【摘要】 蒸散发(Evapotranspiration,ET)是重要的生态水文过程,尤其是在干旱和半干旱地区,对环境变化起着至关重要的作用。以疏勒河流域为例,利用DEM,MODIS和气象数据,基于能量平衡原理的SEBAL(Surface Energy Balance Algorithms for Land)模型,运用ArcGIS软件在栅格尺度上反演出该流域的地表蒸散量,并探究其时空变化特征。结果显示:(1)疏勒河流域2000—2015年8月基于栅格的地表多年平均日蒸散量变化范围为0～8.52mm,空间差异十分显著,从东南向西北呈现逐渐减少趋势,上游蒸散量大于中下游区域;(2)2000—2015年疏勒河流域大部分地区的8月份地表月蒸散量呈减小趋势;(3)疏勒河流域2000—2015年8月份地表月蒸散量时空变异显著,中、上游地区蒸散量较大且时间稳定性差;(4)2015年4个月份地表月蒸散量变化显著(7月>4月>10月>1月),但其空间分布格局相似。研究蒸散量的时空动态定量评价结果对于疏勒河流域的环境模拟、气候变化研究、灌溉和水资源管理,以及深入了解我国干旱半干旱气候区水循环机理具有重要意义。更多还原

【Abstract】 Evapotranspiration(ET)is an important ecological hydrological process,especially in arid and semi-arid areas,which plays a vital role in environmental change studies.Based on the energy balance principle SEBAL(Surface Energy Balance Algorithms for Land)model in Shule River Basin with DEM,MODIS and meteorological data,we applied ArcGIS software to estimate the ET value of the basin based on the grid scale,and explored characteristics of temporal and spatial variation of ET.The results showed that:(1)the spatial variation range of mean daily ET values in August was 0～8.52 mm on the grid of over Shule River Basin during the period from 2000 to 2015,which had a significant difference in spatial patterns;SEBAL model also showed that spatial patterns of mean daily ET gradually decreased from the southeast to the northwest of Shule River Basin,and that the mean daily ET in the upper reaches of Shule River was greater than ET in the middle and lower reaches of Shule River;(2)the monthly ET of August in 2000—2015 showed the decreasing tendency in most areas over Shule River Basin;(3)the monthly ET and the time stability of value of August in the middle and upper reaches in 2000—2015 were higher than those in the lower reaches,and the spatial difference was significant;(4)the monthly ETs of the four months in 2015 changed significantly,the valuedecreased in the order:July>April>October>January,and ETs had similar spatial pattern.The quantitative evaluation on temporal and spatial dynamic of ET has an important significance for the environmental simulation,climate change research,irrigation and water resources management in Shule River Basin in order to gain a better understanding of the mechanism of water cycle in arid and semiarid climate zone.更多还原