The effects of watershed physical properties on bed load morphometric and sedimentologic characteristics along downstream: a case study from Ghalesar watershed in Mazandaran Province

Litnology and sedimentology factors affect on downstream changes in bed load shape and can be useful to detect watershed hydrological processes as they are very important to design hydraulic structures and reservoir management. This research was conducted in Qalesar River in Mazandaran Province with main river length of 24 Kilometers. After recognition of the study area, 11 sections were selected toward downstream for bed load sampling. Laboratory analysis were done using gravel meter and sieving method to measure and calculate some bed load shape characteristics. Also physical properties of each sub-watershed were extracted using Arc/GIS 9.2 software. Finally, in order to determine most effective physical characteristics on bed load shape, data were analyzed using SPSS 16. Results of statistical analysis indicate the best model between D50 and length of 1 order channel in bivariate regression equations and between D50 and distance from upstream in multi-variate regression equations