Analysis of twenty years of categorical land transitions in the Lower Hunter of New South Wales, Australia

Abstract

Abstract Land use and land cover change (LUCC) studies are drawing increased attention due to their importance in ecosystem management. Post-classification change detection provides a “from-to” change matrix; however, traditional analysis of the change matrix is not sufficient to provide systematic signals of LUCC. This paper analyzes the details of the matrix to compute the quantity, allocation, and dominant signals of land use and land cover (LULC) transitions in a popular tourist destination, the Lower Hunter of New South Wales, Australia. We use classified maps that were derived from Landsat imageries of 1985 and 2005. We applied a change detection analysis based on an extended transition matrix of the two classified maps, and extracted systematic transitions. We then explored how changes are influenced by the resolution of the maps. The net quantity change less than 7% of the study area, while the total change is more than 28%, the latter due to considerable swap changes. Multiple-resolution analysis reveals that about half of the total change is attributable to spatial reallocation of the categories over distances less than 2.3 km. Vineyard has experienced substantial changes in terms of gross gains and gross losses, in spite of its small net change. The three transitions: Pasture/scrubland to Vineyard, Vineyard to Pasture/scrubland and Vineyard to Built-up are the systematic transitions in the landscape. The transition of Vineyard to Built-up around the centre of the study area and the expansion of Vineyard away from centre is associated with tourism, which is also extending into the new outer vineyards and wineries. This in-depth analysis has enabled us to quantify and to visualize the major signals of transitions of LULC categories in the study region.