The Ordering Analysis of Waterways Drainage Basins of Iran

IntroductionPhysiography is a part of earth science studies in which the physical characteristics of the drainage basin such as area, perimeter and relief, slope, direction, etc. are studied. The studies that examine the physical characteristics and shape of a basin are called Physiography. Knowledge of the physiographic characteristics of a basin along with information about the climatic conditions of the region can provide us with a relatively accurate image of the quantitative and qualitative function of the hydrological system of that basin (Pitlick, 1994). The increase in the rank of waterways in a drainage basin is under the influence of various geomorphological, geological, and climatological ecosystems and contexts. In dealing with open systems, the researchers’ assumption is usually on the effectiveness of specific and accessible vectors and the evaluation of the system's behavior in relation to those vectors. The area of study in this research includes Iran. Iran with an area of about 1648195 square kilometers is approximately located between 25-40 degrees north latitude and 44-64 degrees east longitude. Materials and MethodsIn this study, the accuracy of physiographic relationships in the basins was discussed. The existing relationships and the connection between them represent the relation of physiographic characteristics of the basin. In dealing with open systems, the researchers’ assumption is usually on the effectiveness of specific and accessible vectors and the evaluation of the system's behavior in relation to those vectors. Accordingly, in this study, the increase in the rank of the waterways drainage basin of Iran in the form of 984 sub-basins was investigated in terms of the bifurcation ratio, total length of waterways, the total average of waterways, and basin area. The relation between the equal rank of waterway and drainage basin area and also the relation between specific retention constant and slope and drainage density are among the physiographic characteristics of the drainage basin that were evaluated in this study. For this purpose, first, the layer of main rivers and waterways was prepared from DEM 30*30 extracted from the SRTM satellite. After extraction of the waterway in Arc GIS 10.3 software, Iran's rivers were ranked based on the Horton-Strahler theory. The relation between the equal rank of waterway and drainage basin area and also the relation between specific retention constant and slope and drainage density are among