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Issuesutilisation des terresLandLibrary Resource
There are 9, 839 content items of different types and languages related to utilisation des terres on the Land Portal.
Displaying 1933 - 1944 of 4598

Land-use and land-cover change detection in a semi-arid area of Niger using multi-temporal analysis of Landsat images

Journal Articles & Books
Décembre, 2013
Niger
Afrique occidentale

Recent studies using low-resolution satellite time series show that the Sahelian belt of West Africa is witnessing an increase in vegetation cover/biomass, called re-greening. However, detailed information on local processing and changes is rare or lacking. A multi-temporal set of Landsat images was used to produce land-cover maps for the years 2000 and 2007 in a semi-arid region of Niger, where an anomalous vegetation trend was previously detected.

Influence of vegetal cover and time of placing in acorns germination in a dehesa

Conference Papers & Reports
Décembre, 2005
Espagne

The natural regeneration in the dehesa has been object of numerous studies, due to the ecologic and economic importance of such ecosystems. In this work is exposed a test of acorns germination of Quercus ilex L. subsp. ballota (Desf.) Samp, in the North of Córdoba (Spain), under three environmental conditions corresponding to the most traditional land uses of the dehesa: grazing, cereal sowing and fallow, each one with a different vegetal cover. A fourth group of acorns was placed in a tree nursery under controlled conditions.

Feature extraction for high-resolution imagery based on human visual perception

Journal Articles & Books
Décembre, 2013

Feature extraction is highly important for classification of remote-sensing (RS) images. However, extraction of comprehensive spatial features from high-resolution imagery is still challenging, leading to many misclassifications in various applications. To address the problem, a shape-adaptive neighbourhood (SAN) technique is presented based on human visual perception. The SAN technique is an adaptive feature-extraction method that not only considers spectral feature information but also the spatial neighbourhood as well as the shape of features.

Changes in the fragmentation and ecological stability of the Morava River floodplain forest in the course of the 20th century

Policy Papers & Briefs
Mars, 2009
République tchèque

This paper presents the results of an analysis of the changes in the fragmentation and ecological stability of the floodplain forest geobiocoenoses in the Protected Landscape Area Litovelske Pomoravi, Czech Republic. Using GIS methods, it was determined that the fragmentation within the study area had increased slightly and the ecological stability of the landscape had decreased slightly between the years 1938 and 2006, although the latter remained on a fairly high level.

ecological footprint housing component: A geographic information system analysis

Journal Articles & Books
Décembre, 2012

The ecological footprint (EF) and its unit, the global hectare, share a reputation of effectively communicating the connection between local awareness and global impact. One use of a Geographic Information System (GIS) in urban planning is decision support, while the potential of the ecological footprint in GIS has not developed significantly. The smaller the spatial unit in GIS, the more accurate and flexible are the available GIS analyses.

Plant-livestock-soil-hydrology interactions in the northeastern region of India

Journal Articles & Books
Décembre, 2009
Inde

In a multidisciplinary study, highly significant interactional effects were found among land use, livestock component, soil properties and rainfall. On an average, 16.2 to 82.2 tonnes of sediment yield km−2 and more than 90% of rainwater was retained in-situ in new land use systems as against 3621.3 tonnes of sediment and 66.3% rainwater retention in shifting cultivation, because of poor land cover. Good vegetation cover reduced the runoff load, resulting in significant reduction in the soil and nutrient erosion.

Resolving large‐scale pressures on species and ecosystems: propensity modelling identifies agricultural effects on streams

Journal Articles & Books
Décembre, 2016

Although agriculture is amongst the world's most widespread land uses, studies of its effects on stream ecosystems are often limited in spatial extent. National monitoring data could extend spatial coverage and increase statistical power, but present analytical challenges where covarying environmental variables confound relationships of interest. Propensity modelling is used widely outside ecology to control for confounding variables in observational data.

Development of a Watershed‐Based Geospatial Groundwater Specific Vulnerability Assessment Tool

Journal Articles & Books
Décembre, 2014
Géorgie

This study assesses and characterizes the vulnerability of unregulated groundwater systems to microbial contamination in 18 counties in the state of Georgia using a contamination risk screening strategy based on watershed characteristics and elements of the Safe Drinking Water Act's Wellhead Protection program. Environmental data sources analyzed include septic systems, elevation, land use and land cover data, soil, vegetation coverage, demographics, and livestock.

Rapid assessment of historic, current and future habitat quality for biodiversity around UK Natura 2000 sites

Journal Articles & Books
Décembre, 2015

Changes in landscape composition and structure may impact the conservation and management of protected areas. Species that depend on specific habitats are at risk of extinction when these habitats are degraded or lost. Designing robust methods to evaluate landscape composition will assist decision- and policy-making in emerging landscapes. This paper describes a rapid assessment methodology aimed at evaluating land-cover quality for birds, plants, butterflies and bees around seven UK Natura 2000 sites.