Investigation of the root system of riparian Tamarix tree,indirect flow of river in order to use in practical slopes stability

Root system is effective on increase soil shear strength and slop stability. This study investigates the root system of Tamarix trees on slope of riverbanks indirect flow. Five trees (from TAMARIX species) which grow on the river beech were selected in a distance about one km on SAIMEREH River in Ilam Province. Circle profile trenching method was employed to obtain characteristics. In direct flow, number and diameter of roots was measured on up and down region of plants. Results show that the number of roots on up region is about 11.6 percent more than down region. For all diameters, the number of roots in up region is more than down region. The average of root diameters on up region is bigger than down region. Total root area on up region is about 23 percent more than down region. On up region thick roots contain more percent of total root but on down region it inverse. It is concluded that, indirect flow, root system of riparian trees on riverbank is asymmetrical.