摘要
地表蒸散量的准确估算对全球气候变化研究以及水资源的科学管理意义重大。本文以毛乌素沙地腹地——内蒙古乌审旗为例,应用基于互补相关原理的平流-干旱模型,结合1km分辨率的NOAA/AVHRR、MODIS反照率资料和气象资料,对乌审旗1981￣2003年的地表蒸散量进行了估算,并对其时空分布进行了分析。结果表明:(1)乌审旗多年平均年蒸散量为252mm,变化在200￣310mm之间,从西北向东南递增;多年平均年蒸散量的相对变率在10%￣24%之间,从西北向东南递减;逐年蒸散量分布趋势基本一致,都是从西部地区向东部地区递增。(2)以2002年为例,按照土地利用/土地覆盖类型划分,蒸散量最大的是水体,耕地次之,再次是草地和林地,沙地最小。(3)蒸散量年际变化大,最大年份在300mm以上,最小年份在200mm左右;从年内变化看,蒸散量呈“单峰”正态分布,一年内蒸散量主要集中在6￣9月份。(4)通过误差分析可以看出,乌审旗蒸散量的模型估算值比实际测量值偏低,大约低9%左右。
Accurate estimation of surface evaporatranspiration （ET） is important in the study of global climatic change, scientific management of water resources. In this paper, the evapotranspiration from 1981 to 2003 in Wushen County, located in the Mu Us Sandland, was estimated by using Advection-Aridity Model based on the complementary relationship hypothesis with lkm resolution reflectance data of NOAA/AVHRR and MODIS and meteorology data. The temporal and spatial distribution of ET was analyzed. The results showed： （1） The annual average of ET of Wushen County is 252 mm. Spatially, it increases from northwest to southeast. The multiyear relative variation of ET in Wushen County is from 10% to 24%, larger in northwestern and southeastern parts and smaller in eastern and southern places. Seen from the yearly spatial distribution of the ET, there is the same trend that ET increases from west to east. （2） Ordered in land cover and land use in 2002, ET decreases in following sequence： water body, crop field, grassland, shrub, forestland and sand land. （3） Interannual change of ET in Wushen County is large while the maximum value is up to 300mm and the minimum value is only 200 ram. The monthly distribution of ET takes a ＇ bell＇ shape, with peak in about July to September.
出处
《地理科学进展》
CSCD
北大核心
2006年第4期79-87,共9页
Progress in Geography
基金
国家高技术研究发展计划(863计划)"西北半干旱生态植被建设区节水综合技术体系集成与示范"项目(2002AA2Z4271)资助
关键词
地表蒸散量
遥感
内蒙古乌审旗
surface evapotranspiration
remote sensing
Wushen County in Inner Mongolia
