GIS-Based Risk Assessment of Debris Flow Disasters in the Upper Reach of Yangtze River

This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree, vulnerability, risk degree, etc. Among these methodologies, historical and potential hazard degree was comprehensively considered into hazard assessment and hazard index was presented to indicate the debris-flow hazard degree. Regarding debris-flow vulnerability assessment, its statistical data and calculating procedure were based on the hazard-degree regionalization instead of administrative divisions, which improved the assessing scientificity and precision. These quantitative methodologies integrated with Geography Information System （GIS） were applied to the risk assessment of debris flows in the upper reach of Yangtze River. Its results were in substantial agreement on investigation data and the actual distribution of debris flows, which showed that these principles and methodologies were reasonable and feasible and can provide basis or reference for debris-flow risk assessment and disaster management.

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992 is extracted from the dynamic polygons of 2002. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992 to 2002. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

Remote Sense and GIS-Based Division of Landslide Hazard Degree in Wanzhou District of the Three Gorges Reservoir Area

An evaluation model divided landslide hazard degrees in Wanzhou District of Three Gorges Reservoir Area. The model was established by GIS techniques and took land use/cover, stratum characters, slope aspect, slope gradient, elevation difference and slope shape as evaluation factors. The data of land use/cover were obtained by remote sensing, and the weights of the factors mentioned above were established by the analytic hierarchy process （AHP）. The results indicate, low danger areas in the studied area account for 66.51%, and high danger areas and very high danger areas occupy 1/3 of the total area. The regions of high and very high danger are mainly located around the urban area of Wanzhou District and on the banks of the Yangtze River with a relatively large area, where collapse and landslide directly threats densely populated areas and Three Gorges Reservoir. Slope destabilization, if occurs, will bring huge loss to social economy. All research results are consistent with the actual conditions; therefore, they can be regarded as a useful basis for planning and constructing of the reservoir area.

The GIS and analysis of earthquake damage distribution of the 1303 Hongtong M=8 earthquake

The geography information system of the 1303 Hongtong M=8 earthquake has been established. Using the spatial analysis function of GIS, the spatial distribution characteristics of damage and isoseismal of the earthquake are studied. By comparing with the standard earthquake intensity attenuation relationship, the abnormal damage dis-tribution of the earthquake is found, so the relationship of the abnormal distribution with tectonics, site condition and basin are analyzed. In this paper, the influence on the ground motion generated by earthquake source and the underground structures near source also are studied. The influence on seismic zonation, anti-earthquake design, earthquake prediction and earthquake emergency responding produced by the abnormal density distribution are discussed.

Areas of the global major river plumes

River plumes are the regions where the most intense river-sea-land interaction occurs, and they are char- acterized by complex material transport and biogeochemical processes. However, due to their highly dy- namic nature, global river plume areas have not yet been determined for use in synthetic studies of global oceanography. Based on global climatological monthly averaged salinity data from the NOAA World Ocean Atlas 2009 （WOA09）, and monthly averaged salinity contour maps of the East and South China Seas from the Chinese Marine Atlas, we extract the monthly plume areas of major global rivers using a geographic information system （GIS） technique. Only areas with salinities that are three salinity units lower than the average salinity in each ocean are counted. This conservative estimate shows that the minimum and max- imum monthly values of the total plume area of the world＇s 19 largest rivers are 1.72× 106 kin2 in May and 5.38× 106 klTl2 inAugust. The annual mean area of these river plumes （3.72× 106 knl2） takes up approximately 14.2% of the total continental shelves area worldwide （26.15 × 106 km2）. This paper also presents river plume areas for different oceans and latitude zones, and analyzes seasonal variations of the plume areas and their relationships with river discharge. These statistics describing the major global river plume areas can now provide the basic data for the various flux calculations in the marginal seas, and therefore will be of useful for many oceanographic studies.

The application of the main-elements analysis technology based on GIS in the regional pollution source analysis and environmental quality improvement

In order to improve the use efficiency of environmental data intbrmation which has existed and to be produced, correctly control the situation of the regional environmental pollution, and supervise the regional environmental pollution recovery and urban planning, the paper crests the main-elements analysis module based on Super-Map GIS, beyond which, using the information of environmental pollution discharge data of some typical areas of Beijing. The paper analyses those representative regional environmental discharge data by the systemic main-clements analysis module, speedily discoveries and explains the regional environmental major control factors in the studying region. According to the special points of social, economical and environmental in the region, the paper gives out the improvement policies of regional environmental quality and practicable environmental engineering disposed project. This research not only indicates the development direction of the urban environmental management, but also builds up a main frame of the urban environmental planning. This paper and its relative works provide an efficiently digital management tool for the urban regional environmental management and explore the feasible method and mode for the improvement of urban regional environmental quality.

Research on the Relationship between Active Faults and Earthquakes in the Junction Area of the China North-South Seismic Belt and Central Orogenic Belt Based on GIS

Research on the relationship between faults and seismicity in the junction area of China's north-south seismic belt and central orogenic belt based on the Geography Information System (GIS) has been done.For each of the 16 faults in this area,we build a 25km buffer zone and use overlay analysis to investigate the seismicity and its characteristics on each fault.The results unveil the main seismic faults as follows:the western segment of the northern-edge of the west Qinling fault,the southwestern segment of the Lixian-Luojiabao fault,the southeastern segment of the Lintan-Dangchang fault,the southwestern segment of the Wenxian fault,the Huya fault,and the Xueshan fault.The most active faults are the Huya and Xueshan faults,then the Tazang fault,the Lixian-Luojiabao fault and the northern piedmont of the Guanggaishan-Dieshan fault.The research zone can be divided into four areas according to focal depth,which gets deeper from north to south.The profile of focal depth indicates the geometry and mechanical property of faults,and further reveals the movement model of eastward extrusion of the Tibetan plateau and southeastward escape of masses,thus providing basis for the protection against earthquakes and hazard mitigation in this area.

The risk assessment of disasters induced by typhoons in Shandong province based on historical data during 1985-2010

In the present paper,the risk assessment of disasters induced by typhoons in Shandong Province has been carried out based on the basis of the analyses of the historical data during 1985-2010.In order to reduce the impact of the social and economic development status on the evaluation results in various periods,the normalized evaluation method was used to analyze the annual typhoon-induced damage in the concerned period.The quantitative comprehensive index is proposed with fuzzy mathematics,and the effect of typhoon-induced disasters is systematically investigated with the proposed index.In the analyses of the various hazard factors,the damage induced by the typhoon is combined with human and social factors,and further is comprehensively analyzed based on a GIS platform.The assessment results indicate that the normalized damage induced by typhoons presents the downward trend year by year and regional differences with significant temporal-spatial characteristics.The results of the present study are expected to be beneficial to disaster prevention and mitigation in Shandong Province.

Information geography: A new fulcrum of geographic ternary world

The development trend of ternary space requires the construction of the information space for information mapping,transmission and transformation of geographic elements and social-human elements. Relevant researches of information geography from the perspective of Geographic Information Science and human geography are reviewed in this paper, then the concept interpretation of information geography from the perspective of ternary space is proposed. It is presented in this paper that information geography can be constructed with a framework using seven geographic elements as the basic expressing dimensions and seven social-human elements as the basic aggregating core. Information geography analyzes spatio-temporal distribution, structural characteristics, evolution process and interactions of various elements in the information space. And it eventually realizes the actual description, multi-scenario simulation, multi-objective decision-making and multi-channel control of the physical world and the social-human world.

Information geography: The information revolution reshapes geography

The information revolution has been one of the driving forces to the innovation in geography. However, environmental remote sensing, geographic information science and technology, and geocomputing, which once resided within the family of geography, are gradually moving close to information science but are alienated from geography. Therefore, it is necessary to reexamine the interactive convergence of geography and information science, and advance the disciplinary system of geographic science to accommodate the researches with information as subjects and methods. In this paper, we propose to reformulate the relationship between geographic science and information science with a new discipline, i.e., information geography, which not only refers to the geography of information but also a methodological system for studying geography using information science.This paper summarizes the background of information geography’s emergence, its definition, and the difference and similarities with other disciplinary concepts. The impact of information geography on geographic paradigm shift is also investigated from the ontological, epistemological, and methodological perspectives.

Disciplinary structure and development strategy of information geography in China

The advent of the information era has resulted in exceptional advances in geographic science.The domain of geographic science has expanded from traditional physical and human geography to physical,human,and information geography,resulting in the emergence of the field of information geography.Three subdisciplines have gradually formed,i.e.,geographic remote sensing science,geographic information science,and geographic data science.With a view towards preparing a description of the disciplinary structure of geographic science for the“Development Strategy of Discipline and Frontier Research in China(2021-2035)”,this article summarizes the history,definition,and disciplinary structure of information geography.The strategic layout of the discipline,along with the goals and key directions of priority development fields,are also highlighted.The insights into this new discipline provided in this paper will promote the development and application of remote sensing and geographic information within the framework of geographic science,advancing the synthesis of geographic research and the integrated development of geographic science.

Core or edge? Revisiting GIScience from the geography-discipline perspective

As an inter-disciplinary area between geography and computer sciences, geographical information science(GIScience) inherits the spatial analysis tradition of the former. Together with other branches of information geography, it seeks the balance between universality and particularity of geographical laws by combining methods from neighboring disciplines(such as big data and artificial intelligence) with the special nature of geographical spaces. Meanwhile, at the core position of the geography discipline, GIScience makes geography stronger from two directions: "strengthening the theoretical foundation" and "improving technology and promoting the practical applications".

Disciplinary structure of geographic science in China

International and domestic circumstances have led to new opportunities and higher requirements for the development of geographic science in China.In this paper,we propose a modified disciplinary structure for geographic science in China in the new era.Geographic science in China can be categorized into four secondary disciplines,i.e.,integrated geography,physical geography,human geography,and information geography,according to the current situation and expected trends.The tertiary disciplines under each secondary discipline are nearly fully developed,and a few quaternary disciplines under the tertiary disciplines are widely accepted and used in China.We hope this new disciplinary structure can play a breakthrough role in improving the branches of geographic science,promoting the development of emerging disciplines under the framework of geographic science,and supporting national and international development strategies in the new era.