THE INFLUENCE OF TREES IN THE MINOR RIVERBED OVER THE WATERFLOW AND STABILITY OF THE RIVERBED. CASE STUDY

Rezumat

Over time, spontaneous vegetation develops in the rivers, which influence the flow of water. In general, the vegetation on the banks strengthens the riverbed and has a positive influence on the stability of the riverbeds. The presence of vegetation increases the roughness of the riverbed, reduces the speed of the water, increases the water level in the river, increases the water level in the nearby groundwater layer. Sometimes this vegetation materializes in large trees. How do they influence the flow of water and the stability of the riverbanks?. Large tree roots contribute to increased stability. Large tree body (over 2-3" diameter) become rigid and thus become a punctual resistance to water flow. Local turbulence and high local velocities of water are created which lead to erosion of the banks. These erosions develop and dislocations occur on the banks of the minor riverbank. There is a location in the minor riverbed of the Barlad river, where the presence of large trees has contributed to the erosion of the riverbed and the endangerment of the levees in the major riverbed. It is proposed a limitation of the stiffness of the tree body according to its diameter for the trees in the minor riverbed.