流域系统的泥沙灾害类型及其划分原则

泥沙灾害按驱动力、灾害发生的地貌学系统、灾害的表现形式及具体灾害系统，分层次逐级划分成自然动力与人为动力泥沙灾害2个灾列；流域水质，沟道坡面、河道及平原河口海岸4个泥沙灾害类：侵蚀型、输移（搬运）型、堆积型、复杂型及关联型5种泥沙灾害型；最后分别列出2系列的49个及54个灾种。这是一种比较综合、系统的分类原则和类型划分。从流水地貌、泥沙运动及灾害学相结合来看，泥沙灾害具有自然地理地带性、垂直分带性、群发性、继发性和周期性、渐发性和突发性，以及复杂性和非线性等特征。

Sediment Disasters, Their Types and Classification Principles in Drainage System

The sediment disaster is defined as phenomena of erosion, transportation and accumulation of material on land surface, which gradually advances or surpasses threshold so as to cause casualties and economic loss. It belongs to an independent natural hazard system. The sediment disaster appears when the productivity reaches to a certain level and possesses special attributes in natural, sociology and disaster science, hi accordance with dynamics, geomorphologic location, behavior and particular, it can be divided into two subsystems: natural dynamic and man-induced ones. Then a subsystem is heartily typed as the drainage network, slope and gully, channel and plain-estuary-coastline and classified into 5 patterns, i. e. erosion, transportation, accumulation, complexity and cascading, including 49 and 54 kinds for each subsystem. It is a kind of more comprehensive principle and more systematic classification of sediment disaster up to now. Based on fluvial geomorphology, sediment mechanics and disaster science, the sediment disaster is characterized by: 1) geographic-horizontal zoning, 2) vertical zoning, 3) occurring in group, 4) inherit and period, 5) gradually and sharply changing with human environment vibration, and 6) complexity and non-linear figure, etc. Further study and in-depth analysis should be conducted on real characteristics of various high-concentrated sediment disaster, their processes and mechanism, the coupling relationships among various sediment disasters and quantitative relations between the two subsystems of sediment disaster.