Study on Land Use Change and Ecological Response: A Case of the Pearl River Delta Wetland Agricultural Area

Land use has changed rapidly in many wetland-agricultural regions of China over the past 30 years, such as in Pearl River Delta (PRD), resulting in its ecological environment changes as well. In this paper, land use pattern changes and the ecological responses in the PHD were analyzed using Landsat TM data, CBERS data, HJ1 data, and Beijing-1 data, in the late 1980s, 1995, 2000, 2005, 2008 and 2010. The aim of this paper is to improve the understanding of land use change and ecological responses comprehensively in order to assist the sustainable development of the region. Firstly, the mathematical methodology was developed for studying spatial pattern changes of land use, involving the degree index model of land use dynamic, and transformation model of land use. Based on these models, the spatial-temporal process of land use was calculated and analyzed. Then the ecological responses of land use change were analyzed by calculating the landscape indexes and quantifying the ecosystem services value of land use. The results show that the areas of cropland, grassland, wetland and unused land all decreased during five consecutive time intervals, while the area of built-up land, woodland and water body all increased. Meanwhile, the spatial pattern of land use also experienced a great change. The average patch area of cropland continued to decrease and its fragmentation degree increased, while the landscape dominance of water body and built-up land was greater and their distribution tended to be concentrating. Meanwhile, the overall landscape fragmentation degree of the study area decreased. The uniformity of the distribution of different landscape types became higher, and the total ecosystem services value of land-use type decreased by 4.17 million Yuan. The ecosystem services value provided by different land use types and different ecological service functions were also experienced great changes.