Prediction of rivers and floods in Dashtyari region for 2030 horizon

In recent years, flooding of rivers has resulted in destructive implications, especially in the coastal areas. Dashtyari coastal plain is located in the southeastern of Iran. The occurrence of destructive floods has led to extensive damage to agricultural facilities, buildings, and residents of the region in recent years. Morphometric factors of the river and its surroundings land-uses and their changes in the future are effective and necessary factors in the planning of coastal plains. Remote sensing is an applicable tool to investigate the past, present, and postcondition of rivers. The GIS-Ready layers included satellite images (Landsat 5, 1987; 7, 2001; 8, 2019; Sentinel-2, 2020), and specific software (Envi 5.3, ArcGIS 10.4.1, and Idrisi TerrSet), as well as the existence and fieldwork documents, have been used to achieve the research aims. Probability values of land-use changes in 2019 were obtained based on Markov chains. Accordingly, the highest probability of changes 24.87% and 23.5% were obtained between the river and plain units, and between farms and river, respectively. Then, an automatic cell prediction map of 2019 is accomplished with the overall kappa coefficient of 95%. According to the accuracy of the output of the cellular Automata Markov model, forecasted Land use and river morphology maps for 2030 were developed. Further, possible changes in the river environment were obtained by fitting the two maps of 2019 and forecasting 2030. Moreover, bank erosion was identified in the 6 critical points along the Kajo, Dashtyari, and Bahu rivers. Finally, the destructive flood event in January 2020 in the Dashtyari region was investigated to match the results with natural events.