Distributed hydrological model for mapping evapotranspiration using remote sensing inputs
Distributed hydrological model for mapping evapotranspiration using remote sensing inputs
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DOI：
10.1016/j.jhydrol.2004.08.029
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发表时间：
2005-04-10
影响因子：
6.4
通讯作者：
Geng, XY
中科院分区：
文献类型：
--
作者：
Chen, JM;Chen, XY;Geng, XY
分布式水文模型[Wigmosta，M.S.，维尔，L.W.，Lettenmaier，D.P.，1994.复杂地形分布式水文植被模型。水资源研究30（6），1665-1679]进一步发展，以模拟详细的空间和时间变化格局的蒸散量（ET）周围的通量塔网站。除了气象、地形和土壤数据外，该模型还利用光学遥感数据（30米分辨率的陆地卫星TM）来描述植被类型和叶面积指数的分布情况。利用叶面积指数可以对主要的水文过程进行基于过程的建模，包括蒸腾、降水截留和植被和土壤的蒸发。水流内和之间的五个层（overstore，understore，苔藓/凋落物，土壤非饱和区，土壤饱和区）每天进行建模。九个像素的移动窗口被用来考虑横向地下流。该模型被应用到一个小流域的尺寸约为16公里× 12公里的萨斯喀彻温省，加拿大。模拟ET的时间变化与涡度协方差ET测量位于流域内的黑云杉林分进行了比较。该立场是老黑云杉在南部研究区在北方生态系统-大气研究（BOREAS）在1994年。虽然黑云杉站点位于一个平坦的地区，在通量塔的150米范围内的地形变化小于1.5米，有约10.5毫米的水分流失，通过饱和地下水在1994年的生长季节，占同期降雨量的5.7%。尽管研究的流域有温和的地形变化，地形不仅对地下水位，而且对土壤水分和饱和水再分布有相当大的影响。这表明在绘制ET图时受地形影响的水文过程建模的重要性。(c)2004 Elsevier B. V.保留所有权利。
A distributed hydrological model [Wigmosta, M.S., Vail, L.W., Lettenmaier, D.P., 1994. A distributed hydrology-vegetation model for complex terrain. Water Resource Research 30 (6), 1665-1679] is further developed to simulate the detailed spatial and temporal variation patterns of evapotranspiration (ET) around a flux tower site. In addition to meteorological, topographical and soil data, the model utilizes optical remote sensing data (Landsat TM at 30 m resolution) to characterize the distributions of vegetation types and the leaf area index (LAI). The use of LAI allows process-based modeling of major hydrological processes including transpiration, precipitation interception, and evaporation from vegetation and soil. Water flows within and between five strata (overstore, understore, moss/litter, soil unsaturated zone, and soil saturated zone) are modeled on a daily basis. A moving window of nine pixels is used to consider the lateral subsurface flow. The model is applied to a small watershed of dimension of about 16 km X 12 km in Saskatchewan, Canada. The temporal variations of simulated ET are compared with eddy-covariance ET measurements over a black spruce stand located within the watershed. The stand was the Old Black Spruce in the Southern Study Area during the Boreal Ecosystem-Atmosphere Study (BOREAS) in 1994. Although the black spruce site is located in a flat area with less than 1.5 m topographical variation within 150 m of the flux tower, there was about 10.5 mm water loss through saturated subsurface flow during the growing season of 1994, accounting for 5.7% of the rainfall in same period. Even though the watershed studied had gentle terrain variations, the topography had considerable influence not only on the water table but also on the soil moisture and saturated water redistribution. This suggests the importance of modeling hydrological processes as influenced by topography in mapping ET. (c) 2004 Elsevier B.V. All rights reserved.