On geomorphological dispersion in natural catchments and the geomorphological unit hydrograph
On geomorphological dispersion in natural catchments and the geomorphological unit hydrograph
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自然流域地貌分散性及地貌单元水位线研究
DOI：
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发表时间：
1994
期刊：
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通讯作者：
M. Sivapalan
中科院分区：
文献类型：
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作者：
J. Snell;M. Sivapalan
自从Rodriguez-Iturbe和Valdes(1979)引入地貌瞬时单位线(GIUH)以来，已经有许多不同的方法来表示流域的地貌，以确定该流域的水文响应。我们考察了三种通过网络中可用路径的概率和长度来引入地貌的方法：(1)使用Horton序比来推导这些路径参数的解析表达式；(2)直接从Strahler序网络中提取这些概率和长度，而不使用Horton序比；(3)使用直接从流域的数字高程模型(DEM)中提取的贡献面积-径流距离函数，而不假设Strahler流的排序。我们使用这些技术来推导Rinaldo等人定义的GIUH和地貌弥散系数。(1991)在澳大利亚西南部地区的两个集水区。由面积-距离函数得到的地貌离散系数以比其他方法更基本的方式表达了流域内的自然离散，由该函数得出的GIUH表现出比基于Strahler排序的任何一种方法大一个数量级的潜在离散。我们研究了一个网络的“完备性”的概念，我们从这个概念中得出了集水参数，以及这个概念如何与支持一个从集水区DEM派生的网络的阈值区域相关联。
Since the introduction of the geomorphological instantaneous unit hydrograph (GIUH) by Rodriguez-Iturbe and Valdes (1979) there have been a number of different approaches to expressing the geomorphology of a catchment for determining the hydrological response of the catchment. We examine three approaches by which geomorphology can be introduced through the probabilities and lengths of the pathways available within a network: (1) using the Horton order ratios to derive analytical expressions for these pathway parameters, (2) extracting these probabilities and lengths directly from a Strahler ordered network without using the Horton order ratios, and (3) using a contributing area-flow distance function extracted directly from the digital elevation model (DEM) of a catchment without the assumptions of Strahler stream ordering. We use these techniques to derive the GIUH and the geomorphological dispersion coefficient as defined by Rinaldo et al. (1991) for two catchments in the southwestern region of Australia. The geomorphological dispersion coefficient derived from the area-distance function expresses the natural dispersion within the catchment in a more fundamental manner than the other methods, and the GIUHs derived from this function exhibit an underlying dispersion of an order of magnitude greater than either of the approaches based on Strahler ordering. We look at the concept of the “completeness” of a network from which we derive catchment parameters and how this concept is related to the threshold area supporting a network derived from a catchment DEM.