Modeling urban growth in the middle basin of the Heihe River, northwest China

The middle basin of Heihe River has witnessed rapid urban growth and excessive agricultural activities during the last two decades, mainly because of its economic development and increasing population pressure. In this study, we aimed to understand the growth dynamics of the region, to forecast its future expansion, and to provide a basis for regional management. We calibrated and validated a SLEUTH model with historical data derived from different sources, which comprised remotely sensed and strategic planning data records from 1995, 2000, 2005, and 2009. Three scenarios based on local regional ecological planning were designed to simulate the spatial pattern of urban growth in different conditions. The first scenario allowed urban expansion without any additional managed growth limitations and the continuation of the actual historical trend. The second scenario was limited based on environmental considerations and managed growth was assumed with moderate protection. The third scenario simulated managed growth with strict protection on wetland reserves and productive agricultural areas in the study area. We consider that the results of these models of growth in the study area obtained under different scenarios are of great potential use to city managers and stakeholders. We also suggest that scale sensitivity and spatial accuracy are among the factors that must be considered in practical applications. We urge future researchers to build on the present study to produce models for similar regions in northwest China.