Spatial Patterns and Gradient Heterogeneity of Driving Forces of Landscape Change in Foshan City

Great attentions have been paid on landscape pattern changes and the driving forces for rapidly urbanizing areas in recent years.Based on TM images of Foshan City in 1991 and 2005,landscape metrics,landscape change driving forces index(LCDI) and landscape gradient index(LCGI) were selected to analyze the changes of landscape pattern and spatial gradient heterogeneity of driving forces with GIS and geostatistics.The results indicate that the landscape pattern changed remarkably from 1991 to 2005.Changes of cultivated lands and constructional lands were dominant in the whole landscape change.The area of cultivated lands reduced greatly from 37.50% to 15.09%.Meanwhile,the total area of construction lands increased 98 570 hm2 during 1991—2005,with the highest LCDI value.According to the results of landscape metrics analysis,the fragmentation degree of cultivated lands and garden lands were relatively high,due to the intense human disturbances in these lands.Woodlands showed symmetrical spatial characteristics.Construction lands had the highest fragmentation degree of all the landscapes in the city,although strong spatial distribution centrality was found in constructional lands.Through spatial analysis on synthetic driving forces of the landscape changes,the spatial gradient heterogeneity became increasingly evident from 1991 to 2005,closely related to landscape patterns and driving forces.Spatial gradient analysis on driving mechanism of landscape pattern change is proven helpful in identifying the relationship between landscape patterns and processes,which could potentially enhance our understanding of the pattern and direction heterogeneity of landscape pattern changes.