Abstract Flash floods are unexpected, localized flood events that occur when an exceptional amount of rain falls happens over a short period time. In South Asia, it is mostly disastrous, for example, in 2017 flash killed approximately 1200 people from India, Nepal, and Bangladesh. However, also common Dhaka megacity, Bangladesh due to its geographic location, monsoon climatic condition surround...

The Australian Bureau of Meteorology is the lead national agency for flood forecasting and warning services in Australia, working in partnership with agencies at the State and Local Government levels. These services cover river basins with response times ranging from 6-12 hours through to very large basins with flood travel times of the order of weeks. Flash flood warning services are also prov...