Spatial and temporal characterization of land-use in the Buffalo National River Watershed

Abstract

Today there is much concern about the potential contamination, overuse and development of scenic rivers in more or less pristine environments. The objective of this work was to quantify the spatial and temporal changes in land-use occurring in a watershed draining a nationally protected river. The Buffalo National River of Arkansas was chosen to serve as an example of how Geographic Information System (GIS) technology can rapidly assess the environmental changes that have occurred within a watershed. GIS was used to develop a spatial database of the watershed and to describe differences in land-use data from five sample years during 1965–92. Over this time span, approximately 40 000 ha of forest were lost and converted primarily to pasture. The average rate of loss of forest was 1480 ha/yr. During this same period, the average rate of gain of pasture was 1381 ha/yr. Buffer analyses showed that pasture increased at a higher percentage rate in the buffer zones surrounding the Buffalo River than in the tributaries of the Buffalo River, and a large proportion of the increase was on higher slopes. Land-use changes were dynamic with a greater area converted to pasture than area of pasture converted to forest in the watershed. The cleared forest lands were mostly near older pastures and along streams. The reforested lands tended to occur in the more isolated areas. The Buffalo River Watershed has undergone changes in land-use that may have had impact on the water quality of the region.