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In recent years, earthquake, typhoon, snowflake and other natural disasters happened frequently and cause large number of casualties and economic losses. It needs to be further improved under the circumstances of sudden natural disasters. The solution to the problem is to provide data support for emergency response and scientific decision-making to commanders by uploading accurate, reliable and instant...
Tailings are major hazard in the event of dam-break accident, which once happened would lead to significant casualties, property damage and environmental pollution in downstream area. Two-dimensional GIS constrained by the spatial expression and data structure cannot be effectively used to describe the topography of tailing dam, dam body, hydro-geological and other spatial data information, which...
This study aims to estimate the spatial distribution patterns of three typical meteorological factors: maximum temperature, minimum temperature and precipitation in JiTai basin. Forty-seven-year monthly mean meteorological data were interpolated using Inverse distance weight (IDW), Ordinary kriging (OK) and Tension spline function (TPF). Cross-validation was applied to evaluate the accuracy of the...
Evaluation of spatial accessibility are always the research hotspot in space planning, geography and so on. This article makes full use of two GIS-based accessibility measures including the two-step floating catchment area method and the gravity-based method to examining spatial accessibility to town and rural in Dachang County. Based on communicant and socioeconomic data of Dachang County in 2009,...
This paper proposes a geospatial web portal for the Tibetan Plateau ecological safety data services based on web services, portal technology and GIS technology. It serves as an online data supporting platform for geospatial data integration, management, submission, publishing and sharing. Its framework presents a three layer architecture consisting of data resource layer, data service layer, data...
Shanghai which is China's largest economic center has also gradually integrated into the global city network since 1978. We use mapinfo to analyze the location of 1086 office buildings in Shanghai downtown. Shanghai as an emerging global city has formed a polycentric mode of producer services. Quantitative researches show that industrial restructuring and expansion of producer services have significant...
Recently, urban sprawl becomes common phenomenon overseas and in domestic. Urban sprawl is a discontinuous development pattern and impacts on environment, economic and social aspect, including landscape fragmentation, species decrease, bio-diversity decrease and habitat destruction. Many researches indicate the relationship indeed exists between transportation accessibility and urban sprawl. The raise...
Total digital mapping system should be qualified for the functions of GIS and map publication. In other words, it can deal with kinds of geographic data and can make different type of maps. In this paper, some questions are raised that we should think over before the data model is built up that based on the analysis of the system feature. After that, a new data model frame of the whole system is put...
The basic task of Major Function Oriented Zone (MFOZ) is to optimize the structure of national land use. The research is concentrated on the process of applying 3S technologies. Based on the analysis of the need, identity, and content, we investigate the theory foundation and appliance of various 3S technologies, including database, model-base, spatial analysis, spatial multi-criteria decision, cellular...
Interpolation is a significant problem in Geographic Information System and many other fields. Kriging interpolation is thought as optimal interpolation which has high quality but time-consuming at the same time. We use Quad-Tree method which is thought as the only suitable method to locate the pixel images in two-dimension to create spatial index. There are mainly three variants of kriging. We mainly...
Assessment of flood risk is important to flood disaster forewarning and decision management. However, there are many uncertainty factors that influence flood risk assessment. In order to solve this problem, this paper proposes an information fusion method based on DS-AHP (Dempster-Shafer and Analytic Hierarchy Process) to deal with uncertainty information, and fuzzy set theory and GIS methods are...
With the rapid development of information technologies and GIS techniques, raster data amount is growing on an unprecedented scale. Existing WebGIS based on local file systems and RDBMS cannot manage very large raster data efficiently because of limited storage capacity of single node. Although expensive storage devices are used to enlarge capacity, WebGIS is still vulnerable to suffer from single...
The work present in this paper focuses on using CBERS imagery data to acquire some information such as land use/cover change (LUCC) by means of remote sensing and GIS and to find out an appropriate classification method to CBERS imagery by applying and comparing some classification methods. CBERS CCD imageries of Xuzhou city in 2001, 2005 and 2008 were classified by using decision tree classifier,...
Edge detection is the process of localizing pixel intensity transitions. The goal of this paper is to find ways to extend gravitational method to multispectral images. This paper considers the edge detection problem in feature space. Different from the old gravitational method, in feature space, each image pixel is considered as a celestial body with a mass represented by its spectral intensity instead...
Under the driving of global climate change and rapid urbanization, the occurrence of extreme storm surge events becomes more and more frequent, which leads to immense disaster risk for eastern coastal china. This study proposes a DPSR theory model to describe the coastal storm surge disaster risk system, simulates the flood routing under compounded scenarios, and the inundated depth and scope of the...
In recent years, as expansion of city size and urban population, waterlogging has become more frequently in Guangzhou. It has seriously affected people's routine life. In this study, an urban waterlogging model based on SCS (Soil Conservation Service) model and the GIS was built and was applied to assess hazard risk of waterlogging in Tianhe District of Guangzhou, China. It consists of three parts:...
Taking IGBP/GCTE terrestrial transects (NETC and CST) as study areas, the present work extracted NDVI of terrestrial eco-regions in the transects using the MODIS/16-day NDVI from 2004.04 to 2010.08, to investigate the phonological responding of different ecosystems to global changing in Northeast Asia through monitoring the pheological trends such as Onp, EndP, DurP, MaxP, MaxV and RanV from actual...
The remote sensing image fusion technique has been developed quickly and applied, which is an important remote sensing research topic. How to choose the right fusion method is one of the challenges that the field face. PCA, Brovey, IHS and Multiplicative are used to fuse QuickBird and SPOT5 low-resolution multispectral and high-resolution panchromatic images. The fused images are analysed and evaluated...
By using traditional statistic quantile method, Geography Information system (GIS) analysis and spatial autocorrelation statistical techniques, this paper calculated the grid population density, detected the trend of population distribution, studied the spatial relationship and characteristics between prefectures through spatial autocorrelation statistical techniques. The conclusions are got from...
Gap fraction, which is the probability that a light penetrates through the canopy unintercepted and reaches the surface under the canopy, is characteristic geometric parameter of canopy's structure, and has great influence on radiative transfer of the vegetation. In this article, a photographic method was introduced to efficiently and accurately calculate the gap fraction of three-dimensional (3D)...
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