Study of Quality & Pollution of Urmia Gadarchay Catchment, Using Water Quality Index and WRASTIC Vulnerability Model

Study area of this study is Gadarchay Catchment (Part of Urmia Basin) that has been affected by the agricultural and industrial activities as well as population points. In this study, quality and pollution of Gadarchay Catchment Using Iran Water Quality Index and WRASTIC Vulnerability Model has been investigated to improve water quality, preventing of pollution and reducing pollution load by using management mitigation plans.

After collecting the history of study and completing the information, the catchment area have been assigned and divided to eight zones. Then sampling stations have been chosen by some criterions and sampling program have been started seasonally and the water quality index using IRWQISC have been estimated.

The quality of rivers was in partly bad to partly good. The vulnerability of the catchment area has been calculated 59 that show the high sensitivity of the river catchment area. Availability of pollutants in the study area for example fisheries, bird houses, slaughter house, industrial areas and urban and rural areas by the river and discharge of waste water, causes wide pollution in river specially in mid-zone and downstream of the catchment area. These pollutants are increasing due to the growth of population and industrial and agricultural development.

For improvement of water quality and preventing of pollution, management mitigation plans are used and proposed plans including one structural plan, four non-structural plans and two joint plans are planned. Also it’s useful to detect pollutant sources and quality conservation acts and pollution control in case of monitoring of water quality projects and reforming the existing water quality monitoring.