Spatial discretization is the cornerstone of all spatially-distributed numerical simulations including watershed hydrology. Traditional square grid spatial discretization has several limitations including inability to represent adjacency uniformly. In this study, we developed a watershed delineation model (HexWatershed) based on the hexagon grid spatial discretization. We applied this model to two different types of watershed in the US and we evaluated its performance against the traditional method. The comparisons show that the hexagon grid spatial discretization exhibits many advantages over the tradition method. We propose that spatially distributed hydrologic simulations should consider using a hexagon grid spatial discretization.

空间离散化是所有空间分布数值模拟（包括流域水文学）的基础。传统的方格空间离散化具有几个局限性，包括无法统一表示邻接关系。在这项研究中，我们基于六边形网格空间离散化开发了分水岭划界模型（HexWatershed）。我们将此模型应用于美国的两种不同类型的流域，并对照传统方法评估了其性能。比较表明，六边形网格空间离散比传统方法具有许多优势。我们建议空间分布水文模拟应考虑使用六角形网格空间离散化。