NBA2018_Rivers500_PES2017_and_all_dams_AEA2

This GIS layer summarizes the river condition, river ecosystem types, flagship and free-flowing river information.

This is a second update of the NBA rivers layer which was issued with the launch of the NBA 2018, and includes the condition, Ecosystem Threat Status (ETS) and Ecosystem Protection Level (EPL) information for the rivers. Mapping the locality of wetlands is essential so that they may be classified into the different wetland ecosystem types across the country, which in turn can be used along with other data to identify wetlands of conservation significance.

Van Deventer, H., Smith-Adao, L., Mbona, N., Petersen, C., Skowno, A., Collins, N.B., Grenfell, M., Job, N., Lötter, M., Ollis, D., Scherman, P., Sieben, E. & Snaddon, K. 2018. South African National Biodiversity Assessment 2018: Technical Report. Volume 2a: South African Inventory of Inland Aquatic Ecosystems (SAIIAE). Version 3, final released on 3 October 2019. Council for Scientific and Industrial Research (CSIR) and South African National Biodiversity Institute (SANBI): Pretoria, South Africa. Report Number: CSIR report number CSIR/NRE/ECOS/IR/2018/0001/A; SANBI report number http://hdl.handle.net/20.500.12143/5847.

There are no access limitations for this item.

There are no access limitations for this item.

WGS 1984

Projection: Albers

False_Easting: 0.0

False_Northing: 0.0

Central_Meridian: 25.0

Standard_Parallel_1: -24.0

Standard_Parallel_2: -33.0

Latitude_Of_Origin: 0.0

Linear Unit: Meter (1.0)

The GIS layer of origin is the 1:500 000 rivers data layer that DWA has coded for geomorphological zonations. CSIR subsequently used this layer to add information. 97 coastal rivers were added from the Chief Directorate Surveys and Mapping’s (CDSM) 1:50 000 rivers GIS layer. Add-in rivers were based on missing South African estuaries along the coast line. In the regional review workshops, experts were asked to highlight any other rivers of conservation significance and the layer was updated.

Free-flowing rivers were expertly reviewed and updated during the NFEPA project in 2011. The PES of rivers was updated during 2016/17, which included the free-flowing and flagship rivers. The artificial wetland was also updated during the NBA 2018 process and together with the DWS dams_2016 layer the free-flowing and flagship rivers were reassessed according to the set criteria above. Where dams and artificial wetlands intersected with the free-flowing and flagship rivers and condition change occurred. River condition in free-flowing rivers also changed after the confluence with a degraded tributary. In these cases the free-flowing/flagship rivers’ PES status was updated to reflect the change resulting in some free-flowing/flagship rivers being removed from the list identified during the NFEPA process. However, where the free-flowing river was identified in the expert consultation process, regardless of the “C” PES condition, the river remained free-flowing/Flagship. Where no river condition changes were recorded the free-flowing/Flagship rivers remained unchanged.

For the NBA 2018 the PES of rivers was updated during 2011/17, which included the free-flowing and flagship rivers. The artificial wetland was also updated during the NBA 2018 process and together with the DWS dams_2016 layer the free-flowing and flagship rivers were reassessed according to the set criteria above. Where dams and artificial wetlands intersected with the free-flowing and flagship rivers, condition change occurred. River condition in free-flowing rivers also changed after the confluence with a degraded tributary. In these cases, the free-flowing/flagship rivers’ PES status was updated to reflect the change resulting in some free-flowing/flagship rivers being removed from the list identified during the NFEPA process (Van Deventer, et al., 2018; Skowno et al., 2018).

SANS 1878

FGDC-STD-001-1998