SAR based flood risk analysis: A case study Kerala flood 2018

Abstract A short span of abnormal precipitation in the year 2018 has ravaged the southwestern state of Kerala. It has resulted in widespread flooding and landslides with more than 400 casualties. The present study has implemented the SAR (Synthetic Aperture Radar)-based Sentinel 1C band satellite data. The researchers have analyzed the remotely sensed data to examine the severely affected areas. The study area included Alappuzha, Kottayam, Thrissur, and Pathanamthitta districts. The daily and monthly precipitation data is acquired from the Indian Meteorological Department (IMD) and Tropical Rainfall Measuring Mission (TRMM). During 2018, Kerala has experienced a severe escalation in the volume of rainfall from June onwards till September. The current study has analyzed the spatial and temporal variation in the extent of severe flooding in Kerala during the monsoon months of 2018. The south-central parts of Kerala are most severely impacted by flooding. The districts of Alappuzha and Kottayam were severely affected, followed by Thrissur and Pathanamthitta, moderate to low. The outcomes of this assessment would be helpful for risk-informed planning in the pre-disaster context and help in decision-making for response planning and early recovery.