Aller au contenu principal

page search

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

AGROVOC URI:

Displaying 85 - 96 of 1964

ecological condition of geographically isolated wetlands in the southeastern United States: The relationship between landscape level assessments and macrophyte assemblages

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

Geographically isolated wetlands (GIWs) are common features of the Dougherty Plain physiographic region in southwestern Georgia. Due to lack of protection at the state and federal levels, these wetlands are threatened by intensive agricultural and silvicultural land uses common in the region.

automated approach for updating land cover maps based on integrated change detection and classification methods

Journal Articles & Books
Décembre, 2012

Updating land cover maps from remotely sensed data in a timely manner is important for many areas of scientific research. Unfortunately, traditional classification procedures are very labor intensive and subjective because of the required human interaction. Based on the strategy of updating land cover data only for the changed area, we proposed an integrated, automated approach to update land cover maps without human interaction.

Variations of urban greenness across urban structural units in Beijing, China

Journal Articles & Books
Décembre, 2013
Chine

Urban structural units (USUs) are work (or similar) units in urbanized areas. In this study, USUs based on urban land use and land cover were used to explain and compare urban ecological conditions within Beijing. This study focused on the spatial pattern of land use for different USUs in urban areas. The results showed that 453 USUs belong to 12 primary USUs and to 38 different secondary USUs. The percentage of built-up area was highest in those regions with hotels, and lowest in areas with cemeteries.

High-resolution satellite remote sensing: a new frontier for biodiversity exploration in Indian Himalayan forests

Journal Articles & Books
Décembre, 2013

Satellite imagery with fine spectral and spatial resolution and high temporal resolution provides a unique opportunity to map and monitor biodiversity. The aim of this article is (i) to review the state of the use of high-resolution remote sensing for ecological studies in the Indian Himalayan Region (IHR) and (ii) to suggest further potential avenues of research in the region using this technology.

Potential of polarimetric Radarsat-2 data in geological mapping – a case study in parts of Dharwar craton, India

Journal Articles & Books
Décembre, 2013
Inde

Polarimetry is a technique for quantitatively estimating the change in polarization in a backscattered electromagnetic signal (in this case a radar signal) with reference to the polarization of the incident signal for estimating the geophysical properties (roughness and dielectric constant) of surface elements. In this study, quadrapole Radarsat-2 data have been utilized for mapping geological elements in Archaean terrain based on their geophysical parameters preserved in the four polarization channels of Radarsat-2 data.

Pre-processing of TerraSAR-X Data for Speckle Removal: An Approach for Performance Evaluation

Journal Articles & Books
Décembre, 2012

Measures to select despeckling filter to remove speckles from TerraSAR-X image have been evaluated for an area having varied land cover classes. Gamma, Lee, Sigma, Mean, Median and Frost filters were applied in different window sizes. These images are visually compared and four parameters viz. Noise Mean Value (NMV), Noise Variance (NV), Mean Square Difference (MSD) and Equivalent Numbers of Looks (ENL) are calculated.

Space and time dynamics of urban water demand in Portland, Oregon and Phoenix, Arizona

Journal Articles & Books
Décembre, 2015

Critical to effective urban climate adaptation is a clearer understanding of the sensitivities of resource demand to changing climatic conditions and land cover situations. We used Bayesian Maximum Entropy (BME) stochastic procedures to estimate temperature and precipitation at the very small scale of urban Census Block Groups (CBGs) in Phoenix, Arizona and Portland, Oregon, and then compared average household water use patterns by climate conditions and land cover characteristics between and within the two cities.

Land-use land-cover change and ecosystem loss in the Espinal ecoregion, Argentina

Journal Articles & Books
Décembre, 2013
Argentine

Land-use land-cover (LULC) changes are one of the major threats to biodiversity worldwide, since their principal consequences are the loss, fragmentation or degradation of the habitat available for most species. Therefore, in order to provide guidelines for environmental management at the regional scale and thus reverse the trend in degradation, transformations of natural remnants into anthropogenic land uses must be identified and quantified.

Radar analysis of fall bird migration stopover sites in the northeastern U.S

Journal Articles & Books
Décembre, 2014

The national network of weather surveillance radars (WSR-88D) detects flying birds and is a useful remote-sensing tool for ornithological study. We used data collected during fall 2008 and 2009 by 16 WSR-88D radars in the northeastern U.S. to quantify the spatial distribution of landbirds during migratory stopover. We geo-referenced estimates based on radar reflectivity, of the density of migrants aloft at their abrupt evening exodus from daytime stopover sites, to the approximate locations from which they emerged.

Unsupervised and supervised classification of hyperspectral imaging data using projection pursuit and Markov random field segmentation

Journal Articles & Books
Décembre, 2012

This work presents a classification technique for hyperspectral image analysis when concurrent ground truth is either unavailable or available. The method adopts a principal component analysis (PCA)-based projection pursuit (PP) procedure with an entropy index for dimensionality reduction, followed by a Markov random field (MRF) model-based segmentation. An ordinal optimization approach to PP determines a set of ‘good enough projections’ with high probability, the best among which is chosen with the help of MRF model-based segmentation.

Agricultural expansion: land use shell game in the U.S. Northern Plains

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

Land area planted to row crops has expanded globally with increased demand for food and biofuels. Agricultural expansion in the Dakota Prairie Pothole Region (DPPR), USA affects a variety of agricultural and non-agricultural land-use types, including grasslands and wetlands that provide critical wildlife habitat and other ecosystem services. The purpose of this study was to quantify recent changes in rural land cover/land use, analyze trends, and interpret results in relation to climate, agronomic practice, and ethanol production.

Relationships between land cover and the surface urban heat island: seasonal variability and effects of spatial and thematic resolution of land cover data on predicting land surface temperatures

Journal Articles & Books
Décembre, 2014

We investigated the seasonal variability of the relationships between land surface temperature (LST) and land use/land cover (LULC) variables, and how the spatial and thematic resolutions of LULC variables affect these relationships. We derived LST data from Landsat-7 Enhanced Thematic Mapper (ETM+) images acquired from four different seasons.