In this study, five open access gridded precipitation (GP) products (CFSR, MSWEPv1.1, PERSIANN-CDR, CMORPH, and CHIRPSv2.0) and local climate data were evaluated over the Grande de San Miguel (GSM) River Basin in El Salvador. The main purpose was to identify optional data sources of precipitation for hydrological modelling given that ground-based precipitation gauges in El Salvador are scarce and their data includes important temporal and spatial gaps. Firstly, a direct comparison was made between the precipitation data from the five GP products and from the rain gauges. Secondly, the SWAT model was used to simulate the streamflow regimen based on the precipitation datasets. The analysis of results showed that the models produced correct predictions, and the accuracy increased as models were calibrated to each specific precipitation product. Overall, PERSIANN-CDR produced the best simulation results, including streamflow predictions in the GSM basin, and outperformed other GP products and also the results obtained from data precipitation gauges. The findings of this research support the hydrological modelling based on open-access GP products, particularly when the data from precipitation gauges are scarce and poor.

中文翻译：

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网格降水产品对萨尔瓦多一个测量不当的盆地的水流模拟的影响评估

在这项研究中，在埃尔的 Grande de San Miguel (GSM) 河流域评估了五种开放式网格降水 (GP) 产品（CFSR、MSWEPv1.1、PERSIANN-CDR、CMORPH 和 CHIRPSv2.0）和当地气候数据。萨尔瓦多。鉴于萨尔瓦多的地面降水量计稀缺且其数据包括重要的时间和空间差距，主要目的是为水文建模确定可选的降水数据源。首先，对来自五个 GP 产品和雨量计的降水数据进行了直接比较。其次，基于降水数据集，使用SWAT模型模拟水流方案。结果分析表明，模型产生了正确的预测，并且随着模型针对每个特定的降水产品进行校准，精度会提高。总体而言，PERSIANN-CDR 产生了最好的模拟结果，包括 GSM 盆地的流量预测，并且优于其他 GP 产品以及从数据降水量计获得的结果。这项研究的结果支持基于开放获取 GP 产品的水文建模，特别是当降水量计的数据稀缺且贫乏时。