Google Earth Engine（GEE）——全球湖泊数据集HydroLAKES v1.0（大于10公顷的湖泊）

Canadian hydrographic dataset (CanVec)

Canada (entire country)

Vector; 1:50,000

Natural Resources Canada (2013)

863550

Shuttle Radar Topographic Mission (SRTM) Water Body Data (SWBD)

56° South to 60° North

Raster; 1 arc-second (~30 m at the equator); vectorized and smoothed

Slater et al. (2006)

282571

MODerate resolution Imaging Spectro-radiometer (MODIS) MOD44W water mask

Russia above 60° North

Raster; 250 m; vectorized and smoothed

Carroll et al. (2009)

167435

US National Hydrography Dataset (NHD)

Alaska (entire state)

Vector; 1:24:000

U.S. Geological Survey (2013)

58496

European Catchments and Rivers Network System (ECRINS)

Europe above 60° North and entire Norway

Vector; varying resolutions (~1:250,000)

European Environment Agency (2012)

50699

Global Lakes and Wetlands Database (GLWD)

World

Vector; 1:1 million

Lehner and Döll (2004)

3023

Global Reservoir and Dam database (GRanD)

World

Vector; varying resolutions (1:1 million or better)

Lehner et al. (2011)

1133

Other (own mapping)

World

Vector; varying resolutions (1:1 million or better)

n/a

781

Total

1427688

Hylak_id

Unique lake identifier. Values range from 1 to 1,427,688.

Lake_name

Name of lake or reservoir. This field is currently only populated for lakes with an area of at least 500 km2; for large reservoirs where a name was available in the GRanD database; and for smaller lakes where a name was available in the GLWD database.

Country

Country that the lake (or reservoir) is located in. International or transboundary lakes are assigned to the country in which its corresponding lake pour point is located and may be arbitrary for pour points that fall on country boundaries.

Continent

Continent that the lake (or reservoir) is located in. Geographic continent: Africa, Asia, Europe, North America, South America, or Oceania (Australia and Pacific Islands)

Poly_src

Source of original lake polygon: CanVec; SWBD; MODIS; NHD; ECRINS; GLWD; GRanD; or Other More information on these data sources can be found in Table 1.

Lake_type

Indicator for lake type: 1: Lake 2: Reservoir 3: Lake control (i.e. natural lake with regulation structure) Note that the default value for all water bodies is 1, and only those water bodies explicitly identified as other types (mostly based on information from the GRanD database) have other values; hence the type ‘Lake’ also includes all unidentified smaller human-made reservoirs and regulated lakes.

Grand_id

ID of the corresponding reservoir in the GRanD database, or value 0 for no corresponding GRanD record. This field can be used to join additional attributes from the GRanD database.

Lake_area

Lake surface area (i.e. polygon area), in square kilometers.

Shore_len

Length of shoreline (i.e. polygon outline), in kilometers.

Shore_dev

Shoreline development, measured as the ratio between shoreline length and the circumference of a circle with the same area. A lake with the shape of a perfect circle has a shoreline development of 1, while higher values indicate increasing shoreline complexity.

Vol_total

Total lake or reservoir volume, in million cubic meters (1 mcm = 0.001 km3). For most polygons, this value represents the total lake volume as estimated using the geostatistical modeling approach by Messager et al. (2016). However, where either a reported lake volume (for lakes ≥ 500 km2) or a reported reservoir volume (from GRanD database) existed, the total volume represents this reported value. In cases of regulated lakes, the total volume represents the larger value between reported reservoir and modeled or reported lake volume. Column ‘Vol_src’ provides additional information regarding these distinctions.

Vol_res

Reported reservoir volume, or storage volume of added lake regulation, in million cubic meters (1 mcm = 0.001 km3). 0: no reservoir volume

Vol_src

1: ‘Vol_total’ is the reported total lake volume from literature 2: ‘Vol_total’ is the reported total reservoir volume from GRanD or literature 3: ‘Vol_total’ is the estimated total lake volume using the geostatistical modeling approach by Messager et al. (2016)

Depth_avg

Average lake depth, in meters. Average lake depth is defined as the ratio between total lake volume (‘Vol_total’) and lake area (‘Lake_area’).

Dis_avg

Average long-term discharge flowing through the lake, in cubic meters per second. This value is derived from modeled runoff and discharge estimates provided by the global hydrological model WaterGAP, downscaled to the 15 arc-second resolution of HydroSHEDS (see section 2.2 for more details) and is extracted at the location of the lake pour point. Note that these model estimates contain considerable uncertainty, in particular for very low flows. -9999: no data as lake pour point is not on HydroSHEDS landmask

Res_time

Average residence time of the lake water, in days. The average residence time is calculated as the ratio between total lake volume (‘Vol_total’) and average long-term discharge (‘Dis_avg’). Values below 0.1 are rounded up to 0.1 as shorter residence times seem implausible (and likely indicate model errors). -1: cannot be calculated as ‘Dis_avg’ is 0 -9999: no data as lake pour point is not on HydroSHEDS landmask

Elevation

Elevation of lake surface, in meters above sea level. This value was primarily derived from the EarthEnv-DEM90 digital elevation model at 90 m pixel resolution by calculating the majority pixel elevation found within the lake boundaries. To remove some artefacts inherent in this DEM for northern latitudes, all lake values that showed negative elevation for the area north of 60°N were substituted with results using the coarser GTOPO30 DEM of USGS at 1 km pixel resolution, which ensures land surfaces ≥0 in this region. Note that due to the remaining uncertainties in the EarthEnv-DEM90 some small negative values occur along the global ocean coastline south of 60°N which may or may not be correct.

Slope_100

Average slope within a 100 meter buffer around the lake polygon, in degrees. This value is derived from the EarthEnv-DEM90 digital elevation model at 90 m pixel resolution. Slopes for each pixel were computed with latitudinal corrections for the distortion in the XY spacing of geographic coordinates by approximating the geodesic distance between cell centers. For 12 lakes located above the northern limit of the EarthEnv-DEM90 digital elevation model (83°N), slopes were computed from the GTOPO30 DEM of USGS at 1 km pixel resolution. -1: slope values were not calculated for the largest lakes (polygon area ≥ 500 km2)

Wshd_area

Area of the watershed associated with the lake, in square kilometers. The watershed area is calculated by deriving and measuring the upstream contribution area to the lake pour point using the HydroSHEDS drainage network map at 15 arc-second resolution. -9999: no data as lake pour point is not on HydroSHEDS landmask

Pour_long

Longitude of the lake pour point, in decimal degrees.

Pour_lat

Latitude of the lake pour point, in decimal degrees.