Many grid-based spatial hydrological models suffer from the complexity of setting up a coherent spatial structure to calibrate such a complex, highly parameterized system. There are essential aspects of model-building to be taken into account: spatial resolution, the routing equation limitations, and calibration of spatial parameters, and their influence on modeling results, all are decisions that are often made without adequate analysis. In this research, an experimental analysis of grid discretization level, an analysis of processes integration, and the routing concepts are analyzed. The HBV-96 model is set up for each cell, and later on, cells are integrated into an interlinked modeling system (Hapi). The Jiboa River Basin in El Salvador is used as a case study. The first concept tested is the model structure temporal responses, which are highly linked to the runoff dynamics. By changing the runoff generation model description, we explore the responses to events. Two routing models are considered: Muskingum, which routes the runoff from each cell following the river network, and Maxbas, which routes the runoff directly to the outlet. The second concept is the spatial representation, where the model is built and tested for different spatial resolutions (500 m, 1 km, 2 km, and 4 km). The results show that the spatial sensitivity of the resolution is highly linked to the routing method, and it was found that routing sensitivity influenced the model performance more than the spatial discretization, and allowing for coarser discretization makes the model simpler and computationally faster. Slight performance improvement is gained by using different parameters’ values for each cell. It was found that the 2 km cell size corresponds to the least model error values. The proposed hydrological modeling codes have been published as open-source.

中文翻译：

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时空水文模型结构及参数化分析

许多基于网格的空间水文模型都面临着建立连贯的空间结构来校准这种复杂的，高度参数化的系统的复杂性。需要考虑到模型构建的基本方面：空间分辨率，路由方程式限制和空间参数的校准及其对建模结果的影响，这些都是通常在没有进行适当分析的情况下做出的决策。在这项研究中，对网格离散化水平进行了实验分析，对过程集成进行了分析，并对路由概念进行了分析。为每个单元建立HBV-96模型，随后将单元集成到一个互连的建模系统（Hapi）中。萨尔瓦多的吉博亚河流域被用作案例研究。测试的第一个概念是模型结构的时间响应，它们与径流动力学高度相关。通过更改径流生成模型描述，我们探索了对事件的响应。考虑了两种路由模型：Muskingum，将径流从沿河网络的每个单元中路由出去； Maxbas，将径流直接路由到出口处。第二个概念是空间表示，在其中构建模型并针对不同的空间分辨率（500 m，1 km，2 km和4 km）进行测试。结果表明，分辨率的空间敏感性与路由方法高度相关，并且发现路由敏感性比空间离散化对模型性能的影响更大，并且允许进行更粗糙的离散化会使模型更简单且计算速度更快。通过为每个单元使用不同的参数值，可以略微提高性能。发现2 km的像元大小对应于最小的模型误差值。拟议的水文建模规范已作为开源发布。