An appraisal of flood events using IMD, CRU, and CCSM4-derived meteorological data sets over the Vaigai river basin, Tamil Nadu (India)

The study of the impact on climate change on water resources provides useful information for long-term trend analyses of important issues such as control of floods, management of drought, agricultural production, etc. This work is an attempt to assess the flood events in Vaigai watershed, Tamil Nadu (India). The Mann–Kendall test was performed to assess the rainfall and temperature trends on data extracted from Climatic Research Unit (CRU) and Community Climate System Model 4 (CCSM4) model for historical and future scenarios. The CCSM4 model was compared with India Meteorological Department and CRU data sets to analyze the performance and consistency of model data among the years of flood, viz., 1993, 2010, and 2015. The CCSM4 model was able to capture, in a few instances, the historical as well as future flood events over the region. The maximum rainfall (738.11 mm) was predicted for 2021 followed by 2038 and 2040, and the lowest rainfall (43.40 mm) was predicted for 2036. Besides, the temperature increased by 1 °C and rainfall was mostly maximum in September corresponding to the south-west monsoon (SWM) season. The predicted increases in rainfall can result in flash floods, which have serious implications on the agricultural sector and water resources of the basin, while the decreasing rainfall during the other seasons helps to reduce the flood severity.