共查询到20条相似文献，搜索用时 31 毫秒
1.
A. Roy B. S. S. Devi B. Debnath M. S. R. Murthy 《Journal of the Indian Society of Remote Sensing》2010,38(3):387-399
Development of forest connectivity and corridors are critical for biodiversity conservation and also ensures energy and genetic
exchange across greater spatial extent. A model has been developed to geospatially identify the potential ecological corridors
based on the vegetation type and land cover data in association with spatial disturbance profile. The model formulates the
route of least impedance due to (1) disturbance (a function of fragmentation, juxtaposition, Interspersion & proximity to
roads/settlements) and (2) vegetation type and land cover. This is because the movement of genetic information and materials
follow the path of least resistance across a landscape. The paper explores the utility of the approach to spatially generate
ecological corridors connecting 14 protected areas of Orissa. The model has been able to identify the potential route connecting
the different protected regions with 85–87% of the corridor in the natural areas. Of the 14 protected areas, only 12 could
be connected by the model as they confirm to the criteria for the corridor establishment. 相似文献
2.
A Space‐Time Raster GIS Data Model for Spatiotemporal Analysis of Vegetation Responses to a Freeze Event 
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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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Claudia Pittiglio Andrew K. SkidmoreHein A.M.J. van Gils Herbert H.T. Prins 《International Journal of Applied Earth Observation and Geoinformation》2012,14(1):61-72
The role of corridors in mitigating the effects of landscape fragmentation on biodiversity is controversial. Recent studies have highlighted the need for new approaches in corridor design using long-term datasets. We present a method to identify transit corridors for elephant at a population scale over a large area and an extended period of time using long-term aerial surveys. We investigated environmental and anthropogenic factors directly and indirectly related to the wet versus dry season distribution of elephant and its transit corridors. Four environmental variables predicted the presence of elephant at the landscape scale in both seasons: distance from permanent water, protected areas and settlements and vegetation structure. Path analysis revealed that altitude and monthly average NDVI, and distance from temporary water had a significant indirect effect on elephant distribution at local scale in dry and wet seasons respectively. Five transit corridors connecting Tarangire National Park and the northern as well as south-eastern wet season dispersal areas were identified and matched the wildlife migration routes described in the 1960s. The corridors are stable over the decades, providing landscape connectivity for elephant. Our approach yielded insights how advanced spatial analysis can be integrated with biological data available from long-term datasets to identify actual transit corridors and predictors of species distribution. 相似文献
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The vector assignment p-median problem (VAPMP) (Weaver and Church in Transp Sci 19(1):58–74, 1985) was one of the first location-allocation models developed to handle split assignment of a demand to multiple facilities. The underlying construct of the VAPMP has been subsequently used in a number of reliable facility location and backup location models. Although in many applications the chance that a facility fails may vary substantially with locations, many existing models have assumed a uniform failure probability across all sites. As an improvement, this paper proposes a new model, the expected p-median problem as a generalization of existing approaches by explicitly considering site-dependent failure probabilities. Multi-level closest assignment constraints and two efficient integer linear programming (ILP) formulations are introduced. While prior research generally concludes that similar problems are not integer-friendly and cannot be solved by ILP software, computational results show that our model can be used to solve medium-sized location problems optimally using existing ILP software. Moreover, the new model can be used to formulate other reliable or expected location problems with consideration of site-dependent failure probabilities. 相似文献
5.
Yao Yao Penghua Liu Ye Hong Zhaotang Liang Rouyu Wang Qingfeng Guan Jingmin Chen 《Transactions in GIS》2019,23(5):1029-1047
The rapid development of urban retail companies brings new opportunities to the Chinese economy. Due to the spatiotemporal heterogeneity of different cities, selecting a business location in a new area has become a challenge. The application of multi‐source geospatial data makes it possible to describe human activities and urban functional zones at fine scale. We propose a knowledge transfer‐based model named KTSR to support citywide business location selections at the land‐parcel scale. This framework can optimize customer scores and study the pattern of business location selection for chain brands. First, we extract the features of each urban land parcel and study the similarities between them. Then, singular value decomposition was used to build a knowledge‐transfer model of similar urban land parcels between different cities. The results show that: (1) compared with the actual scores, the estimated deviation of the proposed model decreased by more than 50%, and the Pearson correlation coefficient reached 0.84 or higher; (2) the decomposed features were good at quantifying and describing high‐level commercial operation information, which has a strong relationship with urban functional structures. In general, our method can work for selecting business locations and estimating sale volumes and user evaluations. 相似文献
6.
Performance evaluation is a critical step for land use/land cover (LULC) change modelling. It can be conducted through pixel quantity and its geographical location according to majority of current approaches. It is hence important to know to what extent spatial patterns of a given landscape are properly replicated in simulated LULC maps. Therefore, a new validation metric, named as landscape accuracy metric (LAM), is introduced by inspiration from landscape ecology. Unlike pixel quantity validation metrics, model performance is measured by LAM through quantifying spatial patterns including structure, composition and configuration attributes. The functionality of LAM was studied to assess the performance of the built-up change simulation under historical, ecological and stochastic scenarios, applying Cellular Automata Markov model. LAM is a flexible measure such that modellers can apply this metric through adding or eliminating various metrics of their interest in a selective manner and under different environmental circumstances. 相似文献
7.
GIS and Intelligent Agents for Multiobjective Natural Resource Allocation: A Reinforcement Learning Approach 总被引：1，自引：0，他引：1
An important component of natural resource management is determining how to allocate resources within a landscape to different stakeholders in a manner that satisfies multiple objectives. Developing decision making tools for assisting natural resource allocation is a challenging endeavor as stakeholders' objectives typically exist at varying spatial scales, their actions are defined by the spatial constraints in which they operate, and the spatial distribution of resources can be altered due to system disturbances. The nature of such challenges suggests the need for a geographic approach that can investigate these spatial complexities in order to generate a suitable set of solutions. The objective of this study is to develop and evaluate an Intelligent Agent Model for multiobjective natural resource allocation. The model integrates agent-based modeling in a GIS environment with reinforcement learning – a heuristic method for generating, evaluating, and improving multiobjective decision making solutions. The model is implemented by simulating a forest management scenario in which agents that represent forest companies learn how to harvest trees in a manner that maximizes economic return while minimizing the adverse ecological impact to the surrounding landscape. In addition, the model simulates forest disturbances of varying frequencies and intensities to determine how disturbance events affect the decision-making ability of agents. The model is validated to demonstrate that it can provide practical solutions to natural resource decision making. 相似文献
8.
While cellular automata have become popular tools for modeling land‐use changes, there is a lack of studies reporting their application at very fine spatial resolutions (e.g. 5 m resolution). Traditional cell‐based CA do not generate reliable results at such resolutions because single cells might only represent components of land‐use entities (i.e. houses or parks in urban residential areas), while recently proposed entity‐based CA models usually ignore the internal heterogeneity of the entities. This article describes a patch‐based CA model designed to deal with this problem by integrating cell and object concepts. A patch is defined as a collection of adjacent cells that might have different attributes, but that represent a single land‐use entity. In this model, a transition probability map was calculated at each cell location for each land‐use transition using a weight of evidence method; then, land‐use changes were simulated by employing a patch‐based procedure based on the probability maps. This CA model, along with a traditional cell‐based model were tested in the eastern part of the Elbow River watershed in southern Alberta, Canada, an area that is under considerable pressure for land development due to its proximity to the fast growing city of Calgary. The simulation results for the two models were compared to historical data using visual comparison, Ksimulation indices, and landscape metrics. The results reveal that the patch‐based CA model generates more compact and realistic land‐use patterns than the traditional cell‐based CA. The Ksimulation values indicate that the land‐use maps obtained with the patch‐based CA are in higher agreement with the historical data than those created by the cell‐based model, particularly regarding the location of change. The landscape metrics reveal that the patch‐based model is able to adequately capture the land‐use dynamics as observed in the historical data, while the cell‐based CA is not able to provide a similar interpretation. The patch‐based approach proposed in this study appears to be a simple and valuable solution to take into account the internal heterogeneity of land‐use classes at fine spatial resolutions and simulate their transitions over time. 相似文献
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近年来,我国公路对自然生态环境的影响随着通车里程的增加而日益显著。在公路选线的过程中,全面分析拟建公路走廊带内景观破碎度的空间分异特征,可有效减少公路修建对生态环境的不利影响。本文利用遥感分类技术和GIS(地理信息系统)空间分析方法,以湖南长湘公路走廊带某段土地斑块和景观分类为基础,借助斑块密度指数、最大斑块指数和相似邻近比指数,在斑块类型水平和景观水平两个层面全面分析公路走廊带内自然林地景观、农业景观和城乡建设景观破碎度的空间分异特征。结果表明:长湘公路走廊带内景观破碎度高的地区主要分布在大型斑块边缘、平原地区以及公路沿线;自然林地景观和农业景观的破碎度较低,城乡建设景观的破碎度较高;城乡建设景观的破碎度与公路相关性最强,表现出顺应公路走向的条带状蔓延特征。该研究成果可为公路选线方案的制订和完善提供环境影响方面的参考。 相似文献
10.
为有效地组织大范围地表覆盖数据验证,需要发动和组织来自不同地域、不同机构的专家,但往往缺少网络化环境下的协同验证方法和工具。针对这一问题,将互联网+、服务计算技术等与地表覆盖验证业务相融合,提出了互联网+地表覆盖验证服务模型,构建了面向互联网+的地表覆盖验证业务流程和方法,研制了基于景观形状指数（landscape shape index,LSI）抽样算法的在线验证系统GLCVal（global land cover validation）,为大范围、高分辨率地表覆盖数据验证提供了新思路、新方法。利用所提出的方法与系统,与GEO（Group of Earth Observation）、UN-GGIM（the United Nations Initiative on Global Geospatial Information Management）等组织合作开展了GlobeLand30的全球验证,有效支持了跨区域专家的主动参与、多角色协同,促进了验证资源联通和共享,提高了验证效率。 相似文献
11.
空间选址问题涉及因素错综复杂，模型建立困难，GIS的发展为空间选址问题提供了新的技术手段，其应用于空间选址可以克服以往一些模型的不足之处，具有广阔的应用前景。本文主要对影响空间选址的因素进行了归纳总结，并对GIS技术在空间选址中的应用现状进行了一定的探讨分析。 相似文献
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Ubiquitous taxi trajectory data has made it possible to apply it to different types of travel analysis. Of interest is the need to allow someone to monitor travel momentum and associated congestion in any location in space in real time. However, despite an abundant literature in taxi data visualization and its applicability to travel analysis, no easy method exists. To measure taxi travel momentum at a location, current methods require filtering taxi trajectories that stop at a location at a particular time range, which is computationally expensive. We propose an alternative, computationally cheaper way based on preprocessing vector fields from the trajectories. Algorithms are formalized for generating vector kernel density to estimate a travel-model-free vector field-based representation of travel momentum in an urban space. The algorithms are shared online as an open source GIS 3D extension called VectorKD. Using 17 million daily taxi GPS points within Beijing over a 4-day period, we demonstrate how to generate in real time a series of projections from a continuously updated vector field of taxi travel momentum to query a point of interest anywhere in a city, such as the CBD or the airport. This method allows a policy-maker to automatically identify temporal net influxes of travel demand to a location. The proposed methodology is shown to be over twenty times faster than a conventional selection query of trajectories. We also demonstrate, using taxi data entering the Beijing Capital International Airport and the CBD, how we can quantify in nearly real time the occurrence and magnitude of inbound or outbound queueing and congestion periods due to taxis cruising or waiting for passengers, all without having to fit any mathematical queueing model to the data. 相似文献
14.
城市园林绿化,具有数量庞大、种类繁多、覆盖范围广等特点,为城市绿化日常管理工作增加了难度。合理、高效地组织城市绿化空间数据,是城市园林绿化数字化管理的关键与核心。本文提出了以Arc SDE空间数据引擎为基础,分析城市园林绿化数据特点,制定绿化数据结构,采用分层方式管理绿化数据,实现园林绿化要素的一张图管理。实践验证表明,此方案具有较好的可行性与实用性,可为园林绿化管理提供精确的空间位置服务,提高工作效率。 相似文献
15.
Estimating the uncertainty of land-cover extrapolations while constructing a raster map from tabular data 总被引：2，自引：0，他引：2
This paper presents novel techniques to estimate the uncertainty in extrapolations of spatially-explicit land-change simulation models. We illustrate the concept by mapping a historic landscape based on: 1) tabular data concerning the quantity in each land cover category at a distant point in time at the stratum level, 2) empirical maps from more recent points in time at the grid cell level, and 3) a simulation model that extrapolates land-cover change at the grid cell level. This paper focuses on the method to show uncertainty explicitly in the map of the simulated landscape at the distant point in time. The method requires that validation of the land-cover change model be quantified at the grid-cell level by Kappa for location (Klocation). The validation statistic is used to estimate the certainty in the extrapolation to a point in time where an empirical map does not exist. As an example, we reconstruct the 1951 landscape of the Ipswich River Watershed in Massachusetts, USA. The technique creates a map of 1951 simulated forest with an overall estimated accuracy of 0.91, with an estimated users accuracy ranging from 0.95 to 0.84. We anticipate that this method will become popular, because tabular information concerning land cover at coarse stratum-level scales is abundant, while digital maps of the specific location of land cover are needed at a finer spatial resolution. The method is a key to link non-spatial models with spatially-explicit models. 相似文献
16.
The idea of public participation GIS involves the use of GIS tools to help laypcople understand the spatial consequences of proposed projects, evaluate alternatives, and create new solutions. The widening use of information networks creates opportunities for making GIS a widely accessible decision-making tool, bypassing the constraints of location and time. This paper presents a prototype software that enables group collaboration across space and time using the Internet infrastructure. The prototype, called Spatial Understanding and Decision Support System (SUDSS), was designed to facilitate a controlled experiment in collaborative group work aimed at solving a realistic land-use planning problem. The paper discusses design considerations for a distributed public GIS and presents the functionality of SUDSS using the example of group participation in developing a land-use zoning plan. 相似文献
17.
一种简单加入空间关系的实用图像分类方法 总被引：10，自引：0，他引：10
遥感图像分类是遥感图像处理的一项基本内容，也是遥感应用中关键的一步。为了提高分类的精度，一方面是对光谱信息的合理利用；另一方面，可以加入新的信息源，即进行多源数据处理，并加入地学知识，尤其是对空间信息的利用是至关重要的。但是由于地学知识的复杂性及空间信息利用的难度以及数据源的限制，尚无公认的实用方法。该文提出了一种简单加入空间关系的分类方法，在没有其它数据源的情况下，利用空间关系特性，在分类中构造两个空间关系波段，实现空间约束，部分消除仅依赖光谱数据分类而引起的同物异谱和同谱异物造成的分类错误。简单实用，同时也验证了空间关系在分类中的重要性。 相似文献
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室内导航网络是实现室内路径规划和导航的基础。针对现有室内导航网络存在拓扑连通结构不合理、生成路径几何形态不自然等问题,本文依据人类长期以来形成的“抄近路”习性及“避碰”安全需求,提出了一种符合人行走习惯的室内导航网络及其自动生成算法。该导航网络将室内可通行空间划分为普通房间和走廊,普通房间内网络映射为房间结点与门结点的直线连接;形状复杂的走廊空间则依据空间尺度和凹凸性被细分为狭窄走廊空间和开阔走廊空间,狭窄走廊空间以中轴线作为路线,开阔走廊空间则将门结点和通道口结点连接形成完全图;最后将房门结点连接到走廊路线,形成完整室内导航网络。试验结果表明:该模型及其生成算法能够依据室内空间尺度对复杂通行空间进行合理分区,生成与空间特征一致的导航网络结构,使得规划生成的最短路径形态更符合人们的行走习惯。 相似文献
20.
顾及尺度效应和景观格局的土地利用数据综合指标研究 总被引：6，自引：0，他引：6
从尺度效应和土地利用案观格局影响两个层面研究土地利用数据综合的宏观和微观综合指标,设计土地利用数据综合的指标体系和指标定量化描述模型.在全国各个土地利用分区采集不同尺度的具有典型代表性的土地利用数据样本集,通过空间统计分析等方法,得到土地利用数据综合中的宏观控制性指标和微观图形综合指标的尺度变化规律及其与土地利用格局的关系.以一个县为试验区,验证其合理性.Abstract： Indices for land use data generalization are critical for generating multiscale land use maps and databases. Previous research suffers from two major setbacks. Firstly, determination of threshold values for multi-scale land use data generalization in a large area, such as a nation, remains subjective. A second problem is general ignorance of landscape pattern. This paper studies the index system of land use data generalization from both scale and landscape pattern perspective. We discuss the macro and micro indices of land use data generalization with consideration of spatial scales and landscape pattern. To quantitatively relate the indices and scale and landscape pattern metrics, land use data samples have been collected at multiple spatial scales in various land use regions across China. Based on statistic analysis, we then generate both macro and micro control rules for land use data generalization at various spatial scales and land use patterns. Finally, we prove the proposed method and achieved results to be effective and reasonable with sample data at county level. 相似文献