首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11篇
  免费   0篇
力学   1篇
数学   4篇
物理学   1篇
综合类   5篇
  2022年   1篇
  2018年   1篇
  2017年   2篇
  2014年   1篇
  2007年   1篇
  2005年   2篇
  1996年   1篇
  1993年   1篇
  1970年   1篇
排序方式: 共有11条查询结果,搜索用时 9 毫秒
1.
Based on the collection of land use maps of three repre sentative years (1972, 1986 and 1995) with a scale of 1 = 100 000, which were derived from interpreted aerial photographs and field surveys, landscape pattern were studied in Wenchuan County of Aba Prefecture, northwest of Sichuan Province, China, Six land use categories were classified according to the actuality of the study area and digitized by manual with the assistance of Geographic Information System (GIS). Landscape spatial and temporal changes were analyzed quanti ficationally by a series of structure, shape, pattern indices, which indicated that grassland dominates in number of patch while both grassland and shrub-land dominate in total area of patch over time. During the last 23 years, the fractal dimension of grassland and shrub-land were decreased while the other types were increased. Highest dominance and fragmentation and lowest diversity characterized the landscape of 1972. In 1986, the landscape pattern had the highest diversity and lowest dominance and fragmentation, which is contrary to the pattern in 1972, Slight change of diversity, dominance and fragmentation has been displayed from 1986 to 1995.  相似文献   
2.
通过北京奥运会申办前(2001年)和申办成功后(2001年以后)的遥感影象数据,以奥林匹克公园周边区域为例,进行土地利用信息提取、变化信息对比分析,得到近年由于奥运会建设,而发生的土地利用类型的变化数据,并从政策驱动因子、经济驱动因子、两方面对变化的原因进行了分析,同时预测了北京奥运会的举办可能产生的对其他企业的影响.  相似文献   
3.
约克夏地区的冰川喀斯特代表了英国奔宁山区喀斯特景现的基本特征。喀斯特景观价值的多样性和土地地产权的多属性决定了土地的多功能、开发的多目的和利用的多层次。因此,以牛羊为主的畜牧业用地、石灰石为主的采矿用地以及用于科研、教学、探险和旅游目的的保护用地在约克夏国家公园内有机地融为一体,形成了奔宁山区独特的土地资源开发、利用与保护形式。  相似文献   
4.
In this paper, we present a multi-objective linear fractional programming (MOLFP) approach for multi-objective linear fuzzy goal programming (MOLFGP) problem. Here, we consider a problem in which a set of pair of goals are optimized in ratio rather than optimizing them individually. In particular, we consider the optimization of profit to cash expenditure and crop production in various seasons to land utilization as a fractional objectives and used remaining goals in its original form. Further, the goals set in agricultural production planning are conflicting in nature; thus we use the concept of conflict and nonconflict between goals for computation of appropriate aspiration level. The method is illustrated on a problem of agricultural production system for comparison with Biswas and Pal [1] method to show its suitability.  相似文献   
5.
土地利用/覆被变化(LUCC)问题是全球环境变化关注的热点问题之一。研究伊洛河流域的土地利用变化对黄河流域生态保护与高质量发展具有重要意义。基于长期的LandsatTM卫星遥感影像、 R语言弦图可视化模型以及线性模型冗余分析(RDA分析),对伊洛河流域1990年—2020年30年间的土地利用时空变化特征、土地覆被的流量、流向及内在驱动因素进行了分析。结果表明:(1) 1990年—2020年间,伊洛河流域的土地变化呈现林地先减小后增加、耕地先增加后减小、建设用地整体增加、水域整体减小的变化趋势;(2)在数量上,1990年—2020年每10年间,耕地和林地的总变化量最大,建设用地次之,水域、草地和未利用土地的变化量很小;(3) 1990年—2000年、 2000年—2010年、 2010年—2020年的土地利用类型相互转换主要以耕地和林地的相互转化为主,土地利用变化程度呈上升趋势,在2010年—2020年达到最高;(4) 1990年—2020年间,林地重心整体向东北方向偏移,耕地的重心整体向南迁移,林地和耕地重心的变化与退耕还林政策有关。建设用地总体围绕洛阳市主城区,这与社会经济发展和城镇...  相似文献   
6.
在城市土地利用总体规划和城市规划实践经验的基础上,论述了城市土地利用总体规划的理论涵义,在土地规划管理系统中的地位,与城市规划的关系、主要内容与基本方法等四个问题。  相似文献   
7.
One objective in regional planning is the creation of communities with great accessibility. Thus we should plan the locations of inhabitants and the activities of the region so that the total accessibility will be maximized subject to some restrictions. This is a quadratic programming problem, which can be solved by quadratic programming techniques, but we cannot then take into account the uncertainties of the problem.In this paper a new criterion function is proposed for accessibility, uncertainty problems in regional land-use planning. It is derived from Hurwicz's generalized maximin principle. Many advantages are gained, for the planning problem is separated into linear programming problems, the uncertainties are taken into consideration as in game theory and the methods of parametric programming are available.A simplified problem of the populations of three town areas is studied and the method is generalized for problems of many activities and areas.  相似文献   
8.
The focus of the National Cooperative Soil Survey is shifting from producing static, printed soil survey reports to providing a dynamic resource of soils information for a wide range of needs. The National Soil Information System (NASIS) is the core component of this vision and is designed to manage and maintain soil data from collection to dissemination. NASIS supports this conceptual shift in three important areas: (1) collection of new information in compliance with standards, (2) application of expert knowledge to make information usable for a variety of purposes, and (3) dissemination of information to a wide variety of users. This paper demonstrates the use of NASIS for evaluating the suitability of military lands for vehicle related land-use activities.  相似文献   
9.
利用DEA-VRS模型,对新疆46个开发区2011-2014年土地利用效率进行了评价,结果发现:1)从整体来看,新疆开发区开发区土地配置不断优化,土地利用效率逐年提高;2)开发区整体的效率与最优效率水平之间仍存在较大差距,土地利用效率仍处于较低的水平;3)开发区间的工业用地效率差异明显,开发区等级越高,土地利用效率也越高,国家级开发区土地利用效率明显高于自治区级开发区.利用2011-2014年46个新疆开发区的面板数据,构建随机效应Tobit模型,估计了微观开发区属性和宏观政策两类因素对开发区土地利用效率的影响.估计结果表明,开发区的产业结构、专业化程度和经济密度均会对用地效率产生正向影响.而工业用地出让方式的变化和工业用地价格也是影响开发区的土地利用效率的重要因素.  相似文献   
10.
In this research paper, we define and test an ELECTRE III-based approach to the construction of non-compensatory composite indicators; these indicators are used for the evaluation of environmental and social performances of urban and regional planning policies. We tested the methodology for the construction of the Land-Use Policy Efficiency Index (LUPEI) on the municipal scale applied to a sample of municipalities in the Apulia Region (Southern Italy). Based on the literature review concerning composite indicators, we found that linear aggregation rules are the most widely applied aggregation procedures for composite indicators. However, their applicability depends on a set of strong theoretical and operational conditions. If these conditions do not hold, then other aggregation and weighting procedures must be applied to construct the composite indicators. We tested the ELECTRE III via a fruitful interaction with three experts who were participating in a focus group. We found that composite indicators are powerful tools when it comes to the assessment of multidimensional planning issues. Since each sub-indicator provides different information and responds to different goals, rankings and assessment based on mono-indicator frameworks can lead to incomplete or even biased results that do not consider an integrated approach to land-use policy efficiency. Moreover, both experts and decision-makers appreciated the role of composite indicators in increasing knowledge and providing deeper insights into complex phenomena in the domains of urban and regional planning.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号