蒸散发是连接土壤-植被-大气间水热交换的最重要环节,是水循环模拟、地表过程模拟的关键参数.本研究基于巴音河流域气象、下垫面数据建立SWAT(Soil and Water Assessment Tools)模型,利用流域径流观测数据对其进行校准后提取各子流域蒸散发量,用以验证同时空尺度GLEAM(the Global Land Evaporation Amsterdam Model)v3数据集的精度.最终在保证GLEAM v3数据集适用性的前提下探讨了巴音河流域地表蒸散发量、土壤蒸发量和植物散发量的时空变异规律.结果表明:(1)GLEAM在巴音河流域的适用性良好,月尺度上其模拟的地表蒸散发量与SWAT模型模拟的相应子流域蒸散发量的R2＞0.87,NSE＞0.81,|PBIAS|＜2;(2)在空间上,巴音河流域多年平均地表蒸散发量(140～269mm)、土壤蒸发量(98～135mm)及植物散发量(22～129mm)均表现出由东北部高海拔山区到西南部山前平原逐渐递减的分布特征;(3)地表蒸散发量、土壤蒸发量和植物散发量在季节上的空间分布特征除冬季外亦基本呈现由东北部高海拔山区到西南部山前平原逐渐递减的分布特征;(4)地表蒸散发量、土壤蒸发量及植物散发量的逐年变化趋势与流域降水量的变化趋势相同,三者的多年月平均值和多年日平均值呈现出明显的季节特征,峰值出现在7月,最低值出现在12月,各个时间尺度上土壤蒸发量均大于植物散发量.
Spatial-temporal variation of surface evapotranspiration of hydrology and water environment in alpine inland river basin:a case study in Bayinhe River basin
Evapotranspiration is the key process of the soil-vegetable-atmosphere,is the key parameter of hydrological and land processes modelling.This research first measured the performance of GLEAM(the Global Land Evaporation Amsterdam Model)in Bayinhe River Basin with the simulation results of the SWAT(Soil and Water Assessment Tools)model,then discussed the spatial and temporal variation of the actual land evapotranspiration,bare soil evaporation and plant transpiration based on the ET dataset of GLEAM.The result show that:(l)the performance of the GLEAM is good compared to SWAT simulated ET in each sub-basins of the Bayinhe River with the R2 value of over 0.87,NSE value of over 0.81 and PBIAS value between-20％～20％;(2)the spatial variation of the multiple years average of the actual evapotranspiration(140～269mm),bare soil evaporation(98～135mm)and plant transpiration(22～129mm)is reducing from high-altitude mountainous area of northeast to plateau area of southwest;(3)actual evapotranspiration,bare soil evaporation and plant transpiration reducing from high-altitude mountainous area of northeast to plateau area of southwest in the spring,summer and autumn;(4)the trend of the yearly actual evapotrans-piration,bare soil evaporation and plant transpiration is the same as yearly precipitation.The monthly and daily trends of the three factors show seasonal variation.The highest value appeared in July and the lowest appeared in December.And totally,bare soil evaporation is higher than plant transpiration.
alpine inland river basinsurface evapotranspirationGLEAMSWAT
NETL
NSTL
万方数据
