摘要
基于多源遥感数据产品,利用Shuttleworth-Wallace(S-W)模型估算了黑河上中游流域2000—2010年潜在蒸散发(potential evapotranspiration,ETP),并考虑不同土地覆被类型,分析了ETP的时空变化特征及影响要素,分别利用ETP和ET0驱动水文模型,比较径流模拟精度。结果表明:1基于高精度遥感数据,S-W模型可模拟区域ETP。黑河上中游流域,夏季ETP对年值的贡献最大,各土地覆被类型的ETP年内变化趋势一致。总体而言,植被条件越好,ETP越小;2在研究区内,相对湿度对ETP变化的影响最大,叶面积指数(LAI)对ETP变化的影响与辐射相近。植被越稀疏,ETP对气象要素及LAI的敏感性越强;3与ET0相比,ETP能够更好地描述陆面蒸散发能力,相同条件下使用ETP驱动水文模型模拟精度更高。
On the basis of the MODIS LAI remote sensing products, China Meteorological Forcing Dataset and other multi-source datasets, the Shuttleworth-Wallace （S-W） model, which considers the temporal Variation of leaf area index （LAI） , was applied to estimate potential evapotranspiration （ETp） during the period of 2000-2010 in the upstream and midstream areas of the Heihe River basin. To investigate the temporal and spatial variability of ETp, sensitivity of ETp to meteorological parameters and LAI was calculated for each land cover type. To compare ETp and ETo values for runoff simulation, a conceptual hydrologic model with precipitation and ETp or ETo was developed in the upstream area of the Heihe River basin. Results showed that： （1） S-W model, based on high-resolution remote sensing datasets, was able to accurately estimate annual and seasonal ETp in large river basins with complex underlying surfaces as well as in ungauged basins. The values of ETr in summer contributed more to the annual value than those of other seasons. ETp in areas with different land cover types varied greatly. Generally speaking, ETp decreased with the development of vegetation. （2） In the study area, ETp was most sensitive to relative humidity. The sensitivity of ETp to LAI was as great as that to net solar radiation. The sensitivity of ETa to meteorological parameters and LAI became greater with the decline of vegetation. （3） Compared with hydrologic model with ETo calculated by P-M model, the model with ETp better simulated the depth of runoff at Yingluoxia hydrologic station. Hence, ETp calculated by S-W model was more suitable for the simulation of runoff in the present study.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2015年第5期614-623,共10页
Advances in Water Science
基金
国家自然科学基金重大计划重点支持项目(91125015)
国家建设高水平大学公派研究生项目(201406040178)~~
