Journal Of Iranian Water Engineering Research

Journal Of Iranian Water Engineering Research

The impacts of drought and vegetation changes on flooding in Bandan watershed

Document Type : Research Article

Authors
َAlireza Sirati 1
Abdolhamid Dehvari 2
Morteza Dehghani 3
1 MSc student, Rangeland and Watershed Management Department, Faculty of Soil and Water Resources, University of Zabol, Zabol, Iran
2 Assistant Professor, Rangeland and Watershed Management Department, Faculty of Soil and Water Resources, University of Zabol, Zabol, Iran
3 PhD in Watershed Management, Deputy Director General of Natural Resources and Watershed Management of South Khorasan, Birjand, Iran
10.22034/ijwer.2025.522929.1089
Abstract
In this study, the flood vulnerability of the Bandan watershed due to drought and vegetation change was assessed. Annual rainfall fluctuations and drought periods were determined using the normalized percentage index. Physiographic features of the watershed, such as gradient, were extracted from the 30-m resolution DEM using ArcGIS 9.3 software. The soil hydrological group map was created by superimposing soil, geological, and gradient maps. The vegetation cover index (NDVI) was obtained from ETM+ and TM Landsat images in the spring of 1990, 2006, and 2009 using ENVI 4.7 software and classified with a factor of 0.1. A land use map was created using satellite images and used to extract the final CN map (in three periods) using superposition analysis with hydrological groups and NDVI maps. The results show that the weighted average CN changed from 69.8 in 1990 to 73.9 and 71.7 in 2006 and 2009, respectively. This indicates that drought is a major concern and will increase the risk of flooding in the region in the future.
Keywords
Drought
Normal Difference Vegetation Index
Curve Number
Bandan Watershed
Subjects