Jiangsu Coastal Land Use/cover Change And Its Ecological Effect Research

Researches on land use/cover change(LUCC) now are the frontier problems for discussion in the researches on the global environmental change. However, conducting case studies on LUCC in typical areas are one of the most important ways to understand global changes. Coastal zones have become the hot fields of LUCC because of their special sea and land ecosystem environment. In the paper, Jiangsu coast is selected as a typical area for case study. Taking the present land use map of 1987 and TMs of 1997 and 2006 as the data sources, using 3S (RS,GIS,GPS), combining with theories and methods from Geography, Landscape ecology, Statistics, Science of land evaluation, integrating a series of models, this thesis, by making use of the union of qualitative and quantitative ways, analyzes the temporal and spatial characters, driving mechanism, process, change tendency and regulation of dynamic change of land use. The results can not only provide decision basis for land resources management and exploitation but also a reference for similar areas home and abroad.Based on the mainline of "temporal process" and "spatial pattern", this paper deeply analyzes the temporal and spatial evolution of land use in Jiangsu coast by using the models of land use change amplitude, dynamic degree, change velocity, land use degree, landscape deviation degree, information entropy of land use structure, concentration index, uniformity degree index and transformation matrix.Combining qualitative analysis with quantitative diagnosis, This thesis systematically studies driving forces of land use change to disclose principal driving factors and their driving mechanism of Jiangsu coast under different temporal and spatial scale and regional background by means of factor analysis and canonical correlation analysis, et al..In this paper, the author rebuilds dynamic evolution course of land use spatial pattern and predicts the dynamic development of land use spatial structure in the future based on four presupposition scenarios including scenario of food security, scenario of ecological security, scenario of economic development and scenario of comprehensive development by using "Logistic regression+CLUE-S" model.The major conclusions of this paper are as follows:(1) Arable land, waters, coastal tidal-flat area and swamp are principal land cover types, and arable land and aquaculture land(Included in the waters) accounting for three fourths. Total regional land areas gradually increase, and major total change coming from waters, unused land, arable land and construction land. The total and annual change amplitude of waters are maximal in all land use types. The total change amplitude obeys the following sequence:waters(1713.07km2)>unused land (749.10 km2)> arable land (654.84km2)> construction land (-610.24km2)>grassland(-297.24 km)> forest land(-67.96 km). Dynamic degree change obeys the laws: waters(32.69%)>grassland(-5%)>construction land (-3.91%)>unused land (2.75%) >forest land(-1.75%). Land use degree comprehensive index of Jiangsu coast is 211-307. the overall Land use degree comprehensive index of research areas are low and drop obviously. Shifting mode and intensity of every land use type exist great difference. The roll-in of arable land exceeds roll-out. However, roll-out of any other land use type exceeds roll-in. The shifting intensity obeys following sequence:unused land (7.20)> construction land (5.02)>arable land(2.88)>forest land(2.37)> waters(2.17).(2)Less information entropy indice of land use structure mean diversity of land use in Jiangsu coast lower between 1987 and 2006. However they are gradually rising up. More landscape deviation degree indice, most of them above 70 percent, indicate higher artificial degree of land use. Concentration indice are higher, partial value above 0.5, and appear declining tendengcy. On the contrary, uniformity degree indice are lower, most of them below 0.5, and take on ascending tendency. Synthesizing above results, artificial degree of land use in Jiangsu coast is higher, land use simplification degree of all administration cells is higher and take possession of higher concentricity. Along with the diversity of land use modes, concentricity of land use is declining and uniformity degree is going up in Jiangsu coast.(3)Judging from location indice, arable land of Yancheng has universal predominance, location advantage of waters focus on Lian yungang and Yancheng, developed and waiting developing at hand ports of Jiangsu coast have some potential advantage in construction land, and unused land possesses generally advantage in all Jiangsu coast.(4)Sedimentation and erosion change of coast and sea-level-rise form the foundation for LUCC of Jiangsu coast. Population exists throughout human being history. However it exerts on LUCC only by mans of social economic and policy impact. Since modern times, particularly after the liberation of China, LUCC of Jiangsu coast has being mainly driven by social as well as economic factors, such as three reforms of land ownership, economic system restructuring, three times to enclose tideland for cultivation and coast development strategy of eastern Jiangsu. Principal driving force of LUCC will possible come from coast development strategy promotion in the future, including coastal spatial exploration pattern, marine industry development, construction of important eco-function areas etc..(5) Land use modes and intensity of Jiangsu coast have dramatically changed within the last few decades because of a series of social and economic changes, such as tideland development characterized by "Water controlling and cultivation rising on a large scale in the 50s and 60s last century" and "reclamation and Migration exploit, comprehensive exploitation of cropping, and breeding in the 70s and 80s last century", exploitative engineering of million mu tideland during "the ninth five-year and the tenth five-year Plan, coast development strategy of eastern Jiangsu in the 90s last century. Along with which there are many ecological environment problems and lead to a series of ecological environment effect including sedimentation and erosion change of coast, area change of regional wetland, regional change of soil environment, biodiversity and water quality change, etc..(6) This paper chooses the following eight natural and social economy factors as the driving factors(including distance to road, distance to coastline, distance to road, distance to continental shoreline, distance to residence, distance to river, distance to 5m depth contour, population density and density of agricultural output value) and land use type as dependent variable to do logistic regression. Outcomes have good interpretation effects because areas under ROC curve for all land types are above 0.7. This thesis stimulates LUCC of 2006 based on data from remote sensing interpretation by using the CLUE-S model. By contrasting to the interpretation data of 2006, it indicates that emulation and actual result have a better consistency. Kappa index is 0.8675. These show the CLUE-S Model can simulate the LUCC of Jiangsu coast.(7) Based on scenarios of food security, ecological safety, economic development and integrative development, this article simulates the spatial pattern for land cover of Jiangsu coast by CLUE-S in 2015. By means of comprehensive analysis for simulation result of four aforementioned scenarios, the author thinks that the integrative development scenario is more excellent than other scenarios of prospective land use and cover in Jiangsu coast.(8) Guided by the principle of "develop in protecting and protect in developing", "standing out advantage and in line with local conditions", "overall planning, rational division and multi-side coordination", sustainable land use of Jiangsu coast in the future should choose multi-objective optimization strategy as follow:intensively developing port and industry construction, optimizing seashore agriculture, actively developing seashore ecotourism and reasonably building ecological protection shelters.The innovation of this paper can be listed as follows:(1) The author studies land use and cover in Jiangsu coast by using LUCC theories and methods. Where performs qualitative, positioning and quantitative analyses for LUCC of Jiangsu coast during the last two decades to disclose temporal-spatial processes and their laws by taking "temporal process" and "spatial pattern" as paramount, integrating several kinds of multiple quantitative analysis methods and spatial analysis technologies, building a series of temporal dynamics and spatial pattern models. It comprehensively utilize research approaches from geography, environmental science, landscape ecology and land science, which supplements the coastal regional cases of LUCC from the angle of demonstration.(2) Combining qualitative with quantitative analysis means, try to apply time scale mind to disclose the dynamic mechanisms of driving factors for LUCC in Jiangsu coast. The natural factors, including sedimentation and erosion change of seashore and sea level rising et al.., belong to a long time scale and influence the base of LUCC pattern. However the social-economic factors which include population growth, ownership of land and economic system reforms, tidal flat economic development and gradual implement of coastal developing strategy etc.. belong to a short time scale and influence strip changes of land use and cover. Social-economic factors are the main driving forces for the LUCC of Jiangsu coast in the last two decades because there are close correlation between per capita industrial output value and saltern change, country labour power density and construction land change, gross grain output and arable land change. Principal driving force of LUCC in Jiangsu coast will possible come from coast development strategy promotion in the future.(3) In this paper, the Logistics analysis and CLUE-S model have been successfully adopted in research areas for scenario simulation after modifying parameters, whose validity has been testified. Based on the fully research for characteristics of land use and cover in Jiangsu coast, the author sets up four scenarios including food security, ecological safety, economic development and integrative development scenario to simulate spatial pattern of land use. The simulation results indicate that food security, ecological safety, economic development and integrative development scenario respectively belong toâ… -â…£evolution stage of marine industry structure. By means of comprehensive analysis for simulation results of four aforementioned scenarios, the author thinks the integrative development scenario is more excellent than other scenarios of prospective land use and cover in Jiangsu coast under the background from updating of coastal developing strategy.