虚拟现实技术及其在地理学中的应用

虚拟现实是一项涉及计算机图形学、人机交互技术、传感技术、人工智能等领域的综合集成技术。它用计算机生成逼真的三维视、听、嗅觉等感觉，使人作为参与者通过适当装置，自然地对虚拟世界进行体验和交互，最终使得参与者产生身临其境之感。在分析虚拟现实定义及软件硬件构成的基础上，提出了虚拟地理环境的概念及其技术实施路线，探讨了现实技术在地理学中的应用前景。     

区域尺度城市增长时空动态模型及其在京津唐都市圈应用

Dynamic urban expansion simulation at regional scale is one of the important re-search methodologies in Land Use/Cover Change (LUCC) and global environmental change influenced by urbanization.However,previous studies indicate that the single urban expan-sion simulation for future scenarios at local scale cannot meet the requirements for charac-terizing and interpreting the interactive mechanisms of regional urbanization and global en-vironmental change.This study constructed a regional Dynamic Urban Expansion Model (Reg-DUEM) suitable for different scenarios by integrating the Artificial Neural Network (ANN) and Cellular Automaton (CA) model.Firstly we analyzed the temporal and spatial character-istics of urban expansion and acquired a prior knowledge rules using land use/cover change datasets of Beijing-Tianjin-Tangshan metropolitan area.The future urban expansion under different scenarios is then simulated based on a baseline model,economic models,policy models and the structural adjustment model.The results indicate that Reg-DUEM has good reliability for a non-linear expansion simulation at regional scale influenced by macro-policies.The simulating results show that future urban expansion patterns from different scenarios of the metropolitan area have the tremendous spatio-temporal differences.Future urban ex-pansion will shift quickly from Beijing metropolis to the periphery of Tianjin and Tangshan city along coastal belt.     

自然灾害风险评估与分级方法论探研——以山西省地震灾害风险为例

自然灾害发生的可能损失一直是灾害风险评估上的难题.本研究以自然灾害风险评估经典模型为基础,提出了新的自然灾害风险评估与风险等级划分方法,利用历史灾情和孕灾环境解决风险评价中致灾因子破坏力与灾害发生的可能,并以山西省地震灾害风险为例进行了定量化评估研究.主要改进在于:确定灾害损失率和环境参数以建立地震灾害可能损失计算模型...     

基于虚拟现实的远海岛礁地理环境物联网监测系统设计与实现

针对远海岛礁生态环境监测与保护无法满足环境要素实时监测与智能处置需求,在分析现有环境要素感知与智能危机应对技术的基础上,融合虚拟现实和物联网技术,研发了远海岛礁地理环境实时监测系统。该系统依据传感器类型设计存储表格,以支持多源异构传感器数据统一组织与管理;利用物联网技术采集远海岛礁水体、土壤、气象、植被等地理环境数据,实现了感知数据的无线传输、接入与远程数据存储;利用虚拟现实技术,在远海岛礁三维场景建模的基础上,实现了场景漫游与互操作,并结合物联网技术实现了虚实一体化的智能感应设备的远程控制。基于该系统,管理人员不仅能获取远海岛礁实时地理环境数据,还能远程操作智能感应设备(如植被浇灌水阀),解决了以往需要人工往返岛礁的管理问题,有效地提高了工作效率。     

东南沿海中小流域平原区洪水淹没模拟

我国东南沿海中小流域洪水过程短,调节能力差,洪水灾害严重。而该区洪水灾害主要发生在流域中下游冲洪积平原上,为此本文以我国东南沿海甬江流域奉化江下游为实验区,探讨了将遥感和地理信息系统应用于中小流域洪水淹没模拟研究的方法和途径。开展了基于遥感和GIS的流域降雨径流和洪水演进模型的研究,建立了基于数字高程模型的洪水淹没范围和灾情评估模型。最后利用遥感、遥测和GIS信息,对实验区洪水淹没和灾情评估进行了验证分析,并取得了较满意的成果,从而为中小流域防洪减灾决策研究提供了经验。     

基于遥感和GIS技术的荒漠化动态分析——以宁夏盐池为例

荒漠化是当今全球和中国最为严重的环境与社会经济问题之一,它的危害已深入到自然与社会经济的各个方面。选取荒漠化问题突出的宁夏盐池县作为研究区,通过3期遥感TM影像(1986年、1996年、2000年),运用GIS的分析手段,综合土地利用图、地形图和其他资料形成盐池县3期荒漠化现状图及两阶段动态图。盐池荒漠化土地类型的结构变化表明,荒漠化受非荒漠化类型土地限制,其面积有所减小,但程度在加重。荒漠化发展的原因是自然因素与人为因素共同作用的结果。     

地震灾害预测和应急模拟系统的设计与应用——以永安市城市应急系统为例

城市防震减灾是地震潜在频发区提高自然灾害防治能力建设的重要方面。本文结合福建省永安市城市防震减灾信息管理系统的建设,探讨设计防震减灾数值模型,分析模型集成的关键技术,构建了地震风险评估、建筑物易损性评价、生命与财产损失估算、救援与救灾管理调度等模型和基于GIS开发的震害预测和应急模拟系统。该系统在福建省永安市的实际应用表明,通过对地震灾害预测结果的分析,可加强城市抗震中的薄弱环节,为灾区政府应急响应和制订对策提供决策支持辅助信息,从而显著提高城市防震减灾的综合能力。     

Wetland changes in Jianghan Plain and simulation with GIS

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文化遗产保护与开发的思考

经济建设发展与文化遗产保护之间的紧张关系到处存在。既不能以牺牲珍贵文物为代价,换取旅游业的发展,也不能因为保护而拒游客于门外。为此重申“中国原则”,即以“实现人类文明延续和可持续发展的必然要求”为准则。对石窟文化的保护,初步解决了游客拥挤对壁画、彩塑的潜在威胁,加强了对风沙侵蚀危害的防范,但仍然面临许多社会和自然环境问题。古城遗址的发现,涉及对古环境反演的科学问题。利用考古发掘的丰富信息,联系古自然环境变化和人文影响、物质传播的大背景,可能有助于开豁诠释、论证古代文明和古文化的新思路。破解中原许多古城遗址之谜,也需要从重建、虚拟古环境着手。古建筑的修复或重建,既要遵循“修旧如旧”的原则,也要考虑适应现代环境与生态功能,适度采用现代新工艺和新材料。考古发掘、文化遗产保护工作中,运用环境遥感监测技术,不乏成功先例。作者建议,进一步推广田间考古格网的经验,构建多层次的格网管理信息系统,促进文化遗产保护与开发的能力建设与现代化。     

Optimization of simulation and visualization analysis of dam-failure flood disaster for diverse computing systems

Simulation and subsequent visualization in a network environment are important to glean insights into spatiotemporal processes. As computing systems become increasingly diverse in hardware architectures, operating systems, screen sizes, human–computer interactions and network capabilities, effective simulation and visualization must become adaptive to a wide range of diverse devices. This paper focuses on the optimization of simulation and visualization analysis of the dam-failure flood spatiotemporal process for diverse computing systems. First, an adaptive browser/server architecture of the dam-failure simulation application was designed to fill the hardware performance and visualization context gap that exists within diverse computing systems. Second, a data flow and an optimization method for multilevel time-series flood data were given to provide more support to network simulation, visualization and analysis on diversified terminals. Finally, a user interaction friendly and plugin-free prototype system was developed. The experiment results demonstrate that the methods addressed in this paper can cope with the challenge in simulation, visualization and interaction of a dam-failure simulation application on diversified terminals.     

区域尺度城市增长时空动态模型及其应用

区域尺度城市增长动态模拟(Reg-UGM) 是城市化影响下的土地利用/覆盖变化以及全球 环境变化研究的重要手段之一。针对单个城市增长未来情景模拟难以在区域尺度刻画与解释 城市化影响下的土地利用/覆盖变化以及与全球环境变化交互过程与作用机理主要问题,本研 究集成人工神经网络模型(ANN) 与元胞自动机模型(CA) 构建适合不同情景的区域尺度城市 增长动态模型,通过1979 年以来高分辨率遥感信息探测获取的4 个时段京津唐都市圈城市增 长时空特征分析提取先验知识规则,模拟京津唐都市圈在基准模式、经济模式、政策模式与 结构调整模式未来不同情景模式下城市增长过程。研究表明,Reg-UGM在模拟区域尺度受国 家宏观政策等影响城市非线性增长过程具有较好的可靠性,为进一步研究城市化影响下的宏 观生态效应提供前提保障。模拟结果显示京津唐都市圈在不同情景模式下城市增长呈现较大 的时空格局差异,未来城市增长结构调整模式更符合区域城市化的实际情况,未来区域城市 增长将由特大城市向中小城市转移,滨海沿线城镇发展带将经历更快的城市增长过程。     

考虑防灾减灾能力的洪涝灾害灾损率曲线构建——以里下河地区的李中镇为例

作为恢复力的重要内容之一,承灾体的防灾减灾能力是评估灾害经济损失的重要参考因素。根据在里下河地区李中镇调研所得数据,绘制初始灾损率散点图,构建了初始灾损率曲线;然后考虑防灾减灾能力因素,绘制实际的灾损率散点图和拟合曲线。结果显示：①在0.05的显著性水平下,住宅区、工业区、商业区、公共设施区和农业区五类承灾体财产的淹没水深与灾损率均存在乘幂函数关系。②考虑防灾减灾能力因素后,洪涝灾害对不同承灾体的经济损失有所减少。住宅区财产在淹没水深3 m时经济损失减少了34%,工业区在2 m时经济损失减少了17%,商业区在3 m时经济损失减少了24%,公共设施部门在2 m时经济损失减少了11%。防灾减灾能力因素对住宅区洪涝灾害经济损失的影响更加明显。本文作为有关灾损率曲线研究的有益补充,结果可为类似地区城镇的防灾减灾决策及灾害风险管理提供参考。     

Integrating multi-agent evacuation simulation and multi-criteria evaluation for spatial allocation of urban emergency shelters

The timely and secure evacuation of residents to nearby urban emergency shelters is of great importance during unexpected disaster events. However, evacuation and allocation of shelters are seldom examined as a whole, even though they are usually closely related tasks in disaster management. To conduct better spatial allocation of emergency shelters in cities, this study proposes a new method which integrates techniques of multi-agent system and multi-criteria evaluation for spatial allocation of urban emergency shelters. Compared with the traditional emergency shelter allocation methods, the proposed method highlights the importance of dynamic emergency evacuation simulations for spatial allocation suitability analysis. Three kinds of agents involved in evacuation and sheltering procedures are designed: government agents, shelter agents, and resident agents. Emergency evacuations are simulated based on the interactions of these agents to find potential problems, for example, time-consuming evacuation processes and road congestion. A case study in Jing’an District, Shanghai, China was conducted to demonstrate the feasibility of the proposed method. After three rounds of simulation and optimization, new shelters were spatially allocated and a detailed recommended plan of shelters and related facilities was generated. The optimized spatial allocation of shelters may help local residents to be evacuated more quickly and securely.     

Identification of geomorphic process units in Kärkevagge, northern Sweden, by remote sensing and digital terrain analysis

Sediment transport processes in the Kärkevagge are investigated concerning their spatial and temporal characteristics due to long–term monitoring. Within this study remote sensing techniques and GIS modelling in connection with geomorphic mapping are applied for identification and characterization of geomorphic process units. Relationships between geomorphometric parameters and slope processes like solifluction, talus creep and rockfall have been analysed. Multitemporal Landsat–TM5 scenes are used as source for landcover characteristics (Normalized Difference Vegetation Index) after preprocessing involving orthorectification and topographic normalization in order to remove possible terrain–induced effects. Additionally, a digital elevation model with a resolution of 20 m for the Kärkevagge catchment is developed and parameters like slope gradient, slope aspect and profile curvature are extracted as input for the analysis of the sediment transport system. The combination of landcover information, geomorphometrical and topological features allows the definition of areas for single process activities. They show specific sediment displacement characteristics depending on material conditions, topological and geometrical features. Geomorphic process units, which show a homogenous composition, are extracted from these available layers.     

Identification of geomorphic process units in Kärkevagge, northern Sweden, by remote sensing and digital terrain analysis

Sediment transport processes in the Kärkevagge are investigated concerning their spatial and temporal characteristics due to long–term monitoring. Within this study remote sensing techniques and GIS modelling in connection with geomorphic mapping are applied for identification and characterization of geomorphic process units. Relationships between geomorphometric parameters and slope processes like solifluction, talus creep and rockfall have been analysed. Multitemporal Landsat–TM5 scenes are used as source for landcover characteristics (Normalized Difference Vegetation Index) after preprocessing involving orthorectification and topographic normalization in order to remove possible terrain–induced effects. Additionally, a digital elevation model with a resolution of 20 m for the Kärkevagge catchment is developed and parameters like slope gradient, slope aspect and profile curvature are extracted as input for the analysis of the sediment transport system. The combination of landcover information, geomorphometrical and topological features allows the definition of areas for single process activities. They show specific sediment displacement characteristics depending on material conditions, topological and geometrical features. Geomorphic process units, which show a homogenous composition, are extracted from these available layers.     

城市暴雨内涝综述：特征、机理、数据与方法

建成环境的高空间异质性与致灾过程的复杂性给城市暴雨内涝研究带来巨大的挑战,具体表现为模型代表性不够、计算效率低、基础数据和验证数据匮乏。以机器学习为代表的人工智能技术、高分遥感和互联网大数据的快速发展则为城市暴雨内涝研究提供了新的契机。论文结合人工智能、高分遥感和互联网大数据等新技术发展,从特征、机理、数据与方法4个维度对暴雨内涝的研究现状和发展趋势进行了系统总结,主要结论包括：① 暴雨内涝具有短历时性、空间散布性、连锁性和突变性,其热点呈现空间上的动态迁移特征。② 降雨时空特征和城市化程度决定暴雨内涝灾害的量级,地形条件尤其是微地形则决定发生位置和内涝频率。地形控制作用指数(topographic control index, TCI)对暴雨内涝发生位置具有良好的指示能力。③ 排水管网、高精度地形和不透水面分布是暴雨内涝模拟的关键基础数据;降雨过程的高时空变异性是暴雨内涝近实时预报预警的主要瓶颈,需要充分利用天气雷达观测提高其精准度;互联网众包大数据是获取高空间覆盖度暴雨内涝灾情信息的新途径,但也面临不同类型信息融合、提炼和质量控制的挑战。④ 结合水动力模拟与机器学习可建立兼具物理基础和计算效率的暴雨内涝模拟方法,是实现近实时模拟与快速预报预警的有效途径。     

Relationships between rainfall and landsliding in the Middle Hills,Nepal

Many studies have documented major landslide events in mountain areas following heavy rainfall amounts. In the Himalaya, landslides occur during every monsoon period, but the role of rainfall in triggering these failures is not clear. This paper reports the results of a three-year study (1991-1993) into landsliding in the Likhu Khola drainage basin, Middle Hills, Nepal. Considerable annual variability in numbers, types and sizes of landslides was noted. Some of this variability can be explained by fluctuations in rainfall amounts and intensities, but many landslides were explained more easily by other controlling factors. In situations where slopes are extensively terraced for agriculture, with some terraces being intensely irrigated and others not, relationships between landsliding and rainfall amounts are complex and no simple explanations can be made.     

基于FloodArea模型新疆山洪淹没模拟及致灾临界雨量阈值的研究——以皮里青河流域为例

以皮里青河流域为研究区,运用小时降水、土地利用类型、数字高程（DEM）、实测淹没深度等数据,基于FloodArea模型对研究区2010年5月2日、2012年6月3日、2016年5月9日、2016年6月17日洪水过程进行再现模拟,通过精度验证并建立了降水－淹没深度的关系,在此基础上确定了4个淹没等级对应的致灾临界雨量。相关分析得出喀拉亚尕奇乡累计8 h降雨量与模拟洪水淹没深度的相关性最好,达到了0.96,潘津乡降雨累计5 h的相关性最好,为0.99;通过实测数据对模拟淹没深度进行精度检验得出,喀拉亚尕奇乡和潘津乡两个考察点相对误差分别为0.47 m和0.1 m,误差率分别为31.33%和7.69%,FloodArea模型对研究区洪水过程模拟的效果较好,可以反映出该区域的洪水淹没情况,能为无水文资料的山区流域的山洪过程进行较为精准的模拟;按照山洪灾害等级划分标准和降水-淹没深度的关系得出,预警点累计5 h降水得到对应4个等级的致灾临界雨量阈值分别为：四级17.84 mm、三级32.39 mm、二级54.21 mm、一级76.04 mm。