| Abstrakt: |
Several factors affect the rate of annual sediment basin. Components of the basin and drainage network have a very important role in river sedimentation rate. This study calculated morphometric parameters of basin such as: area (A), the perimeter (P), the ratio of a circle (Re), elongation ratio (Rf), mean height (H), mean slope (S), drainage density (Dd), drainage frequency (Df) along the channels (BL), fault density (DF), the percentage of Quaternary formations (PQ), bifurcation ratio (Rb), the number of hierarchical anomaly (Ha), hierarchical anomaly index (Δ a), density hierarchical anomaly (ga) in the 17 Basins in the North east of Iran. Then, the annual sedimentation rate of the basins (t / y per square kilometer) and the annual sediment suspended (ss) of each station were determined by multivariate statistical methods and using discharge and sediment data Khorasan Razavi regional water authority. Then the annual sedimentation rate of the basins (tons per year per square kilometer) was calculated. Finally, linear regression and correlation coefficients were evaluated among the components of the basin and the rate of annual sediment. The results of the research show that the highest annual sedimentation rates are in the Torghabeh and Radekan basins, respectively, with 1533.1, 1437.1 tons / km2. The lowest annual sedimentation rate is in Yangaje and Bar watersheds with 224.1, 462.3tons / km2 per year. According to the calculations of P, Ga, A, L, Ha, Δa, and Re indexes, with the values of 0.301, 0.249 0.232 and 0.230, respectively, have the most correlation with the annual sedimentation rate. In addition, there is a relatively weak correlation between PQ, S, Dd, Rb and annual sedimentation rates. In the case of other parameters, there is no correlation with the annual rate of sedimentation of the basins. The analysis indicated that annual precipitation rates are not entirely affected by morphometric factors in research basins. Factors such as intensity and duration of precipitation, soil type, land use and vegetation in estimating the annual sedimentation rate of the basins should be considered to achieve more accurate results. [ABSTRACT FROM AUTHOR] |
