Study On Land-cover Change And Its Ecological Benefits In Coastal Zone Of Southern Fujian

Abstract:Fujian Province is the maritime province, there are a vast sea and a number of rich marine resources. Its coastline is 3752km, and it is the second highest in the nation and the first winding rate in the country. Minnan coastaline is about half of the coastaline of Fujian Province, so its coastal zone has a very good representation. Economic and social development needs the expanding of the city with its shoreline resources inevitably decline. This research is based on remote sensing, geographic information system techniques to study the major land use and land cover change, analysis the reasone of vegetation cover change and changes to its water resources, analysis the trends of ecological security and make a comprehensive assessment of the ecological effects of proposed land use. To improve the economic, social and environmental sustainability.The following major elements:1,Based on remote sensing data of 1994,2001 and 2006. Using ERDAS software to make landscape type maps, calculate the area of landscape patches, number, shape and other spatial characteristics. The results showed that:(1) The area of woodland drop sharpply between 1994-2001; and the total forest area remained between 2001 and 2006. Human occupation of forest land, forest fires, pests and diseases are the most important factor of the area change. Grassland and unused land are the greatest degree of human disturbance. (2) From 1994 to 2006, the strong change of patches number Explain that the level of protection of human being on the land and cultivated land fragmentation is inversely, and the protection of human on farmland is significantly. (3) The human activities on the impact of landscape fragmentation and the intensity of human activitiesbasic is proportional relationship. Since 1994 to 2006, the more intense human activities, the greater the degree of landscape fragmentation. (4) The activities of human on the overall landscape dominance is very significant. Embodied in urban and rural areas, the proportion of its area rise in the last 12 years. Comprehensive view, increased urbanization, population growth, industrial development will undoubtedly have negative effects to coastal landscape2,Based on the 1994 Landsat TM (thematic mapper), the 2001 Landsat ETM+ (enhanced thematic mapper) and 2006 Landsat TM satellite images of three-phase, explore the changes of the water between 1994 and 2006. To obtain Change information of the water with detection and information extraction and a series of remote sensing technology. The results showed that the waters increased 2652 hm2 between 1994 and 2006. Between 1994 and 2001, which reduced 7148hm2, mainly in the south of the study area, urban land expansion of the study area, and the development of aquaculture caused reduction of the sea in that period. from 2001 to 2006, the area of the sea increased 9800 hm2, in east interchange of South port,north port,middle port of the Jiulong River, the sea area increase the most dramatic; followed by the Quanzhou City Luoyang River waters and Tongan Bay, Dadeng Island and the sea area of Nanan City. The reason is over-development of aquaculture wetlands, and destruction of coastal mangroves, causing part of the beach area reduced, water area increase finally.3,Based on vegetation index (NDVI) and vegetation cover as the decomposition model, a vegetation coverage of remote sensing quantitative model was made within a TM image scale, based on the studies of 3 Dynamic changes of vegetation coverage in 1994,2002 and period of 2006. The results showed that:(1) From 1994 to 2006, high vegetation cover reduces 64110 hm2, middle vegetation coverage increased 7263hm2, low vegetation cover reduces 15799.5hm2. (2) From 1994 to 2001, the proportion of low vegetation coverage increased by 49.22%, compared with 1994, high vegetation cover of vegetation reduced significantly, the annual change rate is-48061hm2. Restoration area is only 3.13% of the degraded area. At the time, the vegetation cover of the study area go to the direction of deterioration rapidly. (3) From 2001 to 2006, the work of returning farmland to forests and afforestation is good in this period, the restore vegetation area is 25 times of the area of degraded vegetation. Regional distribution of vegetation types, the more close to the beach area, the greater changed, indicating that the regional human activities continue to expand to the coastline, vegetation distribution area will also be increasing instability with the process of urbanization in the study area, the task of ecological restoration is difficult.4,With the characteristics of becoming City rapidlly, based on the P-S-R framework and mutation series method, built an urban ecological security evaluation model, to give an objective evaluation to the ecological security from 1994 to 2006. The results showed that:(1) With the impact of rapid urbanization and population growth, the ecological security gains in 2001, after that, returned toⅤonce again in 2006, and the system pressure rise to the same trend. Human activities on the system caused large load. (2) From 1994 to 2006, the membership values of the ecological security of the system state and system response are rising, indicating that the response of people to the system safety is positive and effective. However, population pressure and resource pressures is the main threat to ecological security in the study area. (3)Catastrophe Theory is the strongly objective and highly quantitative, did not use weights to avoid the subjectivity of human empowerment. Using Mutation model to calculate specific value of various indicators of the ecological security, can comparison all levels of the quantitative of different indicators.Proposed to strengthen the natural landscape restoration work. In particular, it was the use of human activity which can directly affect the landscape features. Combined with human socio-economic factors, planned step by step to restore forest and protect the arable land. we can use the coastal resources to the development of economic forests and shelterbelts to control population growth, strengthen the importance of coastal natural resources, develop some relevant recovery strategy.