The application of two-dimensional shallow-water equations models (2D-SWEs) for the description of hydrodynamic-based surface runoff computations is becoming a reference approach in rainfall-runoff simulations at the catchment scale. Due to their ability in generation of flow patterns throughout the basin, they can be used not only as an advanced method for flood mapping studies and hazard assessment but also as an innovative tool for the analysis of river drainage networks, opening new perspectives for several environmental processes. In particular, in this work we put the river networks in a 2D-SWEs framework, meaning that the traditional tree-like fluvial structure, represented by a skeleton composed of a set of lines, is replaced by a collection of points discretizing the 2-D geometry of the river structure itself, for which the values of the hydrodynamic values are provided by the numerical simulations. This approach is used here to derive a new scaling property that relates the specific discharge threshold, used to identify the river network cells, to the total areas of the network cells themselves. The hydrodynamic and geomorphological interpretation of this power law function and the influence of grid resolution, on some relevant parameters of this curve, have inspired the development of a heuristic procedure for non-uniform grid generation, able to detect the most hydrodynamically active areas of the basins for which the grid refinement process makes sense. Moreover, information related to how much grid refinement is needed is provided as well. The performances of this procedure are very promising in terms of accuracy of simulated discharges, hydrodynamic behaviour of the river network and flooded areas, reducing significantly the computational times in respect to the use of fine uniform grids.

二维浅水方程模型（2D-SWEs）在描述基于水动力的地表径流计算中的应用正在成为流域尺度降雨-径流模拟的一种参考方法。由于它们具有在整个流域生成流型的能力，因此它们不仅可以用作洪水地图研究和灾害评估的高级方法，而且还可以作为分析河流排水网络的创新工具，从而为多种环境开辟了新视野。流程。特别是，在这项工作中，我们将河网置于2D-SWEs框架中，这意味着以一组由线组成的骨架表示的传统树状河流结构被离散化2- D河流结构本身的几何形状，为此，通过数值模拟提供了流体力学值。在此使用此方法来导出新的缩放属性，该属性将用于识别河流网络小区的特定排放阈值与网络小区本身的总面积相关联。该幂律函数的流体动力学和地貌解释以及网格分辨率对该曲线的一些相关参数的影响，启发了非均匀网格生成启发式方法的开发，该方法能够检测出水力作用最活跃的区域。网格细化过程有意义的盆地。此外，还提供了与需要多少网格细化有关的信息。就模拟放电的精度而言，该程序的性能非常有前途，