Spatial and temporal evaluation of global rainfall products in a data-scarce region: The Dez Basin, Iran

Journal of Water and Land Development

article

Mostafa Khoshchehreh¹  Mehdi Ghomeshi¹  Ali Shahbazi¹  Hossein Bolboli¹  Hamed Saberi²  Ali Gorjizade¹ 

[1] Shahid Chamran University of Ahvaz, Faculty of Water Science Engineering, Department of Water and Hydraulic Structures;Khorramshahr University of Marine Science and Technology, Faculty of Engineering

关键词: CMORPH;    ERA5;    ERA-Interim;    PERSIANN-CCS;    precipitation datasets;    reanalysis data;    satellite-based precipitation;   

DOI  :  10.24425/jwld.2021.136158

学科分类：农业科学（综合）

来源: Instytut Technologiczno-Przyrodniczego / Institute of Technology and Life Sciences

【 摘 要 】

The limitation in approachability to rainfall data sources with an appropriate spatial-temporal distribution is a signifi-cant challenge in different parts of the world. The development of general circulation models and mathematical algorithms has led to the generation of various rainfall products as new sources with the potential to overcome the shortage in data-scarce basins. In this study, the performance of the PERSIANN-CCS and CMORPH satellite-based rainfall product, as well as the ERA5 and ERA-Interim reanalysis, was evaluated based on detection skill and quantitative metrics in a daily, month-ly and seasonal time scales in the Dez basin located in the southwest of Iran. The basin has a wide topographic variation and scattered rain gauge stations. Overall results denote that the ERA5 dataset has the best performance in all statistic veri-fication than other rainfall products. Based on the daily evaluation of all rainfall products, the false alarm rate (FAR) is higher than 0.5, so none of the datasets could capture the temporal variability of rainfall occurrence. This study has covered the western parts of the Zagros steep slopes in which the topographic conditions have a significant effect on the activity of rainfall systems. On a monthly scale, the mean value of the correlation coefficient (CC) for ERA5, ERA-Interim, PER-SIANN-CCS, and CMORPH was equal to 0.86, 0.85, 0.51, 0.39, respectively. The results of seasonal evaluation suggested that all datasets have better rainfall estimation in autumn and winter, and the capability of all datasets dramatically de-creased in the spring. The current paper argues that the ERA5 reanalysis typically outperforms ERA-Interim and can be considered as a reliable rainfall source in the future hydrological investigation in the southwest of Iran.

【 授权许可】

Unknown