Abstract:
Climate change has affected the temperature and rainfall characteristics worldwide.
However, the changes are not equal for all regions and have localized intensity and must be
quantified locally to manage the natural resources. Orissa is an eastern state in India where
agricultural activities mainly depends on the rainfall and thus face problems due to changing
patterns of rainfall due to changing climate. In the present study, attempts were made to study
temporal variation in monthly, seasonal and annual rainfall over the state during the period from
1871 to 2006. Long term changes in rainfall characteristics were determined by both parametric
and non-parametric tests. The analysis revealed a long term insignificant decline trend of annual
as well as monsoon rainfall, where as increasing trend in post-monsoon season over the state of
Orissa. Rainfall during winter and summer seasons showed an increasing trend. Statistically
monsoon rainfall can be considered as very dependable as the coefficient of variation is 14.2%.
However, there is decreasing monthly rainfall trend in June, July and September, where as
increasing trend in August. This trend is more predominant in last 10 year. Based on departure
from mean, rainfall analysis also showed an increased number of dry years compared to wet
years after 1950. This changing rainfall trend during monsoon months is major concern for the
rain-fed agriculture. More over, this will affect hydro power generation and reservoir operation
in the region.
