Traditional delineation and modeling methods do not consider the spatial arrangement and dynamic threshold control of surface depressions. Instead, full structural hydrologic connectivity, uniform well‐connected drainage networks, and an invariant contributing area are often assumed. In reality, depressions play an important role in quantifying functional connected areas (ACs) and contributing area. This study is aimed to develop a new procedure to analyze functional hydrologic connectivity related to topography at a mesoscale, specifically in depression‐dominated areas by (a) characterizing surface topography, (b) quantifying and locating dynamic hydrologic connectivity, and (c) analyzing hydrologic connectivity and threshold‐controlled dynamics of contributing area using a set of dimensionless indicators and a new normalized connected area function. Thorough analyses for different topographic surfaces provided improved understanding of the intrinsic relationship and interaction between structural and functional hydrologic connectivity patterns. In addition, the new procedure was compared against a traditional delineation method, terrain analysis using digital elevation models (TauDEM), to determine structural and functional connectivity. It was found that spatial arrangement and scale of depressions had a direct effect on hydrologic connectivity. A stepwise trend, unique to depression‐dominated areas, highlighted the effect of threshold behaviors on contributing area and ACs. Conversely, dendritic surfaces showed an expedited surface connectivity due to the assumption of depressionless topography. Thus, precisely locating and quantifying ACs and contributing area via the new analysis procedure improve our understanding of the mechanisms of topography‐controlled overland flow and sediment transport dynamics, and hence, the findings are valuable in making informed decisions about water quantity and quality across varying topographic surfaces.

中文翻译：

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径流贡献区时空变化的建模及水文连通性分析

传统的轮廓和建模方法不考虑表面凹陷的空间排列和动态阈值控制。取而代之的是，通常假定完整的结构水文连通性，统一的，良好连接的排水网络以及不变的贡献面积。实际上，凹陷在量化功能连接区域（AC）和贡献区域方面起着重要作用。这项研究旨在开发一种新方法，以分析与中尺度有关的功能性水文连通性，特别是在以凹陷为主的地区，方法是（a）表征表面地形，（b）量化和定位动态水文连通性，（c）使用一组无量纲指标和新的标准化连通面积函数来分析贡献区的水文连通性和阈值控制的动力学。通过对不同地形表面的深入分析，可以更好地理解结构和功能性水文连通性模式之间的内在联系和相互作用。此外，还将该新程序与传统的划定方法（使用数字高程模型（TauDEM）进行地形分析）进行了比较，以确定结构和功能的连通性。研究发现，洼地的空间布置和规模对水文连通性有直接影响。抑郁主导地区独特的逐步趋势突出了阈值行为对贡献区和AC的影响。反过来，由于假定无凹陷地形，树枝状表面显示出加快的表面连通性。因此，通过新的分析程序精确定位和量化ACs和贡献面积可增进我们对地形控制的陆上水流和沉积物输送动力学机制的理解，因此，这些发现对于在各种变化的情况下就水量和水质做出明智的决策方面非常有价值。地形表面。