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51.
This paper reports on recent experience with the development of aspace, an Open Source (OS) library for the geographic visualization and analysis of activity-travel behaviour. The paper begins with an overview of recent progress with respect to the convergence of Open Source technology, spatial analysis, and travel behaviour research. The remainder of the paper focuses on aspace; a collection of functions that, when combined with data describing the geographical location of daily activities, can be used to visualize and describe spatial properties of individual and household activity spaces. These properties include: size, orientation, shape, and the geographical dispersion of activity locations contained within the activity space. Several planar geometries are used to transform measurable spatial properties into intuitive objects for visualizing spatial patterns of activity participation. Experiments are conducted, using data from the first wave of the 2003 Toronto Travel Activity Panel Survey, to demonstrate the potential application of aspace for basic and applied policy-based research into activity-travel behaviour. The toolkit is distributed as a downloadable ‘package’ from the Open Source R Project for Statistical Computing.   相似文献   
52.
以烟台市为例,从生态环境协调性、经济可行性、社会可接受性等方面,构建了2004年城市土地可持续利用评价的指标体系,采用特尔斐等方法计算了其可持续利用度。结果表明,烟台城市土地利用目前仍处于可持续利用起步阶段。  相似文献   
53.
首先对WebGIS的发展状况进行了分析,然后介绍了Web Services的工作原理,给出了面向Geo-Services的城市空间信息基础设施建设的结构模型,并依据该模型对北京市基础地理信息数据库集成项目进行了典型研究.  相似文献   
54.
阐述了无锡市政地下管线信息系统的设计原则、系统结构以及部分功能的设计与实现。  相似文献   
55.
The Late Archaean Closepet Granite batholith in south India is exposed at different crustal levels grading from greenschist facies in the north through amphibolite and granulite facies in the south along a ∼400 km long segment in the Dharwar craton. Two areas, Pavagada and Magadi, located in the Main Mass of the batholith, best represent the granitoid of the greenschist and amphibolite facies crustal levels respectively. Heat flow estimates of 38 mW m−2 from Pavagada and 25 mW m−2 from Magadi have been obtained through measurements in deep (430 and 445 m) and carefully sited boreholes. Measurements made in four boreholes of opportunity in Pavagada area yield a mean heat flow of 39 ± 4 (s.d.) mW m−2, which is in good agreement with the estimate from deep borehole. The study, therefore, demonstrates a clear-cut heat flow variation concomitant with the crustal levels exposed in the two areas. The mean heat production estimates for the greenschist facies and amphibolite facies layers constituting the Main Mass of the batholith are 2.9 and 1.8 μW m−3, respectively. The enhanced heat flow in the Pavagada area is consistent with the occurrence of a radioelement-enriched 2-km-thick greenschist facies layer granitoid overlying the granitoid of the amphibolite facies layer which is twice as thick as represented in the Magadi area. The crustal heat production models indicate similar mantle heat flow estimates in the range 12–14 mW m−2, consistent with the other parts of the greenstone-granite-gneiss terrain of the Dharwar craton.  相似文献   
56.
57.
系统研究了西藏冈底斯带石炭纪—二叠纪火山岩的时空分布、岩相学、元素及Sr、Nd、Pb 同位素地球化学和构造环境、源区性质,并与喜马拉雅带二叠纪火山岩进行了对比研究。冈底斯带石炭纪—二叠纪火山岩近东西向集中分布在冈底斯构造带中北部地带,空间上从东至西火山活动的强度和规模渐次减小,时间上从早至晚火山活动的强度和规模总体由弱到强。冈底斯带石炭纪—二叠纪火山岩形成于活动大陆边缘的岛弧构造环境,从早到晚岛弧造山作用经历了初始岛弧→早期岛弧→成熟岛弧的发展演变过程,火山岩浆来源于富集型地幔部分熔融作用,原始岩浆在形成和演化的过程中有俯冲洋壳及随带的深海沉积物和再循环进人地慢的地壳物质组分的强烈混染,明显不同于受地壳物质组分强烈混染的喜马拉雅带二叠纪陆缘裂陷型火山岩。综合研究冈底斯带及其邻区近年来的最新调查与研究成果,从北向南拟建了石炭纪—二叠纪冈底斯岛弧→雅鲁藏布江弧后裂谷盆地→喜马拉雅陆缘裂陷盆地的弧盆系时空结构演化模式,探讨了冈瓦纳大陆北缘石炭纪—二叠纪活动大陆边缘的岛弧造山作用与青藏高原古特提斯演化的耦合关系及其动力学机制,讨论了冈底斯带松多乡榴辉岩的形成过程。  相似文献   
58.
The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe River Basin,Western China) is given in the paper.The following basic subjects for land-surface processes in arid areas are studied:(1) the general characteristics of the energy budget on ground surface in arid areas;(2) the parameterization of the land surface processes;(3) the interaction between oasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that the sensible heat flux in the surface energy budget is in the majority,and the latent heat flux may be neglected.The influence of atmospheric stratification stability on the turbulent transfer of energy and substance must be considered in parameterization of land surface processes in arid areas.The "cold island effect" phenomenon in oasis and the "humidity inversion" phenomenon in desert near oasis are the result of the interaction between them.The results would improve the understanding of land surface processes in arid areas.  相似文献   
59.
The results of precision temperature logs made to depths of several hundred meters in some 80 wells in Western Canada, most of which are located in the Prairie Provinces, show evidence of warming at the ground surface in the 0.5 K to 3.5 K range (average=2.2±0.7 K, for 80 unevenly distributed sites). Modeling shows that this warming mostly pertains to this century and it has been most substantal in the last four decades if the ramp function of the linear increase of surface temperature is assumed. Using the step function model's increase of surface temperature (land clearing, forest fires, etc.) the calculated onset of warming would pertain mostly to the last two decades. Contour maps of ground temperatures currently and previously and a contour map of the ground warming magnitude dilineate a large regional character of the ground temperature change at the southern marigin of permafrost for the large area of the Prairie Provinces. In many cases however, the magnitude of ground warming is much larger than the magnitude of air warming. This is especially evident for the northern areas of Alberta in the boreal forest ecoprovince. The magnitude of ground warming is equal to the magnitude of surface air warming in southern Alberta in the grassland and aspen parkland ecoprovinces. The analysis of the temperature depth response to the surface warming from well data shows the integrated effect of surface air warming together with the increases in ground temperature due to natural terrain effects and other anthropogenical changes to the surface of the earth.  相似文献   
60.
Surface renewal analysis for sensible and latent heat flux density   总被引:1,自引:1,他引:0  
High frequency temperature measurements were recorded at five heights and surface renewal (SR) analysis was used to estimate sensible heat flux density (H) over 0.1 m tall grass. Traces of the temperature data showed ramp-like structures, and the mean amplitude and duration of these ramps were used to calculate H using structure functions. Data were compared with H values measured with a sonic anemometer. Latent heat flux density (E) was calculated using an energy balance and the results were compared with E computed from the sonic anemometer data. SR analysis provided good estimates of H for data recorded at all heights but the canopy top and at the highest measurement level, which was above the fully adjusted boundary layer.  相似文献   
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