Environmental impacts of land use and land cover change in the Zhujiang Delta, China: An analysis using an integrated GIS, remote sensing, and spatial modeling approach

This dissertation attempts to apply an integrated approach of remote sensing, GIS, and spatial modeling for environmental studies. The feasibility, advantages, and disadvantages of this integrated approach are investigated through land use and land cover change modeling, environmental impact analysis, and stochastic analysis. By applying this approach to the Zhujiang Delta, this dissertation also attempts to examine the environmental implications of China's economic reform policies. This study finds that the integration among remote sensing, GIS, and spatial modeling is necessary and effective for solving many environmental problems. Integration by exchanging data files among these three elements is feasible in spite of its time-consuming and error-prone nature. Satellite remote sensing collects multispectral, multiresolution, and multitemporal data, and turns them into information valuable for environmental studies. GIS technology provides a flexible environment for entering, analyzing, and displaying digital data from various sources, and can incorporate socioeconomic data necessary for environmental problem solving. However, GIS needs to be further integrated with various spatial modeling techniques, because the current generation of GIS lacks the necessary predictive and analytical capabilities. The case study in the Zhujiang Delta examines its land use and land cover changes and environmental impacts between 1989 and 1997. Results show, first, that urban/built-up areas and horticulture farms have increased, while cropland has decreased. These changes are related to industrial and agricultural development as well as population growth during the period. The spatial process of urban expansion shows an intimate relationship with the distance from major roads and from the geometric center of a city. Second, urban land development tends to bring down greenness, raise surface radiant temperatures, and increase surface runoff. In contrast, horticulture farms promote greenness and lowers surface radiant temperatures. Cropland losses might cause a reduction in greenness and a rise in surface temperatures. The spatial patterns of biomass decrease, radiant temperature increase, and surface runoff change are positively correlated with the pattern of. urban expansion. Finally, Markovian modeling indicates that the land conversion process is not homogeneous in time, indicating temporal changes in the transition mechanism. Future land development in the delta is still unpredictable.