Mapping of water-related ecosystem services in the uMngeni catchment using a daily time-step hydrological model for prioritisation of ecological infrastructure investment – Part 1: Context and modelling approach

Authors

  • CJ Hughes Centre for Water Resources Research, University of KwaZulu-Natal, Rabie Saunders Building, Carbis Road, Pietermaritzburg, South Africa
  • G de Winnaar GroundTruth Water, Wetlands and Environmental Engineering, 9 Quarry Road, Hilton, South Africa
  • RE Schulze Centre for Water Resources Research, University of KwaZulu-Natal, Rabie Saunders Building, Carbis Road, Pietermaritzburg, South Africa
  • M Mander FutureWorks, The Southern Right, Brenton on Sea, Knysna, South Africa
  • GPW Jewitt 1. Centre for Water Resources Research, University of KwaZulu-Natal, Rabie Saunders Building, Carbis Road, Pietermaritzburg, South Africa; 2. Umgeni Water Chair of Water Resources Management, University of KwaZulu-Natal, South Africa

DOI:

https://doi.org/10.4314/wsa.v44i4.07

Keywords:

water, ecosystem services, hydrological modelling, ecological infrastructure, water security

Abstract

South Africa is a semi-arid country which frequently faces water shortages, and experienced a severe drought in the 2016 and 2017 rainfall seasons. Government is under pressure to continue to deliver clean water to the growing population at a high assurance of supply. Studies now show that the delivery of water may be sustained not only through built infrastructure such as dams and pipelines, but also through investment in ecological infrastructure (EI). A daily time-step hydrological model was used to map areas which should be prioritised for protection or rehabilitation to sustain the delivery of water-related ecosystem services within the uMngeni catchment. We focused on three water-related ecosystem services, i.e.: water supply, sustained baseflow, erosion control/avoidance of excessive sediment losses. The two key types of degradation were modelled, namely, overgrazing and the invasion of upland areas by Black Wattle (Acacia mearnsii). This, Part 1 of a paper in 2 parts, provides a discussion on the role of EI in delivering water-related ecosystem services, describes the motivation for the study, and the methods used in modelling and mapping the catchment. The results of this modelling exercise are presented in Part 2, which also explores and illustrates the potential hydrological benefits of rehabilitation and protection of EI in the uMngeni Catchment.

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Published

2018-10-31

Issue

Section

Research paper

How to Cite

Mapping of water-related ecosystem services in the uMngeni catchment using a daily time-step hydrological model for prioritisation of ecological infrastructure investment – Part 1: Context and modelling approach. (2018). Water SA, 44(4 October). https://doi.org/10.4314/wsa.v44i4.07