Original Articles
JIN De sheng, SHI Chang xing, CHEN Hao, ZHANG Ou yang
The man induced sediment disaster is identified as a kind of processes for land surface material to advance gradually or to surpass threshold erosion, transportation and accumulation by man’s activities. It possesses special attributes in sociology and disaster science. In accordance with the form of man’s activities, geomorphologic lacation behavior and particular, the man induced sediment disaster can be divided into 4 types: the drainage network, slope and gully, channel and plain estuary coastline. Each type includes 5 subtypes, e.g. erosion, transportation, accumulation, complexity and correlation. There are more than 54 kinds of man made sediment disasters, for example, destroying forest for farming, constructing highway and road, too much small and middle coal mining, cave dwelling, discarded earth and stone into channel sand gullies, excavated beyond normal limit of sand in river bed, desertification of cultivated lands, soil salinization, much more sedimentation above a dam and erosion below one after reservoir building, transporting water from one drainage basin to another one, etc..\;According to combination of man’s activities, geomorphology, and sediment mechanics with disaster science, the man induced sediment disaster is characterized by such properties as (1) accelerating tendency with geographical zonation, (2) sharply changing with human environment alvibration, (3) non order under blind action without special technically training, and (4) complexity and non linear figure, etc. One of the important reasons lead to man induced sediment disaster is the human environment vibration. If it is stable and people have high training, the man induced sediment disaster should be reduced, and vise versa. Therefore, it could be controlled only as through strengthening sediment management, correctly executing the water soil conservation law, and rising people’s understanding of environmental protection by education.
