基于中等分辨率遥感数据的柴达木盆地实际蒸散量的计算  

Actual evapotranspiration estimation in Qaidam Basin based on Moderate Resolution Imaging

作　　者：郭任宏 金晓媚[1] 王晓林[2] 胡光成[3] 

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083 [2]海南省地质调查院,海南海口570206 [3]中国科学院遥感与数字地球研究所遥感科学国家重点实验室,北京100101

出　　处：《地学前缘》2014年第4期107-114,共8页Earth Science Frontiers

基　　金：国家自然科学基金项目(41372250)

摘　　要：在干旱的内陆盆地的水均衡中,蒸散发是主要的排泄方式,准确估算蒸散量是评价可利用水资源量的关键。从区域尺度上研究实际蒸散量对生态环境的保护具有重要的意义。基于表面能量平衡的原理,选取了DEM数据,MODIS数据以及GLDAS数据,以500m的空间分辨率对柴达木盆地2001—2011年的蒸散量进行了估算,并研究了区域蒸散量的时空分布及其与气象站实测水面蒸发量的关系。结果表明：柴达木盆地的年实际蒸散量有逐年增大的趋势,从2001年的72.73mm增加为2011年的182.34mm,2001—2011年最大日均蒸散量介于2.62~3.20mm。柴达木盆地的蒸发系数为0.14。分析NDVI和与其对应的ET的关系可知NDVI=0.055是柴达木盆地裸土和植被的分界点。虽然仅占据了研究区1.92%的区域,但水体的日均蒸散量最大,为2.31mm/d。盆地裸土、稀疏灌木、中等覆盖灌木、草场以及农田2010年6—9月的日蒸散量平均值分别为0.24、0.42、1.21、1.12、1.18mm/d。In an arid inland basin,evapotranspiration（ET）is the major loss related to the water balance and precise estimation of ET is essential for evaluation of available water resources in these areas.The study of actual evapotranspiration on a regional scale has great significance for environmental protection.Based on SEBS algorithm（Surface Energy Balance System）,the ET was estimated using DEM data,MODIS data and GLDAS data over the Qaidam Basin from 2001to 2011at a spatial resolution of 500m.What＇s more,the longterm change and spatial distribution of ET and its relationship with pan observed evaporation in the Qaidam Basin were studied.The result indicated that the annual actual ET of Qaidam Basin increased with time and the value varied from 72.73mm in 2001to 182.34mm in 2011,and the maximum of the mean daily ET varied between 2.62mm and 3.20mm during the year 2001to 2011.The evaporation coefficient is 0.14in the Qaidam Basin.The analysis of NDVI and its corresponding ET presented that the NDVI threshold between bare soil and vegetation is 0.055in the Qaidam Basin.The water bodies had highest mean daily ET（2.31mm/d）though they only make up 1.92% of the study area.The mean daily ET of bare soil,sparse shrub,dense shrub,grassland,farmland and forest in the Qaidam Basin from June to September in the year 2010were0.24mm/d,0.42mm/d,1.21mm/d,1.12mm/d and 1.18mm/d,respectively.

关 键 词：蒸散发 地表能量平衡系统(SEBS) MODIS GLDAS 柴达木盆地 

分 类 号：P641[天文地球—地质矿产勘探]