岔巴沟流域三维地貌多重分形特征量化

流域三维地貌形态的科学量化研究是地貌学研究和流域土壤侵蚀模型研究中的热点问题之一。该文针对流域三维地貌所具有的明显各向异性和三维立体特征,根据多重分形理论,构建了基于GIS的流域三维地貌多重分形计算模型及其实现方法;并以此为基础,结合流域数字高程模型(DEM),计算分析了岔巴沟5个研究子流域的三维地貌多重分形谱及其主要参数,探讨了流域三维地貌多重分形特征及其流域地貌表征意义。研究结果表明,该文建立的基于GIS的流域三维地貌多重分形计算模型可实现流域三维地貌多重分形谱及其特征参数的直接量化;岔巴沟5个研究子流域的三维地貌具有显著的多重分形特征;流域三维地貌多重分形谱及其主要参数可以更加敏感、更加全面地对流域三维地貌的总体特征进行描述,能够分层次地刻画流域内部的精细结构,从而更加突出地表现异常局部地貌变化特征。该文研究成果为流域三维地貌复杂形态的科学准确量化研究提供了一种新思路和新方法。

Qualification of multifractal features of three-dimensional geomorphology in Chabagou catchment

Quantifying three-dimensional geomorphology feature of watershed synthetically and scientifically is one of key problems in the fields of geomorphology and watershed soil erosion prediction model. According to the obvious anisotropy and three-dimensional characteristics of watershed feature, based on multifractal theory, the GIS-based qualification model and its realization method of multifractal spectrums of watershed three-dimensional geomorphology was established firstly in the paper. Based on the established model and DEM data of study watersheds, multifractal spectrums and its main parameters of watershed three-dimensional geomorphology of seven typical sub-watersheds in Chabagou watershed were calculated and analyzed, and the multifractal features of watershed three-dimensional geomorphology of the seven study sub-watersheds and geomorphologic meanings of multifractal spectrums and its main parameters were studied finally. The results indicated that: 1) the qualification model established in the paper could be used to realize direct qualification of multifractal spectrums and its main parameters of watershed three-dimensional geomorphology; 2) the three-dimensional geomorphologies of the five sub-watersheds had significant multifractal features; 3) the multifractal spectrum and its main parameters could express the total three-dimensional geomorphologic characteristics of a watershed more sensitively and comprehensively than the simple fractal, and could scientifically represent and emphasize inner fine structure and abnormity partial variations of watershed three-dimensional geomorphology. The results in the paper provide a new approach and thought for synthetical and scientifical qualification of watershed three-dimensional geomorphology.