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Li J.,Nanjing University | Pu L.,Nanjing University | Pu L.,Key Laboratory of Land Use | Zhu M.,Nanjing University | Zhang R.,Nanjing University
Acta Geographica Sinica | Year: 2012

With the global warming, soil salinization has become a global concern in the world, and about 7% of the global land is threatened by salinity. In addition, this figure is rising. Soil salinization in China is critical, and the area of salt-affected soil is vast, which poses a great threat to agricultural development. This study summarizes the framework of the soil salinization research in China over tha past 70 years, and make comments on the inadequencies in previous studies at home and abroad. This study summarizes the present situation and future tendency of soil salinization research across the world in the last 30 years by using the literature database and data-sharing network, and identifies five research priorities and orientations for providing new ideas to carry out the saline soil research in the future. Source

Liu K.,Hong Kong Polytechnic University | Shi W.,Hong Kong Polytechnic University | Shi W.,Key Laboratory of Land Use | Zhang H.,Hong Kong Polytechnic University | Zhang H.,China University of Mining and Technology
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2011

Classification is one of the most widely used remote sensing analysis techniques, with the maximum likelihood classification (MLC) method being a major tool for classifying pixels from an image. Fuzzy topology, in which the set concept is generalized from two values, {0, 1}, to the values of a continuous interval, [0, 1], is a generalization of ordinary topology and is used to solve many GIS problems, such as spatial information management and analysis. Fuzzy topology is induced by traditional thresholding and as such gives a decomposition of MLC classes.Presented in this paper is an image classification modification, by which induced threshold fuzzy topology is integrated into the MLC method (FTMLC). Hence, by using the induced threshold fuzzy topology, each image class in spectral space can be decomposed into three parts: an interior, a boundary and an exterior. The connection theory in induced fuzzy topology enables the boundary to be combined with the interior. That is, a new classification method is derived by integrating the induced fuzzy topology and the MLC method. As a result, fuzzy boundary pixels, which contain many misclassified and over-classified pixels, are able to be re-classified, providing improved classification accuracy. This classification is a significantly improved pixel classification method, and hence provides improved classification accuracy. © 2010. Source

Cao Y.-G.,University of Science and Technology of China | Cao Y.-G.,Key Laboratory of Land Reconsolidation and Rehabilitation | Bai Z.-K.,University of Science and Technology of China | Bai Z.-K.,Key Laboratory of Land Reconsolidation and Rehabilitation | And 3 more authors.
Journal of Mountain Science | Year: 2013

The Three Gorges project accelerates economic development in the Three Gorges Reservoir Area. This paper aimed to investigate the distribution, changes and features of cultivated land in this area, analyze the forces driving the changes in cultivated land area, and propose the countermeasures for cultivated land management. Transition matrix was used to analyze the features of cultivated land changes, and quantitative analysis and qualitative analysis were adopted to research the driving forces according to the features of cultivated land changes. Cultivated land in the Three Gorges Reservoir Area mainly lay to the northwest of the Yangtze River, especially the upper reaches. The areas of cultivated land increased from 1996 to 1999, then decreased from 2000 to 2006, and finally increased again from 2007 to 2009. The important forces driving changes in cultivated land included government policies, employment and food security, increasing construction land, agriculture structure adjustment, land rearrangement, inundation. During cultivated land management, firstly, it is necessary to insist on the principle of cultivated land protection, standardize land exploitation and strictly restrict the transformation of cultivated land into non-farming land. Secondly, land rearrangement must be implemented, which can not only increase the area of the cultivated land, but also improve the quality of the cultivated land. Thirdly, it is feasible to intensify eco-agriculture construction to increase the quantity and quality of cultivated land. Fourthly, it is helpful to improve the traditional agriculture production methods to promote cultivated land quality. Lastly, it is important to propagandize cultivated land protection and realize the enormous pressure of cultivated land shortage, making more people obligated to protect cultivated land. © 2013 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg. Source

Zhang R.,Nanjing University | Pu L.,Nanjing University | Pu L.,Key Laboratory of Land Use | Zhu M.,Nanjing University
Chinese Geographical Science | Year: 2013

Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infrastructure on land use change is necessary for evaluating the role of transportation development in the process of land use and land cover change in the urban-rural fringe. Taking Qixia District of Nanjing City, Jiangsu Province, China as a typical urban-rural fringe area, this paper analyzes the patterns and characteristics of land use change along three major transportation arteries using land use data from 2000 and 2008. We examine the spatial differentiation and gradient of land use pattern around railway, expressway, and highway corridors to investigate whether land use change in the urban-rural fringe is related to distance from transportation arteries and to clarify the varying impacts of different forms of transport infrastructure on land use patterns. We find that construction land generally tends to be located close to major transportation arteries, and that railways have the most obvious influence on land use change in the urban-rural fringe, while the impact of expressways was not significant. We conclude that there exists a causal relationship between the presence of transportation arteries and land use change in the urban-rural fringe, but this relationship varies across different types of linear transport infrastructure. © 2013 Science Press, Northeast Institute of Geography and Agricultural Ecology, CAS and Springer-Verlag Berlin Heidelberg. Source

Li X.-C.,Shandong Agricultural University | Li X.-C.,Key Laboratory of Land Use | Wang J.,Key Laboratory of Land Use
Kongzhi yu Juece/Control and Decision | Year: 2010

Aiming at the problems of multiple object decision making, based on the theories of fuzzy recognition, the pattern of multi-objective and multi-dimensional fuzzy decision making with feedback is presented in this paper. According to the given weights, the weighting integrated value of decision making is computed. Then, the method of fuzzy recognition with single index is employed to calculate the fuzzy classification of the integrated value. Finally, according to the cause analysis, the fuzzy classification of the integrated value is used to compute the weights of indexes. In the same way, repeating the above processes, the weighting integrated value and fuzzy classification with given accuracy are gotten at the same time, the classification and sequence of decision making set are also gained. The example of steelmaking enterprises evaluating shows the effectiveness of the presented model. Source

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