灌区尺度遥感蒸散发模型时间尺度提升方法研究

Research on Remote Sensing ET Model Temporal Up-scaling Method at Irrigation District Level

以内蒙古河套灌区解放闸灌域为典型研究区,构建基于能量平衡原理的单层遥感蒸散发模型,利用2014年Terra和Aqua卫星的MODIS标准陆地产品模拟蒸散发时空分布,分别探讨将遥感蒸散发模型由卫星过境时刻的瞬时值扩展到日蒸散发的尺度提升方法,以及由未受云层遮挡的日蒸散发扩展到全年的尺度提升方法。由瞬时到日的尺度提升采用日内代表性参数法,避免了对气象数据进行降尺度带来的误差及由瞬时蒸散发到日蒸散发尺度提升过程中的误差,由日到全年的尺度提升采用逐象元插值的方法,使遥感数据的利用得到最大化。

Choosing Jiefangzha Irrigation field in Hetao irrigation district as typical study area ,the study established single layer re‐mote sensing ET model base on energy balance theory .By using MODIS standard land products on-boarded Terra and Aqua satellites in 2014 ,the study discussed temporal up-scaling method from instantaneous level at satellite over-passing time to daily level and from daily level which contaminated by clouds to continuous yearly level separately .Daily representative parameter method was used to up-scale the instantaneous ET to daily ET ,which reduced the error in the processes of meteorological data downscale and ET up-scale;while interpolation based on pixel unit was used to up-scale daily ET at clear days to continuous ET ,which maximum the usage of a‐vailable remote sensing data .