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Agricultural landscape simplification and insecticide use in the Midwestern United States

Journal Articles & Books
Diciembre, 2011

Agronomic intensification has transformed many agricultural landscapes into expansive monocultures with little natural habitat. A pervasive concern is that such landscape simplification results in an increase in insect pest pressure, and thus an increased need for insecticides. We tested this hypothesis across a range of cropping systems in the Midwestern United States, using remotely sensed land cover data, data from a national census of farm management practices, and data from a regional crop pest monitoring network.

CN-Idris: An Idrisi tool for generating curve number maps and estimating direct runoff

Journal Articles & Books
Diciembre, 2011

This article presents a raster-based Geographic Information Systems (GIS) tool called CN-Idris that outputs runoff estimates from land use/land cover and hydrologic soil group maps based on the Natural Resources Conservation Service Curve Number method. The tool enables the user to select among three antecedent moisture conditions and two values of the initial abstraction (Iₐ) parameter, and it has the option to include spatial variation in rainfall input.

Building on qualitative datasets and participatory processes to simulate land use change in a mountain watershed of Northwest Vietnam

Journal Articles & Books
Diciembre, 2011

In this article we investigate if qualitative soil fertility datasets derived during participatory processes can be combined with a corresponding land use change model (i) to improve the understanding of the social-ecological complexity of land use change and (ii) to allow testing of alternative scenarios even in data-poor environments. To test this hypothesis, a participatory assessment approach was combined with the spatially explicit, soil fertility driven FALLOW (Forest, Agroforest, Low-value Landscape Or Wasteland?) model.

Weather and Land Cover Influences on Mosquito Populations in Sioux Falls, South Dakota

Journal Articles & Books
Diciembre, 2011

This study compared the spatial and temporal patterns of Culex tarsalis Coquillett and Aedes vexans Meigen populations and examined their relationships with land cover types and climatic variability in Sioux Falls, SD. Between 24 and 30 CDC CO2-baited light traps were set annually in Sioux Falls from May to September 2005–2008. Land cover data were acquired from the 2001 National Land Cover Dataset and the percentages of selected land cover types were calculated within a 600-m buffer zone around each trap. Meteorological information was summarized from local weather stations. Cx.

Land-cover classification in a moist tropical region of Brazil with Landsat Thematic Mapper imagery

Journal Articles & Books
Diciembre, 2011
Brasil

This research aims to improve land-cover classification accuracy in a moist tropical region in Brazil by examining the use of different remote-sensing-derived variables and classification algorithms. Different scenarios based on Landsat Thematic Mapper (TM) spectral data and derived vegetation indices and textural images and different classification algorithms, maximum likelihood classification (MLC), artificial neural network (ANN), classification tree analysis (CTA) and object-based classification (OBC), were explored.

Boosted decision tree classifications of land cover over Turkey integrating MODIS, climate and topographic data

Journal Articles & Books
Diciembre, 2011
Turquía

This study investigates the impact of using different combinations of Moderate Resolution Imaging Spectroradiometer (MODIS) and ancillary datasets on overall and per-class classification accuracies for nine land cover types modified from the classification system of the International Geosphere Biosphere Programme (IGBP).

Object-based urban detailed land cover classification with high spatial resolution IKONOS imagery

Journal Articles & Books
Diciembre, 2011
Estados Unidos de América

Improvement in remote sensing techniques in spatial/spectral resolution strengthens their applicability for urban environmental study. Unfortunately, high spatial resolution imagery also increases internal variability in land cover units and can cause a ‘salt-and-pepper’ effect, resulting in decreased accuracy using pixel-based classification results. Region-based classification techniques, using an image object (IO) rather than a pixel as a classification unit, appear to hold promise as a method for overcoming this problem.

Five years of carbon dioxide fluxes measurements in a highly vegetated suburban area

Journal Articles & Books
Diciembre, 2011
Estados Unidos de América

Suburban areas continue to grow rapidly and are potentially an important land-use category for anthropogenic carbon-dioxide (CO₂) emissions. Here eddy covariance techniques are used to obtain ecosystem-scale measurements of CO₂ fluxes (FC) from a suburban area of Baltimore, Maryland, USA (2002–2006). These are among the first multi-year measurements of FC in a suburban area. The study area is characterized by low population density (1500inhabitants km⁻²) and abundant vegetation (67.4% vegetation land-cover).

Using multi-scale modelling to predict habitat suitability for species of conservation concern: The grey long-eared bat as a case study

Journal Articles & Books
Diciembre, 2011

Although spatial scale is important for understanding ecological processes and guiding conservation planning, studies combining a range of scales are rare. Habitat suitability modelling has been used traditionally to study broad-scale patterns of species distribution but can also be applied to address conservation needs at finer scales. We studied the ability of presence-only species distribution modelling to predict patterns of habitat selection at broad and fine spatial scales for one of the rarest mammals in the UK, the grey long-eared bat (Plecotus austriacus).

Impacts of dam-regulated flows on channel morphology and riparian vegetation: a longitudinal analysis of Satsunai River, Japan

Journal Articles & Books
Diciembre, 2011
Japón

We examined the impacts of the Satsunai River Dam on the hydrology and development of riparian vegetation along the upper and lower reaches of the Satsunai River downstream from the dam. We estimated frequency curves of the flood discharge during the pre-dam (1976-1996) and post-dam (1997-2006) periods and simulated the flood frequency at sampling points within sites under pre-dam, post-dam and dam-removal (using the pre-dam flood discharge and post-dam cross-sections) scenarios. Changes in channel morphology and land cover were investigated by analyzing aerial photographs.

Developing effective sampling designs for monitoring natural resources in Alaskan national parks: An example using simulations and vegetation data

Journal Articles & Books
Diciembre, 2011

Monitoring natural resources in Alaskan national parks is challenging because of their remoteness, limited accessibility, and high sampling costs. We describe an iterative, three-phased process for developing sampling designs based on our efforts to establish a vegetation monitoring program in southwest Alaska. In the first phase, we defined a sampling frame based on land ownership and specific vegetated habitats within the park boundaries and used Path Distance analysis tools to create a GIS layer that delineated portions of each park that could be feasibly accessed for ground sampling.

Characterizing the error distribution of lidar elevation data for North Carolina

Journal Articles & Books
Diciembre, 2011

Spatial data quality is a paramount concern in all geographical information systems (GIS) applications. Existing standards and guidelines for spatial data commonly assume the positional error is normally distributed. While non-normal behaviour of the error in digital elevation data has been observed in previous research, current guidelines for digital elevation data still assume that the errors for observations in open terrain are normally distributed.