| 张晓明,曹文洪,武思宏,秦伟.泥沙输移比尺度依存及分形特征[J].水利学报,2013,44(10): |
| 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 |
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| DOI： |
| 中文关键词: 泥沙输移比 土壤侵蚀量 输沙量 尺度 典型流域单元 |
| 英文关键词: sediment delivery ratio soil erosion sediment delivery scale typical watershed unit |
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| 中文摘要: |
| 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。 |
| 英文摘要: |
| Sediment delivery ratio （SDR） 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， SDR is usually recognized as a helpful factor when evaluating sediment reduction effects due to soil and water conservation management and making policy-decision on ecological construction. Based on a systematic review on SDR studies at home and abroad during the last 50 years， this paper analyzed and discussed whether SDR has dependence characteristics on scale and its fractal characteristics or not. It was concluded that （1） the definition of SDR formula has embedded in the characteristic of scale；（2） SDR in different watersheds at home and abroad showed correlations with certain temporal and spatial scales， which
means SDR is depended on its scale；（3） SDR could be quantitatively expressed and be scaled using fractal dimension under a certain temporal and spatial scale. The authors found that values of SDR and fractal dimension （D） at 1km2 typical watershed unit were approximately equal to the SDR and D coefficients in corresponding scaling models. This paper pointed out that the calculation and study on SDR can’t be correct without 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 SDR scaling in the future. |
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