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蒸散发是陆面过程中的重要环节,联系着陆面水循环和地表能量平衡.淮河流域地处中国南北气候过渡带,对淮河流域实际蒸散量时空变化的研究,有助于深入理解中国气候过渡带水循环对全球气候变化的响应.应用遥感技术对淮河流域MOD16_ET数据进行精度验证,并分析2000-2014年淮河流域蒸散发时空分布特征.结果表明:MOD16_ET产品在淮河流域内的精度总体上符合要求;淮河流域多年平均蒸散发的空间分布整体上呈南高北低,季节蒸散量的空间分布与年蒸散量的空间分布大体一致;近15 a淮河流域平均的实际蒸散量变化范围为531.7~634.0 mm,且存在不显著的下降趋势,实际蒸散量的季节变化大致呈单峰型分布,且季节变化较为明显,夏季(257.2 mm)>春季(143.7 mm)>秋季(120.7 mm)>冬季(66.6 mm);淮河流域西北部,夏、秋、冬三季的季节蒸散量变化速率对年蒸散量变化速率的贡献较大;淮河流域东部,春季的蒸散量变化速率占年蒸散量变化速率的比重较大.研究结果对于淮河流域内水资源短缺问题的解决、有限水资源的合理利用以及旱涝灾害的监测和预警有着重要的意义.
Evapotranspiration is an important step in the land surface process, which is related to the land surface water cycle and surface energy balance.The Huaihe River Basin is located in the climate transitional zone between north and south of China and the study on the temporal and spatial variation of actual evapotranspiration in the Huaihe River Basin will help to understand the climate transitional zone Water cycle response to global climate change.The accuracy of MOD16_ET data in the Huaihe River Basin was verified by remote sensing and the temporal and spatial distribution characteristics of evapotranspiration in the Huaihe River Basin during 2000-2014 were analyzed.The results showed that the accuracy of the MOD16_ET products in the Huaihe River Basin met the overall requirements, The spatial distribution of annual mean evapotranspiration in the Huaihe River Basin is generally high in the south and low in the north. The spatial distribution of seasonal evapotranspiration is generally consistent with the spatial distribution of annual evapotranspiration. The average actual evapotranspiration in the Huaihe River basin in the recent 15 years ranges from 531.7 to 634.0 mm , And there was an insignificant downward trend. The seasonal variation of actual evapotranspiration was roughly monomodal distribution, and the seasonal variation was obvious. In summer (257.2 mm)> spring (143.7 mm)> autumn (120.7 mm)> winter (66.6 mm) ). The seasonal evapotranspiration rate in the northwestern part, the summer, autumn and winter in the Huaihe River basin contributed significantly to the annual evapotranspiration rate. The Huaihe River In the east of the region, the rate of change of evapotranspiration in spring is larger than the rate of change of annual evapotranspiration.It is very important for the solution of the shortage of water resources in Huaihe River Basin, the rational use of limited water resources and the monitoring and early warning of droughts and floods significance.