Annual groundwater evapotranspiration mapped from single satellite scenes
Annual groundwater evapotranspiration mapped from single satellite scenes
复制标题
DOI：
10.1016/j.jhydrol.2007.07.002
复制
发表时间：
2007-09-30
影响因子：
6.4
通讯作者：
Cooper, David J.
中科院分区：
文献类型：
--
作者：
Groeneveld, David P.;Baugh, William M.;Cooper, David J.
利用微气象设备测量的蒸散发（ET）数据来自在加利福尼亚、新墨西哥州和科罗拉多州的半干旱浅层地下水环境中进行的三项独立研究。这些地区在(1)气候表现上有很大的差异：季风与地中海年降水模式，生长季节相对较长与较短；(2)植被覆盖度：碱灌丛、浅层地下水草甸、盐杉木和棉杨木单一栽培。从24个地点和年份组合中测量的实际ET （ETA）与归一化植被指数衍生的NDVI*配对。利用1999-2002年9个中夏Landsat TM5和TM7场景对应位置的NDVI*，利用单个中夏场景估算年总ETa。NDVI*是对ET （ET *）推导的一个合适的估计，其计算方法是减去年化降水，并通过年化参考ET （ET0）进行归一化。这一关系被用来估计仅从遥感和天气数据得出的年总ETa。残差随着ETa的增加而减小，数据散点平衡良好，表明缺乏系统误差。这些结果证明了一种简单而稳健的方法，可用于从单个仲夏卫星场景中绘制年度ET，作为一阶近似值，适用于任何或半干旱的浅层地下水环境，其中有足够的天气数据来计算年降水量和参考ET。
Evapotranspiration (ET) data measured using micrometeorological equipment were obtained from three separate studies conducted in and and semi-arid shallow groundwater environments in California, New Mexico and Colorado. These locations have great diversity in (1) climate expression: monsoon versus Mediterranean annual precipitation patterns and comparatively long versus short growing seasons; and in (2) vegetation cover: alkali scrub, shallow groundwater meadows, and monocultures of saltcedar and cottonwood. Actual ET (ETA measured from 24 site- and year-combinations was paired with NDVI*, a derivation of normalized difference vegetation index. NDVI* was extracted from corresponding locations in nine mid-summer Landsat TM5 and TM7 scenes during 1999-2002, with single mid-summer scenes used for estimation of annual total ETa. NDVI* was a competent estimator of a derivation of ET, ET*, calculated by subtracting annualized precipitation and normalizing by an annualized reference ET, (ET0). This relationship was used to estimate annual total ETa, derived solely from remote sensing and weather data. Residual error decreased as ETa increased with well-balanced data scatter indicating lack of systematic error. These results demonstrate a simple and robust method that can be used to map annual ET as a first-order approximation from a single mid-summer satelite scene for any and or semi-arid shallow groundwater environment where sufficient weather data exist for calculating annual precipitation and reference ET. (C) 2007 Elsevier B.V. All rights reserved.