Determining of the Oak forest's role on protecting water quality based on the service function in Tang-e Shool, Fars

Surface water is an important source for drinking water, which are under environmental and anthropogenic stresses. There are several evidences confirming that forest cover positively affects water quality. However, little quantitate information is available regarding the impacts of forest canopy cover on purification of drinking water quality in Iran. To achieve this, we selected several forested catchments with different ground canopy cover in Tang-e-Shool forest located in the Fars province and Water Quality Index (WQI) were measured by using physicochemical parameters. The production function of water quality service was also estimated by taking into account other characteristics of the forested micro catchments. Our results showed that the WQI in 30% crown cover is in a good quality scale. Also with an increase of 1% in the crown cover, WQI will improve by 0.8% and an increase of 1% in the area of the micro catchment causes a decline of 0.14 percent of WQI. Also, Aghajari Formation has a negative effect on WQI compare to Asmari. According to this study increasing the crown cover to protect water quality by up to 30%, will minimize treatment costs and the waters provided by these forests can be used for human drinking purposes.