Observed Variability and Long-Term Trends of Rainfall Over India
Pulak Guhathakurta and Jayashree Revadekar
Asian monsoon circulation dominates the climate of south Asia. South-west (SW) monsoon season (June-September) over India is of paramount importance as it contributes about 75 % of the annual rainfall. SW monsoon rainfall over India shows variations in all time scales from diurnal to multi-decadal. It exhibits considerable year to year variability with years of excess rainfall and years of droughts. SW monsoon rainfall plays a crucial role for the sectors like agriculture, disaster management, water resources and power management. Though there is a growth in the service sectors, the Indian economy is still dependent on agriculture and thus the SW monsoon. Instances of droughts and famines associated with weak or deficient monsoons become very critical to the country.
There is a need to review the variability and observed changes of the Indian rainfall and to re-examine the analysis based on longer period of data, 1901-2010. The present analysis deals rainfall variability and trends during the south-west and north-east monsoon (October-December) seasons. Attempts are also made to identify the observed abrupt changes in monsoon rainfall at different spatial scales that may be the result of some abrupt changes in climate.
P. Guhathakurta (H)
Indian Institute of Tropical Meteorology, Earth System Science Organization, Pune, India © Springer Science+Business Media Singapore 2017
M.N. Rajeevan and S. Nayak (eds.), Observed Climate Variability and Change Over the Indian Region, Springer Geology, DOI 10.1007/978-981-10-2531-0_1