基于NDVI先验知识的LAI地面采样方法

针对非均质中低分辨率像元的叶面积指数LAI验证中如何布设基本采样单元ESU的问题,提出基于NDVI先验知识的ESU布设方法,并采用不同植被类型、不同均匀程度的地表作为模拟场,分析对比了方法的精度及稳定性。结果显示,本文方法用NDVI先验知识描述植被的生长空间分布信息,能相对准确地划分植被的不同生长水平,有效降低层内方差。在草地和森林地区的试验中,精度与稳定性均优于传统的随机采样、均匀采样和基于分类图的3种采样方法。因此,本文提出的采样方法为大尺度非均质区域LAI地面验证的采样方案提供了新的设计思路。     

虚拟地理环境知识工程初探

地理知识在虚拟地理环境（Virtual Geographic Environments,VGE）的科研与应用中发挥着极为重要的作用。现有地理知识工程研究整体处于初步探索阶段,且尚未在虚拟地理环境中展开。作为新一代GIS研究的科学方法和技术,虚拟地理环境具有典型的多领域、多协同、多交互、多模型及多感知的特点,但还亟需系统深入地了解VGE地理知识工程的特点、机理及关键技术。本文首先综述了国内外现有知识工程及地理知识工程研究现状,进而提出了VGE地理知识及VGE知识工程的概念和定义。在此基础上,本文分析了VGE地理知识有别于通用知识的特点,并提出了VGE地理知识的分类。最后,针对VGE地理知识工程的构建阐述了需解决的关键问题。本文基于VGE知识工程的初步探索,尝试为智能虚拟地理环境系统的构建提供理论基础,以促进虚拟地理环境中地理知识的快速转换和融合,为解决地理科学“数据丰富但知识贫乏”的问题提供一个可行的研究方向。     

A framework for the seismic assessment of existing masonry buildings accounting for different sources of uncertainty

The current formulation of Eurocode 8 Part 3 and the Italian building code for the seismic assessment of existing buildings accounts for epistemic (knowledge‐based) uncertainties by means of the identification of knowledge levels with associated values of the so‐called confidence factors, applied only as a reduction of material strengths. This formulation does not always produce consistent results and it does not explicitly account for other sources of uncertainty. The paper proposes a probabilistic methodology for the quantification of appropriately defined factors, allowing consideration of the different sources of uncertainty involved in the seismic assessment of masonry buildings by means of nonlinear static analyses. This simple approach, also including an alternative formulation of the confidence factors related with material properties, allows to obtain results which are consistent with the acquired level of knowledge and correctly account for the different sources of uncertainty without requiring to carry out any stochastic nonlinear analysis. Copyright © 2013 John Wiley & Sons, Ltd.     

如何开展地震现场科普宣传工作初探

地震科普宣传工作多是在地震发生之前开展,主要偏重的是如何地震避险。地震灾害发生后对灾区民众如何有效地减轻地震灾害及合理地配合外来救援力量的科普宣传缺乏系统性。本文从地震现场科普宣传的形式、内容及如何更好地实现现场科普宣传三个方面对地震现场科普宣传工作进行分析,旨在为利用地震现场科普宣传维护震区的社会稳定、减轻灾害损失及顺利地开展地震现场救援提出建议。     

Assessing indigenous knowledge systems and climate change adaptation strategies in agriculture: A case study of Chagaka Village,Chikhwawa, Southern Malawi

In Malawi, production from subsistence rain fed agriculture is highly vulnerable to climate change and variability. In response to the adverse effects of climate change and variability, a National Adaptation Programme of Action is used as framework for implementing adaptation programmes. However, this framework puts limited significance on indigenous knowledge systems (IKS). In many parts of the world, IKS have shown potential in the development of locally relevant and therefore sustainable adaptation strategies. This study was aimed at assessing the role of IKS in adaptation to climate change and variability in the agricultural sector in a rural district of Chikhwawa, southern Malawi. The study used both qualitative data from focus group and key informant interviews and quantitative data from household interviews and secondary data to address the research objectives. The study established that the local communities are able to recognise the changes in their climate and local environment. Commonly mentioned indicators of changing climatic patterns included delayed and unpredictable onset of rainfall, declining rainfall trends, warming temperatures and increased frequency of prolonged dry spells. An analysis of empirical data corroborates the people’s perception. In addition, the community is able to use their IKS to adapt their agricultural systems to partially offset the effects of climate change. Like vulnerability to climate change, IKS varies over a short spatial scale, providing locally relevant adaptation to impacts of climate change. This paper therefore advocates for the integration of IKS in programmes addressing adaptation to climate change and vulnerability. This will serve to ensure sustainable and relevant adaptation strategies.     

基于人工神经元网络的空间知识表达与推理方法研究

分析了智能决策支持系统的结构,通过比较指出了基于符号的知识表达与推理方法的不足,阐述了基于神经网络的知识表达与推理的方法,并认为神经网络方法可作为智能空间决策支持系统中符号方法的替代或补充,并通过实例验证了基于神经网络的不确定空间知识表达与推理的有效性.     

论《GIS空间分析》课程建设

综述了GIS空间分析理论的相关知识面和知识点,分析了课程的教学适应性,提出了课程建设的几点建议.     

甘肃省农村居民地震常识情况的调查分析

了解农村居民对地震常识的掌握情况是做好农村震害防御工作的重要参考.本文研究设计了调查表格,对农村居民地震常识的掌握情况进行了调查.通过甘肃省16个县(区)的现场抽样调查,得到了甘肃省农村居民的地震常识掌握情况,并通过对比研究,分析了造成农村居民地震常识掌握不足以及造成差异的影响因素.基于调查结果,本文针对农村居民地震常识的掌握情况,提出了增强农村居民防震减灾知识,提高其震害防御意识的工作建议.     

Design and implementation of a 3D ocean virtual reality and visualization engine

In this study,a 3D virtual reality and visualization engine for rendering the ocean,named VV-Ocean,is designed for marine applications.The design goals of VV-Ocean aim at high fidelity simulation of ocean environment,visualization of massive and multidimensional marine data,and imitation of marine lives.VV-Ocean is composed of five modules,i.e.memory management module,resources management module,scene management module,rendering process management module and interaction management module.There are three core functions in VV-Ocean:reconstructing vivid virtual ocean scenes,visualizing real data dynamically in real time,imitating and simulating marine lives intuitively.Based on VV-Ocean,we establish a sea-land integration platform which can reproduce drifting and diffusion processes of oil spilling from sea bottom to surface.Environment factors such as ocean current and wind field have been considered in this simulation.On this platform oil spilling process can be abstracted as movements of abundant oil particles.The result shows that oil particles blend with water well and the platform meets the requirement for real-time and interactive rendering.VV-Ocean can be widely used in ocean applications such as demonstrating marine operations,facilitating maritime communications,developing ocean games,reducing marine hazards,forecasting the weather over oceans,serving marine tourism,and so on.Finally,further technological improvements of VV-Ocean are discussed.     

The resilience and sustainability of local wetland management institutions in Illubabor and Western Wellega,Ethiopia

Local community based institutions that coordinate the management of natural resources have been linked to socioecological resilience, adaptation and sustainability within rural livelihood systems throughout the developing world. The resilience and sustainability of related local institutions, however, is influenced by their relationship with external actors and institutions, particularly in facilitating, supporting or hindering local institutional arrangements. From this standpoint, this paper examines the case of local community based institutions involved in wetland management in western Ethiopia. Drawing upon the findings of participatory fieldwork undertaken in eight wetland‐using communities of Illubabor and Western Wellega zones in Oromia Region it is argued that although local institutions do play a key role in coordinating wetland management and sustaining the benefits from wetlands, the sustainability and resilience of the institutions themselves is threatened by a range of factors. Despite their grassroots nature, their effectiveness is influenced by their reliance on local government backstopping that appears to have diminished in recent years, as well as a perceived lack of local government support for collective action over individual rights.