Overview

Recognizing the ecological, social and economic importance of wetlands, as well as their threatened status in South Africa, the Wetlands Conservation Programme of the Department of Environmental Affairs and Tourism has committed itself to setting up a national wetland inventory. The project aims to:

• identify where wetlands are, and which are the priority sites for conservation;
• identify the functions and values of each wetland site, including ecological, social and cultural values;
• establish a baseline for measuring future change in wetland area, function and values;
• assist in establishing monitoring programmes;
• provide a tool for planning and management at all levels; and
• permit comparisons and information sharing at all levels (local, national and international).

The inventory was launched at a workshop in November 1997, which was attended by a range of stakeholders including government departments, NGOs, conservation bodies and research institutes. The workshop built on the groundwork laid by an earlier meeting, held in 1988 by the Foundation for Research Development, on wetland inventory and classification.

During the first stage of the inventory, South Africa's wetlands will be mapped and classified. Mapping consists of identifying and delineating wetlands from remotely-sensed images. In order to accomplish this, a wetland classification system, by which the various wetland habitat types are ordered into groups with certain shared natural attributes, has been developed. This was accomplished by modifying for South African use the classification system successfully used by the United States National Wetland Inventory for almost twenty years, known as the Cowardin system. The use of such a system will aid decision-making for conservation and management, facilitate mapping, and provide a means to standardise and define terms used to describe various wetland types.

Aerial photographs are currently considered to be the most accurate form of remotely sensed data for identifying and delineating wetlands. As a general rule, all wetlands conforming to the definition adopted for the inventory and that can be accurately identified and mapped from aerial photos will be included in the inventory. At a 1:50000 scale, the minimum mapping unit is 0.25 hectares.

The extent of wetland information generated by the mapping exercise will be limited to delineated boundaries, location and classification for each wetland. Supplementary attribute information necessary to determine the functions, values and condition of each site will be supplied by using existing inventory information and field surveys. A database coupled to a Geographical Information System will be used to store and manipulate the data generated by the inventory. The database will be maintained by the DEAT, and most of its contents will be available to anyone requiring inventory information.

The most useful products of the inventory will be wetland maps covering the entire country at a scale of 1:50000, which will show where wetlands are located, their boundaries and classification. Wetland attribute information contained within the database will be made available in digital format, possibly by means of the Internet. A variety of reports will be generated by synthesizing the inventory data. These reports will range from site and attribute-specific outputs to national wetland status and trends reports. These reports will be especially valuable in assessing the effectiveness of wetland conservation policies and programmes.

Following the national workshop in November 1997, where the needs and expectations of stakeholders in the inventory were put forward, several products have been developed which will ensure a firm foundation for the inventory: