中文摘要：

泥石流的水系结构能够直观地反映出泥石流本身的发育状态和活动程度,为定量描述泥石流水系结构从而对泥石流的活动强度进行分析,基于GIS系统提取出泥石流水系的三维化数据,根据分形理论自编Matlab程序测定出金沙江流域泥石流三维水系模型的盒维数值,确定水系结构的量化指标,并结合松散物源量、泥沙补给段长度比等指标对研究区内的泥石流进行分析,得出泥石流的活动强度与各影响因素之间深层次规律。随着泥石流活动强度的增长,其影响因素也会跟着增加。而且,在活动强度为15和21处时,活动强度和影响因素的关系曲线均出现拐点。对泥石流活动强度的界定提出新的判据。通过上述方法对金沙江流域的泥石流进行研究,结果发现,矮坝沟的活动强度最大,这一结论与实际相符,验证该方法的科学性和合理性,为泥石流灾害的评估提供新的手段和依据。

英文摘要：

The developmental state and activity level of debris flow can be reflected by its drainage system pattern. A quantitative description of drainage system is very important to the study of debris flow activity intensity.The three-dimensional data of debris flow are extracted by a computer program based on Matlab software which is written according to fractal theory to calculate the fractal dimensions of three-dimensional drainage system along Jinsha River.The quantitative indicators of drainage system were determined to analyze the debris flow in the study area,considering the amount of loose material and length ratio of sediment supply segment.The law between the factors and the activity intensity is summarized.With the activity intensity of debris flow increasing,the index values of factors also increase.What is more,when the activity intensities are 15 and 21,respectively,the curves of the relationships between factors and activity intensities all bend sharply which prove that there is an internal link in the amount of loose material,length ratio of sediment supply segment and fractal dimensions.New judgments to define the activity intensity of debris flow are proposed to supply new method and evidence for debris flow hazard assessment.The typical debris flows along Jinsha River are studied by above-mentionedmethod.From the results,it can be seen that the activity intensity of Aiba groove is the largest which proves that the activity intensities of debris flows determined by new judgments are consistent with the reality.The new judgments are scientific and rational.