A DECISION SUPPORT SYSTEM FOR REHABILITATION AND MANAGEMENT OF RIPARIAN SYSTEMS
The field of river rehabilitation or restoration has experienced considerable growth in the last decade, particularly in Europe, the United States of America and in Australia. In contrast, while there is a growing research interest in river rehabilitation in South Africa, very few significant rehabilitation projects have been undertaken and there is a lack of guidelines specific to South Africa. One of the significant areas of progress in Australia has been the development of a framework for planning rehabilitation projects. This framework was adopted, with slight modification, as the basis for river rehabilitation planning in the project and specific research projects were undertaken to develop components of a decision support system to assist in the planning and implementation of rehabilitation projects.
This research project represents an initial level of investigation aimed at developing a set of tools and approaches that would have general applicability for river rehabilitation in South Africa. They have been developed principally for application in agricultural landscapes, and for streams of third order or less. Achievements of the project are reported with reference to the stated project objectives below:
- Formulation of a procedure which identifies and prioritises sites of intervention and promotes cost-effective rehabilitation of land and riparian systems, and integration of this procedure with the linkages identified in (iv) below
A planning framework and process for river rehabilitation in South Africa was adapted from work done in Australia, as well as on the basis of experience elsewhere in the world. The following techniques, protocols and methods (decision support systems) developed by the project fit sequentially into this framework:
Evaluation of the application and transferability of the procedure to other river systems
- An approach for mapping landscape scale assets
- A methodology for identifying and mapping wetland boundaries from satellite imagery, as well as a new field-based approach to be used in conjunction with the current wetlands delineation procedures
- A technique for identifying and mapping riparian, stream bank and in-channel assets and problems at the scale of a river reach
- A GIS based protocol for identifying priority river reaches for rehabilitation and buffer establishment for sediment control, particularly relevant to the sugar and forestry industries
- A protocol for assessing the nitrate attenuation potential of riparian zones, as well as a protocol for sizing riparian buffers to achieve an approximately 65% reduction in nitrates, particularly relevant to commercial agriculture
- A prototype decision support system for selecting appropriate techniques for:
- streambank rehabilitation
- riparian zone rehabilitation
- A database of appropriate plant species for rehabilitation in South Africa
A specific criterion in the development of the above protocols and decision support systems was to make the approach as broadly applicable as possible. The work leading up to these protocols and methods was tested in a number of areas in KwaZulu-Natal including the Mhlathuze catchment, Maputaland, Natal Midlands, the Drakensberg. While some aspects of the project have focussed on a catchment in the Western Cape, the principal area of application and testing has been KwaZulu-Natal.
However it should be stressed that there is the expectation that the approaches developed will be applicable throughout South Africa, although a full testing and evaluation of all aspects was beyond the scope of this phase of the project. This has emerged as a key recommendation for further research.
Development and enhancement of capacity in rehabilitation and river management amongst previously disadvantaged groups
Development and enhancement of capacity in river rehabilitation and management has been achieved through the following means:
Establishment of effective conceptual and operational linkages between the Land Care initiative of the Department of Agriculture (Directorate of Resource Conservation), management of rivers (Department of Water Affairs and Forestry; River Health Programme, Working for Water Campaign, Ecological Reserve determination initiatives) and other research initiatives (e.g. WRC funded project on DSS development in the Mhlathuze catchment, various initiatives at the Centre for Water in the Environment, University of the Witwatersrand)
- Inclusion of the approach, protocols and decision support systems as a 3-day module within the Integrated Catchment Management elective in the CEAD Masters Programme in 2000 and 2001. This resulted in 15 students being trained in the fundamental principles of river rehabilitation, 3 of which came from previously disadvantaged backgrounds.
- Ten of these students received further mentoring and training as they elected to undertake their dissertation research within the framework of this WRC Project. Four of these students came from previously disadvantaged backgrounds. Four of the eight students who graduated with masters degrees received distinctions for their research products.
- The training course in river rehabilitation in 2002 resulted in a further 20 people being trained, 6 of which came from previously disadvantaged backgrounds.
The various papers presented in the appendices of this report provide a full description of the various methods, protocols and decision support systems. For further detail the six masters dissertations may be consulted. The six appendices provide specific recommendations for further research, development and testing. However two over-arching recommendations are summarised here:
- Catchment-scale implementation, testing and refinement
The principal recommendation emerging from this research is that the techniques and protocols should be tested in a relatively small catchment (<300km2) and through implementation of the rehabilitation planning framework with stakeholders in the catchment. Undertaking this exercise on a catchment basis with an emphasis on establishing priorities for action will provide a rigorous basis for evaluating the utility of the techniques and protocols and will assist in identifying further development needs. Such an exercise could form a sound basis for the development of a catchment management plan.
- Establishment of regional (provincial) centres of expertise
This research project has resulted in the accumulation of a considerable set of resources on river rehabilitation and management. The project has also generated a fair amount of expertise and a number of developing techniques and protocols. Establishing regional centres of expertise would provide a node for the continued development of the discipline and also a resource for stakeholders to access.
The project team acknowledges the financial support of the Water Research Commission and the University of Natal. The support of the staff of the Centre for Environment and Development, and particularly David Catherine and Kerry Roberts is gratefully acknowledged. The contribution of the Steering Committee to the success of the project is noted with thanks. The Steering Committee included: Mr Stuart Armour, Prof Charles Breen, Mr Keith Cooper, Prof Digby Cyrus, Prof Rob Fincham, Mr Peter Gardiner, Dr Peter Goodman, Dr Kathy Hurley, Prof Bruce Kelbe, Ms Jenny Mander, Dr Sizwe Mkhize (WRC Manager), Dr Steve Mitchell (WRC Manger), Ms Anet Muir, Ms Geraldine Munro, Prof Kevin Rogers, and Mr Tony Tucker.