SEDIMENT PRODUCTION BY EROSION AND MATTER MIGRATION IN CATCHMENT
流域侵蚀产沙和物质转移

Recently, study on sediment production by erosion and matter migration is carried out in catchment, as a unit, with which eroded sediment production, transportation and deposition processes have been researched. Therefore, the catchment is taken as an open system with input, transfer and output of energy and matter.Erosion is one of the external cause to produce surface matter transfer, through which soil and bedrock will be damaged, and thus, it is a main focus on processes of erosion, transportation and deposition in drainage basin. Mechanics and' characters of migrating material were neglected in early study on sediment production processes in the United States, and lately, it was focused on rainsplash erosion and transport processes by runoff, and spatial differences for slope erosion processes in the belt between rills. Russian scientists have recongnized that erosion intensity is constrained by many hydraulic figures, from which therefore the erosion processes are classified.By using soil erosion prospect equation, the local erosion can be estimated, but it is necessary to combine with sediment delivery ratio. Aecording to investigation, the sediment delivery ratio of the loess plateau is larger than that of other countries, in addition, in this paper, a sediment load method to estimate rill-gully erosion intensity is also introduced.For the transport of river sediment, two methods are explained, first, one-two dimension matematical model to compute river sediment load, and mathematical model of sediment transportation effected by base level vibration, second statisticl analysis of sediment transport in natural river, and finally, the purpose of study on erosion.sediment production and transportation are briefly dealt with