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1.
地籍管理工作中,不同来源的宗地数据通常存在着诸多差异,识别和匹配不同数据源中的同名宗地图斑是提高数据更新精度与速度的关键,对地籍数据库的集成与信息共享有着非常重要的意义。该文针对地籍数据中宗地图斑的形状及变化特点,提出了一种基于局部相似的简单而有效的匹配方法来提高匹配率,基本原理是通过搜索两个面实体间最优的点对应或特征对应关系判断两个面实体是否匹配,采用形状相似度作为局部相似的判断指标。  相似文献   

2.
This article presents a geometric algebra-based model for topological relation computation. This computational model is composed of three major components: the Grassmann structure preserving hierarchical multivector-tree representation (MVTree), multidimensional unified operators for intersection relation computation, and the judgement rules for assembling the intersections into topological relations. With this model, the intersection relations between the different dimensional objects (nodes at different levels) are computed using the Tree Meet operator. The meet operation between two arbitrary objects is accomplished by transforming the computation into the meet product between each pair of MVTree nodes, which produces a series of intersection relations in the form of MVTree. This intersection tree is then processed through a set of judgement rules to determine the topological relations between two objects in the hierarchy. Case studies of topological relations between two triangles in 3D space are employed to illustrate the model. The results show that with the new model, the topological relations can be computed in a simple way without referring to dimension. This dimensionless way of computing topological relations from geographic data is significant given the increased dimensionality of geographic information in the digital era.  相似文献   

3.
地籍实体的时间变化过程分析   总被引:12,自引:1,他引:12  
王康弘  钟耳顺 《地理研究》2001,20(3):372-379
宗地、土地证书和权利人是地籍信息系统中最基本的两个实体,宗地是土地证书的客体,权利人是土地证书的主体。宗地实体的生命周期实际上就是宗地空间形状及空间拓扑关系不发生变化的时间范围,土地证书的生命周期就是指土地证书客体以及土地证书主体都不发生变化的时间范围。在探讨地籍实体变更规律基础上,本文设计和研究了利用地理信息系统技术和数据库技术记录和回溯地籍实体随时间变化的方法。为地籍信息系统解决历史地籍信息管理提供了理论和技术基础  相似文献   

4.
For modeling the topological relations between spatial objects, the concepts of a bound on the intersection of the boundary and interior, and the boundary and exterior are defined in this paper based on the newly developed computational fuzzy topology. Furthermore, the qualitative measures for the intersections are specified based on the α‐cut induced fuzzy topology, which are (Aα∧?A)(x)<1?α and ((Ac)α∧?A)(x)<1?α. In other words, the intersection of the interior and boundary or boundary and exterior are always bounded by 1?α, where α is a value of a level cutting. Specifically, the following areas are covered: (a) the homeomorphic invariants of the fuzzy topology; (b) a definition of the connectivity of the newly developed fuzzy topology; (c) a model of the fuzzy topological relations between simple fuzzy regions in GIS; and (d) the quantitative values of topological relations can be calculated.  相似文献   

5.
The greening of vacant parcels for urban sustainability continues to gain attention from researchers and practitioners, including its use to ameliorate the urban heat island effect and food deserts. Planning for such uses requires accurate inventories of the amount and distribution of vacant parcels, which may prove difficult to produce for large, sprawling urban complexes. This study provides a systematic approach that combines remote sensing and cadastral data to distinguish different forms of vacant land for the Phoenix, Arizona metropolitan area while reducing computation time. The approach identifies vacant parcels for potential greening, focusing on privately owned land lacking buildings and impervious surfaces. The results for the Phoenix area reveal hot spots of these parcels, many of which reside along the fringe of the metropolis awaiting development. A large number of vacant parcels, however, reside within the metropolitan core and are suitable for greening as well, potentially serving to mitigate the urban heat island effect and food deserts in this region. The identification method and parcel results are detailed.  相似文献   

6.
Urban growth and shrinkage constitute the overall pattern of growing urbanization across the globe.Studies on urban vacant land(UVL)are few,and have proved to be mainly rudimentary and subjective.This paper first presents the definition of UVL based on bibliometric analysis.Typology,morphology,proximate causes,and the multiple functions of UVL are then analyzed at parcel,transect,city,and national levels based on an international review.Results show that UVL can be categorized by land cover,land usage,and land ownership.Worldwide,UVL has been widespread and extensive.For example,the occurrence probabilities of UVL in the cases of Guangzhou and New York are 8.46%-8.88%and 3.17%-5.08%,respectively.The average vacancy rate of residential land amounts to 11.48%in 65 U.S.cities.Generally,UVL shows fragmentation and irregular shape,and significant spatial differences exist at parcel,transect,city,and national levels.Proximate causes,such as excessive land division,irregularly shaped land parcels,decreases in resident population,deindustrialization,land speculation,insufficient investment,and environmental concerns,can all result in UVL.Currently,UVL has become a gray area of social,economic,and ecological space.However,it can also be considered a potential resource for enhancing urban sustainability.Policy implications to promote urban sustainability using monitoring,control,and differential revitalization of UVL are presented.  相似文献   

7.
乐晓辉  陈君娴  杨家文 《地理研究》2016,35(11):2091-2104
大运量的城市轨道交通系统在一定程度上决定了城市的布局结构和土地利用格局。从时空两个维度出发,基于地价和开发强度两个要素,探讨轨道交通影响下的深圳市空间结构动态演变过程。通过描述性分析和空间计量模型实证发现,轨道交通站点周边地价和开发强度在受到距市中心或组团中心距离影响而空间衰减的同时,呈现出明显的站点导向性。轨道交通对城市空间结构的影响在时间上是超前的,规划方案的公示和轨道系统的建成运营均塑造了土地价格梯度和容积率梯度。并且,由于城市建设和历史原因,深圳原特区内外在轨道交通的影响下,地价和开发强度呈现了差异化的增长趋势。研究结果对理解轨道交通对城市空间结构影响及政府财政效应评估等具有积极意义。  相似文献   

8.
北京市居住用地出让价格的空间格局及影响因素   总被引:6,自引:0,他引:6  
崔娜娜  冯长春  宋煜 《地理学报》2017,72(6):1049-1062
以2004-2015年北京市六环内居住用地的交易样本为基本数据,借助ArcGIS、GS+、Surfer和Geoda软件,采用空间趋势面分析、最近邻指数(NNI)、探索性空间分析(ESDA)探讨居住用地出让和居住地价的空间格局特征,并对比OLS和空间回归模型(SLM和SEM)进一步探讨居住地价的影响因素。结果表明:① 北京市居住用地出让数量和出让面积不均衡,五六环间出让的居住用地最多。② 出让地块沿主要道路(如京石高速、京开高速、京沪高速及京藏高速)、地铁线(如地铁1号线、5号线、6号线、15号线、房山线、大兴线及亦庄线)呈轴线扩散,其中远郊区域这一特征更加明显。③ 居住地价从中心向外围总体表现“倒U型”趋势,且呈多中心圈层递减结构。④ 呈集聚分布模式,存在空间自相关,低值集聚区和高值集聚区明显。⑤ 模型对比方面,SLM>SEM>OLS,说明北京市居住地价存在实质性的空间依赖,而非干扰性的空间依赖。周边居住地块的价格、公交站、地铁站、重点小学、占地面积、容积率和出让方式对居住地价有显著影响。  相似文献   

9.
徐羽  李秀彬  辛良杰 《地理学报》2021,76(3):753-763
通过土地流转实现规模化经营是农地利用变化的重要趋势,土地规模化流转市场的租金关乎规模经营主体的形成及其可持续发展,但目前对全国层面耕地规模化流转租金的研究还较为欠缺。基于土地流转信息发布平台的2万余宗规模化流转地块,论文揭示了中国耕地规模化流转租金的总体水平与区域差异,并采用分位数回归方法识别地块属性特征对耕地租金分化的影响及异质性。结果表明:全国耕地平均租金为11339.10元/hm2,租金介于≤ 7500元/hm2、7500~15000元/hm2、15000~22500元/hm2、> 22500元/hm2区间的地块数量比例分别为38.93%、37.97%、14.52%和8.59%;云贵高原区和黄淮海平原区租金较高,比全国平均值分别高出32%和23%,而北方干旱半干旱区租金较低,租金约为全国均值的一半。地块质量特征、地块规模化特征、地块区位特征、地块产权特征对耕地租金具有显著的影响;对低租金地块而言,灌溉条件、土地平整度、道路质量的边际效应更大,而邻近高速公路则对高租金地块具有更强的增值效应。为降低农业生产的土地成本,政府应努力降低土地规模化流转过程中的交易成本、减少农业补贴对农地租金的干预、加强农田基础设施建设与农地流转租金的常态化监测。  相似文献   

10.
The land fallow policy was adopted by central and local governments to encourage the abandonment of water-intensive crops, such as winter wheat, in groundwater over-exploited areas. At the same time, since the 1990s, many households in the North China Plain (NCP) have chosen to replace the winter wheat and summer maize double-cropping system with the spring maize single-cropping system. Therefore, it is crucial to identify target land parcels for winter wheat abandonment and to design reasonable and proper standards for ecological compensation prior to the implementation of the land fallow policy in the NCP. In this study, multi-level logit models were used with household survey data in order to detect determinants across land parcel, household and village levels on household cropping system decisions; the opportunity costs for winter wheat abandonment were also calculated using cost–benefit analysis. The results show that: (1) land quality and irrigation condition at parcel level are two essential elements influencing household cropping system decisions. Nearly 70% of the total area of poor land and more than 90% of the total area of unirrigated land has suffered winter wheat abandonment. Target land parcels for the land fallow policy should be those that are irrigated and of high quality. (2) There were no significant differences between net profits from spring maize and summer maize under similar farming conditions, and the opportunity cost for winter wheat abandonment should be equal to the net profit of winter wheat. (3) The primary purpose of the land fallow policy is to induce groundwater recovery and restoration as a preliminary stage. A higher level of 350 yuan/mu is recommended as subsidy for ecological compensation at this stage. Later, the primary purpose of the policy should be a transition to a balance between exploitation and supplementation of water resources, and a lower level of 280 yuan/mu is recommended as a subsidy at this stage.  相似文献   

11.
Cellular automata (CA) have been widely used to simulate complex urban development processes. Previous studies indicated that vector-based cellular automata (VCA) could be applied to simulate urban land-use changes at a realistic land parcel level. Because of the complexity of VCA, these studies were conducted at small scales or did not adequately consider the highly fragmented processes of urban development. This study aims to build an effective framework called dynamic land parcel subdivision (DLPS)-VCA to accurately simulate urban land-use change processes at the land parcel level. We introduce this model in urban land-use change simulations to reasonably divide land parcels and introduce a random forest algorithm (RFA) model to explore the transition rules of urban land-use changes. Finally, we simulate the land-use changes in Shenzhen between 2009 and 2014 via the proposed DLPS-VCA model. Compared to the advanced Patch-CA and RFA-VCA models, the DLPS-VCA model achieves the highest simulation accuracy (Figure-of-Merit = 0.232), which is 32.57% and 18.97% higher respectively, and is most similar to the actual land-use scenario (similarity = 94.73%) at the pattern level. These results indicate that the DLPS-VCA model can both accurately split the land during urban land-use changes and significantly simulate urban expansion and urban land-use changes at a fine scale. Furthermore, the land-use change rules that are based on DPLS-VCA mining and the simulation results of several future urban development scenarios can act as guides for future urban planning policy formulation.  相似文献   

12.
农户是耕地最主要的经营主体,基于农户视角构建耕地细碎化程度评价指标体系更为合理。本文选取湖北省“江夏区—咸安区—通山县”作为研究区域,采用改进的TOPSIS法,利用农户问卷调查数据,对耕地细碎化程度评价进行了实证研究。结果表明:①耕地细碎化程度衡量指标的选取应基于耕地细碎化的属性特征,从农户微观视角,选取地块平均面积、地块数量、地块间的平均距离3个指标,衡量某一区域的耕地细碎化程度;②耕地细碎化在岗地平原地区与低山丘陵地区间存在显著差异,岗地平原地区的耕地细碎化程度低于低山丘陵地区;③研究区域地形地貌呈现出“北部岗地平原—南部低山丘陵”的分布特征,耕地细碎化的综合程度基本上呈现出“北部低—南部高”的分布规律;④在不同经济发展水平地区耕地细碎化存在显著差异,在岗地平原地区,经济发展水平越高的地区,耕地细碎化程度越高;而在低山丘陵地区,经济发展水平越高的地区,耕地细碎化程度越低。  相似文献   

13.
GIS中对原始矢量数据进行拓扑分析和重建是对其进行存储和使用的前提。引入包括规则格网和四叉树格网在内的索引结构,将全局的矢量拓扑分析转化为单个格网范围内足够少的矢量线段求交过程,减少了运算的复杂度;并用一种重组算法实现将原始矢量数据转化为符合“逢交必断”标准的矢量数据。试验表明,该算法适合海量和高散乱度的矢量数据。  相似文献   

14.
In this paper, a least‐squares based cadastral parcel area adjustment in geographic information systems (GIS) is developed based on (1) both the areas and coordinates being treated as observations with errors; and (2) scale parameters being introduced to take the systematic effect into account in the process of cadastral map digitization. The area condition equation for cadastral parcel considerations of scale parameters and geometric constraints is first constructed. The effects of the scale error on area adjustment results are then derived, and statistical hypothesis testing is presented to determine the significance of the scale error. Afterwards, Helmert's variance component estimation based on least‐squares adjustment using the condition equation with additional parameters is proposed to determine the weight between the coordinate and area measurements of the parcel. Practical tests are conducted to illustrate the implementation of the proposed methods. Four schemes for solving the inconsistencies between the registered areas and the digitized areas of the parcels are studied. The analysis of the results demonstrates that in the case of significant systematic errors in cadastral map digitization, the accuracies of the adjusted coordinates and areas are improved by introducing scale parameters to reduce the systematic error influence in the parcel area adjustment. Meanwhile, Helmert's variance component estimation method determines more accurate weights of the digitized coordinates and parcel areas, and the least‐squares adjustment solves the inconsistencies between the registered areas and the digitized areas of the parcels.  相似文献   

15.
华北地下水超采区冬小麦退耕的生态补偿问题探讨   总被引:10,自引:0,他引:10  
压减冬小麦种植面积是有效减少华北平原地下水用量最为有效的方法。近期,国家和地方政府均出台了土地休耕政策,拟在华北地下水超采区退耕冬小麦,实现“一季休耕、一季雨养”。然而,华北平原已经出现农户主动退耕冬小麦的现象。在此背景下,明确冬小麦退耕的瞄准目标、制订合理适度的补偿标准是土地休耕政策有效实施所面对的核心问题。本文利用农户问卷数据,构建多层次logit模型分析农户种植制度决策的影响因素,并计算冬小麦退耕的机会成本,旨在确定华北平原地下水超采区土地休耕政策的瞄准目标,并为农户补偿标准的制订提供建议。结果表明:① 地块层次的土地质量和灌溉条件是解释农户种植制度差异的关键因素,近70%的四等耕地和90%以上的旱地已退出冬小麦耕作,土地休耕政策应瞄准一、二、三等土地质量的水浇地;② 相似耕作条件的地块种植春、夏玉米的净收益大致相同,土地休耕的机会成本等于种植冬小麦的净收益;③ 仅考虑冬小麦对地下水资源的影响,土地休耕政策初期以地下水回升和地下水环境恢复为主要目标时,建议以350元/亩作为补偿标准参考值,后期目标转为维持地下水资源采补平衡时,可调整至280元/亩左右。  相似文献   

16.
Abstract

Growth in the available quantities of digital geographical data has led to major problems in maintaining and integrating data from multiple sources, required by users at differing levels of generalization. Existing GIS and associated database management systems provide few facilities specifically intended for handling spatial data at multiple scales and require time consuming manual intervention to control update and retain consistency between representations. In this paper the GEODYSSEY conceptual design for a multi-scale, multiple representation spatial database is presented and the results of experimental implementation of several aspects of the design are described. Object-oriented, deductive and procedural programming techniques have been applied in several contexts: automated update software, using probabilistic reasoning; deductive query processing using explicit stored semantic and spatial relations combined with geometric data; multiresolution spatial data access methods combining poini, line, area and surface geometry; and triangulation-based generalization software that detects and resolves topological inconsistency.  相似文献   

17.
A graph-theoretic data model, XRAG (eXtended Relational Attributed Graph), is described. The model and its associated data structure can be used to represent the structural properties (morphological and symbolic) of, and relations (spatial, topological, non-topological, quantitative and symbolic) between, discrete regions identified in a digital remotely-sensed image. The objective in developing this model is to allow second-order thematic information about the scene to be inferred from an analysis of these properties and relations. The paper briefly outlines the application of this model and an associated set of analytical techniques to infer land use from an initial land cover map derived from a digital remotely-sensed image.  相似文献   

18.
Soil erosion is a complex process determined by mutual interaction of numerous factors. The aim of erosion research at regional scales is a general evaluation of the landscape susceptibility to soil erosion by water, taking into account the main factors influencing this process. One of the key factors influencing the susceptibility of a region to soil erosion is land cover. Natural as well as human-induced changes of landscape may result in both the diminishment and acceleration of soil erosion. Recent studies of land-cover changes indicate that during the last decade more than 4.11% of Slovak territory has changed. The objective of this study is to assess the influence of land-cover and crop rotation changes over the 1990–2000 period on the intensity and spatial pattern of soil erosion in Slovakia. The assessment is based on principles defined in the Universal Soil Loss Equation (USLE) modified for application at regional scale and the use of the CORINE land cover (CLC) databases for 1990 and 2000. The C factor for arable land has been refined using statistical data on the mean crop rotation and the acreage of particular agricultural crops in the districts of Slovakia. The L factor has been calculated using sample areas with parcels identified by LANDSAT TM data. The results indicate that the land-cover and crop rotation changes had a significant influence on soil erosion pattern predominately in the hilly and mountainous parts of Slovakia. The pattern of soil erosion changes exhibits high spatial variation with overall slightly decreased soil erosion risks. These changes are associated with ongoing land ownership changes, changing structure of crops, deforestation and afforestation.  相似文献   

19.
土壤厚度信息对土壤碳储量估算、水文-生态过程模拟等有着重要影响,但我国北方石质山区缺乏现势性好、分辨率高的土壤厚度分布数据及其快速获取方法。基于北方石质山区土壤厚度的分布特点,先将地貌信息和植被类型叠加生成制图单元,再根据每类单元的特征,针对性地选取地形参数和地表覆被参数作为指示土壤厚度空间分布的环境变量,结合少量土壤样点,依据模糊推理模型,构建了基于分层制图策略的土壤厚度空间推测方法。以河北省滦平县虎什哈流域为例,利用从ASTER GDEMs提取的地形变量和从我国环境减灾卫星影像(HJ-A)提取的地表覆被信息对土壤厚度进行了推测。结果表明,该方法精度较高,是利用免费地形和遥感数据进行低成本快速土壤制图的实用途径。  相似文献   

20.
对基于案例推理的元胞自动机模型(CBR-CA)进行改进,将各类别的宏观转移概率添加到目标函数中,体现各类别的转变特征,并增加时间权重来确定转移概率,实现时间尺度上的模拟;由于土地覆盖变化的多样性和空间结构的复杂性,利用Monte Carlo(M-C)法确定土地覆盖的最终转换类别。选择黄河源区为试验区,利用1977年、1985年土地覆盖数据建立原始案例库,模拟了该区域1995年、2000年和2006年的土地覆盖变化,模拟的各类别转换的数量精度与实际相吻合,各年份的总体误差分别为0.002%、0.012%和0.005%,空间位置精度总体在70%以上,并进行未来土地覆盖情景预测。该模型可用于多类别、长时间序列区域土地覆盖变化的模拟与预测。  相似文献   

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