Using geographic information systems to project behavior of communal farmers in evolution of land use patterns over time

Analysis was done to relate the knowledge local farmers have on land attributes in terms of soil fertility and topography, and to assess their knowledge of site productivity related to crop cultivation. This was linked to the evolution of land use patterns as a result of population increases over time in a communal land farming system in Mabvute Catchment area in Zaka, Zimbabwe.; Classification of land use was done for 1968, 1975, and 1980 using aerial photographs. Data was collected from the area of study on population levels and area of land cultivated for each year going back to 1953. This information was used to build a statistical relationship between population and area of land cultivated. Rates of population growth were obtained from changes in population obtained from the area.; A C-computer language program was written to read the population growth model and use this to project population changes in the future, read statistical model and make projections on land use changes. This was used to estimate area of land required for crop production in the whole watershed in 1980.; Information on site favorability for cropping was used a land attribute in a GIS database. This was linked to demand for land by a GIS database query process that was used to select most suitable sites and allocate them to crop production. The selection process was used to project spatial spread of cropland between 1968 and 1980. Results were used to predict impacts of crop production on the landscape, ecosystem parameters, and hydrology.; Results indicate that the model was able to track changes in land use over time.