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Identifying a route that avoids obstacles in continuous space is important for infrastructure alignment, robotic travel, and virtual object path planning, among others, because movement through space is not restricted to a predefined road or other network. Vector and raster GIS (geographic information system) solution approaches have been developed to find good/efficient routes. On the vector side, recent solution approaches exploit spatial knowledge and utilize GIS functionality, offering significant computational advantages in finding an optimal solution to this path routing problem. Raster‐based shortest path techniques are widely applied in route planning for wayfinding, corridor alignment, robotics and video gaming to derive an obstacle avoiding path, but represent an approximation approach for solving this problem. This research compares vector and raster approaches for identifying obstacle‐avoiding shortest paths/routes. Empirical assessment is carried out for a number of planning applications, highlighting representational issues, computational requirements and resulting path efficiency. 相似文献
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Indrani Choudhury M. Chakraborty S. C. Santra J. S. Parihar 《Journal of the Indian Society of Remote Sensing》2006,34(1):23-37
Information on various agricultural resource parameters at various levels is essential for proper management and efficient
resource allocation for sustainable agricultural development. Limitations in ground-based method have encouraged the use of
satellite data coupled with geographical information system (GIS) in providing spatial as well as temporal information over
large and inaccessible areas. In the present study, an attempt has been made to generate raster maps using remote sensing
and GIS techniques to characterize the agroecosystem of South 24 Paraganas district of West Bengal, based on land utilization
indices. Information on multi-season landcover derived from the analysis of the multi-temporal RADARSAT-1 SAR and IRS-ID LISS
III data as well as other ancillary information in GIS environment are the basic inputs used in the study. The present analysis
shows that northern and northwestern parts are more diverse in terms of agricultural intensification as compared to the southern
and northeastern parts whereas the central parts show moderate density. In terms of carrying capacity, the high carrying capacity
has been observed in the southern to northeastern parts whereas the northwestern and central parts show moderate and northern
parts show low carrying capacity. Overall, the characterization of agroecosystem using land utilization indices can be identified
as major input to formulate a management plan for sustainable agriculture with concerns for the environment. 相似文献
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针对城市雨水网络传统规划手段落后导致城市地面雨水不能及时有效地收集和排除的问题,该文提出了基于GIS和暴雨洪水管理模型(SWMM)集成的带权雨水网络的构建方法。通过软件互操作模式将SWMM模型封装成.NET托管动态库,实现了其与GIS空间分析组件的无缝集成;以新城区竖向设计高程和规划路网为基础数据,构建顾及路网的格网DEM;基于新城区规划用地类型和研究区暴雨模型,运用GIS空间分析实现了水文参数的自动提取;进一步率定雨水管网权重因子,利用GIS几何网络分析实现了带权有向雨水网络自动构建及布局优化。实验结果表明:该方法较传统方法工作效率更高,且布网方案、雨水出口选择、管力计算等方面更加科学合理。 相似文献
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Along with rapid global urbanization, cities are challenged by environmental risks and resource scarcity. Sustainable urban planning is central to address the dilemma of economic growth and ecosystem protection, where the use of land is critical. Sustainable land use patterns are spatially explicit in nature, and can be structured and addressed using spatial optimization integrating GIS and mathematical models. This research discusses prominent sustainability concerns in land use planning and suggests a generalized multi‐objective spatial optimization model to facilitate conventional planning. The model is structured to meet land use demand while satisfying the requirements of the physical environment, society and economy. Unlike existing work relying on raster data, due to its simple data structure and ease of spatial relationship evaluation, this research develops an approach for identifying land use solutions based on vector data that better reflects the actual shape and spatial layout of land parcels as well as the ways land use information is managed in practice. An evolutionary algorithm is developed to find the set of efficient (Pareto) solutions given the complexity of vector‐based representations of space. The proposed approach is applied in an empirical study of Dafeng, China in order to support local urban growth and development. The results demonstrate that spatial optimization can be a powerful tool for deriving effective and efficient land use planning strategies. A comparison to results using a raster data approach supports the superiority of land use optimization using vector data as part of planning practice. 相似文献
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分析了GIS网络的基本要素和网络关系,提出了完备表达网络的TDN数据结构,从时间和空间效率上进行了推演,并以试验验证了该结构的实用性。 相似文献
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RS与GIS一体化数据结构的研究 总被引:1,自引:0,他引:1
详细阐述了RS与GIS一体化的概念 ,通过对RS与GIS一体化方面的研究与分析 ,进一步明确RS与GIS一体化对空间数据存储结构的要求 ,着重探讨了几种典型的用于RS与GIS一体化的数据结构 ,针对现有数据结构存在的问题与不足 ,提出了一种具有普遍适用价值的基于语义网络的空间数据存储结构 ,并给出一个应用实例 相似文献
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首先,借助传统的9交模型确定了矢栅一体化数据模型拓扑关系的定性表达;其次,利用重叠部分的栅格数目占各个目标的比率来确定交叠分量,同时根据栅格的统计量来描述两目标接近程度的邻近分量;最终,将定性的拓扑关系、用以度量化描述的交叠分量及邻近分量以三元组的形式来描述目标间的拓扑关系,从而更加有效地实现了多类型地理目标拓扑关系的度量化描述。 相似文献
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B Ramesh 《Journal of the Indian Society of Remote Sensing》1995,23(2):65-76
To evaluate a planning area or to implement plan procedures, planners need database in the form of land use, population density, housing density and point information regarding various facilities. At present planning tasks are carried out by manual methods where analytical capabilities are limited. Therefore, there is a need for reliable data as well as comprehensive database information indicating physical factors and good analytical tools. In a development plan various standards are specified in zoning regulations for the development of a city. To get an overall view, how these standards are implemented on the ground in planning period, a GIS application can be useful in analysing various amenity standards with respect to population and distances. In this study, for part of Bhubaneswar, basic data was generated from 1988 aerial photographs and other related information was gathered through field survey and secondary sources. The derived information in the form of a map has been entered into computer through digitization. Vector information was later converted into a raster form for the analysis. As per the planning standards catchment areas were created for limited facilities/services like schools, parks, play ground and accessibility to bus stop from main road. The population actually served by these facilities were calculated and compared with the existing planning standards. This particular study demonstrates the use of GIS in one of the planning tasks especially analyzing the residential areas as per the set standards such that improvement schemes can be proposed accordingly in the deficient areas. 相似文献
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Coupling land use allocation models with raster GIS 总被引:5,自引:0,他引:5
As geographic information systems (GIS) have moved from information storage and retrieval operations towards more decision
support functions, there is a need for more integration of spatial analytical modules that can assist in locational decisions.
This paper presents a methodology for coupling land use allocation models with a raster GIS. For raster systems, the integration
of any decision module has been limited by the size of raster datasets that may contain hundreds of thousands of pixels. Therefore,
decision heuristics have been used rather than exact methods such as mathematical programming models. For the problem of land
use allocation, the special structure of the generalized assignment problem is used here to handle large scale datasets. The
advantage of the mathematical programming approach is the additional information associated with the dual variables and opportunity
costs that can be used in subsequent sensitivity analyses.
Received: 7 April 1998/Accepted: 2 October 1998 相似文献
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为了更加科学、合理地采集符合规程要求的遥感影像解译样本数据,更加真实客观地反映地表覆盖的影像特征,快速高效地完成外业采集工作,笔者根据山区实际特点,结合具体项目实践,利用地理空间分析方法,从采集路线规划、样本点采集布置等方面进行了分析和探讨,为开展相关外业数据采集工作提供借鉴。 相似文献
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A Space‐Time Raster GIS Data Model for Spatiotemporal Analysis of Vegetation Responses to a Freeze Event 下载免费PDF全文
Many past space‐time GIS data models viewed the world mainly from a spatial perspective. They attached a time stamp to each state of an entity or the entire area of study. This approach is less efficient for certain spatio‐temporal analyses that focus on how locations change over time, which require researchers to view each location from a temporal perspective. In this article, we present a data model to organize multi‐temporal remote sensing datasets and track their changes at the individual pixel level. This data model can also integrate raster datasets from heterogeneous sources under a unified framework. The proposed data model consists of several object classes under a hierarchical structure. Each object class is associated with specific properties and behaviors to facilitate efficient spatio‐temporal analyses. We apply this data model to a case study of analyzing the impact of the 2007 freeze in Knoxville, Tennessee. The characteristics of different vegetation clusters before, during, and after the 2007 freeze event are compared. Our findings indicate that the majority of the study area is impacted by this freeze event, and different vegetation types show different response patterns to this freeze. 相似文献
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Airborne radar technology has traditionally been largely devoted to military applications. In recent years, applications in telecommunications, oil exploration and agriculture have proved that radar technology can also be used commercially. This paper focuses on an application of airborne radar technology in the insurance industry and describes the development of a large-scale flood risk assessment model for the River Thames. The model is based upon airborne Synthetic Aperture Radar (SAR) data and was built with commonly used Geographic Information Systems (GIS) and image processing tools. From the Orthorectified Images (ORIs) a land cover map was produced, from which a surface roughness map could be derived. A Digital Elevation Model (DEM) was processed to remove trees and other soft barriers and obtain the effective ground level. This was achieved by using standard GIS processes. The methodology may be applicable to any organisation exposed to flood risk. 相似文献
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We demonstrate a methodology for executing ecosystem models on large regional data sets by organizing and reducing their size prior to executing the model. A knowledge-based (KB) classification method was constructed to aggregate large raster data layers into fewer biophysical landtypes as defined by a climate-soil-vegetation equilibrium. Statistical tests compared simulated seasonal water stress from raster data simulations to their KB landtype and verified that the KB classifications are ordered along a seasonal water stress gradient (p=0.95). The KB method produced a more distinct water stress classification than an alternative GIS overlay classification. Internal concepts modelled by the KB, such as snowpack persistence, were compared to simulated snowpack depletion dates for a range of sites. The KB exhibited the same sensitivity, in direction and magnitude of variation, as simulated snowpack depletion dates from the process model FOREST-BGC. The KB method was 1000 times faster than the optimized versions of the physically based models, justifying the use of a KB as an efficient preprocessor to reduce a large database prior to ecosystem simulations. 相似文献
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A Comparison Between Contour Elevation Data Sources for DEM Creation and Soil Carbon Prediction, Coshocton, Ohio 总被引:1,自引:0,他引:1
A raster and vector GIS was created for the North Appalachian Experimental Watershed (NAEW) from legacy (1960) 1:2,400‐scale contour maps. The intent of the study was to use terrain data for the spatial modeling of soil organic carbon. It was hypothesized that DEMs derived from these data would be more accurate and therefore more useful for terrain‐based soil modeling than those from USGS 1:24,000‐scale contour data. Central tasks for this study were to digitally capture the 1:2,400‐scale maps, convert digital contour data sources to raster DEMs at multiple resolutions, and derive terrain attributes. A flexible approach was adopted, using software outside of mainstream GIS sources where scientifically or practically advantageous. Elevation contours and streamlines were converted to raster DEMs using ANUDEM. DEMs ranging in resolution from 0.5–30 m were tested for accuracy against precision carrier‐phase GPS data. The residual standard deviation was 1.68 meters for the USGS DEM and 0.36 meters for the NAEW DEM. The optimal horizontal resolution for the NAEW DEM was 5 m and for the USGS 10 m. Five and 10 m resolution DEMs from both data sources were tested for carbon prediction. Multiple terrain parameters were derived as proxies for surficial processes. Soil samples (n = 184) were collected on four zero‐order watersheds (conventional tillage, no‐till, hay and pasture). Multiple least squares regressions (m.l.s.) were used to predict mass C (kg m?2, 30 cm depth) from topographic information. Model residuals were not spatially autocorrelated. Statistically significant topographic parameters were attained most consistently from the 5 m NAEW DEM. However, topography was not a strong predictor of carbon for these watersheds, with r2 ranging from 0.23 to 0.58. 相似文献
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YU Nenghai WANG Xiaogang LIU Zhengkai ZHANG Rong 《地球空间信息科学学报》2001,4(3):21-28
1 TheconceptoftheintegrationofRSwithGISTheintegrationofremotesensing (RS)withgeo graphicalinformationsystem (GIS)isahotspotingeographicalinformationscience .TheconceptoftheintegrationofRSwithGIS ,intheviewofProf.LiDeren ,isthatRSisthewaytoobtaintheinforma ti… 相似文献