Data evaluation - Mapbiomas water
Rafaela
10-2023
Mapbiomas Water statistics
Water masses size distribution
To start out analysis, we selected only water areas identified in the state of Mato Grosso.
In the Mapbiomas Water dataset, we found 54357 water masses in Mato Grosso classified as “2 - artificail water body (antrophic dams)”.
The size of these bodies of water ranged from 0.084 to 398.666 hectares.
The total area is estimated at 81036.9215891 hectares.
Below is the distribution of size of all of these water masses:
And below is the distribution of`size and number, according to size classes.
The graphs above show that water masses with area below 2 hectares account for more than 85% of the water masses, but only 38% of the total area.
Land use in the vicinity
In Google Earth Engine, we transformed the water areas into vectors, and drew polygons containing the water area, plus a buffer area of 200 meters. Then, we analyzed the profile of land use in these areas using the Mapbiomas land use data, collection 7.
Below shows the total sum of areas in these buffer areas, according to the land use type.
Considering that the buffer areas include the water mass area, the assumption was that every water mass polygon would contain at least one pixel of water area. That turned out to not be the case. Out of the 54357 areas, only 20022 have some water area contained in it.
Below is the distribution of the percentage of coverage of each land use class within these buffer areas.
Out of the 54357 areas, 51698 have some pasture area in detected in the vicinity. This makes it easier to remove the 2659 areas that have zero pasture area around them.
This already reduces the total water area from 81036.9215891 to 77354.3035704 hectares.
To further understand what type of area is in the surrounding of these impoundments, we also analyzed the presence of other types of water surface in the vicinity.
Below is the distribution of the percentage of coverage of each land use class within these buffer areas, excluding the area covered by the water mass itself.
Solvik et al. statistics
Water masses size distribution
In the Solvik dataset, we found 97557 water masses in Mato Grosso.
The size of these bodies of water ranged from 0.009 to 74.334 hectares.
The total area is estimated at 50104.6152046 hectares.
Below is the distribution of size of all of these water masses:
And below is the distribution of`size and number, according to size classes.
Land use in the vicinity
In Google Earth Engine, we drew polygons containing the water area, plus a buffer area of 200 meters. Then, we analyzed the profile of land use in these areas using the Mapbiomas land use data, collection 7.
Below shows the total sum of areas in these buffer areas, according to the land use type.
Out of the 97557 areas, only 21421 have some water area contained in it.
Below is the distribution of the percentage of coverage of each land use class within these buffer areas.
Out of the 97557 areas, 92961 have some pasture area in detected in the vicinity. This makes it easier to remove the 4596 areas that have zero pasture area around them.
This already reduces the total water area from 50104.6152046 to 47627.0403661 hectares.
Below is the distribution of the percentage of coverage of each land use class within these buffer areas, excluding the area covered by the water mass itself.
