TY - JOUR PY - 2023// TI - Unravelling the causes of 2015 winter monsoon extreme rainfall and floods over Chennai: influence of atmospheric variability and urbanization on the hydrological cycle JO - Urban climate A1 - Konduru, Rakesh Teja A1 - Mrudula, G. A1 - Singh, Vivek A1 - Srivastava, Atul Kumar A1 - Singh, Abhay K. SP - e101395 EP - e101395 VL - 47 IS - N2 - The present study investigates the causes of extreme precipitation events over the coastal Chennai city in India during the winter monsoon season of 2015. Our investigation reveals that atmospheric and anthropogenic variability influenced the hydrological cycle in producing the Chennai floods. Atmospheric perspective linked the extreme rainfall to the natural variability over tropics in the form of convectively coupled equatorial waves (CCEWs). This finding is entirely new compared to Chennai floods' earlier attribution to Bay of Bengal warming and El Nino related easterly bursts. Along with the natural atmospheric variability, anthropogenic variability due to unprecedented urbanization multiplied the catastrophe scale. A prominent land cover change over the Chennai region was found in 2015 with respect to 1992 land cover and land use classification satellite dataset. A kilometre-scale regional climate simulation clearly demonstrated the urbanization impact on the extreme rainfall over Chennai. Also, we found unprecedented changes in hydrologic conditions like surface discharge of rivers in 2015 over the Adyar basin of Chennai using the Global Flood Awareness System simulated dataset. We revealed a daily mean surface discharge >1000 m 3 s − 1 of rivers at every 100 km 2 area over the Chennai city after the extreme rainfall events.

Language: en

LA - en SN - 2212-0955 UR - http://dx.doi.org/10.1016/j.uclim.2022.101395 ID - ref1 ER -