A QUICK TECHNIQUE OF FLOOD DETECTION AND MAPPING BASED ON LAND COVER/LAND USE CHANGES (CASE STUDY: THE 2022 FLOOD EVENT OF TALEGHAN CITY OF IRAN)
Keywords: Instant management, Google Earth Engine, Land cover, Sentinel, Stream, Three hours
Abstract. Flood as one of the most devastating natural disasters, causes significant tangible and intangible damages to watershed residents each year. When flood occurs, changes in land use (LU) and land cover (LC) relative to climate change and other edaphic factors have remarkable impacts on flood generation. Furthermore, application of complicated models with various inputs is costly and time-consuming. In this study, with the aim of determining the parameters affecting the recent floods in the Taleghan watershed, first, maps of the flooded areas and changes in LU and LC was extracted using' Sentinel 1 & 2 by coding the Google Earth Engine. In the extraction of LU, seasonal composites were used and the winter season was eliminated. Next, using the override command in the ARCGIS 10.8.1 software, the extracted maps were combined and evaluated. The results show that the use of urban and forest lands was limited to the lands next to the rivers and streams, which are the places where the floods pass, and this factor has increased exposure to flood. According to the composition of the maps in the Taleghan watershed, floods occurred in areas where there was no LC and the flooded areas we are located in the upper part of villages where natural LC was lost as a result of livestock grazing or human manipulation. It can be concluded that the use of simple models and basic maps can help experts identify flood zones.