Flood risk assessment using fuzzy logic and HEC-HMS: The case of Ojan Chay

Document Type : Research Article

Author

• Marziyeh Esmaeilpour

University of Maragheh

10.22067/geoeh.2023.82202.1359

Abstract

In the current study, the risk of flooding in the Ojan Chay basin, located in Bostan Abad, East Azarbaijan province, was evaluated. A total of 16 spatial variables were taken into consideration. The thematic layers were integrated and analyzed using fuzzy logic in the context of Geographic Information System. The results of overlapping using the fuzzy gamma operator indicated that more than 4.8% of the basin is in the very high risk class. A significant part of these areas corresponds to the bed of the main rivers of the basin and the lands around them. The high risk class is also located mostly in the vicinity of the mentioned class and covers more than 16.6% of the study area. These areas can be mainly affected by floods with a return period of 10 years or more. About 3.2% (11.1 hectares) and 42.9% (35.9 hectares) of the residential areas are located in the very high and high risk class, respectively. The HEC-HMS model was used to simulate rainfall-runoff and identify sub-basins with high flooding potential. The simulation results showed that the flood hydrograph of the sub-basins and the outlet of the basin is largely influenced by geomorphometric features and land cover. High peaks are observed in the sub-basins with the lowest amount of protective cover, high slope, low permeability, abundance of rocky outcrops and impervious surfaces. These sub-basins are especially located in the upstream parts of the basin. Sub basins 1, 3, 7, 11 and 12 have the highest discharge peak.

Keywords

• Flood
• GIS
• Fuzzy logic
• HEC-HMS model. Ojan Chay

Main Subjects

• مخاطرات اقلیمی و اتمسفریک

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