621 research outputs found

    Colorado's wildland-urban interface, current and projected

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    WUI is the wildland-urban interface. It is the area where homes and urban sprawl press against the wildland, and includes both interface and intermix communities.Map created 23 October 2007 by D. Theobald, Colorado State University.WUI is the wildland-urban interface. It is the area where homes and urban sprawl press against the wildland, and includes both interface and intermix communities

    Rural Land-Use Trends in the Conterminous United States, 1950-2000.

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    In order to understand the magnitude, direction, and geographic distribution of land-use changes, we evaluated land-use trends in U.S. counties during the latter half of the 20th century. Our paper synthesizes the dominant spatial and temporal trends in population, agriculture, and urbanized land uses, using a variety of data sources and an ecoregion classification as a frame of reference. A combination of increasing attractiveness of nonmetropolitan areas in the period 1970–2000, decreasing household size, and decreasing density of settlement has resulted in important trends in the patterns of developed land. By 2000, the area of low-density, exurban development beyond the urban fringe occupied nearly 15 times the area of higher density urbanized development. Efficiency gains, mechanization, and agglomeration of agricultural concerns has resulted in data that show cropland area to be stable throughout the Corn Belt and parts of the West between 1950 and 2000, but decreasing by about 22% east of the Mississippi River. We use a regional case study of the Mid-Atlantic and Southeastern regions to focus in more detail on the land-cover changes resulting from these dynamics. Dominating were land-cover changes associated with the timber practices in the forested plains ecoregions and urbanization in the piedmont ecoregions. Appalachian ecoregions show the slowest rates of landcover change. The dominant trends of tremendous exurban growth, throughout the United States, and conversion and abandonment of agricultural lands, especially in the eastern United States, have important implications because they affect large areas of the country, the functioning of ecological systems, and the potential for restoratio

    Improving the spatial resolution of air-quality modelling at a European scale – development and evaluation of the Air Quality Re-gridder Model (AQR v1.1)

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    Currently, atmospheric chemistry and transport models (ACTMs) used to assess impacts of air quality, applied at a European scale, lack the spatial resolution necessary to simulate fine-scale spatial variability. This spatial variability is especially important for assessing the impacts to human health or ecosystems of short-lived pollutants, such as nitrogen dioxide (NO2) or ammonia (NH3). In order to simulate this spatial variability, the Air Quality Re-gridder (AQR) model has been developed to estimate the spatial distributions (at a spatial resolution of 1  ×  1 km2) of annual mean atmospheric concentrations within the grid squares of an ACTM (in this case with a spatial resolution of 50  ×  50 km2). This is done as a post-processing step by combining the coarse-resolution ACTM concentrations with high-spatial-resolution emission data and simple parameterisations of atmospheric dispersion. The AQR model was tested for two European sub-domains (the Netherlands and central Scotland) and evaluated using NO2 and NH3 concentration data from monitoring networks within each domain. A statistical comparison of the performance of the two models shows that AQR gives a substantial improvement on the predictions of the ACTM, reducing both mean model error (from 61 to 41 % for NO2 and from 42 to 27 % for NH3) and increasing the spatial correlation (r) with the measured concentrations (from 0.0 to 0.39 for NO2 and from 0.74 to 0.84 for NH3). This improvement was greatest for monitoring locations close to pollutant sources. Although the model ideally requires high-spatial-resolution emission data, which are not available for the whole of Europe, the use of a Europe-wide emission dataset with a lower spatial resolution also gave an improvement on the ACTM predictions for the two test domains. The AQR model provides an easy-to-use and robust method to estimate sub-grid variability that can potentially be extended to different timescales and pollutants

    Implementing Polar Projections with OGC Services for the Enhancement of AIRS NRT Visualization in LANCE

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    The Atmospheric Infrared Sounder (AIRS) NRT product is one important element in the Land, Atmosphere Near real-time Capability for EOS (LANCE). The LANCE processing of AIRS NRT products and the image generation are performed at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). The Open Geospatial Consortium (OGC) services are being utilized to access AIRS NRT images. The ongoing AIRS NRT imagery enhancement work includes adding a new set of the images in polar projections. Polar projections are commonly used for mapping Antarctica and Arctic regions. We have implemented more precise south polar (EPSG:3031) projection and north polar (EPSG:3413) projection making our OGC service instances more useful and interoperable. Thus, AIRS NRT data can be easily accessed and integrated with other applications. It greatly increases the impact of our data on researches in polar regions.In this presentation, we will introduce the optimized processing workflow for OGC services from data access with spatial-temporal index to data visualization with different SLD, and demonstrate how to use open source software to provide more precise map images in polar projections

    Planetary Boundary Layer Height from AIRS, MERRA-2, and GPS Radio Occultation Data Products at NASA GES DISC, and Insights from Their Profiles Intercomparison

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    The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) provides archive and distribution services for several data products in the Planetary Boundary Layer (PBL) category. As a new variable added to the Atmospheric Infrared Sounder (AIRS) Version 6 support product, the PBL height from AIRS is derived based on the gradients of the retrieved relative humidity profile, and provides the atmospheric pressure at the top of the PBL over the ocean. The GES DISC also hosts the Modern-Era Retrospective analysis for Research and Applications-2 (MERRA-2) product generated by the Goddard Earth Observing System Model Version 5 (GEOS-5) data assimilation system. The PBL height from MERRA-2 is based on the total eddy diffusion coefficient of heat. The monthly PBL height has been made available in the Giovanni system (Giovanni is a Web-based application developed by the GES DISC providing a simple and intuitive way to visualize, analyze, and access vast amounts of Earth science remote sensing data). Recently, the GES DISC began serving the global PBL height climatology product derived from the COSMIC/FORMOSAT-3 and TerraSAR-X Global Positioning System (GPS) radio occultation (RO) measurements from June 2006 to December 2015. In a previous study, we presented the monthly PBL height data from AIRS and MERRA-2 and demonstrated the GES DISC services which support data intercomparison, such as access, plotting, sub-setting, regridding, and generation of a multi-year monthly mean. We also provided intercomparison results, and found that different PBL height definitions contributed to significant differences of PBL height values between AIRS and MERRA-2. In this work, we present the 10-year seasonal climatologies from the AIRS, MERRA-2 and GPS-RO. We also used the cross section and vertical profile services in Giovanni to display and analyze the vertical atmosphere structure over regions where the PBL height derived from the AIRS and MERRA-2 are quite different. The examination of the AIRS and MERRA-2 three-dimensional data found that the relative humidity profiles had larger differences than the temperature profiles. The MERRA-2 gives more details than the AIRS for the vertical distribution of the humidity

    Promoting vulnerability or resilience to HIV? A qualitative study on polygamy in Maiduguri, Nigeria

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    Literature on the links between polygamy and HIV and AIDS is limited and the findings inconclusive. Literature to date in Sub-Saharan Africa has relied mainly on case-control studies and surveys. This qualitative study aimed to explore different community members' perceptions of the links between the practice of polygamy and vulnerability or resilience to HIV and AIDS in Maiduguri, north-eastern Nigeria. The study used focus group discussions and in-depth interviews with religious and community leaders and different groups of women and men in the community. Participant views on the links between polygamy and HIV were varied. However, one clear emerging theme was that it is not the practice of polygamy per se that shapes vulnerability to HIV and AIDS but the dynamics of sexual relations and practices both within and beyond the marital union - whether monogamous or polygamous. The ways in which these social relationships are negotiated and experienced are in turn shaped by religious traditions, gender roles and relations, education and socio-economic status. Within the religious environment of north-eastern Nigeria, where asymmetrical gender roles and relations and connotations of morality shape experiences of sexual interactions, windows of opportunity to promote behaviour-change strategies to support women and men's resilience to HIV need to be carefully created. Health practitioners and planners should develop partnerships with religious and community leaders and women's groups to construct and deliver behaviour-changes strategies

    Where to restore ecological connectivity? Detecting barriers and quantifying restoration benefits

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    Landscape connectivity is crucial for many ecological processes, including dispersal, gene flow, demographic rescue, and movement in response to climate change. As a result, governmental and non-governmental organizations are focusing efforts to map and conserve areas that facilitate movement to maintain population connectivity and promote climate adaptation. In contrast, little focus has been placed on identifying barriers—landscape features which impede movement between ecologically important areas—where restoration could most improve connectivity. Yet knowing where barriers most strongly reduce connectivity can complement traditional analyses aimed at mapping best movement routes. We introduce a novel method to detect important barriers and provide example applications. Our method uses GIS neighborhood analyses in conjunction with effective distance analyses to detect barriers that, if removed, would significantly improve connectivity. Applicable in least-cost, circuit-theoretic, and simulation modeling frameworks, the method detects both complete (impermeable) barriers and those that impede but do not completely block movement. Barrier mapping complements corridor mapping by broadening the range of connectivity conservation alternatives available to practitioners. The method can help practitioners move beyond maintaining currently important areas to restoring and enhancing connectivity through active barrier removal. It can inform decisions on trade-offs between restoration and protection; for example, purchasing an intact corridor may be substantially more costly than restoring a barrier that blocks an alternative corridor. And it extends the concept of centrality to barriers, highlighting areas that most diminish connectivity across broad networks. Identifying which modeled barriers have the greatest impact can also help prioritize error checking of land cover data and collection of field data to improve connectivity maps. Barrier detection provides a different way to view the landscape, broadening thinking about connectivity and fragmentation while increasing conservation options

    Risk factors for dating violence versus cohabiting violence : results from the third generation of the Cambridge Study in Delinquent Development

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    BACKGROUND: Dating violence is an important problem. Evidence suggests that women are more likely to perpetrate dating violence. AIMS: The present study investigates the prevalence of dating violence compared with cohabiting violence in a community sample of men and women and assesses to what extent child and adolescent explanatory factors predict this behaviour. A secondary aim is to construct a risk score for dating violence based on the strongest risk factors. METHODS: The Cambridge Study in Delinquent Development is a prospective longitudinal survey of 411 men (generation 2) born in the 1950s in an inner London area. Most recently, their sons and daughters [generation 3 (G3)] have been interviewed regarding their perpetration of dating and cohabiting violence, utilising the Conflict Tactics Scale. Risk factors were measured in four domains (family, parental, socio-economic and individual). RESULTS: A larger proportion of women than men perpetrated at least one act of violence towards their dating partner (36.4 vs 21.7%). There was a similar pattern for cohabiting violence (39.6 vs 21.4%). A number of risk factors were significantly associated with the perpetration of dating violence. For G3 women, these included a convicted father, parental conflict, large family size and poor housing. For G3 men, these included having a young father or mother, separation from the father before age 16, early school leaving, frequent truancy and having a criminal conviction. A risk score for both men and women, based on 10 risk factors, significantly predicted dating violence. CONCLUSION: Risk factors from four domains were important in predicting dating violence, but they were different for G3 men and women. It may be important to consider different risk factors and different risk assessments for male compared with female perpetration of dating violence. Early identification and interventions are recommended
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