三种蒸散发产品在北半球的验证与比较  

Verification and Comparison of Three Evaporative Products in the Northern Hemisphere

作　　者：李媛 来全[1,2] 刘心怡 LI Yuan;LAI Quan;LIU Xin-yi(School of Geography,Inner Mongolia Normal University,Hohhot,Inner Mongolia,010022;Key Laboratory of Remote Sensing and Geographic Information Systems in Inner Mongolia Autonomous Region,Hohhot,Inner Mongolia,010022)

机构地区：[1]内蒙古师范大学地理科学学院,内蒙古呼和浩特010022 [2]内蒙古自治区遥感与地理信息系统重点实验室,内蒙古呼和浩特010022

出　　处：《中国农村水利水电》2024年第5期206-214,共9页China Rural Water and Hydropower

基　　金：内蒙古自然科学基金(2022MS04006);高层次人才引进科研启动基金项目(2022JBYJ030)。

摘　　要：蒸散发(Evapotranspiration,ET)是水循环的关键环节,在全球水循环和地表能量平衡中扮演着重要角色,对气候、生态系统和水资源管理等方面都有重要影响。因此,蒸散发数据的质量对全球水资源的精确管理至关重要。在北半球进行3种ET产品的精度验证和时空对比,选择更适用于北半球的ET产品,为加强遥感与地面观测相结合的研究提供建议。利用FluxNet2015通量站点月平均实测数据验证3种ET产品,结果发现PML_V2产品在北半球精度最高,其次是GLDAS,最后是MOD16A2,相关系数R分别是0.66、0.57、0.56;均方根误差RMSE分别是2.46、5.68、12.42 mm/月;平均偏差Bias分别是14.36%、16.86%、35.02%。其中GLDAS ET产品具备日尺度ET监测能力,日平均估计值与通量塔站点测量值的一致性较高,相关系数R为0.74,RMSE和Bias分别为1.62 mm/d和27.90%。总体来说,在时间尺度上,3种ET产品均可模拟出北半球季节变化的特征,即夏季蒸散发量较大,冬季蒸散发量较小。夏季3种ET产品在不同土地覆盖类型上均存在高估现象,其他季节的模拟结果与地面观测值的结果一致性较好,其中MOD16A2表现较差,ET值高估现象最为明显。此外,2001-2020年期间非干旱地区,3种ET产品在多数地区空间分布较为一致,相关系数R大于0.6。研究通过评估不同ET产品的不确定性和产品质量,可为在北半球开展蒸散发研究选取适用的ET数据源提供科学建议。Evapotranspiration(ET)is a crucial link in water circulation.It plays an important role in the global water cycle and surface energy balance,and has significant impacts on climate,ecosystems,and water resources management.Therefore,the quality of evapotranspiration data is crucial for the precise management of global water resources.This study conducted accuracy validation and spatiotemporal comparison of three ET products in the Northern Hemisphere,selecting the ET products that is more suitable for the Northern Hemisphere,providing suggestions for strengthening the combination of remote sensing and ground observation research.Using the monthly average measured data from FluxNet2015 flux sites to verify three ET products,it was found that PML_V2 product has the highest accuracy in the Northern Hemisphere,followed by GLDAS,and finally MOD16A2,with correlation coefficients R of 0.66,0.57,and 0.56,respectively;The root mean square error(RMSE)is 2.46,5.68,and 12.42 mm/month,respectively;The average biases are 14.36%,16.86%,and 35.02%,respectively.The GLDAS ET product has the ability to monitor daily scale ET,and the consistency between the daily average estimated value and the measured value at the flux tower site is high.The correlation coefficient R is 0.74,and the RMSE and Bias are 1.62mm/day and 27.90%,respectively.Overall,on the time scale,all three ET products can simulate the seasonal changes in the Northern Hemisphere,with higher summer evapotranspiration and lower winter evapotranspiration.The three ET products in summer all have overestimation phenomena on different land cover types,and the simulation results in other seasons are better than the ground observation values.Among them,MOD16A2 performs the worst,and the overestimation phenomenon is the most obvious.In addition,during the period from 2001 to 2020,except for arid areas,the spatial distribution of the three ET products was relatively consistent in most regions,with a correlation coefficient R greater than 0.6.This study provides scientific recomm

关 键 词：蒸散发 通量塔 Google Earth Engine(GEE) 北半球 精度验证 

分 类 号：P426.2[天文地球—大气科学及气象学]