Climatic changes and trends over a major river basin in India

Abstract

Long-term changes of seasonal and annual surface air temperatures and precipitation of the Mahanadi river basin in India are presented. The long-term trends in these 2 important climatic elements were evaluated by linear trend analysis. The results indicate that there is a highly significant warming trend in the mean maximum, mean minimum and average mean temperatures of the basin based on data from 7 stations for the period 1901-80. Results of the trend analysis of surface air temperatures of individual stations are also presented and discussed. Increase in greenhouse gases in the atmosphere over India, recent land-use pattern changes and agricultural practices in the region appear to have a bearing on the observed i'varrning trend. For rainfall, rnonsoon and annual serles were subjected to trend analysis. Basin rainfall series based on data from 125 stations for the period 1901-80 did not show any significant trend. Moreover, none of 10 selected stations in the basin was characterised by a significant increasing or decreasing tendency in either monsoon or annual rainfall.