Did you know . . . - the National Drought Mitigation Center

Characteristics of Drought in Kerala, IndiaKerala state in India, which is the first area of thecountry to experience the southwest monsoon, has amoist and wet climate. Kerala is in the extremesouthwestern part of the Indian subcontinent; it bordersKarnataka state in the north, Tamil Nadu in theeast, and the Arabian Sea in the west (Figure 1). Theentire state is one of the 35 meteorological subdivisionsin India.Kerala’s climate is tropical monsoon and tropicalsavanna, according to Koppen’s climatic classification(Figure 1). The state normally experiences excessiveseasonal rainfall, with hot summers (except in theextreme southern districts like Trivandrum, wheredry season and hot summer climate prevails). Thethree main seasons of the state are the hot seasonK A R NCannanoreLakshadweep SeaTropical monsoon:Seasonally excessiverainfall, hot summerTropical savannah:Seasonally dry,hot summerAKozhikodeT AAlleppeyKKERALA100 80 60 40 20 0 100MalappuramTrichurAPalghatErnakulamKottayamQuilonTrivandrumIdukkiIndian OceanFigure 1. Climatic classification of Kerala.T A MI LN A DU(March–May), southwest monsoon season (May–September), and northeast monsoon season (October–February).The annual rainfall of the state varies from 3,800mm over the north to 1,800 mm in the extreme south.The potential rainy season for Kerala is the southwestmonsoon period, which contributes more than 80%of the annual rainfall. The monsoon rain decreasesfrom the north to the south. In recent years, a trend ofdecreasing rainfall has been seen both in seasonalrainfall and 10-day extreme rainfall duration.There is significant rainfall variation in north andsouth Kerala. North and south Kerala have tworainfall distribution subzones. In north Kerala, northeastmonsoon rainfall shows a decreasing trend andcontributes about 15% of the annual rainfall. Thismay adversely affect cultivation of the second ricecrop in the area. Southwest monsoon rain, whichcontributes 82% of the area’s total rainfall, does notshow any increasing trend. Similarly, in south Kerala,southwest and northeast monsoon rains have decreasedby 5% and 8.3%, respectively. Mean annualrainfall is also decreasing in south Kerala.The decreasing rainfall over the region, late onsetof the monsoon, failure of the monsoon, and break inthe monsoon in the state lead to many drought situations.Kerala had severe dry spells and droughts in1983, 1985, 1986, and 1987, even though the statehas a wet climate. There were dry spells of 5 and 4weeks in 1985 and 1986, respectively, during thesouthwest monsoon period.Damage due to drought was particularly significantin Kerala in 1987. About 1,500 villages in 14districts were affected, and 9.82 lakh 1 hectares ofcropland and 6 lakh cattle were also affected. DuringJanuary–May 1987, the entire Kerala region wasaffected by drought. About 30% of the rabi season11 lakh = 100,000Drought Network News3