جغرافیا و توسعه (Dec 2021)
Assessing the role of floods in changing the bed of rivers and its impact on rural communities (Case study: Khorram abad river)
Abstract
Floods, as the most common natural hazard over the past decades, have had many environmental and socioeconomic consequences within floodplains. The occurrence of floods in the Khorram abad River in 1 April 2019 changed the riverbed in many parts of the river, resulting in the erosion of agricultural lands, the destruction of gardens and water transfer canals to rice fields. The aim of this study is to evaluate the changes in the riverbed as a result of flooding and erosion of agricultural lands in Cham’s. Various tools such as Sentinel satellite images before flood (22 May) and after the flood (29 April), Google Earth images and Arc GIS and ENVI software have been used to analyze different parts of the research. Research Results shows that the riverbed has widened and shifted at several points and flowed in a different direction. The reason for the displacement was the severity of the floods, loose and erosive alluvial sediments, and the interference of rural communities in the form of the expansion of agricultural lands in the riverside Chams. The relocation and widening of the riverbed has eroded 20 Cham’s of the studied agricultural lands by 48.3 hectares and reduced the rice harvest by 95.7 tons. Other research results indicate the vulnerability of villages based on the amount of damage caused by erosion of rivers and reduction of rice harvest, so that the most damage is done to downstream villages and the least damage is done to villages upstream.
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