(Re)surveying the uses of Geographical Information Systems in Health Authorities 1991–2001

This paper provides a comparative analysis of two separate national surveys of the uptake and use of Geographical Information Systems (GIS) by Health Authorities (HAs) in England and Wales. The surveys were undertaken at two different time points (1991 and 2001), and the intervening period has been characterized by major (and continuing) health sector restructuring. The substantial number of HA mergers between 1991 and 2001 provide a methodological challenge in attempting to make comparisons. A pragmatic approach is adopted and the presentation of results has to be restricted solely to English and Welsh HA data. Our findings show that there has been a considerable increase in the use of GIS since the early 1990s, and there is some evidence of more sophisticated uses for a wider range of policy-related and application tasks. However, we conclude that there is still considerable scope for the wider uptake and use of GIS within the NHS. In addition, our findings provide a baseline with which to monitor the impacts of future organizational restructuring on the uses of GIS within the NHS. We suggest that this is important given the replacement of 95 English HAs with 28 new Strategic HAs (StHAs) from April 2002, and the repercussions of the anticipated shift in GIS responsibility to Primary Care Trusts.     

Mean slope-angle frequency distribution and size frequency distribution of landslide masses in Higashikubiki area, Japan

Landslide mass size frequency distributions and mean slope-angle frequency distributions were calculated for slump, slide, and creep type landslides in the Higashikubiki area. Mean slope-angle frequency distributions closely approximated Weibull distributions. Size frequency distributions show power-law dependencies. Both can be explained by modeling landslides as linked uniform blocks in tensile force. Power coefficients for size frequency distributions were 2.01–2.32 (approximation to power functions) or 2.10–2.24 (approximation to Pareto distributions).     

美国国家公园的地理信息系统(GIS)

通过介绍美国国家公园中GIS的管理与实施经验，结合我国在地质公园的GIS应用情况，达到促进我国国家地质公园及其它国家公园中的GIS应用的目的。     

面向对象的GIS数据模型与实现

介绍了面向对象数据模型的基本概念，重点讨论了面向对象数据模型在地理信息系统中的应用及具体实现途径。     

地裂缝灾害研究现状与展望

1927年美国首先发现地裂缝以来，各国学者对地裂缝的发生、发展进行了细致的研究。美国学者首先从地震研究入手，认为地裂缝的形成受构造因素影响。后逐渐加强研究地下水超采对地裂缝的影响，形成了构造与地下水开采复合成因观点。我国学者重点对汾渭地堑地裂缝成因问题进行了较系统的研究，提出几种成因机理模型，并用GIS技术建立简单的预测预报系统。文章在详细介绍国内、外对地裂缝成因机理和水文特性的研究以及预测、预报工作的同时，对今后研究趋势进行了展望。目前，地裂缝的研究正从以往的定性静态描述转向以过程为目标的精确定量动力学研究。利用相似材料模拟地裂缝的形成与发展，以非线性理论（如分形）对地裂缝系统进行定量的数学描述，建立准确的预测、预报模型（如人工神经网络模型），并与GIS相结合，建立完善的预测、预报系统，减少地裂缝灾害对环境的影响，进而对它加以利用，是今后地裂缝研究的主要方向。     

空间分析方法、应用模型与GIS的关系

首先阐述了空间分析和应用模型的基本概念，进而从地理信息处理系统的功能入手，分析了空间分析、应用模型和GIS的关系，最后指出加强应用模型与GIS的结合以及增强GIS的基本空间分析功能是增强GIS整体功能的二个最有效的方法．     

地理信息系统在管理工作中的应用

地理信息系统可用于地理信息的处理，这是众所周知的，其实地理信息系统有更多用途，提出了将地理信息系统用于管理工作中的一些方法及建议。     

时态GIS初探

时态GIS是GIS一个新兴的研究领域，目前仍处于理论与模型的研究阶段。章总结了时态GIS的研究现状，介绍了时间数据库与时空数据库的概念以及类型。在已有的研究成果基础上，归纳了时态GIS的主要功能，应包括输入、存储、编辑和更新，时空数据库管理，查询和检索，时空分析，显示和输出等功能模块。并提出了基于传统GIS解决时间方面问题的一些思路。     

DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR MANAGING PESTICIDE LOSSES IN AGRICULTURAL WATERSHEDS

1 INTRODUCTION Agricultural use of pesticides has been recognized as one of the important non-point pollution sources in the world, and the pesticide application to agricultural lands has led to large amounts of residues discharged into surface water through runoff (Leonard, 1990). There have been growing concerns about the fate and transport of pesticides in agricultural lands, due to the associated adverse impacts on water environment and human health (Agassi et al., 1995; Ng and Clegg…