GIS‐BASED WATER QUALITY MODELING IN THE SANDUSKY WATERSHED,OHIO, USA1

ABSTRACT: This study focused on the Sandusky Watershed (SW) in Ohio, located within the Great Lakes Basin, with emphasis on two of its subwatersheds, namely Honey Creek (HC) and Rock Creek (RC). The goal was to assess the capabilities of the Soil and Water Assessment Tool (SWAT) to simulate suspended sediment (SS), phosphorus (P) and nitrogen (N) yield in the SW that contribute major sediment and nutrient loads into Lake Erie. The model was calibrated using water flow and water quality parameters for water years 1998 to 1999 and validated model simulations covering the period of water years 2000 to 2001 for monthly conditions. The validation of SS showed correlation coefficients of 0.29 (SW), 0.75 (HC) and 0.69 (RC). Correlation coefficients for P were 0.68 (SW), 0.78 (HC) and 0.37 (RC); for N0₂‐N 0.84 (HC) and 0.38 (RC); for N0₃‐N 0.27 (HC) and 0.76 (RC); for NH₃‐N 0.57 (SW), 0.49 (HC), and 0.13 (RC). In addition, mean errors, root mean square errors, Nash‐Sutcliffe coefficients, and graphs were used to compare simulated to measured data. Simulation success was variable with poor and good simulations, but in most cases, simulated water quality values followed the trend of measured data except for extreme (or intense) rainfall/runoff events. Reviews of 17 applications indicated that the SWAT is suitable for long term continuous simulations but not for storm events. A spatially distributed modeling approach generated maps showing the spatial distribution of SS, P, and N for each simulation element across the Sandusky Watershed.     

空间信息技术在防震减灾工作中的作用

我国是个地震多发国家，地震损失严重。在防震减灾研究中，迫切要求引进先进的科学技术手段，用高新技术推动防震减灾工作的发展。目前遥感技术、地理信息系统和全球定位系统（合称3S）得到了快速发展，以3S技术为主要框架的空间信息技术在防震减灾领域得到了广泛的应用。本文重点阐述了空间信息技术在防震减灾中的作用，并对空间信息技术在防震减灾中的应用趋势作出展望。     

高速铁路安全保障信息系统的研究

高速铁路作为我国铁路运输的一种新形式,安全对其来说更显重要。解决高速铁路安全问题,首先,要不断提高基础设施本身的安全性,更重要的是运用安全保障信息技术,通过建立安全保障信息系统提高安全管理水平,降低事故的发生率。笔者在分析高速铁路新特点的基础上,应用安全系统工程的原理,从人、机、环3方面构建了高速铁路安全保障信息系统,并分析了各个子系统的功能及构成情况;结合目前人工智能领域的智能体技术,提出基于多智能体的高速铁路安全保障信息系统的设计,该系统由监控智能体、判断智能体、诊断智能体、处理智能体、评价智能体和管理智能体组成。     

区域土地资源利用管理信息系统设计与应用——以长江三角洲无锡市滨湖区为例

区域土地资源利用管理信息系统是一种存储、兼容、管理、分析、显示与应用土地信息的计算机监控系统，是建立在地理信息系统（GIS）软件工具之上，并在ComGIS组件Mapobject2．0平台支撑下进行设计和开发应用的。该系统的设计与开发可为区域土地资源合理开发利用规划与产业布局的调整提供科学依据，特别是对高强度开发下的长江三角洲土地资源的可持续利用具有较重要的实际应用价值。     

Using GIS to Identify Functionally Significant Wetlands in the Northeastern United States

/ Of the several automated wetland assessment methods currently available, none are comprehensive in considering all of the primary functions a wetland can perform. We developed a methodology particularly suited to the Northeastern United States that enumerates spatial predictors of wetland function for three primary wetland functions: flood flow alteration, surface water quality improvement, andwildlife habitat. Predictors were derived from several wetland assessment techniques and directly from the literature on wetland structure and function. The methodology was then automated using a Geographic Information System (GIS). The resulting Automated Assessment Method for Northeastern Wetlands (AMNEW) consists of a suite of eight Arc Macro Language (AML) programs that run in the ARC/INFO GRID module. Using remotely sensed land use information and digital elevation models (DEMs), AMNEW produces three separate grids of wetlands that perform each function. The method was tested on four watersheds in Vermont's Lake Champlain Basin. Results and preliminary verification indicate that the method can successfully identify those wetlands in the Northeastern region that have the potential to be functionally important.     

Integration of different data bodies for humanitarian decision support: an example from mine action

Geographic information systems (GIS) are increasingly used for integrating data from different sources and substantive areas, including in humanitarian action. The challenges of integration are particularly well illustrated by humanitarian mine action. The informational requirements of mine action are expensive, with socio-economic impact surveys costing over US$1.5 million per country, and are feeding a continuous debate on the merits of considering more factors or 'keeping it simple'. National census offices could, in theory, contribute relevant data, but in practice surveys have rarely overcome institutional obstacles to external data acquisition. A positive exception occurred in Lebanon, where the landmine impact survey had access to agricultural census data. The challenges, costs and benefits of this data integration exercise are analysed in a detailed case study. The benefits are considerable, but so are the costs, particularly the hidden ones. The Lebanon experience prompts some wider reflections. In the humanitarian community, data integration has been fostered not only by the diffusion of GIS technology, but also by institutional changes such as the creation of UN-led Humanitarian Information Centres. There is a question whether the analytic capacity is in step with aggressive data acquisition. Humanitarian action may yet have to build the kind of strong analytic tradition that public health and poverty alleviation have accomplished.     

基于GIS的铁路行车事故救援系统研究

笔者扼要探讨了构建基于GIS的铁路行车事故救援系统的相关理论和方法 ,提出了该系统的设计目标、功能结构、体系结构以及空间数据库设计的简要准则和空间数据的输入方法。笔者还介绍了结合实际科研项目 ,开发的大秦线事故救援辅助决策支持系统。该系统具有以下几方面的特点 :在以工务信息为主体的基础上 ,实现了车、机、工、电、辆各部门主要业务信息以及事故救援预案信息的初步整合 ;实现了线路录像按里程点播以及录像与线路设备综合图的联动 ;实现了事故救援的辅助决策支持 ,提供了一个可以扩展的理想平台。     

Electronic version of the encyclopaedia of occupational health and safety as a source of definitions

PROBLEM: Continuous progress in the occupational safety and health field, as well as social-economic development, generates a need for access to definitions. Definitions are usually scattered in many sources and not easy to find. Electronic documents give new opportunity to information access. METHOD: As an experiment, the feasibility of automatic full-text searching of definitions was examined using the Encyclopaedia of Occupational Health and Safety, edited by the International Labour Organization (ILO), on CD-ROM. DISCUSSION: The results were compared with the traditional index search by subject, using the paper version of the encyclopedia. The automatic search appeared successful; about 100 definitions were excerpted the automatic way. IMPACT ON INDUSTRY: As in most industries, finding accurate information is a necessity in the safety industry. The electronic document seems to be a powerful instrument as a source of definitions and can be quite easy to use by specialists as well as safety personnel in information processing.     

大兴安岭森林火灾中居民避难行动的调查

本文利用民意测验的方法,通过对大兴安岭特大森林火灾中居民避难行动的调查,对重大灾害发生后避难系统工程进行了探讨,并分别对该工程进行了评价。     

WATERSHED CLASSIFICATION USING CANONICAL CORRESPONDENCE ANALYSIS AND CLUSTERING TECHNIQUES: A CAUTIONARY NOTE1

ABSTRACT: Watershed classification using multivariate techniques requires the incorporation of continuous datasets representing controlling environmental variables. Often, out of convenience and availability rather than importance to the structure of the system being modeled, the environmental data used originate from a variety of sources and scales. To demonstrate the importance of appropriate environmental data selection, classifications of six‐digit hydrologic units (1:24,000) across selected geographic areas within the Interior Columbia River Basin were produced. Canonical correspondence analysis was used to select and test environmental variables important in predicting Rosgen stream types and valley bottom classes. Then, hierarchical agglomerative clustering was used to group (classify) watersheds based on these variables. Statistically significant results were derived from the use of organized classification data with presumed predictive relationships to watershed properties, and a random distribution of environmental variables from the same datasets provided similar results. The results contained herein demonstrate that these analysis techniques do not necessarily select meaningful variables from a broad spectrum of data and that significant results are easily generated from randomly associated data. It is suggested that classifications produced using these multivariate techniques, especially when using multi‐scale data or data of unknown significance, are subject to invalid inferences and should be used with caution.