Research of fractal dimension characteristics on debris flow gully & valley form

With the development of nonlinear science, the study of geological hazards has been infused with new vitality, and new ways of thinking and concepts are going to throw a new breakthrough on the study and forecasting of geological hazards. Fractal theory is one of the important aspects of nonlinear science. In Longnan, an area in south Gansu province of China, as one of the hardest hit areas of debris flow disasters, debris flows not only hinder the normal operation of national highway 212, but also severely affect the economic development and people´s lives along the road. After statistical analysis of the collected data of a total of 232 debris flow gullies and valleys in Longnan along highway 212 is combined with fractal theory, the quantitative relationship between the number of debris flow gullies and valleys and topographic elements has been analyzed, and the integrated fractal dimensions in different drainage areas have been calculated by using a topographic statistical model. The results show: the role of drainage area played in the growth and the formation of debris flow counts the strongest; the growth of debris flow disasters in Bailongjiang River drainage area stands most flourishing; the fractal dimension of topographic elements in the drainage area and the growth features of debris flow are closely related to each other.