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Issuescouverture du solLandLibrary Resource
There are 2, 240 content items of different types and languages related to couverture du sol on the Land Portal.

couverture du sol

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Mapping changes to vegetation pattern in a restoring wetland: Finding pattern metrics that are consistent across spatial scale and time

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

Tidal salt marshes in the San Francisco Estuary region display heterogeneous vegetation patterns that influence wetland function and provide adequate habitat for native or endangered wildlife. In addition to analyzing the extent of vegetation, monitoring the dynamics of vegetation pattern within restoring wetlands can offer valuable information about the restoration process.

Analysis of historic changes in regional ecosystem service provisioning using land use data

Journal Articles & Books
Décembre, 2011
Allemagne

Land use change has a major impact on goods and services that our environment supplies for society. While detailed ecological or biophysical field studies are needed to quantify the exact amount of ecosystem service supply at local scales, such a monitoring might be unfeasible at the regional scale. Since field scale monitoring schemes for ecosystem services or ecosystem functioning are missing, proxy based indicators can help to assess the historic development of ecosystem services or ecosystem functioning at the regional scale.

hybrid method combining pixel-based and object-oriented methods and its application in Hungary using Chinese HJ-1 satellite images

Journal Articles & Books
Décembre, 2013
Hongrie

Pixel-based and object-oriented processing of Chinese HJ-1-A satellite imagery (resolution 30 m) acquired on 23 July 2009 were utilized for classification of a study area in Budapest, Hungary. The pixel-based method (maximum likelihood classifier for pixel-level method (MLCPL)) and two object-oriented methods (maximum likelihood classifier for object-level method (MLCOL) and a hybrid method combining image segmentation with the use of a maximum likelihood classifier at the pixel level (MLCPL)) were compared. An extension of the watershed segmentation method was used in this article.

Land use Dynamics and Landscape Patterns in Shanghai, Jiangsu and Zhejiang

Journal Articles & Books
Décembre, 2013

Land use change and landscape patterns have a large effect on land productivity and ecosystem biodiversity. Based on geographical information system technology and remote sensing data related to land use and land cover of Jiangsu and Zhejiang provinces and Shanghai (Jiang-Zhe-Hu area), we analyzed patterns of landscape change and predicted land use dynamics using the CA-MARKOV model. We also analyzed the conversion rate and area among landscape classes using the CA-Markov model.

Applying land use regression model to estimate spatial variation of PM2.5 in Beijing, China

Journal Articles & Books
Décembre, 2015
Chine

Fine particulate matter (PM₂.₅) is the major air pollutant in Beijing, posing serious threats to human health. Land use regression (LUR) has been widely used in predicting spatiotemporal variation of ambient air-pollutant concentrations, though restricted to the European and North American context. We aimed to estimate spatiotemporal variations of PM₂.₅by building separate LUR models in Beijing. Hourly routine PM₂.₅measurements were collected at 35 sites from 4th March 2013 to 5th March 2014.

Coastal wetland vegetation classification with a Landsat Thematic Mapper image

Journal Articles & Books
Décembre, 2011

Coastal wetland vegetation classification with remotely sensed data has attracted increased attention but remains a challenge. This paper explored a hybrid approach on a Landsat Thematic Mapper (TM) image for classifying coastal wetland vegetation classes. Linear spectral mixture analysis was used to unmix the TM image into four fraction images, which were used for classifying major land covers with a thresholding technique. The spectral signatures of each land cover were extracted separately and then classified into clusters with the unsupervised classification method.

Epistemic uncertainty in predicting shorebird biogeography affected by sea-level rise

Journal Articles & Books
Décembre, 2012

Accurate spatio-temporal predictions of land-cover are fundamentally important for assessing geomorphological and ecological patterns and processes. This study quantifies the epistemic uncertainty in the species distribution modeling, which is generated by spatio-temporal gaps between the biogeographical data, model selection and model complexity. Epistemic uncertainty is generally given by the sum of subjective and objective uncertainty. The subjective uncertainty generated by the modeler-choice in the manipulation of the environmental variables was analyzed.

relationship between precipitation anomalies and satellite-derived vegetation activity in Central Asia

Journal Articles & Books
Décembre, 2013
Asie central

In Central Asia, water is a particularly scarce and valuable good. In many ecosystems of this region, the vegetation development during the growing season is dependent on water provided by rainfall. With climate change, alterations of the seasonal distribution of precipitation patterns and a higher frequency of extreme events are expected. Vegetation dynamics are likely to respond to these changes and thus ecosystem services will be affected.

Mammal defaunation as surrogate of trophic cascades in a biodiversity hotspot

Journal Articles & Books
Décembre, 2013

Preserving large tracts of natural habitats is essential to maintain biodiversity. Nevertheless, even large areas may still suffer from less “visible” impacts such as loss of ecological processes. Because mapping ecological processes over large scales is not practical, an alternative is to map surrogate species that are key for those processes.

integrative model of human-influenced fire regimes and landscape dynamics

Journal Articles & Books
Décembre, 2011

Fire regimes depend on climate, vegetation structure and human influences. Climate determines the water content in fuel and, in the longer term, the amount of biomass. Humans alter fire regimes through increased ignition frequency and by hindering the spread of fire through fire suppression and fuel fragmentation. Here, we present FIRE LADY (FIre REgime and LAndscape DYnamics), a spatially explicit fire regime model that takes into account daily weather data, topography, vegetation growth, fire behaviour, fire suppression and land use changes.

Land-cover change effects on trophic interactions: Current knowledge and future challenges in research and conservation

Journal Articles & Books
Décembre, 2013

Understanding the effects of land-cover alterations on ecosystem functioning has become a major challenge in ecological research during the last decade. This has stimulated a rapid growth in research investigating the links between land-cover change and biotic interactions, but to date no study has evaluated the progress towards achieving this scientific goal.