Research On Characteristics Of The Spatial-Temporal Of Land Use Changes And Driving Force In The Dongjiang River Basin Of Huizhou

Dongjiang River basin in Huizhou, located in the middle reaches and lower reaches of Dongjiang River Basin. It is widely recognized that land use change is a major cause of environmental changes. The Dongjiang River basin in Huizhou has undergone rapid urbanization along with growing economy during the year from 1990 to 2005, which, in turn, has led to great regional land use changes over space and time. Land-use issues of Dongjiang River basin in Huizhou and the resulting environment, the contradiction between people and land issues, will be seriously hampered social and economic sustainable development. It is very important to study the land use change of law and its driving force for optimizing land use, improving and protecting the ecological environment of the Dongjiang River basin in Huizhou, it is also very important to ensure abundant water resources and quality of the Dongjiang River basin. In short, it is very important for sustainable development of the population, resource and environment in east of the Pearl River Delta region as well as Hong Kong.In this paper, the spatial-temporal characteristics of the land use change in the basin from 1990 to 2005 were quantified and comprehensively analyzed through performing change detection on the basis of interpretation of Landsat TM/ETM+ images acquired in 1990, 2000, and 2005. Some quantitative indexes were adopted, involving land use change, annual change rate, and transition matrix. Meanwhile, the gray relational analysis is used to identify the main factors of driving force which impact the various types of land use changes in the area. The main conclusions of the research are:(1) The major land covers are forest and cropland. During the study year, the area of forest and cropland sharply decreased, the percentage of the total area of forest and cropland is 90.05% in 1990 and 88.79% in 2000 down to 86.50% in 2005, the area of construction land increased significantly, from 2.89% in 1990 to 4.35% in 2000 to 6.58% in 2005, The relative change extent of water area and grassland was little water, grassland area decreased slightly.(2) Significant land use changes have taken place in the basin during the period 1990-2005, implying that the region has been experiencing processes of rapid urbanization and a prominent adjustment of the land use structure, which were demonstrated by increases in human-related land use, e. g., the urban built-up areas and decreases in natural land use types, e. g., forest, cropland, water area and grassland.(3) There exist obvious regional differentiation in land use change across the basin during the study year. Comparing with the period 1990-2000, the period 2000-2005 exhibited a more marked increase in the amount of land use change and a increase in the annual change rate.(4) The main directions of land use types transfer were the conversions between woodland and construction land, the conversions between cropland and construction land.There were 266.41km2 crop land transfer to construction land during the period 1990-2000, and 219.18 km2 during the period 2000-2005.(5) Population growth, rapid economic development and technology are probably three major drivers for the spatial-temporal land use changes occurring in the basin. Urbanization level, technology and population is the main driving force of cropland change. the urbanization level, population and economic development is the main driving force of construction land. population and urbanization level is the main driving force of forest and water area. technology, population is the main driving force of grassland area.