论文部分内容阅读
在我国西北干旱和半干旱地区,农业收获主要依靠灌溉保证,灌溉绿洲的蒸散发(ET)是当地水资源的主要消耗.通过遥感估算区域灌溉绿洲的ET对于地区合理利用水资源极其重要,利用M ODIS/Terra影像,基于物理过程的地表能量平衡模型(SEBS),结合WRF模式输出的气候驱动数据和地面观测数据来估算黑河中游地区的地表通量和日蒸散发(ETdaily).估算的ET用不同下垫面的涡动相关仪观测数据进行验证,结果显示:SEBS模型估算的不同下垫面的ETdaily具有很好的拟合效果(R2=0.96,P<0.001),在灌溉绿洲估算的ETdaily比实测值偏高,说明干旱、半干旱地区灌溉绿洲土壤水分胁迫是影响ET的主要因素.模型估算绿洲作物生长期间的ETdaily和实测的ETdaily平均相对误差为12.5%,精度在观测的能量不闭合误差以内且精度比戈壁和沙漠地区高.
In China’s arid and semiarid regions of Northwest China, agricultural harvest mainly relies on irrigation assurance, and the evapotranspiration (ET) of irrigation oases is the main consumption of local water resources. Estimating the ET of regional irrigated oases by remote sensing is extremely important for the rational utilization of water resources in the region. M ODIS / Terra images, physical process based surface energy balance (SEBS) model, combined with WRF-driven climate-driven data and ground-based observations to estimate the surface flux and ETdaily in the middle reaches of the Heihe River. The eddy correlation data from different underlying surfaces were used for validation. The results showed that ETdaily with different underlying surface estimated by SEBS model had a good fitting effect (R2 = 0.96, P <0.001) ETdaily is higher than the measured value, indicating that the soil water stress of irrigated oasis in arid and semi-arid areas is the main factor affecting ET.The model estimated the average relative error of ETdaily and measured ETdaily during oasis crop growth was 12.5% Closure error and precision than the desert and the Gobi high.