Information about the layers available in the NFEPA map
NFEPA WMA maps
National Wetland map 4 (NFEPA wetland map)
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. Wetland condition describes the extent to which a wetland has been modified by human activity. There are many field approaches to assessing wetland condition. However, in the absence of field survey data for most wetlands across the country, wetland condition was modelled by NFEPA to serve as a relative measure that would inform choices in selecting wetland FEPAs.
The flow diagram below shows the data that were used to derive the NFEPA wetland delineations. SANBI’s Wetland Map 1 was used as the base GIS layer. This layer was derived from the National Land Cover 2000, in which wetland polygons are described as “Wetland” or “Waterbody”. The waterbody category does not distinguish between natural or artificial waterbodies. To overcome this problem, SANBI’s National Wetlands Map 1 was combined with the 1:50 000 inland water features from Chief Directorate Surveys and Mapping (DLA-CDSM 2006), to derive National Wetland Map 2 that was divided into 3 GIS layers: wetland, natural waterbody and artificial waterbody. To derive National Wetland Map 3, the wetland and natural waterbody GIS layers were combined to produce a natural waterbody GIS layer. This was then combined with the artificial waterbody GIS layer to produce the National Wetland Map 3, in which wetland polygons have been described as either “natural” or “artificial” waterbodies. Finally, existing sub-national wetland delineations from other biodiversity planning initiatives were added to the National Wetland Map 3 to derive the final NFEPA wetland map. Sub-national data included wetland delineations for:
- Wetlands for the entire KwaZulu-Natal Province (available from Ezemvelo KZN Wildlife);
- C.A.P.E. fine-scale biodiversity planning wetlands of Saldanha/Sandveld, Riversdale plain and Upper Breede River Valley (available from www.bgis.sanbi.org);
- Overberg, Niewoudtville and Kamieskroon wetlands (available from www.bgis.sanbi.org);
- and selected wetlands of conservation importance in Mpumalanga Province (available from Mpumalanga Parks and Tourism Agency).
The delineations were based largely on remotely-sensed imagery and therefore did not include historic wetlands lost through drainage, ploughing and concreting. Irreversible loss of wetlands is expected to be high in some areas, such as urban centres.
Wetland and estuary FEPAs
The NFEPA project was aligned with the National Biodiversity Assessment 2011, which assessed three hundred estuaries along the South African coast. This process resulted in the mapping of the estuarine functional zone (which includes open water area, estuarine habitat and floodplain area) and enabled biodiversity planning to be undertaken using the full extent of the estuary rather than treating the estuary as a point on a map. Biodiversity targets were set for estuarine ecosystem and habitat types, estuarine species, and large scale ecological processes (e.g. connectivity between estuaries). Input data included plant, fish and bird distribution data, estuarine health assessment data, and data on ecological processes (e.g. importance of an estuary as a nursery area for fish). This planning process resulted in the identification of 119 priority estuaries in South Africa. GIS layers used to identify the priority estuaries included the estuarine functional zone, estuary ecosystem types, estuary habitat types, estuarine-dependent species, and estuary condition.
All priority estuaries became FEPAs and the estuarine functional zones were incorporated into the NFEPA Wetland map (National Wetland Map 4). When FEPAs were selected, preference was given to sub-quaternary catchments upstream of priority estuaries, which were used in selecting both wetland and river FEPAs. Wherever possible, river and estuary priorities were aligned but river and estuary condition did not always coincide. Some rivers in a poor condition linked to resilient estuaries able to recover as a result of marine influences, while other estuaries linked to good condition rivers are negatively influenced by local impacts such as coastal developments. This means that in some cases an estuary is identified as a priority but the river upstream is not a FEPA, and vice versa.
FEPA (sub)WMA % Area
Water management area FEPAs
This map shows the percentage of the total area for that Water Management Area that has been identified as a FEPA, calculated for each Water Management Area. This map is intended to convey the message to national level planners and decision makers that the custodianship of freshwater biodiversity is not evenly distributed across the country. Some Water Management Areas have more FEPAs to look after than others (which will make them darker in colour on the map). However, lighter coloured areas still have FEPAs to prioritise, just not as many. An important policy question is how we can support Water Management Areas with a high proportion of FEPAs in achieving our national freshwater ecosystem goals.
Each Water Management Area proportion of FEPAs ranges between 10% (Berg WMA) and 38% (Thukela WMA). This variability is a consequence of river and wetland ecosystem heterogeneity and fish species distribution. For example, the Inkomati and Usutu to Mhlathuze Water Management Areas have high river ecosystem heterogeneity, and therefore a high proportion of FEPAs (32 and 33% respectively).
The proportion of FEPAs in each Water Management Area is also influenced by river condition, because only rivers that are still in good condition (A or B ecological category) can be chosen as FEPAs. For example, the Crocodile (West) and Marico and Olifants Water Management Areas have high river ecosystem heterogeneity, but there are no longer sufficient rivers in a good condition to meet biodiversity targets for river ecosystems, reducing the number of FEPAs identified.
The small proportion of FEPAs identified in these Water Management Areas are generally the only ones left in a good condition. This means that FEPAs in low density Water Management Areas are no less important than those in high density areas. In fact, in cases where low density of FEPAs results from poor condition of rivers and wetlands, the FEPAs that have been identified are arguably more important.
Sub water management area FEPAs
Water Management Areas (WMA) is divided into several Sub-WMAs with the division broadly based on the catchments of large tributaries within the Water Management Area.
The sub-WMA map shows the proportion of each sub-Water Management Area identified as a FEPA, calculated as the percentage of the total area of that sub-Water Management Area identified as a FEPA or associated sub-quaternary catchment.
The map shows that even within Water Management Areas, freshwater biodiversity is not evenly distributed. This has important implications for the development of Catchment Management Strategies, which often use sub-Water Management Areas in the catchment visioning process, and are often managed and implemented at sub-Water Management Area level. Sub-Water Management Areas are also often the level at which water user forums operate. In allocating resources within the Water Management Area, it is important to bear this in mind.
Fish sanctuaries
Fish sanctuaries all species
This layer supports the fish sanctuaries layer by providing a list of all threatened and near-threatened fish species within fish sanctuaries. The aim of identifying these sanctuaries is to keep further freshwater species from becoming threatened and to prevent those fish species that are already threatened from becoming extinct. Fish species with an IUCN status of Critically Endangered or Endangered are identified in this layer. Expert opinion was also used to update the IUCN status for some fish species. Expert opinion status (based initially on IUCN status) is provided for each species and was used to distinguish between sub-quaternary catchments that contain at least one population of Critically Endangered/Endangered versus those containing at least one population of Vulnerable, Near-threatened species.
Fish sanctuaries
Fish sanctuaries are sub-quaternary catchments that are essential for protecting threatened and near-threatened freshwater fish populations that are indigenous to South Africa. They were used by NFEPA as species biodiversity surrogates to supplement the representation of river ecosystem types. A goal of NFEPA is to keep further freshwater species from becoming threatened and to prevent those fish species that are already threatened from becoming extinct.
The SAIAB/Albany fish data were used to guide the choices. This map provides a summary of what the sub-quaternary catchment status is in terms of being selected as a FEPA, Fish Support Area, Fish Relocation & Translocation Area, Fish Rehabilitation Area and Migration Corridors for threatened and near-threatened fish indigenous to South Africa. The distribution of each threatened fish species was examined, using fish point locality data from the South African Institute for Aquatic Biodiversity (SAIAB) and the Albany Museum. These data were supplemented with expert knowledge from experienced fish biologists in different regions of the country. Historical records deemed no longer valid (owing to local extinctions) were excluded. As far as possible, known ‘viable’ populations of fish were chosen as fish sanctuaries, defined as self-recruiting populations. In addition, confirmed localities that were not in the original data, but that were known by regional fish biologists were considered. River condition was used to guide decisions where choices existed, but it was not used as a driving factor because in many cases options only exist for conserving these species in modified rivers (habitat degradation is one of the main drivers affecting conservation status).
Fish sanctuary maps were identified for each species, with five possible categories listed here from the highest to lowest level of protection required:
Fiish sanctuaries: These are sub-quaternary catchments required to meet fish population targets.
- Fish rehabilitation areas: Sub-quaternary catchments which are highly suitable for the re-introduction of threatened fish species that once occurred there, but have since been extirpated, were identified as fish sanctuaries. All of these require some level of habitat rehabilitation and/or the eradication of alien fish species before re-introduction can take place. Fish rehabilitation areas were treated in the same way as fish sanctuaries in the planning process.
- Fish translocation areas: Sub-quaternary catchments where threatened fish species have already been translocated to, outside the known indigenous range. These populations were only selected if the translocation formed part of a conservation intervention and only when the intervention is still seen as a valuable contribution to the conservation of the species. Fish translocation zones were treated in the same way as fish sanctuaries in the planning process.
- Fish migration corridors: Provide links between certain habitats (usually between mainstem and tributary habitat) necessary for the migration of threatened migratory fish species. Fish migration corridors are shown as Fish Support Areas on the FEPA maps, but differ from fish sanctuaries, and fish rehabilitation and translocation areas in that they do not contain a fish symbol on FEPA maps. Fish migration corridors were considered to be lower priority areas compared to fish sanctuaries, and fish rehabilitation and translocation areas, but higher than fish upstream management areas.
- Fish upstream management areas: These are sub-quaternary catchments in which human activities need to be managed to prevent degradation of downstream fish sanctuaries, fish rehabilitation and translocation areas, and fish migration corridors. All fish upstream management areas became Upstream Management Areas on the FEPA maps, although some of the fish upstream management areas were subsequently identified as FEPAs to represent river ecosystem types. Fish upstream management areas were considered the lowest priority areas for the conservation of fish species.
The different areas for the conservation of threatened fish were combined for all species. This resulted in some sub-quaternary catchments containing a mixture of fish sanctuaries, fish rehabilitation and translocation areas, fish migration corridors, and fish upstream management areas for different species. In instances where a sub-quaternary catchment containing more than one fish species had such mixture, it was coded as the category with the highest level of protection. The sub-quaternary catchment area necessary to conserve South Africa’s threatened freshwater fish species is 13%.
The combined GIS layer for fish sanctuary maps was used with river condition to divide fish sanctuaries, and fish rehabilitation and translocation areas into FEPAs and Fish Support Areas, where fish sanctuaries in a good condition (A or B ecological category) were selected as FEPAs, and the remaining ones became Fish Support Areas.
Wetland ecosystem types
Wetland ecosystem types were used by NFEPA for representing natural examples of the diversity of wetland ecosystem types across South Africa. Wetlands of the same ecosystem type are expected to share similar functionality and ecological characteristics. The biodiversity target for freshwater ecosystems in South Africa is 20%, which means that we should keep at least 20% of each wetland ecosystem type in a natural or near-natural condition. This serves to conserve many common species and communities, and the habitats in which they evolve. The coarse-filter surrogate provided by wetland ecosystem type was supplemented with information on Ramsar status, known threatened frog and waterbird occurrences along with expert knowledge on biodiversity importance. These additional data sources were also used in identifying wetland FEPAs.
Wetland ecosystem types were classified according to the national wetland classification system (SANBI 2009). It is a hierarchical classification framework consisting of six levels, with each level requiring increasing levels of detail about the wetland. Level 1 separates wetlands into inland, marine and estuarine systems. Levels 2 to 4 identify broad groups of wetlands sharing similar regional context, landform and broad hydrology. Levels 5 and 6 describe site characteristics such as hydroperiod, geology, vegetation, substratum, salinity, pH and naturalness.
NFEPA automated the classification procedure using GIS, to Level 4 of the national wetland classification system, which describes seven wetland hydrogeomorphic types using the landforms, wetland vegetation groups and the 1:50 000 pans GIS layer (Department of Land Affairs: Chief Directorate Surveys and Mapping 2005 - 2007) and 1:500 000 river network GIS layer. These include depressions, floodplains, valleyhead seeps, channelled valley-bottom wetlands on valley floors, unchannelled valley-bottom, unchannelled valley-bottom wetlands on plains, flats on plains, flats on benches and seeps. Each wetland was assigned the wetland vegetation group that occupied the majority of its area, to characterise the regional context (e.g. climate, soil, geology) within which the wetland occurs. For each wetland, the hydrogeomorphic type was combined with its corresponding wetland vegetation group, producing 791 distinct wetland ecosystem types across the country.
SANBI (South African Biodiversity Institute). 2009. Further Development of a Proposed
National Wetland Classification System for South Africa. Primary Project Report.
Prepared by the Freshwater Consulting Group (FCG), South African National
Biodiversity Institute, Pretoria, South Africa
High groundwater recharge areas
Groundwater is essential for sustaining river flows during dry seasons. It is a process whereby rainwater seeps into groundwater systems and is calculated as an average over many years. Rainfall and geological permeability are the two main factors on which recharge is dependant and will vary among areas. An area where recharge is high is considered to be the recharge hotspots and it is essential that vegetation in these areas is kept intact to maintain the healthy functioning of groundwater dependent ecosystems, which are in the immediate vicinity or several kilometres away from the recharge area.
The map was derived using the 2005 groundwater resource assessment data, at a resolution of 1 km x 1 km (DWAF 2005). Groundwater recharge (mm per year) for each 1 km x 1 km cell was expressed as a percentage of the mean annual rainfall (mm per year) for that cell. This gave a relative idea of where the proportionally highest recharge areas are in the country, compared to using absolute numbers (mm per year). Percentage recharge for each sub-quaternary catchment was expressed as the percentage recharge for the relevant primary catchment to identify areas where groundwater recharge is at least three times more than that of the primary catchment.
Department of Water Affairs and Forestry (DWAF). 2005. Groundwater Resource
Assessment II: Recharge Literature Study Report 3A. Department of Water Affairs and
Forestry, Pretoria, South Africa
