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GIS Tools (gi + tool)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Performance of Buildings under Earthquakes in Barcelona, Spain

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 8 2006
Alex H. Barbat
The seismic hazard in the area of the city is described by means of the reduced 5% damped elastic response spectrum. Obtaining fragility curves for the most important building types of an urban center requires an important amount of information about the structures and the use of nonlinear structural analysis tools. The information on the buildings of Barcelona was obtained by collecting, arranging, improving, and completing the database of the housing and current buildings. The buildings existing in Barcelona are mainly of two types: unreinforced masonry structures and reinforced concrete buildings with waffled slab floors. In addition, the Arc-View software was used to create a GIS tool for managing the collected information to develop seismic risk scenarios. This study shows that the vulnerability of the buildings is significant and therefore, in spite of the medium to low seismic hazard in the area of the city, the expected seismic risk is considerable. [source]

Analyzing Spatial Drivers in Quantitative Conflict Studies: The Potential and Challenges of Geographic Information Systems

INTERNATIONAL STUDIES REVIEW, Issue 3 2009
Nathalie Stephenne
The objective of this literature review is to understand where Graphical Information Systems (GIS) can be useful to address security issues and how it has been used until now. While the geographic drivers of territorial conflicts have been extensively described by a number of political studies, the quantitative analysis of these drivers is quite new. This study traces an evolution from conceptual research to quantitative development. It then discusses the advantages and challenges of applying new geographic techniques to analyze spatial drivers of conflict. We identify the main spatial components in conflict and security, the existing types of information/data and the quantitative methods used. We describe the spatial component of security by looking at: (i) the main sociopolitical concepts linked to territory, (ii) the kind of geographic concepts linked to territory, (iii) measures used to describe such geographic concepts; and (iv) the issues raised in any attempt to integrate geographic concepts into a GIS. We conclude that GIS tools can be useful in the analysis of civil disputes, particularly where subnational level data exists. This paper shows that spatial processing tools in GIS allow us to represent some spatial components and to address new issues such as the fuzzy complexity of border permeability. [source]

Mapping space for water: screening for urban flash flooding

JOURNAL OF FLOOD RISK MANAGEMENT, Issue 1 2008
B. Hankin
Abstract This paper builds on the ,Flooding from Other Sources' project (HA4a), funded as part of Defra's Making Space for Water strategy. The HA4a study concluded that flood risk mapping is feasible for many of the sources of flooding that were investigated, which are not currently covered by the Environment Agency Flood Map, using existing flow modelling and GIS tools. However, there are some major constraints in terms of the need to undertake extensive data collection to allow the generation of useful flood maps that are not dominated by modelling uncertainties. The project anticipated that different levels of data collection and modelling might be needed for different purposes, given the hierarchical nature of UK flood risk assessment and management in the United Kingdom under PPS25 and the EC Floods Directive. This paper compares and contrasts three different approaches to urban flood modelling using topographic analysis, blanket extreme rainfall and semi-coupled sewer/overland routing. The UK summer floods 2007 have highlighted the pressing need for mapping the risk from urban flash flooding, and the Pitt Review has recommended that areas at high risk from surface waters should be urgently identified. This can be done now at some level of detail, and we can be guided as to what level, from our increasing knowledge of vulnerable populations, from records of historical flooding and by using some of the screening methods described herein. [source]

Conserving the evolutionary potential of California valley oak (Quercus lobata Née): a multivariate genetic approach to conservation planning

MOLECULAR ECOLOGY, Issue 1 2008
DELPHINE GRIVET
Abstract California valley oak (Quercus lobata Née) is a seriously threatened endemic oak species in California and a keystone species for foothill oak ecosystems. Urban and agricultural development affects a significant fraction of the species' range and predicted climate change is likely to dislocate many current populations. Here, we explore spatial patterns of multivariate genotypes and genetic diversity throughout the range of valley oak to determine whether ongoing and future patterns of habitat loss could threaten the evolutionary potential of the species by eradicating populations of distinctive genetic composition. This manuscript will address three specific questions: (i) What is the spatial genetic structure of the chloroplast and nuclear genetic markers? (ii) What are the geographical trends in the distribution of chloroplast and nuclear genotypes? (iii) Is there any part of the species' range where allelic diversity in either the chloroplast or nuclear genomes is particularly high? We analysed six chloroplast and seven nuclear microsatellite genetic markers of individuals widespread across the valley oak range. We then used a multivariate approach correlating genetic markers and geographical variables through a canonical trend surface analysis, followed by GIS mapping of the significant axes. We visualized population allelic richness spatially with GIS tools to identify regions of high diversity. Our findings, based on the distribution of multivariate genotypes and allelic richness, identify areas with distinctive histories and genetic composition that should be given priority in reserve network design, especially because these areas also overlap with landscape change and little degree of protection. Thus, without a careful preservation plan, valuable evolutionary information will be lost for valley oak. [source]