Long series of climatological data for 140 years over Kerala in the humid tropics of India indicate cyclic pattern in rainfall with a declining trend in annual and southwest monsoon rainfall during the past 60 years. In contrast, there was an increasing trend in post monsoon rainfall, indicating likely shifts in rainfall patterns. Onset of monsoon over Kerala, the Gateway of monsoon, appears to be little early. If the onset of monsoon is early that is on or before 25th May, the monsoon rainfall is below normal or normal over Kerala. Rise in maximum and minimum temperatures was also noticed since last 49 years over Kerala. The day maxima increase was 0.64° C while the night minimum 0.23°C. Increase in mean annual surface air temperature over Kerala was 0.44°C. Such warming was noticed in the entire West Coast. The difference in maximum and minimum temperatures (temperature range) was widening where thermo-sensitive crops like cardamom, tea, black pepper and cocoa are grown along the high ranges. These changes in thermal and moisture regimes have resulted in climate shifts from B4-B3 to B2-B1, moving Kerala from wetness to dryness within the humid climates. The impact of climate change in the form of climate variability like floods and droughts adversely affected food and plantation crops to a large extent and thus there is an urgent need to adapt crop management, crop improvement and crop protection strategies in tune with projected climate change scenarios so as to mitigate the ill effects of weather aberrations and sustain agricultural production in ensuing decades.

Type: Journal Article
Year: 2014
URL: http://www.isprs.org/proceedings/Xxxviii/8-W3/b2/9-B9-95_ISRO%20F.pdf