泥沙输移比尺度依存及分形特征  

Dependence of sediment delivery ratio on scale and its fractal characteristics

作　　者：张晓明[1] 曹文洪[1] 武思宏 秦伟[1] 

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100048 [2]国家科技评估中心,北京100081

出　　处：《水利学报》2013年第10期1225-1232,共8页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(51009154,31200535);国家自然科学基金创新研究群体基金项目(50721006);流域水循环模拟与调控国家重点实验室自主研究课题(泥ZY1304)

摘　　要：泥沙输移比是连接流域地面侵蚀与河道输沙的纽带,是反映流域侵蚀产沙及输移能力的指标,对正确评价水土保持减沙效益与生态建设宏观决策有重要意义。本文基于对国内外泥沙输移比研究的系统梳理,探讨了流域泥沙输移比的尺度依存及分形特征。分析认为:泥沙输移比在其内涵中深刻体现了对尺度的标定;国内外不同区域内流域泥沙输移比具有尺度依存性,并有严格的尺度域;泥沙输移比可以由分形维数来定量描述,即由1km2左右的典型流域单元的泥沙输移比值和流域的分形维数来建立尺度上推或下推的测算模型。本研究结果明确了泥沙输移比研究不能割裂"尺度性"这一学术认知,并为泥沙输移比尺度效应及转换研究提供了新的思路。Sediment delivery ratio （SDs） is a link to connect surface erosion and gully sediment delivery, which is also an indicator to demonstrate the capacity of sediment erosion and delivery of a certain basin. Hence, Sos is usually recognized as a helpful factor when evaluating sediment reduction effects due to soil and water conservation management and making policydecision on ecological construction. Based on a sys tematic review on SDs studies at home and abroad during the last 50 years, this paper analyzed and dis cussed whether Sos has dependence characteristics on scale and its fractal characteristics or not. It was con cluded that （1） the definition of Sos formula has embedded in the characteristic of scale; （2） Sos in differ ent watersheds at home and abroad showed correlations with certain temporal and spatial scales, which means Sos is depended on its scale; （3） Sos could be quantitatively expressed and be scaled using fractal dimension under a certain temporal and spatial scale. The authors found that values of Sos and fractal di mension （D） at lkm2 typical watershed unit were approximately equal to the Sos and D coefficients in corre sponding scaling models. This paper pointed out that the calculation and study on Sos can＇t be correct with out considering its scale dependence. It is a valid and useful approach to construct SDR scaling models by using fractal dimension, which could be an interesting research topic regarding on Sos scaling in the future.

关 键 词：泥沙输移比 土壤侵蚀量 输沙量 尺度 典型流域单元 

分 类 号：TV142[水利工程—水力学及河流动力学]