South African National Wetland Inventory

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. Several products have been developed which will ensure a firm foundation for the inventory: - Proceedings of the National Workshop of the national workshop, which describes the inventory process in detail and lays out the way forward for the inventory; - A catalogue of existing inventory information in South Africa.

This inventory of inventories was produced with the aim of assisting those in urgent need of inventory information to find available data. It will also provide a reference guide to sources of spatial and attribute information that will assist wetland mapping and population of the inventory database; - A discussion document describing in detail the proposed wetland classification system for South Africa. Information was obtained from "ngo.grida.no/soesa/nsoer/resource/wetland/inventory.htm".