利用ESTARFM模型获取南方红壤区高时空分辨率MODIS遥感蒸散估算数据

Estimating High Spatial and Temporal Resolution MODIS Remote Sensing Evapotranspiration Data in Southern Red Soil Region Based on ESTARFM Model

蒸散发是水分循环的重要环节,影响着作物生长和粮食生产,获得长时序高空间分辨率蒸散发过程数据有助于优化区域水资源配置。基于Landsat和MODIS遥感数据,结合地面观测通量数据和气象数据,利用SEBS模型和ESTARFM模型获得了南方红壤区2019年4−10月高时空分辨率日蒸散量,并分析高时空分辨率日蒸散量时空变化特征及其影响因素。结果表明:高空间分辨率的遥感影像可获得精度更高的遥感蒸散模拟效果,基于Landsat遥感数据驱动的SEBS模型的模拟效果优于基于MODIS遥感数据作为输入的SEBS模型。ESTARFM模型获得的高时空分辨率日蒸散量与实测蒸散量对比,RMSE为0.68mm·d^(−1),R^(2)为0.87。模拟获得的2019年4−10月高时空分辨率日蒸散量在空间变化上与土地利用类型相关。各土地利用类型的蒸散量表现为林地>稻田>其他农用地,在时间变化上,4−8月蒸散量呈上升趋势,8−10月蒸散量则逐渐降低,气温是影响研究区域蒸散量的主要气象因子。基于SEBS模型和ESTARFM模型获得的高时空分辨率蒸散量与实测蒸散量具有良好的相关性,SEBS模型与ESTARFM模型结合的方法可作为估算南方红壤区蒸散量的有效工具。

Evapotranspiration is an important component of the water cycle,influencing crop growth and grain production.Obtaining long-term,high-resolution evapotranspiration data can help optimize regional water resource allocation.Using Landsat and MODIS remote sensing data,along with ground observation flux data and meteorological data,the SEBS model and ESTARFM model are utilized to derive high spatiotemporal resolution evapotranspiration estimates for the southern red soil area from April to October 2019.The spatiotemporal variation characteristics and influencing factors of the high resolution evapotranspiration are analyzed.The results show that high spatial resolution remote sensing images can achieve higher accuracy in simulating remote sensing-based evapotranspiration.The simulation performance of the SEBS model driven by Landsat remote sensing data is better than that of the SEBS model based on MODIS data.Comparison between the high spatiotemporal resolution evapotranspiration obtained by the ESTARFM model and the measured evapotranspiration using a large aperture scintillometer shows a RMSE of 0.68mm·d^(−1)and R^(2)of 0.87.The simulated high spatiotemporal resolution daily evapotranspiration from April to October 2019 is spatially correlated with land use types,with evapotranspiration rates as follows:forest>paddy field>other agricultural land.Temporally,evapotranspiration showed an increasing trend from April to August,followed by a gradual decrease from August to October.Temperature is found to be the main meteorological factor affecting evapotranspiration in the study area.The high spatiotemporal resolution evapotranspiration obtained using the SEBS and ESTARFM models shows good agreement with ground measurements.The combination of the SEBS and ESTARFM models can serve as an effective tool for estimating evapotranspiration in southern red soil regions.