Abstract

Rangeland Productivity Modelling: Developing and Customizing Methodologies for Land Cover Mapping in Namibia

Ms Celeste Espach
Researcher
Ministry of Agriculture, Water & Forestry,
Namibia
Email: cespach@iway.na


There’s an increasing need to precisely describe and classify land cover and land use in Namibia in order to develop sustainable land use systems that are best suited for each agro-ecological zone. Land resources need to be better matched to land use requirements, to increase production, protect the environment and to maintain biodiversity. Land cover mapping formed an integrated part of a pilot project designed to develop methodologies for the quantification of land production potential in Namibia as inputs for land use planning, land valuation, the land taxation programme as well as improved environmental and land management in Namibia. Baseline information on biophysical factors (land cover, vegetation, terrain, soil, climate) and socio-economic factors (land use, farming systems, access to supplies and markets) which influence land productivity in Namibia, were collected and analyzed. The land cover component focused on defining and confirming suitable land cover mapping methodologies, the feasibility thereof, and practical achievable mapping accuracies. A land cover classification system was designed for the whole country and a legend for the pilot area. A land cover map was produced for the pilot area, based on field sample data and supervised classification of multi-seasonal Landsat images. Verification was done through point-based field sample data, an area-based assessment using recent digital orthophotos and a comparison with the MODIS continuous field vegetation dataset. The suitability and limitations of Landsat satellite imagery were investigated for the delivery of desired levels of information in an arid environment. Secondary products of this project are information on the time and costs involved in such an exercise, data requirements and human capacity and infrastructural needs, to be employed in planning the up-scaling of the project to national level at a scale relevant for planning.