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mechanistic modeling system for estimating large-scale emissions and transport of pollen and co-allergens

Journal Articles & Books
Dezembro, 2011
Estados Unidos

Allergic airway diseases represent a complex health problem which can be exacerbated by the synergistic action of pollen particles and air pollutants such as ozone. Understanding human exposures to aeroallergens requires accurate estimates of the spatial distribution of airborne pollen levels as well as of various air pollutants at different times. However, currently there are no established methods for estimating allergenic pollen emissions and concentrations over large geographic areas such as the United States.

Modelling catchment hydrological responses in a Himalayan Lake as a function of changing land use and land cover

Journal Articles & Books
Dezembro, 2013

In this paper, we evaluate the impact of changing land use/land cover (LULC) on the hydrological processes in Dal lake catchment of Kashmir Himalayas by integrating remote sensing, simulation modelling and extensive field observations. Over the years, various anthropogenic pressures in the lake catchment have significantly altered the land system, impairing, inter-alia, sustained biotic communities and water quality of the lake.

Deforestation of montane cloud forest in the Central Highlands of Guatemala: contributing factors and implications for sustainability in Q’eqchi’ communities

Journal Articles & Books
Dezembro, 2015
Guatemala

Cloud forest in the Central Highlands of Guatemala provides important ecosystem services for the Q’eqchi’ Maya but has been disappearing at an increasing rate in recent decades. This research documents changes in cloud forest cover, explores some contributing factors to deforestation, and considers forest preservation and food security implications for Q’eqchi’ communities. We used a transdisciplinary framework that synthesized remote sensing/GIS analysis of land cover change, focus group dialogs, and surveys.

Toward understanding the behavior of carbon dioxide and surface energy fluxes in the urbanized semi-arid Salt Lake Valley, Utah, USA

Journal Articles & Books
Dezembro, 2011
Estados Unidos

This paper describes the Salt Lake Valley urban flux study that was designed to understand the role of vegetation and urbanization on CO₂ and surface energy fluxes over surfaces typical of urbanized and pre-urbanized land cover in the semi-arid Salt Lake Valley. The eddy covariance technique was applied at two different sites with distinct land forms within an urbanizing mountain basin.

Potential ecological distribution of Cytauxzoon felis in domestic cats in Oklahoma, Missouri, and Arkansas

Journal Articles & Books
Dezembro, 2013

The ecological distribution of Cytauxzoon felis, an often-fatal tick-borne apicomplexan that infects domestic cats, has not been evaluated or identified despite its continued emergence. Infection of C. felis is characterized by lethargy, icterus, fever, anorexia, anemia, and death. The natural vertebrate reservoir of C. felis is the bobcat (Lynx rufus). To determine the possible distribution of C. felis in three states where infection is common (Oklahoma, Missouri, and Arkansas), two separate approaches to ecological niche modeling were implemented.

approach for characterizing the distribution of shrubland ecosystem components as continuous fields as part of NLCD

Journal Articles & Books
Dezembro, 2013
Estados Unidos

Characterizing and quantifying distributions of shrubland ecosystem components is one of the major challenges for monitoring shrubland vegetation cover change across the United States. A new approach has been developed to quantify shrubland components as fractional products within National Land Cover Database (NLCD). This approach uses remote sensing data and regression tree models to estimate the fractional cover of shrubland ecosystem components.

Climatic and land cover influences on the spatiotemporal dynamics of Holocene boreal fire regimes

Journal Articles & Books
Dezembro, 2013
Estados Unidos

Although recent climatic warming has markedly increased fire activity in many biomes, this trend is spatially heterogeneous. Understanding the patterns and controls of this heterogeneity is important for anticipating future fire regime shifts at regional scales and for developing land management policies. To assess climatic and land cover controls on boreal forest fire regimes, we conducted macroscopic‐charcoal analysis of sediment cores and GIS analysis of landscape variation in south‐central Alaska, USA.

restricted range of the Ethiopian Bush-crow Zavattariornis stresemanni is a consequence of high reliance on modified habitats within narrow climatic limits

Journal Articles & Books
Dezembro, 2012
Etiópia
África

We attempt to describe and explain the peculiarly restricted distribution of the globally threatened Ethiopian Bush-crow Zavattariornis stresemanni. At a regional scale, models containing only correlates of land cover suggested a far wider distribution of suitable habitat in north-east Africa than the area actually occupied. However, models including only climate variables predicted the known distribution almost perfectly, and suggested that the species’ area of occupancy is delimited by a pocket of climate that is cooler, dryer and more seasonal than surrounding areas.

Drought vulnerability drives land-use and land cover changes in the Rift Valley dry lands of Ethiopia

Journal Articles & Books
Dezembro, 2013
Etiópia

The Ethiopian Rift Valley is a dry land zone where for a long time pastoral communities have made their living from acacia-based woodlands. But many pastoralists have changed from a pastoral way of life to mixed farming over time. The aim of this study was to evaluate land-use and land cover (LULC) changes in the Central Rift Valley dry lands of Ethiopia, and determine the role of drought vulnerability as a driver. A combination of GIS/remote sensing techniques, drought vulnerability analyses, field observation and surveying were employed.

Super-resolution mapping using Hopfield Neural Network with panchromatic imagery

Journal Articles & Books
Dezembro, 2011

Land-cover proportions of mixed pixels can be predicted using soft classification. From the land-cover proportions, a hard land-cover map can be predicted at sub-pixel spatial resolution using super-resolution mapping techniques. It has been demonstrated that the Hopfield Neural Network (HNN) provides a suitable method for super-resolution mapping. To increase the detail and accuracy of the sub-pixel land-cover map, supplementary information at an intermediate spatial resolution can be used.

Global albedo change and radiative cooling from anthropogenic land-cover change, 1700 to 2005 based on MODIS, land-use harmonization, radiative kernels and reanalysis

Journal Articles & Books
Dezembro, 2014
Global

Widespread anthropogenic land-cover change over the last five centuries has influenced the global climate system through both biogeochemical and biophysical processes. Models indicate that warming from carbon emissions associated with land cover conversion have been partially offset if not outweighed by cooling from elevated albedo, but considerable uncertainty remains partly because of uncertainty in model treatments of albedo.

Characteristics and landcover of estuarine boundaries: implications for the delineation of the South African estuarine functional zone

Journal Articles & Books
Dezembro, 2015
África do Sul
África austral

This study investigated whether the current lateral boundary for estuaries in South Africa, i.e. the estuarine functional zone (EFZ), includes all estuarine habitats. The EFZ covers 173 930 ha in 304 estuaries/outlets nationally. Field surveys and analysis of available aerial images showed that 82 (12 956.70 ha) of these estuaries (26%) had estuarine habitats occurring outside of this boundary. As a result of mapping scale, the National Vegetation Map does not represent habitats that are associated with small estuaries (approximately 50% of South Africa's estuaries).