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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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Monitoring dynamic changes of global land cover types: fluctuations of major lakes in China every 8� days during 2000–2010

Journal Articles & Books
Décembre, 2014
Chine

Remote sensing images can be used to delineate variations in the area of lakes and to assess the influence of environmental changes and human activities. However, because lakes are dynamic, results obtained from individual images acquired on a single date are not representative and do not accurately reflect ongoing changes. In this study, we used 8-day moderate resolution imaging spectroradiometer (MODIS) composite data from 2000 to 2010 to map water surface changes over 629 lakes in China.

Remote sensing of land-use change for Kyoto Protocol reporting: the New Zealand case

Journal Articles & Books
Décembre, 2012
Nouvelle-Zélande

It is necessary to estimate the area of afforestation and deforestation in New Zealand, since 1990, to meet reporting obligations under the Kyoto Protocol. We describe a method for national mapping of forest change that achieves high accuracy, but only requires moderate effort. A national coverage of satellite imagery is standardised, classified (automatically) for land cover, and then compared with an existing 1990 land-use map to identify polygons (>1ha) of possible forest change. Each one of these possible change polygons is checked by operators for actual or spurious change.

Raptor Presence Along an Urban–Wildland Gradient: Influences of Prey Abundance and Land Cover

Journal Articles & Books
Décembre, 2014

Native animals are affected differently by urbanization. Some species respond favorably and thrive in human-dominated landscapes, but others are extirpated. Raptors are often sensitive to changes in land cover and prey abundance. We therefore used a combination of broadcast surveys and incidental observations while spot-mapping to evaluate the influences of these two variables on the presence of raptors at 21 sites from 2004–2008 along an urban-to-wildland gradient in western Washington, U.S.A.

Understanding Human–Coyote Encounters in Urban Ecosystems Using Citizen Science Data: What Do Socioeconomics Tell Us?

Journal Articles & Books
Décembre, 2015
États-Unis d'Amérique

The coyote (Canis latrans) has dramatically expanded its range to include the cities and suburbs of the western US and those of the Eastern Seaboard. Highly adaptable, this newcomer’s success causes conflicts with residents, necessitating research to understand the distribution of coyotes in urban landscapes. Citizen science can be a powerful approach toward this aim.

Distribution, Morphometry, and Land Use of Delmarva Bays

Journal Articles & Books
Décembre, 2014
États-Unis d'Amérique

Delmarva Bays are depressional wetlands that are elliptical in shape with sandy rims, and occur mainly in the central portion of the Delmarva Peninsula within the Mid- Atlantic United States. Situated in a region with abundant agriculture, Delmarva Bays and other wetlands may enhance water quality by reducing nutrient and sediment levels in local waters. A significant portion have been drained and converted from forested wetlands to agriculture.

effect of forest fire on mass movement in Lebanese mountainous areas

Journal Articles & Books
Décembre, 2014
Liban

Mass movements are major hazards that threaten natural and human environments. In Lebanon, the occurrence of mass movements increased by almost 60% between 1956 and 2008. Forest fire has emerged as an additional hazard: it destroyed over 25% of Lebanon’s forests in a period less than 40 years. This paper investigates the potential effect of forest fire on the occurrence of mass movements in the Damour and Nahr Ibrahim watersheds of Lebanon. Mass movement and forest fire inventory maps were produced through remote sensing using aerial and satellite images.

Examining the occurrence of mammal species in natural areas within a rapidly urbanizing region of Texas, USA

Journal Articles & Books
Décembre, 2016
États-Unis d'Amérique

In much of the United States and elsewhere, urbanization continues to transform landscapes. In central Texas, anthropogenic conversion of land is due in part to a rapidly growing population in the Austin and San Antonio metro areas and the subsequent infrastructure and resources needed to support that growth. Protected natural areas adjacent to urbanized landscapes are often intended to mitigate the impact of land development by serving as wildlife habitat.

Evaluating weather effects on interannual variation in net ecosystem productivity of a coastal temperate forest landscape: A model intercomparison

Journal Articles & Books
Décembre, 2011
Canada

Forest productivity is strongly affected by seasonal weather patterns and by natural or anthropogenic disturbances. However weather effects on forest productivity are not currently represented in inventory-based models such as CBM-CFS3 used in national forest C accounting programs. To evaluate different approaches to modelling these effects, a model intercomparison was conducted among CBM-CFS3 and four process models (ecosys, CN-CLASS, Can-IBIS and 3PG) over a 2500ha landscape in the Oyster River (OR) area of British Columbia, Canada.

Risk assessment of water soil erosion in upper basin of Miyun Reservoir, Beijing, China

Journal Articles & Books
Décembre, 2009
Chine

This research selected water soil erosion indicators (land cover, vegetation cover, slope) to assess the risk of soil erosion, ARCMAP GIS ver.9.0 environments and ERDAS ver.9.0 were used to manage and process satellite images and thematic tabular data. Landsat TM images in 2003 were used to produce land/cover maps of the study area based on visual interpreting method and derived vegetation cover maps, and the relief map at the scale of 1:50,000 to calculate the slope gradient maps.

Comparison of support vector machine, neural network, and CART algorithms for the land-cover classification using limited training data points

Journal Articles & Books
Décembre, 2012

Support vector machine (SVM) was applied for land-cover characterization using MODIS time-series data. Classification performance was examined with respect to training sample size, sample variability, and landscape homogeneity (purity). The results were compared to two conventional nonparametric image classification algorithms: multilayer perceptron neural networks (NN) and classification and regression trees (CART).

Time–space radiometric normalization of TM/ETM+ images for land cover change detection

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

A novel approach to image radiometric normalization for change detection is presented. The approach referred to as stratified relative radiometric normalization (SRRN) uses a time-series of imagery to stratify the landscape for localized radiometric normalization. The goal is to improve the detection accuracy of abrupt land cover changes (human-induced, natural disaster, etc.) while decreasing false detection of natural vegetation changes that are not of interest. These vegetation changes may be associated with such phenomena as phenology, growth and stress (e.g.

Multi-scale object-based image analysis and feature selection of multi-sensor earth observation imagery using random forests

Journal Articles & Books
Décembre, 2012

The random forest (RF) classifier is a relatively new machine learning algorithm that can handle data sets with large numbers and types of variables. Multi-scale object-based image analysis (MOBIA) can generate dozens, and sometimes hundreds, of variables used to classify earth observation (EO) imagery. In this study, a MOBIA approach is used to classify the land cover in an area undergoing intensive agricultural development. The information derived from the elevation data and imagery from two EO satellites are classified using the RF algorithm.