نوع مقاله : مقاله پژوهشی
1 کارشناسی ارشد ژئومورفولوژی، دانشگاه علوم و فنون دریایی خرمشهر.
2 استادیار ژئومورفولوژی، دانشکده منابع طبیعی دریا، دانشگاه علوم و فنون دریایی خرمشهر.
عنوان مقاله [English]
Introduction: The watershed is a geomorphologic unit suitable for managing natural resources and achieving sustainable development. The drainage network of the catchment area is a series of streams and rivers that guide and drain the surface water flow. These spatial data play an important role in physiographic studies, hydrology, erosion and sedimentation of a catchment area. The network of canals can be considered as a system that is dynamic in a state of equilibrium, in which dependent variables such as form; the slope and horizontal projection of the river or the amount of data and the coincidence that whenever there is a change in the data, This system reacts quickly with the coordination of their morphological characteristics with the new situation. The drainage network pattern is one of the most prominent landforms of the earth's surface. The order and distribution of hydrographic networks are different. The purpose of this study is to identify the factors of balance and imbalance of the right and left side of the research area and which part of the research area has severe asthma and chaos. The basis of this research is the method analysis order matrix of basin Ramhormoz at the beginning of the study. The exact coordinates of basin Ramhormoz boundary from Global Mapper.20 software were taken in Arc GIS 10.5 software using the Dem area of the study; for Draw curves, lane lines and line basin s, slope direction, fracture of streams and formations. Arc GIS software has been used to evaluate the Ramhormoz river basins using the Order Matrix method. To set the categories in matrix form. orders 1 to 1, 2 to 2, 3 to 3, and to the last. order that is the main. order, are placed in tables in the two views (right and left) in the array view. In the following, the. order 1, which joins the large. orders r, is calculated separately and the rest of the orders are calculated in this way (order 2 to 3, 4, 5, ... 3rd to 4th, 5th And other orders). In the study, the split density and drainage density are used. In this study, the number of waterways in the upper reaches of the two sides of the study area with a very significant difference indicates the imbalance in the research area. Erosion, slope changes, channel displacement, channel redirection, tectonic activity of these factors in causing significant differences and effective imbalances on both sides of the research area as well as the manner, extent and stages of changes in the form of the canals affected by time as a The main variable is to create the threshold, and the reason that the canals tend to trigger the chaos process, and even show a slight change, causing them to balance and imbalance. on both sides of the research area, the most balanced average of the lengths of the waterways, the order of waterway 1 falls to the 7th (right 819.2 km and the left is 819.1km). Due to changes in the geomorphological parameters of the basin, due to changes in the parameters of the basin, resulting in no change in their form during the period. The correlation coefficient between the longitudinal lengths of the two sides of the research with the coefficient of determination (0.9932), due to the slope and elevation variations, shortage of the path and length of the branches of the canals, which are located on both sides of the research area, in the right side of the study, correlation relationship Between the length and length of the waterways with the coefficient of determination (0.929), the left side of the study area, the length and length of the waterways with a coefficient of determination (0.8821) indicating the presence of the threshold and the chaos on both sides of the research area and these factors Due to the effects of erosion that indicate tectonic activity, side erosion, floor, grooves, and fault systems, especially in the left-hand region of the research, these factors (other than erosion) are more severe. The imbalance and the threshold on the left of the research area are more intense.
The right side of the study area, with a branching ratio of 3.34 and drainage density of 7.87, the left side of the research area with a split ratio of 3.50 and a drainage density of 4.06, due to the split ratio of the two river research areas, has a moderate construction turbulence. The drainage density is correlated with the amount of erosion. In the right zone of the study, the moderate drainage density is equal to the rate of high erosion, which is due to the high percentage of Aghajari Formation in this research area and the greater proportion of branching in the left side of the research area to the right of the research is due to the Bakhtiari Formation.
The most evolution of the waterways of both parts of the research, especially the left, is the tectonic research, erosion, and formations, Bakhtiari, Gachsaran and Aghajari formations are more than the Mishan Formation and the terraces and Low level alluvial fan and valley terrace deposits in the creation of chaos, Threshold and erosion. Lateral erosion in the right side of the research is more and less erosion of the floor, while the left side erosion of the research is less and the erosion of the floor is greater, these factors are due to imbalance in the two areas of research. Tectonic activity, albeit moderately, interfered with changing the state of the trenches, eroding, shortening the length of the waterways, and varying the number of waterways.
Keywords: Ramhormoz River, Fluvial Geomorphology, Matrix, Order Matrix Model, Threshold.