Validation of crop evapotranspiration products based on eddy-covariance flux observations

نویسندگان

چکیده

高精度的农田蒸散发(ETï¼‰å¯¹äºŽç”°é—´å°ºåº¦ç²¾å‡†çš„æ°´åˆ†å¹³è¡¡é‡åŒ–å’Œæ°´åˆ†äºç¼ºç ”ç©¶å ·æœ‰é‡è¦æ„ä¹‰ï¼Œå¯¹å†œä¸šç²¾å‡†çŒæº‰å’Œå†œç”°æ°´åˆ†åˆ©ç”¨æ•ˆçŽ‡æé«˜å ·æœ‰å®žç”¨ä»·å€¼ã€‚æœ¬ç ”ç©¶åˆ©ç”¨å ¨çƒå ±è®¡28ä¸ªå†œç”°ç«™ç‚¹çš„æ¶¡åŠ¨ç›¸å ³ç³»ç»Ÿï¼ˆEC)通量观测数据,对500 m空间分辨率8 d时间分辨率的MOD16和PML-V2两种遥感蒸散发产品,进行了对比分析与精度评估。评估结果表明,PML-V2 ET产品与EC观测ETç›¸æ¯”ï¼Œå‡æ–¹æ ¹è¯¯å·®ï¼ˆRMSE)变化范围为3.3—22.4 mm/8 d,平均偏差(bias)变化范围为-15.98—13.27 d;MOD16 ET产品与EC观测ET相比,RMSE变化范围为3.81—21.47 d,bias变化范围为-16.42—15.05 d。整体而言,两种产品精度相当,MOD16产品低估8 d ET(bias:-2.31 d,R2:0.452,RMSE:8.82 d),PML-V2产品略高估8 ET(bias:0.51 d,R2:0.455,RMSE:8.81 d);PML-V2产品在18个站点(64%)上表现更优,但是部分站点上MOD16产品对时序变化细节(如到达波峰的季节、年中的下降/上升趋势)的刻画优于PML-V2产品;PML-V2产品未能捕捉到冬小麦和夏玉米轮种而引起的ETå¹´ä¸­å ˆä¸‹é™åŽä¸Šå‡çš„å˜åŒ–è¶‹åŠ¿ï¼Œè€ŒMOD16产品虽然成功捕捉到ETæ—¶åºæ›²çº¿ä¸Šå†¬å°éº¦å’Œå¤çŽ‰ç±³ä¸¤ç§ä½œç‰©å„è‡ªç”Ÿé•¿æœŸå† çš„æ³¢å³°ï¼Œä½†ä»è¾ƒå¤§ç¨‹åº¦ä¸Šä½Žä¼°äº†å†¬å°éº¦ETï¼ˆå¦‚æ ¾åŸŽç«™ç‚¹å’Œç¦¹åŸŽç«™ç‚¹ï¼‰ï¼›å¦å¤–ï¼ŒMOD16产品和PML-V2产品均严重低估了水稻ET(如US-Twtç«™ç‚¹ï¼‰ã€‚æœ¬ç ”ç©¶å¯ä¸ºå†œç”°è’¸æ•£å‘ç®—æ³•å‘å±•åŠå ¶ç²¾åº¦éªŒè¯æä¾›å‚è€ƒã€‚

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ژورنال

عنوان ژورنال: Journal of remote sensing

سال: 2023

ISSN: ['1007-4619', '2095-9494']

DOI: https://doi.org/10.11834/jrs.20222008