REVIEWS OF GEOGRAPHIC SOFTWARE

Geographic Software Reviewed in this article: THE DIFFUSION GAME . Christopher J. Lovelock and Charles B. Weinberg . MAPIT . Raymond J. Kalush , Jr . SIMODEL . Peter A. Williams and A. Stewart Fotheringham . WEATHER FRONTS . P. C. Moyer . WORLD DYNAMICS . Mark Lewis Baldwin     

“摄影与航空摄影”课程互动式教学模式的研究

互动式教学模式以培养学生学习的自主意识和创新能力为目标,既发挥教师的主导作用,又充分体现学生的认知主体作用。摄影与航空摄影是遥感科学与技术专业的专业基础课程,本文提出了针对该课程的互动式教学模式,并进行了课堂教学实践,总结了该模式的创新点和应用价值。     

POTENTIAL EFFECTS OF CLIMATE CHANGE ON FRESHWATER ECOSYSTEMS OF THE NEW ENGLAND/MID-ATLANTIC REGION

Numerous freshwater ecosystems, dense concentrations of humans along the eastern seaboard, extensive forests and a history of intensive land use distinguish the New England/Mid-Atlantic Region. Human population densities are forecast to increase in portions of the region at the same time that climate is expected to be changing. Consequently, the effects of humans and climatic change are likely to affect freshwater ecosystems within the region interactively. The general climate, at present, is humid continental, and the region receives abundant precipitation. Climatic projections for a 2 × CO₂ atmosphere, however, suggest warmer and drier conditions for much of this region. Annual temperature increases ranging from 3–5°C are projected, with the greatest increases occurring in autumn or winter. According to a water balance model, the projected increase in temperature will result in greater rates of evaporation and evapotranspiration. This could cause a 21 and 31% reduction in annual stream flow in the southern and northern sections of the region, respectively, with greatest reductions occurring in autumn and winter. The amount and duration of snow cover is also projected to decrease across the region, and summer convective thunderstorms are likely to decrease in frequency but increase in intensity. The dual effects of climate change and direct anthropogenic stress will most likely alter hydrological and biogeochemical processes, and, hence, the floral and faunal communities of the region's freshwater ecosystems. For example, the projected increase in evapotranspiration and evaporation could eliminate most bog ecosystems, and increases in water temperature may increase bioaccumulation, and possibly biomagnification, of organic and inorganic contaminants. Not all change may be adverse. For example, a decrease in runoff may reduce the intensity of ongoing estuarine eutrophication, and acidification of aquatic habitats during the spring snowmelt period may be ameliorated. Recommendations for future monitoring efforts include: (1) extending and improving data on the distribution, abundance and effect of anthropogenic stressors (non-point pollution) within the region; and (2) improving scientific knowledge regarding the contemporary distribution and abundance of aquatic species. Research recommendations include: (1) establishing a research centre(s) where field studies designed to understand interactions between freshwater ecosystems and climate change can be conducted; (2) projecting the future distribution, activities and direct effects of humans within the region; (3) developing mathematical analyses, experimental designs and aquatic indicators that distinguish between climatic and anthropogenic effects on aquatic systems; (4) developing and refining projections of climate variability such that the magnitude, frequency and seasonal timing of extreme events can be forecast; and (5) describing quantitatively the flux of materials (sediments, nutrients, metals) from watersheds characterized by a mosaic of land uses. © 1997 John Wiley & Sons, Ltd.     

Analysis of Anomalous Characteristics of Regional Crustal Deformation before the September 16th, 2019 Zhangye MS5.0 Earthquake, Gansu, China

To study the crustal movement in the vicinity of the epicenter before the Zhangye M_S5.0 earthquake in 2019, the characteristics of crustal deformation before the earthquake are discussed through the GPS velocity field analysis based on the CMONOC data observed from GPS. The baseline time series between two continuous GPS stations and the strain time series of an area among several stations are analyzed in the epicenter area. The resulting time series of baseline azimuth around the epicenter reflects that the energy of the fault in the northern margin of Qilian Mountain is accumulated continuously before 2017. Besides, the movement trend of azimuth slows down after 2017, indicating the stress accumulation on both sides of the seismogenic fault zone has reached a certain degree. The first shear strain and EW-direction linear strain in the epicentral area of the Zhangye M_S5.0 earthquake remain steady after 2017, and the surface strain rate decreases gradually after 2016. It is illustrated that there is an obvious deformation loss at the epicentral region three years before the earthquake, indicating that a certain degree of strain energy is accumulated in this area before the earthquake.     

公共医疗卫生服务的空间可达性研究——以广州市海珠区为例

本文以第5次人口普查以及医疗卫生机构相关数据为基础,运用空间相互作用理论和模型,得到广州市海珠区各街区的公共医疗卫生服务可达性空间分布,并详细分析了医院等级系数对可达性指数的影响,为医疗卫生事业的发展规划提供辅助决策支持。     

遥感图像人机交互判读方法研究及其应用

对于大型复杂的遥感判读任务,往往需要灵活地运用不同的判读方法,才能取得令人满意的效果,然而传统目视判读和常规计算机分类都难以满足这一要求,笔者设计了屏幕目视判读,改进型监督自动分类,分区自动分类,辅助波段分类,动态变化判读,人机混合判读和多组分工判读等遥感图像人机交互判读方法,把计算机自动分类与人工判读的优势相结合,对于提高图像判读精度,速度和高效率的遥感专题信息生成,帮助判读人员更好地完成各种遥感图像的判读任务都具有重要的意义,该文探讨了以上方法的特点,适用范围与实现方法,并给出了一些实例加以说明。     

Predicting the visualization intensity for interactive spatio-temporal visual analytics: a data-driven view-dependent approach

The continually increasing size of geospatial data sets poses a computational challenge when conducting interactive visual analytics using conventional desktop-based visualization tools. In recent decades, improvements in parallel visualization using state-of-the-art computing techniques have significantly enhanced our capacity to analyse massive geospatial data sets. However, only a few strategies have been developed to maximize the utilization of parallel computing resources to support interactive visualization. In particular, an efficient visualization intensity prediction component is lacking from most existing parallel visualization frameworks. In this study, we propose a data-driven view-dependent visualization intensity prediction method, which can dynamically predict the visualization intensity based on the distribution patterns of spatio-temporal data. The predicted results are used to schedule the allocation of visualization tasks. We integrated this strategy with a parallel visualization system deployed in a compute unified device architecture (CUDA)-enabled graphical processing units (GPUs) cloud. To evaluate the flexibility of this strategy, we performed experiments using dust storm data sets produced from a regional climate model. The results of the experiments showed that the proposed method yields stable and accurate prediction results with acceptable computational overheads under different types of interactive visualization operations. The results also showed that our strategy improves the overall visualization efficiency by incorporating intensity-based scheduling.     

地图与动画的结合与发展

地图动画是一种新型的可视化表现方式。本文回顾了地图动画的发展历史。探讨了地图动画的信息含量,总结了地图动画的有关研究内容,最后以SARS疫情为数据源,制作了关于疫情变化的动态地图,收到较好的视觉效果。     

新时期吉林省参与图们江区域合作研究

吉林省参与图们江地区合作正面临着新一轮全球产业分工体系的调整、区域经济合作进程的加速、东北老工业基地振兴的深入、“长吉图”开放带动先导区的提出等新的发展背景。因此,必须重新审视吉林省与图们江地区的产业分工与合作,并对其进行重新的功能定位,提出新时期的重点发展战略,以进一步推动吉林省全面参与图们江地区的经济合作。