Feasibility of Suspended Sediment Estimation using Water Quality Variables

Nowadays, measuring water quality is very important for comprehensive management of water resources. Suspended sediment is one of the most important water quality factors which greatly affects environment health. However, its measurement needs too much time and money. It was therefore tried in the present study to assess the applicability of modelling relationship between suspended sediment concentration and some easily accessible and cheap water quality factors. Towards this attempt, 61 water samples were taken during October 2007 to July 2008 from main outlet of Tarbiat Modares University Forest Watershed as a representative condition governing northern Iranian forest areas. The samples were taken during different hydrological conditions and corresponding lab analyses were consequently made. The results of regression modeling ultimately proved the relationship between suspended sediment concentration and turbidity, alkalinity, and phosphate with correlation coefficient beyond 0.264 (p=0.006), 0.088 (p=0.018), 0.987 (p=0.001) and respective estimation and verification errors of less than 78% in all classified periods, base flow, and flood conditions, respectively. The models obtained during the study can be then used for estimation of suspended sediment concentration in different hydrological situations.