实用型基础地理信息(数据库)系统

文章以SunwayGIS在中小城市中的应用为基础,探究了地理信息数据库的变化和更新,提出了实施地理信息数据库更新应注意的问题。     

内插地价监测点进行土地级别调整的研究

针对城镇基准地价更新中土地级别范围调整问题,提出了内插地价监测点调整土地级别技术在建立地价动态监测体系的基础上,运用合适的空间内插模型,通过插值计算得到城镇内每个点的地价,然后根据一定的地价幅度生成等值线图,进而由地价等值线图结合原有土地级别进行土地级别范围的确定和调整。     

SPOT-5遥感数据在土地利用更新调查中的几何精度分析

新一轮土地利用现状更新调查即将开始,SPOT-5遥感数据易获取、价格适宜,但是对其几何精度能否满足1∶1万土地利用现状调查要求存在争议。本文从遥感混合像元成像原理及随机误差的概率分布规律等方面定量分析了SPOT-5遥感数据的误差大小。研究结果表明:应用SPOT-5遥感数据可解译识别宽度≥0.75m的线状地物,面积≥0.0225ha(公顷)的面状地物,面积≥0.75ha的图斑解译量算面积误差<5%,其几何精度能满足1∶1万土地利用现状调查要求。     

Temporal and spatial variations in density and velocity fields of the waters of Gareloch,Scotland

 Spatial variations in the density and velocity fields have been observed in the Gareloch (Scotland) during surveys in 1987–1988 and 1993–1994. The variation of the density field has been analyzed on a variety of time scales from semidiurnal to seasonal in order to quantify effects caused by the forcing factors of tidal mixing, freshwater input, and wind. Initial results indicate that water density in the loch is controlled (to a major degree) by the freshwater input from runoff from the local catchment area and from freshwater entering on the flood tide from the Clyde Estuary. It is estimated that during winter periods the high freshwater flows from the rivers Leven and Clyde into the Clyde Estuary account for up to 75% of the freshwater creating the density structure in the loch. Analysis of long-term dissolved oxygen data reveals that major bottom water renewals occurred between July and January in the years 1987–1994. Major bottom water dissolved oxygen renewals have a general trend but during the year sporadic renewals can take place due to abnormal dry spells increasing the density of the water entering from the Clyde, or consistently strong winds from the north reducing stratification in the loch and producing better mixed conditions. Velocities vary spatially, with the highest velocities of up to 0.6 m s^–1 being associated with the velocity jet effect at the constriction at the sill of the loch. Observed near-surface mid-loch velocities increased as the vertical density gradients in the upper layers increased. This indicates for the observed conditions that increased stratification in the upper layers inhibits the entrainment rate and hence rate of gain of thickness of the wind-driven surface layer, resulting in increased surface velocities for a given wind speed and direction. The main flow is concentrated in the upper 10 m and velocities below 10 m are low. Observed mean spring tide surface velocities are on average 30% greater than mean neap tide surface velocities. Received: 22 May 1995 · Accepted: 23 August 1995     

基于SLQAS的上海石库门里弄保护与更新研究

基于GIS构建上海里弄查询分析系统(SLQAS),并对2006—2012年上海内环线以内210个地块石库门里弄的更新进程分析发现,石库门更新呈现出显著的行政逻辑,位于街道中心的石库门率先更新,而后才涉及街道边界的石库门,为此,要加强街道边界地区、综合价值较高的石库门里弄管理,并进一步划定保护与更新范围,创新保护更新的方法和模式,强化政府、企业、公众等各主体对城市更新的参与。期待对我国城市更新及其文脉传承等有所裨益。     

Combining the dissipation method and surface renewal analysis to estimate scalar fluxes from the time traces over rangeland grass near Ione (California)

The dissipation method, the method preferred for estimating scalar surface fluxes over open water has not traditionally been used by agronomists, whereas the surface renewal (SR) theory in conjunction with the analysis of the scalar time trace offers tremendous advantages for estimating fluxes over agronomic crops. For a steady and horizontally homogeneous flow, it is shown that the dissipation method and SR analysis are closely related. As a consequence, a new dissipation–SR analysis expression for estimating scalar surface fluxes was derived. The new equation requires no calibration, and the scalar time trace measured at a frequency capable of identifying canopy‐scale coherent structures (typically 4–10 Hz in agriculture) is the only input required. Sensible and latent heat flux estimates obtained from 10 Hz air temperature and water vapour concentration measurements in the inertial sub‐layer (2 m height) over short, homogeneous rangeland grass at a site where similarity does not hold gave similar results to those measured with the eddy covariance (EC) method. For unstable cases, the new equation provided a root mean square error of 57 W m^?2 for the surface energy‐balance closure. For stable cases, the performance was difficult to evaluate because the EC fluxes were similar in magnitude to the sensor error. It is concluded that the proposed method can contribute to a better understanding of hydrological processes and water requirements by providing an accurate, less costly, alternative method to indirectly estimate evapotranspiration as the residual of the energy balance equation. Copyright © 2009 John Wiley & Sons, Ltd.     

全数字摄影测量方法在地理信息数据更新中的应用

社会的飞速发展对测绘工作提出了新的要求,数据的现势性、数据采集的快速性矛盾逐渐突出,传统的数据更新方法生产成本高,更新周期长,已不能满足社会高速发展的需要。探索一条快速、高效的数据更新方法迫在眉睫。该文全面介绍了利用全数字摄影测量方法对已有1∶1万3D数字产品进行更新的方法和技巧,在很大程度上缩短了数据更新周期,降低了数据更新的成本,提高了工作效率。     

基于高新技术产品更新的产品收益增加方法探讨

从讨论高新技术企业的产品更新与其对企业发展的影响入手,重点分析了更新过程中的收益状况对产品更新乃至企业持续发展的影响,提出了产品更新中改进老产品的销售对新产品推出、对企业产品更新以及对企业持续发展的重要意义;最后提出采用新的理论和方法完善企业产品更新时的收益增加的设想,并做了案例分析.     

MapGIS在聊城市农村土地更新调查中的应用

该文阐述了MapGIS软件在农村土地更新调查中的可行性、具体应用方法及实际操作中应注意的问题。实践证明,该软件能够满足农村土地更新调查数据库建设的要求,使用该软件可使土地调查成果得到更好地维护和更新。     

基于多维感知的城市活力空间特征研究

基于多维感知对城市活力进行综合评价并探索其用地特征,是提升城市智慧化水平、实现精准规划和有机更新的重要基础。本研究以厦门岛为例,基于社交媒体签到数据、夜间灯光影像数据、POI数据和LBS大数据,从社会、经济、文化和空间4个维度感知城市活力,使用核密度、数据网格化和最优聚类法,分析城市活力的空间特征,并探讨不同活力区域的土地利用结构、功能多样性和开发强度等用地特征。研究发现：(1)基于多源数据的城市活力多维感知方法可精准、有效评估城市空间特征和发展动态;(2)厦门岛社会、经济、文化和空间维度城市活力的空间分布存在一定差异,4类活力区域呈现出西部连绵成带、东部围绕商务区和大型设施集中的特征;(3)各类活力区域的用地特征存在较大差异。第一类区域的公共管理与公共服务用地占比和第二类区域的商业服务业用地占比最高,均接近20%。集聚可显著提升城市活力,建设用地周边1000 m范围内的功能混合度更为重要。居住和商业服务业设施用地的活力水平随着开发强度的降低而降低,高值区容积率均在2.0以上。