From the pre-monsoon and post-monsoon period groundwater level data of 22 years (1984-2005) reveals that Sagar district experienced only mild category drought condition during 1984, 2000, 2001 and 2002. It is hoped that this study will be useful for Kharif crop planning in the Ken basin.