基于MOD16数据的焉耆盆地蒸散量变化研究

蒸散量是水资源转化中非常关键的变量,特别是对当前变化环境下干旱区作物耗水量的时空变化与预测具有重要的作用。基于2001—2019年MOD16数据产品,通过遥感反演蒸散量数据,对焉耆盆地实际蒸散量(AET)和潜在蒸散量(PET)的时空变化进行分析,结果表明:(1)MOD16蒸散产品和小型蒸发皿实测数据较为一致(R2=0.94),其精度可以用于分析和探究焉耆盆地蒸散量的时空分布特征。(2)多年平均AET与PET分别为128.7 mm和1381.5 mm,年际变化尺度上AET呈上升趋势,PET呈下降趋势。(3)多年平均AET与PET在空间分布上呈现出明显的差异特征且表现出相反的趋势,年际AET与PET线性倾斜率处于基本不变趋势。(4)AET与PET的变化趋势与焉耆盆地膜下滴灌技术的普及与气象要素(蒸发量、相对湿度、平均气温)的改变具有内在的联系。

Study of the variation trend of evapotranspiration in the Yanqi Basin based on MOD16 data

Evapotranspiration is a key variable in water resource transformation,and it plays an important role in spatiotemporal variation and prediction of crop water consumption in arid regions under the current environmental changes.Based on MOD16 data products from 2001 to 2019,this paper analyzes the spatial and temporal changes of actual evapotranspiration(AET)and potential evapotranspiration(PET)in the Yanqi Basin in Xinjian Province,China,through remote sensing inversion of evapotranspiration data.The findings reveal that:(1)The measured data of MOD16 evapotranspiration products and small evaporating dishes were relatively consistent(R2=0.94),and their accuracy can be used to study and analyze the spatial and temporal distribution characteristics of evapotranspiration in Yanqi Basin.(2)The annual mean AET and PET were 128.7 mm and 1381.5 mm,respectively.On the scale of interannual change,AET exhibited an upward trend,whereas PET exhibited a downward trend.(3)The spatial distribution of the perennial averages of AET and PET exhibited obvious differences and opposite trends,and the linear inclination rate of annual AET and PET was basically unchanged.(4)The trend of variation of AET and PET is intrinsically related to the popularization of drip irrigation technology under plastic film in Yanqi Basin and the change of meteorological factors(evaporation,relative humidity,average temperature).