基于CFD技术的河谷型城市风环境模拟——以兰州市城关区为例

本文应用CFD软件对多种流场的强大模拟功能,模拟小尺度的兰州市城关区风环境。选用SRTM资料表征兰州市城关区的地形,应用ArcGIS生成兰州市地形模型,计算相关参数,将计算得到的地形粗糙度和兰州多年气候资料转化为CFD模型的数字参数及模拟边界条件等,首次模拟得到河谷型地区兰州城关区的风环境。结果表明:（1）河谷型地区中,气流过山时风速达最大值,依山体高度增大,而在背风坡风速值明显降低,达到0～1 m·s-1;（2）气流过境时在沿河谷前进,且在谷底风速值达0～1 m·s-1;（3）在模拟城市热岛效应的对比实验中,地块加热对气流过境有停滞作用。     

石漠化斑块动态行为特征与分类评价

对石漠化土地的特征进行全面深入的探讨,有助于石漠化土地分类治理和生态恢复重建。本文以SPOT5影像(分辨率2.5m)和航片(空间分辨率1m)为基本数据源,辅以实地踏勘和农户访问,通过跟踪每个石漠化斑块在2个时段的演变关系,研究了贵州清镇簸箩村1973-2005年石漠化斑块的新增(延展、新生)、消融和未变等动态变化特征。结果发现轻度石漠化土地斑块与其他石漠化类型在空间上存在着强烈的转换,相互之间的频繁转换使斑块具有不稳定性而处于一种波动状态。从各类石漠化斑块的来源看,存在一些斑块由无石漠化直接到极强度石漠化斑块之间的转换。根据石漠化斑块的动态演替行为认为,可将研究区2005年的石漠化分为未变石漠化、新生石漠化、延展石漠化,并据此提出石漠化强度指数和石漠化的治理对策。     

The knowledge–space dynamic in the UK bioeconomy

The loss of manufacturing employment to lower cost economies has meant that countries like the UK have sought to promote innovation in areas such as biotechnology. The emergence of the 'bioeconomy', however, has been highly uneven, with concentrations of activity in certain countries and particular regions in those countries. In the UK, for example, there are four major concentrations of the bioeconomy. Each of these concentrations exhibit distinct patterns of knowledge and spatial inputs into the innovation process, meaning that it is important to consider the knowledge–space dynamic in and of each region.     

自然与人文交互作用下的干旱区典型绿洲耕地动态变化驱动力分析——以新疆于田绿洲为例

 绿洲是干旱区独特的自然景观,是人们生产生活的载体。如何在保持经济发展、提高人民生活水平的基础上保护有限的耕地资源,是关系到干旱区绿洲和谐以及可持续发展的重要问题。选取干旱区典型绿洲——于田县1949\_2004年的自然与人文统计资料,首先分析了五十余年来该县耕地变化的情况。然后从自然与人文两个角度对影响耕地面积变化的因子进行分析,结果表明,自然因素往往构成一定区域绿洲发展的基本限制,人为因素在短时期内,对耕地的变化起着决定性作用,这种作用如果顺应自然因素的限制,则对绿洲发展有利,绿洲稳定性增强;反之,绿洲稳定性减弱,由于新疆绿洲外围多为戈壁及沙漠,因此,对绿洲的利用要遵循自然规律,以保护绿洲为前提,合理利用水等自然资源,否则绿洲的面积随时都有可能缩小。     

Synchronising geometric representations for map mashups using relative positioning and Linked Data

Map mashups, as a common way of presenting geospatial information on the Web, are generally created by spatially overlaying thematic information on top of various base maps. This simple overlay approach often raises geometric deficiencies due to geometric uncertainties in the data. This issue is particularly apparent in a multi-scale context because the thematic data seldom have synchronised level of detail with the base map. In this study, we propose, develop, implement and evaluate a relative positioning approach based on shared geometries and relative coordinates to synchronise geometric representations for map mashups through several scales. To realise the relative positioning between datasets, we adopt a Linked Data–based technical framework in which the data are organised according to ontologies that are designed based on the GeoSPARQL vocabulary. A prototype system is developed to demonstrate the feasibility and usability of the relative positioning approach. The results show that the approach synchronises and integrates the geometries of thematic data and the base map effectively, and the thematic data are automatically tailored for multi-scale visualisation. The proposed framework can be used as a new way of modelling geospatial data on the Web, with merits in terms of both data visualisation and querying.     

中国市场群落发展机制

市场群落的崛起已成为21世纪初中国市场经济发展的新景观，在概述市场群落的基本特点后，揭示其形成和演化的动力机制；继而对单个市场与群落型市场上经营者的行为方式特征进行了比较分析，表明群落型市场具有多方面的竞争优势；指出市场群落的空间扩张还促进了经济国际化与本地化的有机融合发展，同时认为，市场群落持续发展的根本在于保证商人的可持续发展，并提出了相应的对策建议。     

地籍信息系统中动态地块存储的实现

该文归纳了地籍信息系统中地块动态变化的基本类型 ,提出了存储动态变化信息的两种解决方案 ,分别称之为基于多边形的数据结构和基于弧段的数据结构 ,讨论了它们具体的实现 ,并比较其优缺点