摘要
流域地貌形态科学、准确和综合量化成为建立具有广泛适用性的流域土壤侵蚀预报模型的关键科学问题之一。分形理论的提出为流域地貌形态定量研究开辟了新的思路。本文依据分形理论,在建立小流域概化模型基础上,采用模拟降雨试验、高精度摄影测量和G IS技术,对流域模型地貌形态分形特征与侵蚀产沙定量耦合关系进行了研究。结果表明,基于消除了降雨特征影响的相对输沙率,可将流域模型侵蚀产沙过程划分为初期、活跃期和稳定期3个阶段;在不同侵蚀产沙时段,流域模型地貌形态分形信息维数Di呈现与相对输沙率Sr基本类似的变化趋势,即先增大再减小、最后趋于平稳;流域模型相对输沙率Sr与地貌形态分形信息维数Di以乘幂形式呈显著正相关,相关指数r2为0.7423;地貌形态分形信息维数Di较好反映了地貌形态特征对流域模型侵蚀产沙过程的影响,可以作为流域模型侵蚀产沙过程预报地貌形态特征综合量化指标。
Quantifying topographic feature of watershed synthetically and scientifically is one of key problems forwatershed soil erosion prediction model that is used everywhere. Fractal theory has provided new solution for study on quantifying topographic feature of watershed. Based on fraetal theory and the general model of small watershed quantitative coupling relationship between topographic fraetal feature and sediment yield was studied by simulation rainfall experiment, high precise photogrammetry and GIS technology. The results showed that the process of soil erosion and sediment yield of watershed model took on phase characteristic with early phase, active phase and stable phase according to relative sediment transport rate, which avoided the influence of rainfall characteristic on soil erosion and sediment yield process of watershed model. During the different phase, the variation trend of fraetal information dimension （Di） of watershed model topographic feature was similar to that of relative sediment transport rate （Sr） of watershed model, which took on rising firstly, then falling down and becoming stable. Relative sediment transport rate （Sr） of watershed model and the fractal information dimension （Di） presented positive correlation with power function. The correlation exponent r^2 was 0. 742 3. Fractal information dimension （D~） of topographic feature of watershed model has perfectly described the influence of topographic feature on soil erosion and sediment yield process of watershed model, and it can be as the integrated index of quantifying topographic feature for soil erosion and sediment yield prediction of watershed model.
出处
《水土保持学报》
CSCD
北大核心
2006年第2期1-4,9,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金(40301026)
中国博士后科学基金(200333518)
温州大学重点基金(2002Z28)
关键词
流域地貌
流域模型
分形信息维数
定量耦合关系
topographic feature of watershed
watershed model
fractal information dimension
quantitative coupling relationship
