Fractal Behavior and Its Relationship with Hydromorphometric Characteristics over Catchments of Binaloud Northern Hillslopes

Fractal dimension is a parameter used to indicate the complexity of data. The analysis of fractal dimension of river networks and their basins facilitate the perdition of their behavior in the future. This paper focuses on the relationship between fractal dimensions of basins and the morphometric characteristics of drainage networks. Therefore, through an analysis of fractal dimension of basins and its comparison with morphometric characteristics, the fractal behavior of these basins are investigated. At the first, six rivers including Torough, Golestan, Esjil, Golmakan, Frizi and Akhlamad located in the northern slopes of Binaloud were selected. The boundaries of basins were determined using aerial photos, imagery data, and topographic maps. Then, hydromorphometric and hydrologic parameters such as length of each river network, the number of networks, basin area, the main channel length of each basin and their fractal dimensions were measured. Results showed the basin of Esjil and Torough Rivers indicate highest and lowest fractal dimension respectively. The results also indicated a significant and meaningful relationship between fractal dimensions of basins, drainage networks, forms, final patterns and morphometric characteristics. Moreover, we found an inverse relationship between the fractal dimension and the area of basins under study. Accordingly, Esjil basin with the lowest area (226.79 km) shows the highest river bifurcation fractal dimension of (3.21) while Torogh basin with the greatest basin area (2370.4 km) indicates the lowest river bifurcation fractal dimension (1.74). In this context, a positive relationship was observed between morphometric parameters and fractal dimension of river bifurcation and drainage density, so that the greatest correlation coefficient was found between the fractal dimension of river bifurcation and the shape of the basin (0.939). Furthermore, the highest correlation was between the fractal dimension of drainage density and bifurcation ratio (0.937).