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There are 2, 238 content items of different types and languages related to couverture du sol on the Land Portal.

couverture du sol

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Conservation of Forest Birds: Evidence of a Shifting Baseline in Community Structure

Journal Articles & Books
Décembre, 2010
États-Unis d'Amérique

Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance.

Image simulation from multitemporal landsat images

Journal Articles & Books
Décembre, 2015

Multitemporal datasets can provide information on the different acquisition patterns of pixel values. The resultant generation of simulated images based on these patterns becomes practical and easy. In this paper, we propose a simple model for creating a simulated image based on a set of multitemporal satellite images and meteorological data utilizing a temporal correlation of multitemporal images. The satellite images and meteorological data used for the model can be easily accessed through open data sources.

Environmental suitability of a highly fragmented and heterogeneous landscape for forest bird species in south-eastern Brazil

Journal Articles & Books
Décembre, 2012
Brésil

Assessment of the suitability of anthropogenic landscapes for wildlife species is crucial for setting priorities for biodiversity conservation. This study aimed to analyse the environmental suitability of a highly fragmented region of the Brazilian Atlantic Forest, one of the world's 25 recognized biodiversity hotspots, for forest bird species. Eight forest bird species were selected for the analyses, based on point counts (n = 122) conducted in April–September 2006 and January–March 2009.

Land-cover data improve bioclimatic models for anurans and turtles at a regional scale

Journal Articles & Books
Décembre, 2009
Canada

We investigated whether accounting for land cover could improve bioclimatic models for eight species of anurans and three species of turtles at a regional scale. We then tested whether accounting for spatial autocorrelation could significantly improve bioclimatic models after statistically controlling for the effects of land cover. Nova Scotia, eastern Canada. Species distribution data were taken from a recent (1999-2003) herpetofaunal atlas. Generalized linear models were used to relate the presence or absence of each species to climate and land-cover variables at a 10-km resolution.

Effect of catchment properties on runoff coefficient in a karst area of southwest China

Journal Articles & Books
Décembre, 2014
Chine

Frequent human activities and climate change in the karst region of southwest China since the 1950s have led to the investigation of response of runoff to climate and catchment properties. Runoff coefficient (Rc) as an expression variable of the catchment response to rainfall is important to describe runoff dynamics and to estimate available streamflow for utilization. In this study, the equations of Rc associated with its attributors of climate condition and catchment property were derived using the Budyko framework.

Modeling the radiation balance of different urban underlying surfaces

Journal Articles & Books
Décembre, 2012

An urban net all-wave radiation parameterization scheme is evaluated using annual datasets for 2010 recorded at a Beijing urban observation site. The statistical relationship between observed data and simulation data of net radiation has a correlation coefficient of 0.98 and model efficiency of 0.93. Therefore, it can be used to simulate the radiation balance of Beijing. This study analyzes the variation in the radiation balance for different underlying surfaces. To simulate radiation balance differences, we set four pure land-cover types (forest, grass, roads, and buildings).

Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

Journal Articles & Books
Décembre, 2011

This study has analyzed the global nitrogen loading of rivers resulting from atmospheric deposition, direct discharge, and nitrogenous compounds generated by residential, industrial, and agricultural sources. Fertilizer use, population distribution, land cover, and social census data were used in this study. A terrestrial nitrogen cycle model with a 24-h time step and 0.5° spatial resolution was developed to estimate nitrogen leaching from soil layers in farmlands, grasslands, and natural lands.

Multi-scale land cover dynamics of semiarid scrubland in Baja California, Mexico

Journal Articles & Books
Décembre, 2014
Mexique

Land use and cover changes trigger multi-factorial responses with tangible and intangible effects. Driving forces governing changes are scale-, place- and time-dependent; because of their complexity, a multi-scalar analysis is required to determine conjoint causation. Studies using multi-scalar approach in semiarid scrubland ecosystems are scanty. This paper investigates land use changes on the largest semiarid scrubland ecosystem of Mexico, the Baja California Peninsula, using a multi-scalar analysis approach.

Carbon dioxide exchange of a Sitka spruce plantation in Scotland over five years

Journal Articles & Books
Décembre, 2012

Scotland's 17% forested land cover sequesters 10% of Scotland's emissions of greenhouse gases. The expected rise of forested land cover to 25% by the middle of this century make forests an important component of the national carbon budget. This paper presents the carbon exchange measurement methodology, results, and modeling associated with a five-year experiment at a plantation forest in Scotland, UK, as part of a European initiative to develop and verify vegetation carbon-exchange models. We have developed a site specific correction for advective flux loses.

Acacia nilotica-based silvipastoral systems for resource conservation and improved productivity from degraded lands of the Lower Himalayas

Journal Articles & Books
Décembre, 2014
Inde

High population density and unscientific land use practices have induced severe land degradation in the fragile Lower Himalayan ecosystem of India. Land cover management has been an effective strategy in managing land degradation through the reduction of water, soil and nutrient losses and improvement in soil fertility and quality.

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

Journal Articles & Books
Décembre, 2011
États-Unis d'Amérique

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.