It is very significant for urban development and urban wetland protection and utilization to probe into the process and reasons of urban wetland landscape dynamics. Taking the information of remote sensing and detaile...It is very significant for urban development and urban wetland protection and utilization to probe into the process and reasons of urban wetland landscape dynamics. Taking the information of remote sensing and detailed land survey data as the basic information sources, with the help of RS and GIS, according to the principles and methods of landscape ecology, this paper analyzed wetland landscape pattern dynamics and its reasons in Kaifeng City, Henan Province of China, from 1987 to 2002. The results show that the total wetland area in Kaifeng City firstly reduced by 20.1% from 1987 to 1990 and then increased from 1990 to 2002, with an average annual growth rate of 3.3%. At the same time, landscape fragment degree and landscape dominance degree increased, respectively from 0.64 to 0.72 and from 0.3754 to 0.5563, but mean patch area, maximum patch area, patch fractal dimension reduced. As far as single landscape element concerned, fi'om 1987 to 2002, patch area, patch number, patch density, patch shape and patch location changed in varying degrees in all wetland types in Kaifeng City, among which rice field changed most and others relatively less. In the recent 20 years, rice fields, lake wetlands, puddles and ponds had a higher stability, but river and bottomland wetlands were mostly transformed to land use types. The change of wetland landscape pattern was the result of the combined action of the Huanghe (Yellow) River, urban expansion, wide cultivation of rice, and rapid development of fishery. Among them human activities were the main driving factors for wetland landscape changes.展开更多
Competition used to be a steady,slow-moving phenomenon,dominated by the giant companies of the Western world.Two-thirds of the companies listed on the Fortune Global 500 in the 1960s were still there 15 years later.Ne...Competition used to be a steady,slow-moving phenomenon,dominated by the giant companies of the Western world.Two-thirds of the companies listed on the Fortune Global 500 in the 1960s were still there 15 years later.New competitors were easy to spot because they were well known,展开更多
This paper systematically studied the landscape dynamic changes in Liangshui Natural Reserve (LNR) in Heilongjiang Province, northeast China during three periods (1950s, 1970s and 1990s), by applying landscape space m...This paper systematically studied the landscape dynamic changes in Liangshui Natural Reserve (LNR) in Heilongjiang Province, northeast China during three periods (1950s, 1970s and 1990s), by applying landscape space model------Markov model. The results indicated that the landscape structure in LNR changed and the types of landscape patches increased. The phenomena of increasing and reducing of landscape types happened at the same time and the matrix— natural Pinus koraiensis decreased year by year. The law of transformation of landscape types matches well with the results concluded from statistical data, survey data, and the developing process inherent succession of the forest. By analyzing landscape dynamic changes, some scientific management measures were put forward in this paper.展开更多
Based on 4 phases of Thematic Mapper(TM) images of the Core Area of Yancheng National Nature Reserve in Jiangsu Province of China in 1996,2002,2006 and 2010,this paper analyzed the temporal and spatial changes in Spar...Based on 4 phases of Thematic Mapper(TM) images of the Core Area of Yancheng National Nature Reserve in Jiangsu Province of China in 1996,2002,2006 and 2010,this paper analyzed the temporal and spatial changes in Spartina alterniflora landscape and the corresponding impacts on coastal wetlands in combination with Remote Sensing(RS) and Geographical Information System(GIS) technologies. The methods of field survey,transfer matrix,landscape diversity indicators and mass center were applied. The results indicated that:(1) S. alterniflora expansion brought about obvious changes in wetland landscape composition and structure,which seriously influenced the evolution process of wetland landscapes.(2) The transition rates of S. alterniflora marsh area were different dramatically in four periods.(3) The expansion of S. alterniflora promoted the siltation in tidal mudflat. It led to increase of the elevation and outward expansion of land. Understanding the temporal and spatial pattern of S. alterniflora is favorable for preservation,utilization and management of wetlands with S. alterniflora and the other coastal wetland landscapes.展开更多
In this study, historical landscape dynamics were investigated to(i) map the land use/cover types for the years 1972, 1987, 2000 and 2014;(ii) determine the types and processes of landscape dynamics; and(iii) as...In this study, historical landscape dynamics were investigated to(i) map the land use/cover types for the years 1972, 1987, 2000 and 2014;(ii) determine the types and processes of landscape dynamics; and(iii) assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies(and Kappa statistics) were of 68.86%(0.63), 91.32%(0.79), 90.66%(0.88) and 91.88%(0.89) for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of –2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation.展开更多
基金Under the auspices of Key Research Institution of Education Ministry (No. YRCSD-06B-06)
文摘It is very significant for urban development and urban wetland protection and utilization to probe into the process and reasons of urban wetland landscape dynamics. Taking the information of remote sensing and detailed land survey data as the basic information sources, with the help of RS and GIS, according to the principles and methods of landscape ecology, this paper analyzed wetland landscape pattern dynamics and its reasons in Kaifeng City, Henan Province of China, from 1987 to 2002. The results show that the total wetland area in Kaifeng City firstly reduced by 20.1% from 1987 to 1990 and then increased from 1990 to 2002, with an average annual growth rate of 3.3%. At the same time, landscape fragment degree and landscape dominance degree increased, respectively from 0.64 to 0.72 and from 0.3754 to 0.5563, but mean patch area, maximum patch area, patch fractal dimension reduced. As far as single landscape element concerned, fi'om 1987 to 2002, patch area, patch number, patch density, patch shape and patch location changed in varying degrees in all wetland types in Kaifeng City, among which rice field changed most and others relatively less. In the recent 20 years, rice fields, lake wetlands, puddles and ponds had a higher stability, but river and bottomland wetlands were mostly transformed to land use types. The change of wetland landscape pattern was the result of the combined action of the Huanghe (Yellow) River, urban expansion, wide cultivation of rice, and rapid development of fishery. Among them human activities were the main driving factors for wetland landscape changes.
文摘Competition used to be a steady,slow-moving phenomenon,dominated by the giant companies of the Western world.Two-thirds of the companies listed on the Fortune Global 500 in the 1960s were still there 15 years later.New competitors were easy to spot because they were well known,
基金the "Tenth Five-year Plan" National Key Projects in Science and Technology (Grant No. 2001BA510B02-02)
文摘This paper systematically studied the landscape dynamic changes in Liangshui Natural Reserve (LNR) in Heilongjiang Province, northeast China during three periods (1950s, 1970s and 1990s), by applying landscape space model------Markov model. The results indicated that the landscape structure in LNR changed and the types of landscape patches increased. The phenomena of increasing and reducing of landscape types happened at the same time and the matrix— natural Pinus koraiensis decreased year by year. The law of transformation of landscape types matches well with the results concluded from statistical data, survey data, and the developing process inherent succession of the forest. By analyzing landscape dynamic changes, some scientific management measures were put forward in this paper.
基金Supported by the National Natural Science Foundation of China(41071119)Jiangsu Key Laboratory of Environmental Change & Ecological Construction+1 种基金Jiangsu University Philosophy Social Science Research Project(KYZ16514)Jiangsu Teachers University of Technology of Social Science Fund Project(KYY14521)
文摘Based on 4 phases of Thematic Mapper(TM) images of the Core Area of Yancheng National Nature Reserve in Jiangsu Province of China in 1996,2002,2006 and 2010,this paper analyzed the temporal and spatial changes in Spartina alterniflora landscape and the corresponding impacts on coastal wetlands in combination with Remote Sensing(RS) and Geographical Information System(GIS) technologies. The methods of field survey,transfer matrix,landscape diversity indicators and mass center were applied. The results indicated that:(1) S. alterniflora expansion brought about obvious changes in wetland landscape composition and structure,which seriously influenced the evolution process of wetland landscapes.(2) The transition rates of S. alterniflora marsh area were different dramatically in four periods.(3) The expansion of S. alterniflora promoted the siltation in tidal mudflat. It led to increase of the elevation and outward expansion of land. Understanding the temporal and spatial pattern of S. alterniflora is favorable for preservation,utilization and management of wetlands with S. alterniflora and the other coastal wetland landscapes.
基金funded by the German Federal Ministry for Education and Research (BMBF)hosted by the Kwame Nkrumah University of Science and Technology of Kumasi,Ghana+1 种基金the Laboratory of Botany and Plant Ecology (University of Lome, Togo) for fieldwork supportthe contribution of CGIAR-DS through the funding to Quang Bao Le
文摘In this study, historical landscape dynamics were investigated to(i) map the land use/cover types for the years 1972, 1987, 2000 and 2014;(ii) determine the types and processes of landscape dynamics; and(iii) assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies(and Kappa statistics) were of 68.86%(0.63), 91.32%(0.79), 90.66%(0.88) and 91.88%(0.89) for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of –2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation.