Human Role on Upper Holocene River Morphology and Formation of Dust Hotspots in Southwest Khuzestan Province

Large areas of Khuzestan province are among the most susceptible areas for dust production. There are seven domestic dust producing hotspots in the province. Some of them, like the No.1 Dust hotspot (south Hoor al-Azim), are in fact flood and alluvial plains lowlands of the Persian Gulf and Mesopotamia that have lost contact with large rivers such as Karkhe for many years. Such a problem, along with the subsequent droughts, has made a vast plain southwest of Khuzestan province hotspot dust storms. In this regard, the present study intends to investigate the role of human in relation to morphodynamic changes of Karkheh River and dust hotspots. This research was conducted using Landsat satellite images from 1991, 1998, 2002, Liss sensor from the IRS satellite of 2006, Google Earth images, sediment sampling and field surveys. During the research process, all sedimentary environments and sub-environments of sediments leading to the dust zone were identified and then long-term and mid-term changes in the river were extracted using spatial and spectral indices. The results showed that there were at least three abandoned rivers in the study area. The longest of them is the abandoned Jofier Canal, about 50 kilometers long, which flowed to the south of the Hoor al-Azim in a very long time. This canal is more important than others because of the possibility of feeding the number one dust hotspot. Certainly by restoration this canal, wind erosion combat can be directed towards ways to create and strengthen water harvesting systems that increase soil roughness, soil moisture and vegetation, and increase wind erosion thresholds.