Revealing the spatio-temporal variability of evapotranspiration and its components based on an improved Shuttleworth-Wallace model in the Yellow River Basin
Revealing the spatio-temporal variability of evapotranspiration and its components based on an improved Shuttleworth-Wallace model in the Yellow River Basin
复制标题
基于改进的Shuttleworth-Wallace模型揭示黄河流域蒸散量及其组成部分的时空变化
DOI：
10.1016/j.jenvman.2020.110310
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发表时间：
2020
影响因子：
8.7
通讯作者：
Hua-Wu Wu
中科院分区：
文献类型：
--
作者：
Zhi-Yun Jiang;Zhi-Guang Yang;Si-Yi Zhang;Chao-Ming Liao;Zhong-Min Hu;Ruo-Chen Cao;Hua-Wu Wu
从蒸散量（ET）的组成部分（土壤蒸发和植物蒸腾）中识别蒸散量（ET）的时空变化可以极大地提高我们对水循环和生物地球化学过程的理解。然而，在区域尺度上高精度地将蒸散分解为蒸发（E）和蒸腾（T）仍然是一个挑战。利用改进的Shuttlewallace（SWH）模型对黄河流域1981-2010年蒸散量进行分区，揭示了黄河流域蒸散量及其各分量的时空变化规律。对影响蒸散量及其各分量时空变化的环境因子进行了评价。结果表明，黄河流域近30年来的年平均蒸散量、蒸散量和蒸散量分别为372.18 mm、179.64 mm和192.54 mm;黄河流域年平均蒸散量和蒸散量的空间分布均表现为自东南向西北递减的趋势，时间变化则表现为显著的递增趋势，其速率分别为1.72 mm/a和1.54 mm/a。这意味着T解释了ET的变化，而E在最近几十年没有明显变化。此外，归一化植被指数（NDVI）和温度是控制黄河流域ET和T变化的主要因子。其中，以NDVI为主导因子的蒸散量和蒸散量面积分别占全流域的63.82%和78.47%。而E的变化受复杂因素的影响，西部高寒地区蒸发主要受温度控制。我们的研究结果不仅对该地区制定可持续的水资源管理和生态恢复政策具有重要意义，而且还为区域或全球尺度的ET分配方法提供了有价值的见解。
Identifying the spatio-temporal variations of evapotranspiration (ET) from its components (soil evaporation and plant transpiration) can greatly improve our understanding of water-cycle and biogeochemical processes. However, partitioning evapotranspiration into evaporation (E) and transpiration (T) at regional scale with high accuracy still remains a challenge. This study has aimed to reveal the spatio-temporal variations of evapotranspiration and its components by using an improved Shuttleworth-Wallace (SWH) model to partition ET in the Yellow River Basin during 1981–2010. The environmental factors affecting the spatial and temporal variations of evapotranspiration and its components were also assessed. Results showed that the mean annual ET, T and E in the Yellow River Basin were 372.18 mm, 179.64 mm, and 192.54 mm, respectively, over the last 30 years. The spatial pattern of mean annual ET and T displayed a decreasing trend from southeast to northwest in the Yellow River Basin, and the temporal variation showed a significant increasing trend with rates of 1.72 mm yr−1and 1.54 mm yr−1, respectively. It meant that T accounted for the variations of ET, while E showed no significant changes in recent decades. Moreover, the normalized differential vegetation index (NDVI) and temperature were identified as the main factors controlling the variations of ET and T in the Yellow River Basin. Among them, the area with NDVI as the dominant factor for ET and T could reach 63.82% and 78.47% of the whole basin respectively. However, the variations of E were affected by complex factors, and evaporation in the western alpine region was mainly controlled by temperature. Our findings are expected to not only have implications for developing sustainable policies of water management and ecological restoration in this region, but also provide valuable insight in methodology of ET partitioning in regional or global scale.