Towards a potential research agenda to guide the implementation of Spatial Data Infrastructures—A case study from India

Recently, Spatial Data Infrastructures (SDIs) has been a rapidly expanding field and broadly assumed to underpin the development of information society and the knowledge economy. In this paper, we argue that the anticipated benefits of SDIs have largely not yet been generally realized in practice due to a lack of a robust theoretical framework as well as insufficient empirical research to guide the implementation efforts. We posit that learnings from the allied discipline of Information Infrastructures, which has matured during the 1990s in response to the proliferation of distributed, complex, and heterogeneous networked systems, can provide a useful theoretical lens to inform the emerging domain of SDIs. We focus on three key concepts identified in the domain of information infrastructure theory, viz. the installed base, reflexive standardization, and cultivation approach to design, to develop a theoretical framework, which is then applied to analyse the ongoing initiative to establish National Spatial Data Infrastructure (NSDI) in India. This analysis helps us to provide the basis to articulate a potential research agenda—for both theory and practice—which, we believe, offers the promise to better conceptualize and implement SDIs, particularly in developing country settings like India.     

Prediction of Aquifer Vulnerability to Pesticides Using Fuzzy Rule-Based Models at the Regional Scale

Contamination of ground water has been a major environmental concern in recent years. The potential for ground-water contamination by pesticides depends on porous media, solute, and hydrologic parameters. Although sophisticated deterministic computer models are available for assessing aquifer-contamination potential on a site-by-site basis, most deterministic models are too complex for vulnerability assessment on a regional scale because they require input data that are spatially and temporally variable, and which may not be available at this scale. Therefore, development of an affordable model that is robust under conditions of uncertainty at the watershed scale with minimum input of field data becomes a useful ground-water management tool. The purpose of this study was to examine the usefulness of fuzzy rule-based techniques in predicting aquifer vulnerability to pesticides at the regional scale. The objectives were to (1) develop fuzzy rule-based models using the same input parameters contained in an index-based model (i.e., the modified DRASTIC model), (2) determine the sensitivity of fuzzy rule model predictions, (3) compare the outputs of the fuzzy rule-based models with those of the modified DRASTIC model and with the results of aquifer water-quality analyses, and (4) examine the spatial variability of field parameters around contaminated wells of the Alluvial aquifer in Woodruff County Arkansas. The fuzzy rule-based model for objective (1) was developed using similar parameter weights and ratings as the modified DRASTIC model. For objective (2), fuzzy rule-based models were created using fewer parameters than the modified DRASTIC model. Sensitivity of the fuzzy rule-based models was determined using different combinations of weights of the four input parameters in DRASTIC. It was found that variations in the weights of the input parameters and number of fuzzy sets influenced the location of the aquifer-vulnerability categories as well as the area within each fuzzy category. The fuzzy rule models tended to predict somewhat higher vulnerabilities of the Alluvial aquifer than the modified DRASTIC model. The fuzzy rule base that had the soil-leaching index (S) as the highest weight was chosen as the best fuzzy rule model in predicting potential contamination by pesticides of the aquifer. In general, the fuzzy rule models tended to overestimate the vulnerability of the aquifer in the study area.     

An efficient measure of compactness for two-dimensional shapes and its application in regionalization problems

A measure of shape compactness is a numerical quantity representing the degree to which a shape is compact. Ways to provide an accurate measure have been given great attention due to its application in a broad range of GIS problems, such as detecting clustering patterns from remote-sensing images, understanding urban sprawl, and redrawing electoral districts to avoid gerrymandering. In this article, we propose an effective and efficient approach to computing shape compactness based on the moment of inertia (MI), a well-known concept in physics. The mathematical framework and the computer implementation for both raster and vector models are discussed in detail. In addition to computing compactness for a single shape, we propose a computational method that is capable of calculating the variations in compactness as a shape grows or shrinks, which is a typical application found in regionalization problems. We conducted a number of experiments that demonstrate the superiority of the MI over the popular isoperimetric quotient approach in terms of (1) computational efficiency; (2) tolerance of positional uncertainty and irregular boundaries; (3) ability to handle shapes with holes and multiple parts; and (4) applicability and efficacy in districting/zonation/regionalization problems.     

GIS创新实习平台的构建

分析了地理信息系统创新实习存在的问题,提出了构建地理信息系统创新实习平台的解决方案,设计出地理信息系统创新实习平台总体结构,并从数据服务器、应用服务器及应用示例三方面构建了地理信息系统创新实习平台。     

地震应急预案信息管理系统的开发技术研究

地震应急预案是地震应急管理工作的基础和首要环节,应急预案的信息管理系统的开发对该工作的数字化、规范化和信息化十分重要。本文对地震应急预案管理信息系统的研制开发过程进行了技术回顾,介绍了工作思路和技术方案,并简要说明了地震应急预案管理信息系统的功能及使用。     

网络信息安全的模糊综合评判

通过分析网络信息安全的现状,提出了物理安全、逻辑安全和安全管理三个一级评判指标和26个二级评判指标,利用模糊综合评判方法对某单位局域网信息安全实例进行了评判,提出了一种基于圆形分布的隶属度分布函数,并进行了使用和验证。     

基于数学形态学的高分遥感影像地震重点目标信息提取

重点目标是抗震救援的关键, 重点目标的破坏大多与目标本身的破坏或破坏前后的形态变化有关。 本文利用数学形态学方法对地物形态特征(包括形状、 大小、 方向等)处理的优势和思路, 构建了重点目标信息提取流程和算法, 并利用海地地震的高分辨率遥感影像, 对震后油罐破损状态的分离和提取、 以及对机场跑道旧损状态的提取。 试验结果表明, 对于形态上能够明显区别于背景的重点目标, 可以利用灰度和结构信息通过数学形态学进行提取。 而且数学形态学算法构造灵活, 处理速度快, 便于硬件实现, 对应急救援的快速处理有一定应用前景。     

基于GIS的油田电力系统网络分析系统的实现

随着GIS技术及相关学科的不断发展,GIS在石油业应用越来越广。电力网络是油田系统的重要组成部分。基于ArcObjects组件对象,开发实现了油田电力网络断电影响分析和故障源分析等网络追踪分析功能,对提高油田系统的科学化管理和决策具有重要意义。     

地形要素变化信息标报系统的设计与实现

针对信息化条件下地理信息动态更新对变化发现技术的迫切需求,研究设计了基于网络的多级有序互动式地形要素变化信息标报系统：首先讨论了系统的总体设计思路以及三层体系结构,概述了系统中的发布订阅、地理信息博客和多级访问控制三个模块的设计,在上述设计基础上,给出了系统功能设计;通过模拟数据介绍了系统的主要实现结果。     

面向服务的山西省地理信息公共服务平台建设

结合山西省地理信息公共平台建设,着重说明以公共地理框架数据库建设为核心的数据体系建设和目录服务注册为核心的地理信息公共在线服务体系的建设;探索地理空间数据共享与发布的作业流程和工作基准,为地理信息的共享打下数据基础,解决了多源空间数据的注册、发现与绑定问题,构建了开放式服务体系。