地理空间传感网信息公共服务平台的设计与实现

随着对地观测技术的发展,传感器类型与数量不断增加,为了高效管理传感网中相关的信息与服务资源,便于用户按需、全面和准确地获取并应用这些资源,基于传感网信息模型和服务接口规范,设计并实现了地理空间传感网信息公共服务平台GeoSensor。该平台通过调用和组合传感器注册服务、传感器观测服务、实时制图服务和卫星位置服务等多种服务,实时获取传感器、观测数据和数据产品等信息资源,并在天地图上以图形、文字、表格和视频等方式形象生动地展示这些信息资源。GeoSensor系统实现了对遥感、移动和原位等类型的对地观测传感器及其观测数据等资源的在线搜索、即时获取、网络控制和实时制图,可满足应急处理时对传感器检索、观测数据获取、传感器控制和数据产品生成等功能的需求。     

New metrics for managing and sustaining the ocean's bounty

Policies are arising around the world, most recently in the United States, that mandate the implementation of marine spatial planning as a practical pathway towards ecosystem-based management. In the new United States ocean policy, and several other cases around the globe, ecosystem services are at the core of marine spatial planning, but there is little guidance on how ecosystem services should be measured, making it hard to implement this new approach. A new framework is shown here for practical, rigorous ecosystem service measurement that highlights contributions from both natural and social systems. The novel three-step framework addresses traditional shortcomings of an ecosystem services approach by giving managers and scientists the tools to assess and track: (1) the condition of the ecosystem (supply metrics), (2) the amount of ocean resources actually used or enjoyed by people (service metrics), and (3) people's preference for that level of service (value metrics). This framework will allow real world progress on marine spatial planning to happen quickly, and with a greater chance for success.     

Evaluation of ecosystem services: A case study in the middle reach of the Heihe River Basin,Northwest China

Ecosystem services evaluation aims at understanding the status of ecosystem services on different spatial and temporal scale. In this paper, we selected the middle reach of the Heihe River Basin (HRB), which is the second largest inland river basin in China, as one of the typical area to estimate the ecosystem services values (ESVs) corresponding to the land use changes. Based on the land use data and ecosystem service value coefficients, the total ecosystem services values (TESVs) of the middle reach of the HBR are quantitatively calculated, which were 9.244 × 108, 9.099 × 108, 9.131 × 108 and 9.146 × 108 USD in 1988, 2000, 2005 and 2008 respectively. During 1988–2008, the decrease of grassland, forest land, water area and unused land contributed 148.94%, 57.85%, 87.87% and 16.42% respectively to the net loss of TESVs, while the dramatic increase of cultivated land improved the TESVs with contribution of −211.08% to the net loss of TESVs. Expansion of cultivated land, which especially caused the loss of grassland and forest land, directly exerted negative impacts on the provision of ecosystem services in the study area. The findings of this research indicated that land use change was an important form of human activities, which had a strong impact on ecosystem services.     

服务业区位选择的交通网络指向研究——以北京城市中心区为例

基于空间句法、核密度估计和皮尔森相关分析等方法,以北京城市中心区为例,结合空间句法轴线模型与百度POI（Points of Interest）数据,探讨服务业区位选择的交通网络指向规律。结果表明：①北京城市中心区的交通网络总体呈现“东优西劣、北优南劣、西南最劣”的空间格局,高层级网络则呈现“中心环状集聚—外围多极分布”的分布模式。②与高穿行度交通网络相比,高整合度交通网络的区位指向性更强,在不同尺度均更易诱发服务业的集聚。③总体而言,服务业区位选择的交通网络指向性明显,但不同类型服务业的区位指向程度依据研究尺度的不同具有显著差异,并据此将25类主要服务业划分为街区指向型、街道指向型、双重指向型和无指向型四类。本文对探索服务业集聚发展规律、提高服务业和交通网络规划的科学性具有参考意义,并可为北京城市中心区服务业存量优化提供决策依据。     

Functionally assessing the sustainability of regional ecosystem services: a case study of Hohhot City

"The value of the world's ecosystem services and natural capital" by R.Costanza et al.in 1997 is generally regarded as a monument to the research of valuing ecosystem services.However,the classification of ecosystem services,the method of various services summation,and the purpose for static global value had many criticisms.Based on a summary of these criticisms and suggestions,further study direction—on the sustainability of ecosystem services—is presented.The two basis indicators in ecology—productivity and biodiversity,respectively characterize the ability of producing and self-organizing—not only represent the internal function of ecosystem,but also can be proportioned to its external function of supporting and providing for human life.Theoretically,the two indicators combined could physically assess the sustainability of ecosystem services based on the traditional procedure of Costanza's.The case study of Hohhot City in 1995-2005 shows that the new model reflects the changes of ecosystem services at spatial and temporal scale,and the functionally adjusted assessment shows the sustainability of Hohhot City became gradually stronger during the study decade.But due to the enormous value per unit of water ecosystem,the minimal loss of water area leads to the final result being opposite to the processing analysis,which gives a clue to the further experimental testing research.     

海洋信息网格服务平台的设计与实现

本文针对海洋信息的分布性、信息类型及格式的多样性、数据的海量性,以及数据处理的计算量大等特性,对地理信息系统、网格技术、Web服务技术,以及远程可视化技术等进行了综合研究。首先,探讨了海洋信息网格服务平台构建的关键技术,包括海洋信息网格技术、网格环境下海洋信息的集成方法,以及远程可视化技术,并提出了海洋信息网格服务平台的系统架构;其次,选定南海海域为实验区,以Argo数据、海温和海流数据为实验数据,实现了海洋信息网格服务平台原型系统。该平台可以集成异构、分布式环境中的数据服务和应用服务,为用户提供透明的、"一站式"的海洋环境信息Web应用。该系统为海洋用户充分利用各种海洋环境信息,提高海洋工作的效率,减少重复性投资、充分合理利用现有设备和资源提供了借鉴。同时实验表明,本文所提出的技术路线是可行和正确的。     

温度对微食物网生物代谢的影响

生态学代谢理论(metabolic theory of ecology, MTE)指的是生物的代谢速度随着温度的升高而增加,随生物个体大小(即生物量)的增加而异速增长。根据MTE理论可预测异养过程与自养过程对温度的反应不同,低温对异养代谢的抑制要明显;而随着温度升高,异养代谢升高的速度比自养代谢升高的速度要快。MTE理论可以对海洋浮游微食物网生物的代谢研究进行理论指导,用于解释一些低温造成的海洋浮游生态学现象,以及预测全球变暖的影响。多年来人们一直根据MTE理论开展理论分析和实验检验,发现低温会抑制细菌和微型浮游动物的生长,并可以降低微型浮游动物的摄食率。春季高纬度海区的海水温度会抑制细菌的生长,而浮游植物则几乎不受影响,从而造成春季水华发生。温度和底物浓度是冷海(水温≤4℃)细菌生长率低的原因,但在永冷海(周年温度≤4℃的海区,包括极地海区和深海的大部分)中究竟是低温还是底物浓度限制了细菌的生长率仍被争论。全球变暖的预测认为本世纪海洋表层温度会升高2～6℃。根据MTE理论,温度升高对自养和异养过程的影响不同,围隔实验证明全球变暖将导致水华与细菌、水华与微型浮游动物的时滞变小,促进微型浮游动物对细菌和浮游植物的摄食,改变有机物质自养生产和异养消耗之间的平衡,使更多的物质和能量进入呼吸作用,使得生态系统变得更加异养。但在温度升高对海洋细菌生长效率和细菌生物量变化的研究方面,MTE理论还有一定的局限性,需要进一步的理论分析和实验检验。     

An ontology-based framework for extracting spatio-temporal influenza data using Twitter

Early detection of influenza outbreaks is one of the key priorities on a national level for preparedness and planning. This study presents the design and implementation of Fluwitter, which is a spatio-temporal web-based prototype framework for pseudo real-time detection of influenza outbreaks from Twitter. Specifically, the framework integrates PostgreSQL database server with PostGIS spatial extension, Twitter streaming client, pre-processor, tagger and similarity calculator for semantic information extraction (IE). The IE of tagged terms is supported by Natural Language Processing (NLP) techniques, DBpediaSpotlight and WordNet Similarity for Java (WS4J), while data analytics, visualization, and mapping are supported by GeoServer and other GIS Free Open Source Software (FOSS). The prototype was calibrated to maximize detection of influenza using rules developed from ontology-based semantic similarity scores. The Twitter-generated influenza cases were validated by weekly hospitalization records issued by Ohio Department of Health (ODH). The optimized rule produced a final F-measure value of 0.72 and accuracy (ACC) value of 94.4%. The validation suggested the existence of moderate correlations for the beginning of the time period Southeast region (r?=?0.52), the Northwestern region (r?=?0.38), and the Central region (r?=?0.33) and weak correlations for the entire time period. The potential strengths and benefits of the prototype are shown through spatio-temporal assessment and visualization of influenza potential in Ohio.     

基于本体论的海洋流场语义分析与表达研究

随着海洋观测技术的不断发展,人类获取的海洋数据也快速增长,由于海洋流场是整个海洋系统物质流和能量流输送的主要渠道,基于这些观测数据进行海洋流场迁移变化规律分析及可视化表达研究,对所有涉海领域均具有非常重要的意义。然而,由于海洋时空大数据集合的多源性和异构性等原因,至今尚未有令人满意的海洋流场数据集成共享和动态可视化分析工具,从而导致这些异源异构数据难以实现统一标准下的集成组织与语义共享。为了实现海洋流场语义层次上的统一描述,本文在分析了海洋流场多维特征、拓扑特征、模糊特征等基础上,基于本体论的语义构建思想,提出并构建了基于四元组O=（C,P,R,I）的本体组织基础结构,其中C表示概念集合、P表示属性集合、R表示概念间的关系集合、I表示实例集合,通过对概念、属性、关系结构的进一步定义,共同组合构成了海洋流场整体本体结构。为了给出清晰的本体语义建模过程,以海流现象局部本体构建为例,在对成因性、空间性、时间性、运动性等本体属性分析的基础上,进行了海流概念、本体属性、语义关系的描述和定义,从而为海洋流场组织提供一个规范性框架。进而借助OWL语言本体建模的优势,以地转流为例进行了其形式化表达和本体类构建。研究结果表明,基于本体的海洋流场语义分析方法能有效地解决传统海洋现象描述中的异构问题,可为海洋信息共享与集成研究提供参考。