Dynamic Monitoring Of Land Use Change In Longhai County Based On Remote Sensing And Thematic Research

Regional land use change is an important aspect of global change. The problem of population, resources, and environment are intensifying, which lead to remarkable land use change. Longhai County is an important food supplying base and agriculture demonstrating section. With the fast economical development and the rapid increase of population, the county of Longhai has witnessed significant land use changes during the last decade. Remote Sensing technology is very important for monitoring land use change and detecting land use change areas. Based on two satellite images from Landsat TM/ETM+, land use types are measured through the method of maximum likelihood classification. Land use change areas are determined and extracted by using post-classification comparison. For further study on the time and spatial characteristic of land use change in Longhai County from 1989 to 2000, the mathematical methodologies are established. The analysis of the change information indicates that land use in Longhai County has changed greatly during the study period. The areas of the main land-use type such as arable land (paddy field and dry land), orchard, built-up land, unused land, have changed in different extent. Socio-economic data are integrated with land use change data to explore the inherent mechanism in Longhai County. It is found that the main driving forces to land use change in the county include the fast development of industry, the rapid growth of population and the improvement of urbanization, the benefit of agricultural production, et al.With the help of GIS technology, arable land features that are obtained from the results of computer auto-classification, are used to spatial overlay analysis. The change law and tendency of arable land during 11 years inLonghai County are analyzed comprehensively in quantity, space and quality.Jiulongjiang River Mouth is used as a study case. Atmospheric correction, water extraction, image enhancing and interpreting are carried to the remotely sensed data. At the same time Soil Index is introduced to enhance the characteristic of distribution and movement of suspended sediment in the current. The distribution information of suspended sediment in Jiulongjiang River Mouth is extracted and measured by density slicing method. Based on it, the qualitative analysis is implemented for the law and transportation of suspended sediment in Jiulongjiang River Mouth. Moreover, the dynamic changes of coastal lines in Jiulongjiang River Mouth are also analyzed by mask-out and image overlay method.