Water Occurrence Mask of Lakes and Reservoirs

Product Water Occurrence

General

The product of the water occurrence mask is created in the processing of the surface area time series. It is used for filling of remaining data gaps caused by voids, clouds or snow. Example of water occurrence mask However, it can also provide important information for hydrological applications since it contains information about water occurrence of a lake or reservoir since the 1980s. An exemplary water occurrence mask is shown for Ray Roberts Lake in the right figure.

Processing Strategy

This product is estimated within the processing strategry of surface areas for lakes and reservoirs. Therefore, more information can be found here.

Data Holding

DAHITI currently provides 180 water occurrence masks distributed over all continents, except Antarctica. In Africa (5 time series), Asia (3), Australia (1), Europe (5), North America (155), and South America (7) water occurrence masks are available. The water occurrence masks in DAHITI are freely available and can be downloaded after a short registration process. The amount of water occurrence masks is permanently increasing.

Data Versions

This product is processed in the processing chain of surface areas.
More information can be found here.

Data Format

The water occurrence mask is stored as GeoTiff. The spatial resolution is 0.0001° which is about 10m.

user@dahiti:/> gdalinfo  water_occurrence_mask.tif
Driver: GTiff/GeoTIFF
Files: water_occurrence_mask.tif
Size is 3901, 2713
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (-97.178600000000003,33.577800000000003)
Pixel Size = (0.000100000000000,-0.000100000000000)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  COMPRESSION=LZW
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  ( -97.1786000,  33.5778000) ( 97d10'42.96"W, 33d34'40.08"N)
Lower Left  ( -97.1786000,  33.3065000) ( 97d10'42.96"W, 33d18'23.40"N)
Upper Right ( -96.7885000,  33.5778000) ( 96d47'18.60"W, 33d34'40.08"N)
Lower Right ( -96.7885000,  33.3065000) ( 96d47'18.60"W, 33d18'23.40"N)
Center      ( -96.9835500,  33.4421500) ( 96d59' 0.78"W, 33d26'31.74"N)
Band 1 Block=3901x1 Type=Float32, ColorInterp=Gray

Description of pixel values:

Pixel value Description
0 - 100 Percentage of Water Occurrance

Citation

Find more topics on the central web site of the Technical University of Munich: www.tum.de