Monitoring and detection of Lorestan 1398 flood using satellite data in Google Earth Engine

Flood is one of the most important natural disasters in Iran. Floods carry adverse effects such as life and financial risk in the years to come, as floods are more likely to occur and also because population growth is likely to result in more people settling in flood-vulnerable areas. Monitoring and revealing flooded areas has a lot of function in managing the crisis and reducing the damages of the areas in case of the possibility of future floods. Based on this, the purpose of this study is to monitor and detect the flood event of 1398 in Lorestan province using satellite data in Google Earth Engine system. This system can be used to process and analyze flood maps without the need to download data or use high computing hardware. In this article, the time series data of TRMM and GPM satellites were extracted for the period of one year and one month of Farvardin 1398 and showed that the peak of heavy rainfall was on the 5th and 12th of Farvardin. Images related to the detection of flooded areas were also produced and analyzed using the data of Sentinel 1 and Landsat 8 satellites. The spatial survey of the flood areas in the relevant images shows that the cities of Noorabad, Al-Shatar, Borujerd, Durood, Azna and Khorramabad were the most and most prone to flood areas in Lorestan province and were more affected by floods than other cities. Also, the surface area of flooded areas for April 2018 in Lorestan province was estimated as 673.82 square kilometers. Finally, the results of land cover studies showed that the advance of flood was more in areas with grasslands, agricultural lands and urban and built areas.