Monitoring changes and ranking threat factors of Miangharan wetland, Khuzestan Province

Wetlands are valuable ecosystems that provide a variety of environmental services such as water storage and supply, erosion and flood control, and biodiversity conservation. Migratory birds including waterfowls and shorebirds are among wetland-dependent species whose survival depends on wetlands. Ecological conditions and water quality of a wetland depend on the characteristics of its surrounding environment, including the type and ratio of land use and land covers. Miangharan wetland is one of the valuable wetlands in Iran, located in the southwest of the country in Khuzestan province. The current study was conducted to monitor land cover changes in Miangharan wetland over a period of 30 years and to rank destructing factors of this wetland. Satellite images were utilized from the mid-winter of 1990, 2000, 2010 and 2018 and land use maps of different years were produced and analyzed. Five land use classes including urban area, agricultural area, wetland, rocky outcrop and forests were identified using supervised classification. Destruction factors were identified through field observation and reports. The analytic hierarchy process (AHP) was used to rank the destruction factors of the wetland. A questionnaire was designed and completed by 20 environmental experts in Khuzestan province and analyzed, using Expert Choice software. Result showed that the wetland area has been decreased up to 80% from 1990 to 2018 and agricultural and urban areas have increased by 40%. Based on the results, the highest calculated weights were related to three threatening factors including sewage inflow (0.35), agricultural activities near the wetland (0.16) and natural drought (0.15). A correct and accurate understanding of the process of changes in a wetland and its threatening factors, provide a basis for preventing and dealing with these factors, as well as the prevention and accurate implementation of wetland conservation plans.