Observational analysis of heavy rainfall during southwest monsoon over India

Abstract

The climate of south Asia is largely dominated by monsoon circulation. Most of the rainfall received in India is during the 4 months of southwest monsoon season. In recent years, India has faced frequent and severe floods that caused havoc in terms of economic loss and loss of human lives. The devastating floods are occurring almost every year but the places are not same for every occurrence. Most of these floods are categorized as flash floods which are generally associated with heavy precipitation. Heavy precipitation with cloud burst also caused disasters, particularly in northern states of the country. It may be mentioned that the information on the changes in extreme weather events is more important than the changes in mean pattern for better disaster management and mitigation. There is also high temporal variability of monsoon rainfall. This causes the extreme years with high monsoon rainfall departure from the long period mean value, the positive departure causing flood and negative departure causing drought. The variability of monsoon rainfall has been studied by many climate scientists and they have also drawn several conclusions. However the study of variability of rainfall is different from the studies of other climate parameters.