ETMonitor全球1公里分辨率地表实际蒸散发数据集

地表实际蒸散发是陆表水循环的关键环节，同时也是能量平衡的重要支出项，且与地表碳收支密切相关，其准确估算不仅对于研究地球系统和全球气候变化具有重要意义，而且对于水资源有效开发利用、农作物需水生产管理、旱情监测和预测、天气预报等方面具有十分重要的应用价值。ETMonitor全球逐日1公里分辨率地表实际蒸散发数据集是基于多参数化、适用于不同土地覆盖类型的地表蒸散发遥感估算模型ETMonitor计算得到，输入数据主要采用的遥感数据包括GLASS产品（叶面积指数、植被覆盖度和反照率）、MODIS产品（地表覆盖、积雪覆盖）、动态地表水体覆盖、ESA CCI土壤水分、GPM降水等，并结合欧洲中期天气预报中心的ERA5全球大气再分析数据等。利用ETMonitor模型在日尺度上估算1公里分辨率像元尺度的植被蒸腾、土壤蒸发、冠层降水截留蒸发、水面蒸发和冰雪升华，并对各分量求和获得逐像元逐日蒸散发量。利用FLUXNET等地面观测数据进行直接验证，估算结果与地面实测数据一致性较好，逐日蒸散发验证RMSE为0.93mm/d，误差为0.08 mm/d，相关系数为0.75。本数据集将ETMonitor估算获得的逐日蒸散发值（https://doi.org//10.12237/casearth.6253cddc819aec49731a4bc2）进行累积求和运算，获得逐月蒸散发，并转为经纬度投影进行公开发布。本数据集覆盖全球，时间步长为每月，空间分辨率为1公里，单位为mm/月，数据类型为整型，缩放系数为0.1，无效值填充-1。

Actual land surface evapotranspiration (ET) is a critical component of the terrestrial water cycle, a major outgoing term of the energy balance, and closely correlated with surface carbon budgets. Accurate estimation of ET is not only of great significance for Earth system and global climate change research, but also has vital application values in efficient development and utilization of water resources, crop water demand management, drought monitoring and prediction, weather forecasting, and other relevant fields.
The ETMonitor Global Daily 1-km Resolution Actual Land Surface Evapotranspiration Dataset is calculated using the ETMonitor remote sensing-based ET estimation model, which adopts multi-parameterization and is applicable to various land cover types. The main remote sensing input datasets include GLASS products (leaf area index, vegetation coverage, and albedo), MODIS products (land cover, snow cover), dynamic surface water cover, ESA CCI soil moisture, GPM precipitation, etc., combined with global atmospheric reanalysis data such as ERA5 from the European Centre for Medium-Range Weather Forecasts (ECMWF).
The ETMonitor model is used to estimate pixel-scale vegetation transpiration, soil evaporation, canopy precipitation interception evaporation, open water evaporation, and snow/ice sublimation at the daily scale with 1-km resolution, and the per-pixel daily actual evapotranspiration is obtained by summing these components. Direct validation using ground observation datasets such as FLUXNET indicates that the estimated results exhibit good consistency with in-situ measurements, with a RMSE of 0.93 mm/d, a bias of 0.08 mm/d, and a correlation coefficient of 0.75 for daily ET.
For this dataset, the daily ET values estimated by ETMonitor (https://doi.org//10.12237/casearth.6253cddc819aec49731a4bc2) are accumulated to generate monthly ET products, which are then projected in geographic (longitude-latitude) coordinate system and publicly released. This global dataset has a monthly temporal resolution, 1-km spatial resolution, unit of mm/month, integer data type, a scaling factor of 0.1, and uses -1 as the fill value for invalid data.

搜集汇总

背景与挑战

背景概述

ETMonitor全球1公里分辨率地表实际蒸散发数据集是一个覆盖全球、时间范围为2000年6月至2019年12月的月尺度遥感产品，空间分辨率为1公里，数据量达105.62 GB，可开放获取。该数据集基于ETMonitor模型，融合多源卫星观测（如GLASS、MODIS）和ERA5再分析数据，估算逐日地表实际蒸散发（包括植被蒸腾、土壤蒸发等分量）并累积为月值，经地面观测验证具有较高精度（RMSE 0.93 mm/d，相关系数0.75），适用于水循环、气候变化和水资源管理研究。