Hydrological data and modelling

Soil and Water Assessment Tool (SWAT) datasets 

Water Resource Commission project C2019-2020-00089: A South African national input database to run the SWAT model in a GIS

This ongoing study led by Dr Jay le Roux at the University of the Free State will collate multiple geo-spatial datasets at a national scale and interpret/format the data for use as baseline input to run the ArcSWAT model for any catchment in SA. 

> Digital elevation model (DEM) (90 x 90 m)

The hydrologically improved DEM was created from the SRTM 90 x 90 m DEM (Weepener et al., 2012). The extent of the 90 m Improved DEM includes areas in bordering countries for catchments such as the Orange, Molopo and Limpopo Rivers.

> Digital elevation model (DEM) (30 x 30 m) 

The 30 x 30 m DEM for South Africa was created from the Shuttle Radar Topography Mission (SRTM) 30 x 30 m DEM.  The DEM has not yet been hydrologically improved.

> SWAT  Land cover map

This following maps are available in the WRO:

South African National Land-Cover (SANLC) 2013

South African National Land-Cover (SANLC) 2018

South African National Land-Cover (SANLC) 2020

> SWAT Soil type map

This map and attribute table was prepared from the Land Type Database of SA  and is currently undergoing testing in WRC Project  C2019-2020-00089.

> Other SWAT tools:

SWAT-LUT (a standalone user-friendly graphical interface for updating land use in SWAT)

Primary catchment boundaries and rivers overlayed onto the 90 m Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) (Weepener et al., 2012).

HAMSA (under development)

One important aim of the WRO is to have a ‘plug-and-play’ functionality for the Soil and Water Assessment Tool (SWAT) to facilitate hydrological modelling in South Africa. This will be achieved through the application of SWAT within the proposed HydrologicAl Model for South Africa (HAMSA) on-line platform. It is based on HAWQS, a web-based interactive water quantity and water quality modelling system that was developed for the United States. HAWQS substantially enhances the usability of SWAT to simulate the effects of management practices based on an extensive array of crops, soils, natural vegetation types, land uses, and other scenarios for hydrology, as well as for water quality parameters such as sediment, pathogens, nutrients, biological oxygen demand, dissolved oxygen, pesticides, and water temperature.

Other data

Global Runoff Data Centre (GRDC)

Global soil moisture data - European Space Agency (ESA) Climate Change Initiative

ISRIC - Soil and Terrain Database for Southern Africa (SOTERSAF)

Satellite imagery (Modis, Landsat, Sentinel etc.) - we recommend you access these data through Earth Engine, beginner tutorial here

ARC Soil, Climate and Water  - Land Type Maps and Memoirs (catalogue) (pdf)

Water Observation and Information System (WOIS) (Africa) (ESA Tiger initiative)

European Space Agency Land Cover maps and tools

World Resources Institute - Aqueduct (tools to identify and evaluate water risks)