| 基于REOF的两种卫星降水产品(IMERG和MSWEP)在金沙江流域降水分区尺度精度评估 |
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| 引用本文： | 薄会娟,林青霞,李璐,魏冲,龚成麒.基于REOF的两种卫星降水产品(IMERG和MSWEP)在金沙江流域降水分区尺度精度评估[J].湖泊科学,2024,36(2):620-633. |
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| 作者姓名： | 薄会娟 林青霞 李璐 魏冲 龚成麒 |
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| 作者单位： | 三峡大学水利与环境学院, 宜昌 443002;三峡库区生态环境教育部工程研究中心, 宜昌 443002 |
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| 基金项目： | 国家自然科学基金项目(52009065)和湖北省教育厅科学技术研究项目(Q20221209)联合资助。 |
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| 摘 要： | 高时空分辨率降水产品的精度评估是卫星降水用于水文气象干旱等研究的前提。本研究提出在降水分区尺度下评估IMERG和MSWEP两种卫星降水产品的精度,并与不分区尺度(即流域尺度)进行比较。首先采用旋转经验正交函数(REOF)对金沙江流域(JSB)进行降水分区,通过贡献率得出8个分区较为适合。然后识别降水的空间分布特征,发现2种降水产品都可以很好地捕捉降水呈现出的从上游到下游逐渐增加的趋势。最后在日尺度、降水发生概率和极端降水探测能力3个方面对降水产品在分区尺度和不分区尺度的性能进行评估。结果表明,在日尺度上,MSWEP的精度在多数降水分区优于IMERG,被推荐5次(1、3、6、7和8区),集中在流域的中游。同时流域尺度也推荐MSWEP。在降水事件发生概率方面,MSWEP能再现不同等级降水强度的概率密度分布,但过高估计0.1~1 mm/d降水事件的发生概率;而IMERG过高估计小于0.1 mm/d降水事件的概率。在极端降水探测能力方面,流域尺度的KGE值都是正值,且IMERG优于MSWEP,但分区尺度上,KGE值在部分降水分区中存在负值,表明IMERG和MSWEP均不能很好地探测出该区的极端降水事件。本研究成果表明降水分区尺度是必需的,能够更加精细地评估降水产品。研究结果可为具有类似气候条件的卫星降水评估提供参考。
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| 关 键 词： | 降水分区 旋转经验正交函数 IMERG MSWEP 精度评估 |
| 收稿时间： | 2023/7/13 0:00:00 |
| 修稿时间： | 2023/10/7 0:00:00 |
Accuracy evaluation of two satellite precipitation products (IMERG and MSWEP) at precipitation zoning scale based on REOF in the Jinsha River Basin |
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| Bo Huijuan,Lin Qingxi,Li Lu,Wei Chong,Gong Chengqi.Accuracy evaluation of two satellite precipitation products (IMERG and MSWEP) at precipitation zoning scale based on REOF in the Jinsha River Basin[J].Journal of Lake Science,2024,36(2):620-633. |
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| Authors: | Bo Huijuan Lin Qingxi Li Lu Wei Chong Gong Chengqi |
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| Institution: | College of Hydraulic and Environment, China Three Gorges University, Yichang 443002, P.R. China;Engineering Education Center of Ecological Environment of the Three Gorges Reservoir Area, Ministry of Education, Yichang 443002, P.R. China |
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| Abstract: | The accuracy evaluation of with high spatiotemporal resolution precipitation products is the prerequisite for satellite precipitation to be used in the research of hydrometeorology and drought. In this study, we proposed to evaluate the accuracy of IMERG and MSWEP satellite precipitation products at the precipitation zoning scale, while comparing with non-zoning scale (i.e. basin scale). Firstly, the rotated empirical orthogonal functions (REOF) method was used to divide the JinSha River Basin (JSB) into 8 partitions according to the contribution rate. Then, based on the spatial distribution characteristics of precipitation, it was found that both precipitation products can effectively capture the trend of precipitation gradually increasing from upstream to downstream. Finally, the performance of precipitation products at the precipitation zoning scale and non-zoning scales was evaluated in three aspects: daily scale, probability of precipitation occurrence, and extreme precipitation detection capability. The results showed that on a daily scale, the accuracy of MSWEP was superior to IMERG in most precipitation zones, and was recommended 5 times (1, 3, 6, 7, and 8), concentrated in the middle reaches of the basin. At the same time, MSWEP was also recommended for watershed scale. In terms of the probability of precipitation events, MSWEP could reproduce the probability density distribution of different levels of precipitation intensity, but overestimated the probability of 0.1-1 mm/d precipitation events; And IMERG overestimated the probability of precipitation events less than 0.1mm/d. In terms of extreme precipitation detection ability, the KGE values at the basin scale were both positive, and IMERG was better than MSWEP. However, at the zoning scale, the KGE indicator had negative values in some precipitation zones, indicating that neither IMERG nor MSWEP could effectively detect extreme precipitation events in the precipitation zones. Therefore, our findings indicated that the precipitation zoning scale was necessary to evaluate precipitation products in a more refined manner. The research results can provide reference for satellite precipitation assessment with similar climate conditions. |
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| Keywords: | Division of precipitation rotated empirical orthogonal functions (REOF) IMERG MSWEP accuracy evaluation |
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