对大地遥感卫星图像进行时间序列分析以确定全球森林范围和变化特征的结果。
第一个 "和 "最后一个 "波段是大地遥感卫星光谱波段(红、近红外、SWIR1 和 SWIR2)的第一个和最后一个可用年份的参考多光谱图像。参考复合图像代表了这些波段中每个波段的生长季节质量评估观测数据集的中值观测数据。
请参阅 1.11 版更新的用户说明以及相关期刊文章:Hansen、Potapov、Moore、Hancher 等:"21 世纪森林覆盖变化的高分辨率全球地图"。科学》342.6160 (2013):850-853.
2000-01-01T00:00:00 - 2023-12-31T00:00:00
Copied
ee.Image("UMD/hansen/global_forest_change_2023_v1_11")
30.92 meters
Name | Description | Min | Max | Units | Wavelength |
---|---|---|---|---|---|
treecover2000 | Tree canopy cover for year 2000, defined as canopy closure for all vegetation taller than 5m in height. | 0 | 100 | % | |
loss | Forest loss during the study period, defined as a stand-replacement disturbance (a change from a forest to non-forest state). | ||||
loss Bitmask | Bit 0: Forest loss during the study period. 0: Not loss1: Loss | ||||
gain | Forest gain during the period 2000-2012, defined as the inverse of loss (a non-forest to forest change entirely within the study period). Note that this has not been updated in subsequent versions. | ||||
gain Bitmask | Bit 0: Forest gain during the period 2000-2012. 0: No gain1: Gain | ||||
first_b30 | Landsat Red cloud-free image composite (corresponding to Landsat 5/7 band 3 and Landsat 8/9 band 4). Reference multispectral imagery from the first available year, typically 2000. | 0.63-0.69µm | |||
first_b40 | Landsat NIR cloud-free image composite (corresponding to Landsat 5/7 band 4 and Landsat 8/9 band 5). Reference multispectral imagery from the first available year, typically 2000. | 0.77-0.90µm | |||
first_b50 | Landsat SWIR1 cloud-free image composite (corresponding to Landsat 5/7 band 5 and Landsat 8/9 band 6). Reference multispectral imagery from the first available year, typically 2000. | 1.55-1.75µm | |||
first_b70 | Landsat SWIR2 cloud-free image composite (corresponding to Landsat 5/7 band 7 and Landsat 8/9 band 7). Reference multispectral imagery from the first available year, typically 2000. | 2.09-2.35µm | |||
last_b30 | Landsat Red cloud-free image composite (corresponding to Landsat 5/7 band 3 and Landsat 8/9 band 4). Reference multispectral imagery from the last available year, typically the last year of the study period. | 0.63-0.69µm | |||
last_b40 | Landsat NIR cloud-free image composite (corresponding to Landsat 5/7 band 4 and Landsat 8/9 band 5). Reference multispectral imagery from the last available year, typically the last year of the study period. | 0.77-0.90µm | |||
last_b50 | Landsat SWIR1 cloud-free image composite (corresponding to Landsat 5/7 band 5 and Landsat 8/9 band 6). Reference multispectral imagery from the last available year, typically the last year of the study period. | 1.55-1.75µm | |||
last_b70 | Landsat SWIR2 cloud-free image composite (corresponding to Landsat 5/7 band 7 and Landsat 8/9 band 7). Reference multispectral imagery from the last available year, typically the last year of the study period. | 2.09-2.35µm | |||
datamask | Three values representing areas of no data, mapped land surface, and permanent water bodies. | ||||
datamask Bitmask | Bits 0-1: Three values representing areas of no data, mapped land surface, and permanent water bodies. 0: No data1: Mapped land surface2: Permanent water bodies | ||||
lossyear | Year of gross forest cover loss event. Forest loss during the study period, defined as a stand-replacement disturbance, or a change from a forest to non-forest state. Encoded as either 0 (no loss) or else a value in the range 1-23, representing loss detected primarily in the year 2001-2023, respectively. | 0 | 23 |
gainForest gain during the period 2000-2012, defined as the inverse of loss (a non-forest to forest change entirely within the study period). Note that this has not been updated in subsequent versions.gain Bitmask
first_b30Landsat Red cloud-free image composite (corresponding to Landsat 5/7 band 3 and Landsat 8/9 band 4). Reference multispectral imagery from the first available year, typically 2000.0.63-0.69µmfirst_b40Landsat NIR cloud-free image composite (corresponding to Landsat 5/7 band 4 and Landsat 8/9 band 5). Reference multispectral imagery from the first available year, typically 2000.0.77-0.90µmfirst_b50Landsat SWIR1 cloud-free image composite (corresponding to Landsat 5/7 band 5 and Landsat 8/9 band 6). Reference multispectral imagery from the first available year, typically 2000.1.55-1.75µmfirst_b70Landsat SWIR2 cloud-free image composite (corresponding to Landsat 5/7 band 7 and Landsat 8/9 band 7). Reference multispectral imagery from the first available year, typically 2000.2.09-2.35µmlast_b30Landsat Red cloud-free image composite (corresponding to Landsat 5/7 band 3 and Landsat 8/9 band 4). Reference multispectral imagery from the last available year, typically the last year of the study period.0.63-0.69µmlast_b40Landsat NIR cloud-free image composite (corresponding to Landsat 5/7 band 4 and Landsat 8/9 band 5). Reference multispectral imagery from the last available year, typically the last year of the study period.0.77-0.90µmlast_b50Landsat SWIR1 cloud-free image composite (corresponding to Landsat 5/7 band 5 and Landsat 8/9 band 6). Reference multispectral imagery from the last available year, typically the last year of the study period.1.55-1.75µmlast_b70Landsat SWIR2 cloud-free image composite (corresponding to Landsat 5/7 band 7 and Landsat 8/9 band 7). Reference multispectral imagery from the last available year, typically the last year of the study period.2.09-2.35µmdatamaskThree values representing areas of no data, mapped land surface, and permanent water bodies.datamask Bitmask
lossyearYear of gross forest cover loss event. Forest loss during the study period, defined as a stand-replacement disturbance, or a change from a forest to non-forest state. Encoded as either 0 (no loss) or else a value in the range 1-23, representing loss detected primarily in the year 2001-2023, respectively.023
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}
] */
ee.Geometry.Polygon(
[[[-111.37186963558197, 41.621164801215464],
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[-100.12186963558197, 34.14087733236979],
[-100.12186963558197, 41.621164801215464]]], null, false);
var image = ee.Image("UMD/hansen/global_forest_change_2023_v1_11")
print(image)
Map.addLayer(image.clip(geometry),{},'sss')
Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend.