利用中国静止气象卫星资料估算黄河源区蒸散发量

Estimation of evapotranspiration over the Yellow River’s source area from national geostationary meteorological satellite data

摘要: 以黄河源区为研究区域,选取2009年9月该区域的中国静止气象卫星(FY-2D)观测资料,结合地面气象观测资料,基于能量平衡原理,估算了研究区域的逐时陆面蒸散发量。结果表明:在晴天条件下,利用陆表能量平衡系统模型求出蒸散发量的大小;在阴天条件下,利用FY-2D云顶反照率资料,根据太阳辐射在大气中的衰减过程,得出地表太阳辐射收支,进而求出蒸散发量的大小。卫星遥感估算的逐时蒸散发量与地面观测值相比,平均相对误差15.2%,估算误差在可接受的合理范围内,为实现陆面蒸散发量的业务化奠定了一定的基础。

Abstract: The evapotranspiration (ET) from the source area of the Yellow River was estimated from the national geostationary meteorological satellite data and ground observation for September 2009. The ET estimation uses the energy balance approach. Under clear-sky conditions, the Surface Energy Balance System (SEBS) model can be applied for the ET estimation; whereas under cloudy conditions, the ET estimation is based on the solar radiation for different cloudy conditions, which considers the solar radiation attenuation process in the atmosphere. The result shows that the average daily estimated ET varies between 2.0 mm and 3.0 mm with a single-peak value in the source area, and compares well to the ground measurements with an average relative error of 15.2%.