12,829 research outputs found

    Landscape metrics and indices : an overview of their use in landscape research

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    The aim of this overview paper is to analyze the use of various landscape metrics and landscape indices for the characterization of landscape structure and various processes at both landscape and ecosystem level. We analyzed the appearance of the terms landscape metrics/indexes/indices in combination with seven main categories in the field of landscape ecology [1) use/selection and misuse of metrics, 2) biodiversity and habitat analysis; 3) water quality; 4) evaluation of the landscape pattern and its change; 5) urban landscape pattern, road network; 6) aesthetics of landscape; 7) management, planning and monitoring] in the titles, abstracts and/or key words of research papers published in international peer-reviewed scientific journals indexed by the Institute of Science Information (ISI) Web of Science (WoS) from 1994 to October 2008. Most of the landscape metrics and indices are used concerning biodiversity and habitat analysis, and also the evaluation of landscape pattern and its change (up to 25 articles per year). There are only a few articles on the relationships of landscape metrics/indices/indexes to social aspects and landscape perception

    Visual Landscape Assessment for Development Landscape Structure: Case study at Taiping, Perak

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    The landscape is an important national resource outstanding natural and cultural inheritance which is widely appreciated. This study attempts to evaluate visual landscape of Taiping District in relations to the larger landscape scale in Peninsular Malaysia. A Landscape Character Assessment was conducted on the visual landscape taken for several points in Taiping, Perak and surrounding area to see changes in the landscape. The aim of this study is to provide a visual structure for landscape classification of the Taiping District area that will contribute to the decision making in development and management in Malaysia. Ensuring the opportunity taken during district planning processes is important.Keywords: Landscape character assessment, visual landscape, landscape structure.ISSN: 2398-4287© 2017. The Authors. Published for AMER ABRA by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia

    Sensitivity of cropping patterns in Africa to transient climate change

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    The detailed analysis of current cropping areas in Africa presented here reveals significant climate sensitivities of cropland density and distribution across a variety of agro-ecosystems. Based on empirical climate-cropland relationships, cropland density responds positively to increases in precipitation in semi-arid and arid zones of the sub-tropics and warmer temperatures in higher elevations. As a result, marginal increases in seasonal precipitation lead to denser cropping areas in arid and semi-arid regions. Warmer temperatures, on the other hand, tend to decrease the probability of cropping in most parts of Africa (the opposite is true for increases in rainfall and decreases in temperatures relative to current conditions). Despite discrepancies and uncertainties in climate model output, the analysis suggests that cropland area in Africa is likely to decrease significantly in response to transient changes in climate. The continent is expected to have lost on average 4.1 percent of its cropland by 2039, and 18.4 percent is likely to have disappeared by the end of the century. In some regions of Africa the losses in cropland area are likely to occur at a much faster rate, with northern and eastern Africa losing up to 15 percent of their current cropland area within the next 30 years or so. Gains in cropland area in western and southern Africa due to projected increases in precipitation during the earlier portions of the century will be offset by losses later on. In conjunction with existing challenges in the agricultural sector in Africa, these findings demand sound policies to manage existing agricultural lands and the productivity of cropping systems.Climate Change,Crops&Crop Management Systems,Global Environment Facility,Common Property Resource Development,Rural Poverty Reduction

    Comparing regional differentiation of land cover changes in natural and administrative regions of the Czech Republic using multivariate statistics

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    The detection and evaluations of land cover changes represent the major task for landscape transformation studies in post-communistic countries. The results of such evaluation are, however, highly influenced by spatial delimitation of monitored units as natural or administrative regions. Moreover, the objective quantitative assessment of land cover changes and their typologies in different types of regions can be hardly done by traditional map-interpretation approach. The aim of the present research was to evaluate the differences in results of land cover changes in the Czech Republic detected in natural (93 geomorphological units) and administrative (77 districts) regions using multivariate statistics. To analyse land cover (LC) changes we used STATISTICA 9 software. The application of principal component analysis (PCA), factor analysis (FA) and cluster analysis (CA) reveals the main overall trends in land cover changes in the Czech Republic. We applied PCA, CA and FA to land cover data from CORINE projects in 1990, 2000 and 2006. We analyzed LC changes in geomorphological units of Czechia as a whole. We made our calculation based on standardised data for land cover classes. The final number of variables (LC classes) used in the study was 11, drawing upon generalisation of only those land cover classes that are present in Czech landscape. For both sets of territorial units (i.e. natural and administrative), we calculated the Euclidean distance (full connections) between the cases (territorial units). The k-means method and hierarchical clustering were used for clustering. Based on these methods we set the typology of land cover changes in natural and administrative units. Finally, we assessed the differences between these typologies as regards statistical distribution of regions among the individual types. The factors influencing differences between these typologies are discussed, concluding in considerations on a role of spatial delimitation in land cover changes studies.

    FLIAT, an object-relational GIS tool for flood impact assessment in Flanders, Belgium

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    Floods can cause damage to transportation and energy infrastructure, disrupt the delivery of services, and take a toll on public health, sometimes even causing significant loss of life. Although scientists widely stress the compelling need for resilience against extreme events under a changing climate, tools for dealing with expected hazards lag behind. Not only does the socio-economic, ecologic and cultural impact of floods need to be considered, but the potential disruption of a society with regard to priority adaptation guidelines, measures, and policy recommendations need to be considered as well. The main downfall of current impact assessment tools is the raster approach that cannot effectively handle multiple metadata of vital infrastructures, crucial buildings, and vulnerable land use (among other challenges). We have developed a powerful cross-platform flood impact assessment tool (FLIAT) that uses a vector approach linked to a relational database using open source program languages, which can perform parallel computation. As a result, FLIAT can manage multiple detailed datasets, whereby there is no loss of geometrical information. This paper describes the development of FLIAT and the performance of this tool

    Macroinvertebrates, Heavy Metals and PAHs in Urban Watercourses

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    Good quality stream water and sediments are crucial for the support of healthy stream flora and fauna but urban runoff degrades watercourses leaving a legacy of pollution in the stream sediments. The sediment pollution load influences the development of macroinvertebrates which, as the lowest member of the food chain, influences the whole ecological structure. This review focuses on defining the sources and impacts of zinc, nickel, copper and oil derivative polycyclic aromatic hydrocarbon (PAH) contaminants in urban runoff. The impact of pollutants as measured by laboratory, field and modelling procedures are considered. Land use, position and connectivity of the runoff and sediment are seen to have an effect on the ecological integrity of the watercourse but case examples are sparse. The literature indicates that while reduced species diversity has been identified at a number of sites the dynamics are not well understood nor well modelled. These results are compared with field evidence from a study of 62 headwater streams with urban industrial and motorway land uses. From the review and field results it is evident that there is still an important need for process-based field measurements of urban water quality parameters. Forecasting the ecological status of watercourses would seem to benefit from data on sediment chemistry that considers the interaction effects of metals and PAHs

    Spatial aspects of the design and targeting of agricultural development strategies:

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    Two increasingly shared perspectives within the international development community are that (a) geography matters, and (b) many government interventions would be more successful if they were better targeted. This paper unites these two notions by exploring the opportunities for, and benefits of, bringing an explicitly spatial dimension to the tasks of formulating and evaluating agricultural development strategies. We first review the lingua franca of land fragility and find it lacking in its capacity to describe the dynamic interface between the biophysical and socioeconomic factors that help shape rural development options. Subsequently, we propose a two-phased approach. First, development strategy options are characterized to identify the desirable ranges of conditions that would most favor successful strategy implementation. Second, those conditions exhibiting important spatial dependency – such as agricultural potential, population density, and access to infrastructure and markets – are matched against a similarly characterized, spatially-referenced (GIS) database. This process generates both spatial (map) and tabular representations of strategy-specific development domains. An important benefit of a spatial (GIS) framework is that it provides a powerful means of organizing and integrating a very diverse range of disciplinary and data inputs. At a more conceptual level we propose that it is the characterization of location, not the narrowly-focused characterization of land, that is more properly the focus of attention from a development perspective. The paper includes appropriate examples of spatial analysis using data from East Africa and Burkina Faso, and concludes with an appendix describing and interpreting regional climate and soil data for Sub-Saharan Africa that was directly relevant to our original goal.Spatial analysis (Statistics), Agricultural development., Burkina Faso., Africa, Sub-Saharan.,

    The European heat wave 2003: early indicators from multisensoral microwave remote sensing?

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    An extreme heat wave affected large parts of Europe in 2003 with severe socioeconomic impacts. The extreme warm weather conditions lasted over a couple of months with positive temperature anomalies of 5°C for large parts of Europe. Simulations of the event using regional climate models revealed that a pronounced precipitation deficit in the beginning of the year, together with an early onset of the vegetation, resulted in a severe deficit of the soil water content. This amplified the course of the heat wave due to an increasing sensible heat flux from the land surface. The monitoring of temporal and spatial dynamics of soil water content can be accomplished using remote-sensing-based techniques. The present paper addresses the question whether there have been early indicators for the low soil water content using either physically based land surface modeling or remote-sensing-based monitoring techniques. The course of the spring surface soil moisture evolution is investigated using observations from two different microwave remote sensing sensors. An intercomparison of the high-resolution data from the European ENVISAT satellite and coarse resolution data from the AMSR-E mission is made. Remote-sensing-derived soil moisture products are compared against the results from a deterministic land surface model. The model enables to relate the year 2003 anomalies to a long-term (30 years) climatology. The year 2003 remote sensing derived soil moisture dynamics is compared against a multiyear climatology. The results reveal a negative surface soil moisture anomaly in 2003. The results indicate that there was in general potential to monitor the spatial and temporal dimensions of the low surface soil water content early in 2003 using remote sensing techniques. Both remote sensing data sets indicate a consistent soil moisture decrease in early 2003. A good agreement between the observed surface soil moisture and soil moisture simulations from a land surface process model was found. An outlook to the use of remote-sensing-based soil moisture estimates for large-scale monitoring of surface soil moisture trends is given. Copyright 2009 by the American Geophysical Union
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