Monsoonal Droughts in India-A Recent Assessment

Abstract

Drought frequencies during the years 1901-2010 were investigated over three spatial units-All India, 5 Homogeneous Regions (HR) and 36 Meteorological subdivisions (MSs). The All-India rainfall trend is in fact indicative of no trend, while the Northeast HR (NER) shows a significant decrease. Furthermore, a significant decrease in rainfallis to be observed over Himachal Pradesh, Madhya Pradesh, Maharashtra and the Southern Peninsular region, and a significant increase over West Bengal, Punjab, Haryana, Coastal Karnataka, North Interior Karnataka and Rayalaseema. There have been 21 All-India drought years during the last century, of which 13 were linked to El Ninõ. When compared with HRs, the WCR is highly prone to El Ninõ while the NER is not affected by this global tele-connection. Western Uttar Pradesh, Eastern Rajasthan, Uttarakhand, Vidharbha and Telangana shared 11-10 drought occasions with El Ninõ. Maximum frequencies of droughts (21) were reported for East Madhya Pradesh within the WCR and Orissa within the Central Northeast Region (CNER), while Andaman, Nicobar and Rayalaseema experienced minimum drought episodes (12) over the last century. Sixty percent of the MSs in the West Central Region (WCR) and the Northwest Region (NWR) were coherent with All-India droughts. During the years 1918, 1972 and 2002, the majority of HRs (except NER) witnessed normal or below-normal rainfall. Western Madhya Pradesh within the WCR saw maximum drought events (13). The highest degree of simultaneous occurrence of drought years between the MSs and all-India concern Eastern Rajasthan, Western Madhya Pradesh, East and West Uttar Pradesh. The study also found that the MSs in HRs highly affected are East Rajasthan (NWR), West Madhya Pradesh (WCR), West and East Uttar Pradesh (CNER), NER and Coastal Karnataka (Peninsular Region). Western Uttar Pradesh, Eastern Rajasthan, Vidarbha and Telangana had 10-11 occasions when El Ninõ and Drought years occurred.