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Feng L.,Renmin University of China | Guo H.,Renmin University of China | Wang J.,Key Laboratory of Land Use | Wang J.,China Land Surveying and Planning Institute | And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2010

This research establishes a comprehensive evaluation index system of economic security of land resources by using Delphi and AHP methods. An empirical analysis of China is conducted. The conclusions are as follows. Firstly, the economic security of land resources in China keeps on improving from 1999 to 2008, and it is on the level of ″basic security″ since 2007. Secondly, from the perspective of each criterion layer, quality security and efficiency security improve year by year, and reach the level of ″security″. The main restricting factors of China's economic growth are quantity security, structure security and price security, keeping ″unsafe″ or even ″highly insecure″ state for a long period of time. Finally, from the perspective of each index, several index evaluation values significantly increase, such as some quality security indexes (unit acreage production, environmental investment proportion of GDP) and some efficiency security indexes (unit acreage investment in fixed assets, unit acreage GDP, multiple crop index). The unfavorable factors are: arable land area per capita decreases year by year, approaching ″absolutely unsafe″ in 2008; land reclamation area and unused land area per capita also keep on decreasing; forest cover stays at low level; residential land prices and commercial land prices fluctuate sharply in recent years.

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.

Han L.,Key Laboratory of Land Use | Wang J.,Key Laboratory of Land Use | Lu C.,Key Laboratory of Land Use | Xie J.,Beijing Municipal Bureau of Land and resources
2nd International Conference on Information Science and Engineering, ICISE2010 - Proceedings | Year: 2010

Water quality safety early warning system is the key point of ensuring the water resources safety and sustainable use. This paper describes early warning system of water quality safety by using RBF (Radical Basis Function) neural network model. The system consists of four parts: water quality monitoring, early warning of water quality evaluation, early warning signal identify of water quality, and decision management. The study is applied to determining and analyzing the hazard degree of water quality safety in Songhua River Basin. Results show that the degree of water quality is in grade four, which is at serious alert. The practice and the result of the fuzzy evaluation method prove that it is feasible and scientific that the study combining RBF model with early warning system of water quality safety, and good effect is achieved. © 2010 IEEE.

Wu J.,State Oceanic Administration | Chen P.,State Oceanic Administration | Liu Y.,Wuhan University | Wang J.,Key Laboratory of Land Use
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

As a kind of secondary geological disaster caused by strong earthquake, the earthquake-induced landslide has drawn much attention in the world due to the severe hazard. The high-resolution remote sensing, as a new technology for investigation and monitoring, has been widely applied in landslide susceptibility and hazard mapping. The Ms 8.0 Wenchuan earthquake, occurred on 12 May 2008, caused many buildings collapse and half million people be injured. Meanwhile, damage caused by earthquake-induced landslides, collapse and debris flow became the major part of total losses. By analyzing the property of the Zipingpu landslide occurred in the Wenchuan earthquake, the present study advanced a quick-and-effective way for landslide extraction based on NDVI and slope information, and the results were validated with pixel-oriented and object-oriented methods. The main advantage of the idea lies in the fact that it doesn't need much professional knowledge and data such as crustal movement, geological structure, fractured zone, etc. and the researchers can provide the landslide monitoring information for earthquake relief as soon as possible. In pixel-oriented way, the NDVI-differential image as well as slope image was analyzed and segmented to extract the landslide information. When it comes to object-oriented method, the multi-scale segmentation algorithm was applied in order to build up three-layer hierarchy. The spectral, textural, shape, location and contextual information of individual object classes, and GLCM (Grey Level Concurrence Matrix homogeneity, shape index etc. were extracted and used to establish the fuzzy decision rule system of each layer for earthquake landslide extraction. Comparison of the results generated from the two methods, showed that the object-oriented method could successfully avoid the phenomenon of NDVI-differential bright noise caused by the spectral diversity of high-resolution remote sensing data and achieved better result with an overall accuracy of 92.16%, while of the pixel-oriented one could only get 71.32%. As the high-resolution remote sensing has been widely utilized in many fields, the object-oriented image analytical technique will have an extensive application. © 2014 Copyright SPIE.

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.

Li J.,Nanjing University | Pu L.,Nanjing University | Pu L.,Key Laboratory of Land Use | Zhu M.,Nanjing University | And 3 more authors.
Environmental Earth Sciences | Year: 2014

Urbanization has an important effect on the soil ecosystem. Anthropogenic activities during urban sprawl are the sources and methods of migration, transition, and concentration of heavy metals in the soil. In this paper, the Yangtze River delta, the fastest urbanization area in China, was selected to study the influence of urbanization on heavy metal concentration in the soil. The analysis was performed on 218 samples collected from a typical industrial town in the delta. The content of six heavy metals (Hg, Cd, As, Pb, Cu, and Zn) was measured, which showed that the soil was seriously polluted by heavy metals, particularly Hg. In the study area, human activities were the major factors for the heavy metal concentration in the soil. The average content of Hg in the 0-500 m zone from the urban core was 1.4 mg/kg, about five times higher than the grade II threshold of the Chinese Environmental Quality Standard for Soils. The content of Hg, Cd, Pb, and Cu decreased gradually with increasing distance from the core of the built-up area, especially Hg. The influence of the anthropogenic activities was found to be anisotropic, and effects in the direction of 315° and 225° were most significant. Hg pollution in the 225° direction of the study area was more serious. These results suggested that the urbanization process affects not only the content but also the spatial pattern of heavy metal concentration in the soil. © 2013 Springer-Verlag Berlin Heidelberg.

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.

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.

Chen Y.,Key Laboratory of Land Use | Chen Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Li X.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Wang J.,Key Laboratory of Land Use
Chinese Geographical Science | Year: 2011

Based on the data from the Cost-benefit Data of Farm Produce and the China Agricultural Yearbook, this paper aims to examine the spatial and temporal change characteristics of total grain production and its affecting factors. The results show that: 1) During 1980 to 2007, total grain production increased from 3.20 × 10 8 t to 5.02 × 10 8 t in China, with annual increasing rate of 1.68%. From the regional disparities, most of the regions present increasing trend of total grain production except for several regions with higher level of economic development; 2) Grain sown area decreased from 1.17 × 10 8 ha in 1980 to 1.06 × 10 8 ha in 2007, which has negative effect on total grain production; 3) The increase of grain yield per unit area caused by land use intensity changes contributed to the increase of total grain yield greatly. However, as the land use intensity showed that farmers pay more attention to labor-saving input but not yield-increasing input, the less enthusiasm of farmers in grain production may become an important constraint on future grain production increase in China; 4) Based on the results, this paper proposed different land management policies in different regions, for example, the government should protect cultivated land, promote large scale production. As to the less developed regions, the government should pay more attention to agricultural subsidies to promote farmers' enthusiasm in grain production. © 2011 Science Press, Northeast Institute of Geography and Agroecology, CAS and Springer-Verlag Berlin Heidelberg.

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.

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