ABSTRACT

Small watersheds are ideal objects for studying the evolution of hydrological and water resources at small scales. Whether precipitation products can meet the runoff simulation of small watersheds is the main purpose of this study. With NOAA-CPC-US precipitation as a reference, in nine small watersheds of the United States, accuracy of the precipitation products such as PERSIANN, PERSIANN-CDR, TRMM-3B42V7, GPM-IMERG, StageIV, and ERA5 is analyzed. By driving the CREST hydrological model using these datasets, the runoff simulation effects were evaluated. Result shows the precipitation products match the NOAA-CPC-US from high to low in the order of StageIV, PERSIANN-CDR, GPM-IMERG, PERSIANN, ERA5, and finally TRMM-3B42 V7. These datasets have relatively low accuracy in the northern high latitude area and the western mountains, while accuracy is better in the central, southern, and eastern parts of the United States. In the runoff simulation effectiveness evaluation, the daily runoff of watersheds is simulated during the same verification period. The results show that: NOAA-CPC-US and StageIV have good simulation effect in small watersheds. In the northern and western United States, the PERSIANN, PERSIANN-CDR, GPM-IMERG, and ERA5 for runoff simulation should be used with caution. TRMM-3B42V7 is not suitable for runoff simulation in small watershed.

摘要

小流域是研究小尺度水文和水资源演变的理想对象。降水产品能否满足小流域径流模拟是本研究的主要目的。以NOAA-CPC-US降水为参考，在美国9个小流域，分析了PERSIANN、PERSIANN-CDR、TRMM-3B42V7、GPM-IMERG、StageIV、ERA5等降水产品的准确性。通过使用这些数据集驱动 CREST 水文模型，评估径流模拟效果。结果表明，降水产物与NOAA-CPC-US从高到低依次为StageIV、PERSIANN-CDR、GPM-IMERG、PERSIANN、ERA5，最后是TRMM-3B42 V7。这些数据集在北部高纬度地区和西部山区精度较低，而美国中部、南部和东部的准确度更高。在径流模拟有效性评价中，模拟同一验证期内流域的日径流。结果表明：NOAA-CPC-US和StageIV对小流域具有良好的模拟效果。在美国北部和西部，应谨慎使用 PERSIANN、PERSIANN-CDR、GPM-IMERG 和 ERA5 进行径流模拟。TRMM-3B42V7不适合小流域径流模拟。在美国北部和西部，应谨慎使用 PERSIANN、PERSIANN-CDR、GPM-IMERG 和 ERA5 进行径流模拟。TRMM-3B42V7不适合小流域径流模拟。在美国北部和西部，应谨慎使用 PERSIANN、PERSIANN-CDR、GPM-IMERG 和 ERA5 进行径流模拟。TRMM-3B42V7不适合小流域径流模拟。