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© 2020. This work is published under NOCC (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

The improved representation of freshwater and estuarine ecosystems and associated data was a key component of the 2018 National Biodiversity Assessment, and is an essential step in enhancing defensible land use planning and decision making. This paper reports on the enhancement of the National Wetland Map (NWM) version 5 for South Africa and other data layers associated with the South African Inventory of Inland Aquatic Ecosystems. Detail is provided on (i) the extent of wetlands mapped in NWM5, compared to previous versions of the NWMs; (ii) the improved extent of inland wetlands mapped in focus areas in NWM5 relative to NWM4; (iii) the type of cover associated with the wetlands (inundated, vegetated or arid); (iv) the ecotone between rivers and estuaries; and (v) level of confidence for the inland wetlands in terms of how well the extent and hydrogeomorphic units were captured for each sub-quaternary catchment of South Africa. A total of 4 596 509 ha (3.8% of South Africa) of inland aquatic ecosystems and artificial wetlands have now been mapped, with NWM5 delineating 23% more inland wetlands (2 650 509 ha or 2.2% of SA) compared with NWM4.The estuarine functional zone, which encapsulates all estuarine processes, and associated habitats and biota, was refined for 290 systems totalling 200 739 ha, with the addition of 42 micro-estuaries totalling 340 ha. Nearly 600 000 ha (0.5% of SA) of artificial wetlands were mapped in SA. Inland wetlands are predominantly palustrine (55%), with some arid (34%) and a few inundated systems (11%). Ecotones between rivers and estuaries, ecotones where biota and processes continuously vary from freshwater to estuarine, formed a small fraction (<1.5%) of river total extent (164 018 km). Most inland wetlands (-70%) had a low confidence ranking for designation of extent and typing, because they were not mapped by a wetland specialist and not verified in the field. Future improvements of the map should be focused on catchment-based improvements, particularly in strategic water-source areas, areas of high development pressure and those with low confidence designation.

Details

Title
National Wetland Map 5: An improved spatial extent and representation of inland aquatic and estuarine ecosystems in South Africa
Author
van Deventer, Heidi 1 ; van Niekerk, Lara 2 ; Adams, Janine 3 ; Dinala, Millicent Ketelo; Gangat, Ridhwannah 4 ; Lamberth, Stephen J; Lötter, Mervyn; Mbona, Namhla; MacKay, Fiona; Nel, Jeanne L; Ramjukadh, Carla-Louise; Skowno, Andrew; Weerts, Steven P

 Council for Scientific and Industrial Research (CSIR), PO Box 395, Pretoria 0001, South Africa 
 Council for Scientific and Industrial Research (CSIR), PO Box 320, Stellenbosch 7600, South Africa 
 Department of Botany, Nelson Mandela University, PO Box 77000, Port Elizabeth 6031, South Africa 
 School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand (WITS), Private Bag 3, Johannesburg 2050, South Africa 
Pages
66-79
Section
Research paper
Publication year
2020
Publication date
Jan 2020
Publisher
Water Research Commission
ISSN
03784738
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2384851785
Copyright
© 2020. This work is published under NOCC (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.