Lake Victoria Bathymetric Map v7.0 (LVBM)
The first high-resolution bathymetric model of Lake Victoria, Africa


Creative Commons License

LVBM is licensed by Stuart E. Hamilton under a Creative Commons Attribution 4.0 International License.




Dataset Name: LVBM, Lake Victoria Bathymetric Model.

Period: 1900 - 2017.

Type: GIS Raster and point shapefile.

Format: GeoTiff and shapefile.

Format: These data are created under grant NSF: 1518532.

Stable URL: http://bit.ly/LV_Bathy. For all our data for Lake Victoria please visit https://dataverse.harvard.edu/dataverse/LakeVicFish.

Data URL: http://dx.doi.org/10.7910/DVN/SOEKNR.

Citation: Hamilton S.E. 2016 Creation of a Bathymetric Map of Lake Victoria, Africa. http://dx.doi.org/10.7910/DVN/SOEKNR.

Abstract:

A 100 m resolution bathymetric model of Lake Victoria, Africa. The model was created from approximately 4,087,217 points collected by a lead line survey in the 20th Century or recent hydrographic surveys. At least 3,920,000 points are post-2010 surveys using GPS-enabled hydrographic survey systems. The points were either GPS referenced or manually digitized via a process of fitting admiralty maps to the lake shoreline using their graticule. All input data are either non-copyright data collected by our research team or expired UK crown copyright (50+ years old). Points were converted to a raster model by the process of simple kriging. The deepest portions of the lake may not be captured as the lead line had a maximum reach of 200 ft. in some locations. The bathymetric model will continue to be improved as we capture more data. If your research team have additional Lake Victoria bathymetric data, then send the data to us for validation and incorporation. The projection is ESRI: 102024 and the vertical units are meters with a resolution of 1 m. Data include the ~4.2 million bathymetric points, the cross-validation points, the bathymetric raster pictured above, the kriging settings, a standard error map, and the respective world files. Please note the three bays of Mwanza, (TZ) Kisumu (KE), and Port Bell (UG) contain ~120,000 points with the remaining points distributed across the rest of the lake.

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Dataset Name: Lake Victoria Contours.

Period: 1900 - 2017.

Type: GIS vector.

Format: Shapefile, Contour.

Format: These data are created under grant NSF: 1518532.

Stable URL: http://bit.ly/LV_Bathy. For all our data for Lake Victoria please visit https://dataverse.harvard.edu/dataverse/LakeVicFish.

Data URL: http://dx.doi.org/10.7910/DVN/ZSWZIA.

Citation: Hamilton S.E. 2016 Creation of a Bathymetric Map of Lake Victoria, Africa. http://dx.doi.org/10.7910/DVN/ZSWZIA.

Abstract:

A 2 m contour model of Lake Victoria, Africa. The model was created from approximately 4,087,217 points collected by a lead line survey in the 20th Century or recent hydrographic surveys. At least 3,920,000 points are post-2010 surveys using GPS-enabled hydrographic survey systems. The points were either GPS referenced or manually digitized via a process of fitting admiralty maps to the lake shoreline using their graticule. All input data are either non-copyright data collected by our research team or expired UK crown copyright (50+ years old). Points were converted to a raster model using simple kriging. The deepest portions of the lake may not be captured as the lead line had a maximum reach of 200 ft. in some locations. The contours will continue to be improved as we capture more bathymetric data. The projection is ESRI: 102024 and the vertical units are meters with a resolution of 2 m.

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Citable Facts:
Using a 100 m2 grid, we find the average depth of the lake to be almost exactly 40 meters.
At 1:25,000 scale we find the shoreline to be 7,142 km (4,438 mi). This is double earlier estimates, and this is likely due to our higher resolution digitizing.
We cannot state with certainty the maximum depth as the lead line did not hit bottom in all locations and sounding may have missed some areas. We estimate it to be approximately 80 meters and the UN reports 84 meters.
We find the area to be 66,793 km2. This is almost 1,000 km2 (~1.5%) less than earlier estimates and may be partially due to inclusion or not of some wetlands in the south, the inclusion or not of the outflow area into the Nile, the more detailed shoreline and hence islands captured in this analysis, and the projection utilized.We used WKID: 102022 African Equal Area Conic projection for this estimation.
We find the lake contains 985 islands. The earlier UN number was typically around 85 islands.
 
FAQ:
Will the data be updated? As we get more points in an ad-hoc manner.
Where did you obtain the point data? Three major sources: (i) Greater than 90% of the data is acoustic hydrographic data collected by NaFIRRI, TaFIRI, and KMFRI since 2010, (ii) points collected as part of the UK Admiralty map collection greater than 50-years old, and (iii) other old maps.
What is the correct version of the data? Generally, use the latest version.
Can you do "x" for me? Sometimes I can. Usually, I am too busy. Feel free to ask.
Who funded the project? NSF: 1518532 and local fisheries centers.