Lake masks

The ESA CCI Land Cover (LC) project has recently issued products including a high resolution (1/360^o, ~300 m) static map of stable water for the time period 2005-2010.

Within the GloboLakes project a new dataset based on the ESA CCI LC map of stable water has been released and it includes:

• Lake Centre
• Distance to Land
• Distance to Water
• Lake Identifiers (ID)

The dataset is required to locate water pixels where the lake surface water temperature may be safely retrieved.

Lake Mask Dataset Access

The dataset for all inland water at 1/360^o (~300 m) resolution is available from the CEDA catalogue. Please cite the dataset as:
Carrea, L., Embury, O., Merchant, C.J. (2015): GloboLakes: high-resolution global limnology dataset v1. Centre for Environmental Data Analysis, date of citation. doi:10.5285/6be871bc-9572-4345-bb9a-2c42d9d85ceb.

The dataset is described in detail in Carrea et at., (2016).

Lake Centre

We define the lake centre as the point most distant from land. The lake centre dataset has been built with the distance to land and the lake identifier datasets.

The full dataset is available to download at the CEDA catalogue as a csv file. The file includes

• identifier
• name
• country
• centre coordinates (lat/lon)
• lats and lons of a box bounding the lake

for all the GLWD Level 1 lakes along with 29 GloboLakes specific water bodies.

Examples of the lake centre point are shown in Figure 1 for the large Lake Victoria in Tanzania/Uganda/Kenya and in Figure 2 for the smaller Loch Lomond in the United Kingdom. The distance to land for all the water pixels in shown in km and the locations correspondent to the greatest distance to land are highlighted in black.

Distance to Land

The distance to land has been computed for all the water pixel present in the ESA CCI LC water bodies map at 1/360^o (~300 m) resolution. It is available to download in a 2D global grid at the CEDA catalogue as compressed netCDF4 file. Examples of the distance to land dataset for the area around the Lake Victoria in Tanzania/Uganda/Kenya and around the Loch Lomond in the United Kingdom are in Figure 1 and Figure 2.

Distance to Water

The distance to water, complementary to the distance to land, has been computed for all the land pixel present in the ESA CCI LC water bodies map at 1/360^o (~300 m) resolution. It is available to download in a 2D global grid at the CEDA catalogue as a compressed netCDF4 file. Examples of the distance to water dataset are shown in Figure 3 for the area around the Lake Victoria in Tanzania/Uganda/Kenya and in Figure 4 for the area around the Loch Lomond in the United Kingdom. The distances are given in km.

Lake identifiers

The spatial extension for each lake has been extracted from the ESA CCI LC water bodies map, classifying water pixels as belonging to the particular lake. The classification is based on the Global Lakes and Wetlands Database polygons as a first guess, but not only. Due to the complexity of the water bodies extension geometries, the lakes extension has been defined algorithmically and by manual inspection.

The full dataset is available to download in a 2D global grid at the CEDA catalogue as a compressed netCDF4 file where each pixel is labelled with:

• -1 for land
• 0 for sea
• all GLWD Level 1 identifiers and some GloboLakes extra identifiers as listed in the lake centre dataset
• 999999 for all other inland water.

The lake identifiers for each of the 1000 Globolakes can also be found from Figure 1 and Table 1 on the Globolakes Lakes tab.