The increasing frequency of heatwaves, particularly in urban contexts, is one of the perceptible consequences of climate change. A city’s vulnerability to these heatwaves must be determined to develop proper adaptation measures. This article addresses the vulnerability of a medium-sized city in Central Europe, Graz, to heatwaves. Based on secondary data and primary data gathered from expert interviews, we identified certain determinants of vulnerability for the city: temperature, proportion of open and green spaces to developed areas, construction period of buildings, distribution of age and poverty risk, adaptation strategies used, and risk perception levels assessed for decision makers in the city administration. Certain city districts can be classified as particularly vulnerable. A high level of risk perception was detected among all decision makers and some adaptation measures have already been enacted. In particular, inter-organizational collaboration in adaptation networks works effectively. A deficit in efficient communication between researchers, policy makers, and members of the public was perceived to be the main barrier. This case study exemplifies the assessment of a city’s vulnerability to heatwaves on the basis of particular determinants and can be applied to many other cities.
Policy relevance
The method applied revealed potential improvements and opportunities on the policy level. Strong networks for climate change adaptation are most effective if regular meetings take place, allowing trust and friendship to grow between decision makers. More target-group-oriented information is needed. Emergency organizations, in particular, need more information, because the perception of heatwave risks has only been based thus far on personal experiences. By establishing a central authority, more information could be provided on heatwaves in cities. The need to raise the perception of members of the population and motivate them to take personal responsibility during disasters was emphasized by interviewed decision makers. This can be supported by providing advice during heatwaves through newspapers, TV, and radio. People in risk groups and their relatives could be trained in workshops. City areas that are at high risk should be marked on maps to make relevant information more tangible for decision makers. 相似文献
Parts of eastern Africa have experienced substantial climatic variability and extremes during the last few decades. Here we explore the extent to which local place‐based knowledge is used and is relevant to understanding and appropriately responding to place‐based climate variability and change (specifically rainfall) in an area of considerable rainfall variability in south‐western Tanzania. Primary data were collected using focus group discussions and household questionnaire surveys, and secondary data obtained from government institutions. Various changes associated with the frequency, intensity and consistency of rainfall during the period 1960 to 2014 are explored. Findings indicate that knowledge and perceptions associated with climate operate at a local level, and that these are not necessarily applicable to neighbouring regions. Smallholder farmers in the Great Ruaha River Sub‐Basin rely on incremental adaptations of agricultural practices, in response to climatic stresses which have long‐term implications. We argue that incremental adaptations ought to be supplemented by more transformative changes of existing agricultural practices, such as using more climate‐adapted crops and livestock. Moreover, caution is required when examining human perceptions and responses to climate variability and change at the site‐specific scale, as such findings may not necessarily be applicable to broader regions in all cases. 相似文献
Climate change public opinion research has identified conservative political ideology as the primary predictor of skepticism about climate change’s anthropogenic causes. Most farmers in Idaho are politically conservative, but they are also a unique group for whom observing their environment is part of daily life and work. We use data from in-depth interviews with 30 Idaho farmers to examine the relationship between observations of specific environmental changes and climate concern. We find that while most farmers report noticing changes in precipitation patterns, growing season length, and winter temperatures, few farmers connect these with long-term global climate change. These findings have two important implications: 1) direct experience, even in the form of disruption to an individual’s economic security, is not enough to overcome the influence of political ideology on climate change beliefs, and 2) acknowledging climate variation is not sufficient to convince individuals that the changes are produced by human activities. 相似文献
AbstractThe analysis of remote sensing (RS) images, which is often accomplished using unsupervised image classification techniques, requires an effective method to determine an appropriate number of classification clusters. This paper proposes a preliminary analytical method to evaluate the input parameters for unsupervised RS image classification. Our approach involves first analysing the colour spaces of RS images based on the human visual perception theory. This enables the initial number of clusters and their corresponding centres to be automatically established based on the interaction of different forces in our supposed force field. The proposed approach can automatically determine the appropriate initial number of clusters and their corresponding centres for unsupervised image classification. A comparison of the experimental results with those of existing methods showed that the proposed method can considerably facilitate unsupervised image classification for acquiring accurate results efficiently and effectively without any prior knowledge. 相似文献
The process of reading a topographic map requires users to recognize and learn the cartographic symbols of the key (or legend) while interpreting the territory as depicted on the map at a given level of abstraction (the form and nature of features, their saliency and relationships). We present the results of an empirical user study that aims to identify and assess the main graphical characteristics that are used by map users to recognize the design principles which constitute the topographic mapping style adopted by IGN (Institut National de l'Information Géographique et Forestière), France. Our results suggest that 91% of the participants were able to recognize an IGN-France topographic map amongst other topographic map products. We also determine which graphical characteristics play a role in the recognition of this cartographic style, either by visual memory or by visual perception, and identify the representation of relief, including contour lines and shaded relief, as one of the major graphical characteristics of the topographic mapping style of IGN-France. Moreover, the participants of our study considered the representation of touristic POI (points of interest), toponymy, typography, the main roads network, the individual buildings and the forests, to be essential for stylistic recognition. 相似文献
A method to visualize multiple membership maps, called ‘Colour mixture’ (CM) is described and compared with alternative techniques: defuzzification and Pixel mixture. Six landform parameters were used to derive the landform classes using supervised fuzzy k-means classification. The continuous categorical map is derived by GIS calculations with colours, where colour values are considered to represent the taxonomic space spanned by the attribute variables. Coordinates of the nine class centres (landform facets) were first transformed from multivariate to two-dimensional attribute space using factor analysis, and then projected on the Hue Saturation Intensity (HSI) colourwheel. The taxonomic value was coded with the Hue and confusion with Saturation. To improve visual impression, saturation was replaced with whiteness. Classes that were closer in attribute space were merged into similar generic colours. The CM technique limits the derived mixed-colour map to seven generic hues independently of the total number of classes, which provides a basis for automated generalization. The confusion index derived from the mixed-colour map was used to derive primary boundaries and to locate areas of higher taxonomic confusion. 相似文献