中文摘要：

基于MapGIS技术与分形理论,通过计算机编程辅助计算,研究了水系的盒维数值与泥石流各种特征之间的规律。从流域水系的形态及分布特征的角度揭示了流域水系分形维与泥石流危险度之间的深层关系。计算结果分析表明：随着危险等级和特征参数的增加,水系盒维数也呈增长趋势。研究发现通过盒维数的界限值可以界定一条泥石流沟的类型、发育时期和危险程度。其中,分形维1.35和1.42是危险度的界限值,分形维1.34及1.32为泥石流类型和发育期的界限值。

英文摘要：

This paper is trying to describe the characteristics of water system in debris flow drainage basin objectively and accurately so that the debris flow risk level can be determined.Based on the MapGIS and fractal theory,with the aid of computer programming,the relationships between the various features of debris flows and the fractal dimensions of water system are revealed from the view point of morphology and distribution of water system.The results show that along with the increase of the characteristic parameters and the risk level,the fractal dimension of water system exhibits a growing trend.In addition,the threshold values of fractal dimension are found which can be used to define the types,development stages and risk levels of debris flow.It is found that the fractal dimension 1.35 and 1.42 can be taken as the threshold of risk levels of debris flow;and 1.34 and 1.32 can be taken as the threshold of types and development stages of debris flow.