The shape of watersheds
The shape of watersheds
复制标题
分水岭的形状
作者：
Timothée Sassolas;R. Cattin;M. Ferry
自20世纪50年代以来，河网一直是地学和水文学的研究热点。这导致了尺度律的定义，描述了河流切割下景观的组织，后来被统计物理学和分形数学所探索。具有象征意义的哈克定律提出了流域面积和干流长度之间的幂律关系。虽然有大量的文献记载，但Hack的参数仍然有很大的范围。一些作者将这种分散与当地的地质和气候条件联系起来。本文通过对不同气候和地质条件下的大型流域的分析，证实了河网的几何相似性。我们表明，盆地形状主要是哈克系数，而不是指数，独立的外部强迫，如岩性和雨量。世界各地的河流网络遵循具有象征意义的哈克定律，该定律将河流的长度表示为流域面积的函数。作者在这里指出，这种规律并不依赖于岩性或降雨，而是取决于流域的形状，并证实了河网的自相似性。
Since the 1950s river networks have been intensely researched in geosciences and hydrology. This led to the definition of scaling laws that described the organisation of landscapes under fluvial incision and were later explored by statistical physics and fractal mathematics. The emblematic Hack’s Law proposes a power-law relationship between watershed area and main stream length. Though extensively documented, a wide range of values is still reported for Hack’s parameters. Some authors associate this dispersion to local geologic and climatic conditions. Here based on the analysis of large sets of river basins in various climatic and geological settings, we confirm the geometric similarity of river networks. We demonstrate that basin shape is mostly related to Hack’s coefficient and not to the exponent, independently of external forcing such as lithology and pluviometry. River networks worldwide follow the emblematic Hack’s Law, which expresses the length of a stream as a function of its watershed area. Here the authors show this law does not depend on lithology or rainfall, but on the shape of watersheds and confirms the self-similarity of river networks.