The South African National Space Agency (SANSA) has signed a multi-user government licencing agreement to distribute GeoTerraImage’s Mzansi Amanzi national monthly water data products to all South African government departments and their consultants.
The National Water Quantity Information Service, as it’s known under SANSA, is a satellite-based dams volume calculator that runs as a web application in the cloud. It extracts information from Sentinel-2 satellite imagery to calculate the national coverage, monthly surface water extent (area) and dam water volume information of man-made water bodies in South Africa. This is used to estimate usable water supply volume in a particular area. Natural water bodies have been excluded as these tend to be temporary and seldom sustainably suitable for water supply.
The service forms part of SANSA’s Earth Observation Programme, and the country’s Department of Water and Sanitation is already using this data, with other departments having expressed an interest in it. The full set of data can be obtained from the agency as monthly spatial or tabulated (spreadsheet) datasets, namely:
- spatial and numeric data on total surface water location and extent
- spatial and numeric data on individual man-made dam volumes
- spatial and numeric data on summarised total dam volumes per quaternary catchment for the category 2, 3 and 4 dams (Category 1 large dams are reported individually as they often cross several quaternary catchments)
Data for the service date back to January 2016, and will run until the end of June 2022 when the contract ends. Licenced users may retain the data after the contract expires, but may not use it to develop similar or competing products. SANSA says it will use this data to develop further products and services, such as water quality monitoring, dam sedimentation reviews and drought indices.
This national water quantity information is generated with data modelling procedures created jointly by GeoTerraImage and Ekosource. The system is constantly being refined with information from the field to improve the information over time. While it is not a public access service, a portion of the information is publicly viewable through a web map viewer.