Remote sensing and GIS linked to socio-analysis for land cover change assessment

A land cover change assessment was carried out in Neno Extension Planning Area (EPA), Mwanza District in Malawi within one of the micro watersheds of the Shire River. The assessment linked remote sensing and GIS to socio-economic indicators derived from social surveys in the area under study. The exercise was also part of a capacity building program for natural resource scientists in routine environmental monitoring using remote sensing and GIS techniques. The assessment was carried out by the Department of Forestry in collaboration with Clark University (USA). Landsat TM data for the 1984 and 1994 dry season was acquired and analyzed using IDRISI GIS software. Initially the unsupervised classification technique was applied on the non. traditional false colour composite (bands 3,4,5) yielding an aesthetically unacceptable number of clusters. The clusters were then re-classed to finer categories by visual interpretation before ground-truthing. After ground-truthing, error assessment was carried out and a final number of land cover categories were produced. Socio-economic studies carried out on two villages around the hotspot areas established the causes of the environmental change patterns over time as affected by land use, forest product use, infrastructural development and demography, while the GIS showed where the changes had occurred. The results of the combined analysis indicate that the significant factor for change were agricultural expansion and forest product use. Thus, linking GIS and Socio-analysis techniques provides a unique potential for environmental analyses to support decision-making process