Dredging Effects on Plant Species Diversity of River sides, Case Study: Shahrchay River, Urmia

Dredging is the extraction or movement of soil or rock from the seabed, river, ports, etc. Dredging activities are usually carried out in two ways: construction dredging, which is carried out for the first time, and maintenance dredging, which is carried out in two periodic and regular forms. Dredging has objectives that briefly include deepening rivers or lakes or port basins, filling hollows underwater or on land, and replacing poor-quality with good-quality materials. For example, in buildings and structures for foundations and restoration with suitable materials, and most importantly for environmental development, extracting clean materials and placing pollutants on contaminated materials as a covering layer is used (Planning and Budget Organization, 1402).
Shahrchay is a river with a northeast-southwest extension that, after passing through the middle of the city of Urmia, which is now a green space on both sides, and irrigating the fields and gardens of the city, finally enters Lake Urmia. Other names are Barda-Rood, Shahrchay, Barda, Bakshlochay, and Urmia-Rood and Sang-Sorkh. This river originates from Mount Kan-Kaboutar at an altitude of 3271 meters in the mountains of West Azerbaijan Province, and a range of Turkish border mountains is also added to it. After digging a valley for itself in the aforementioned heights, it enters Barda-Sur and passes through it, after receiving a few streams along its route and irrigating the lands along its route, it reaches the village of Band near the city of Urmia (Fig. 1). Here, part of it is branched off to provide drinking water to Urmia city, the rest, after irrigating gardens and agricultural lands, passes near Urmia city and is appropriately called Shahr-e-Chay (Rood-e-Shahr) and then enters Lake Urmia in the south at a place called Mughe-e-Hesar (Khamachi, 1989). Conventional river engineering operations have a significant impact on river ecosystems. Dredging generally reduces the physical heterogeneity of the riverbed and banks and of the habitats. This study aims to expand and improve current knowledge about the impact of dredging on the vegetation cover and diversity in a green space section of an urban river (Shahr-e-Chay, Urmia).