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There are 2, 240 content items of different types and languages related to cobertura de suelos on the Land Portal.

cobertura de suelos

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Plant nitrogen concentration and isotopic composition in residential lawns across seven US cities

Journal Articles & Books
Diciembre, 2016

Human drivers are often proposed to be stronger than biophysical drivers in influencing ecosystem structure and function in highly urbanized areas. In residential land cover, private yards are influenced by individual homeowner preferences and actions while also experiencing large-scale human and biophysical drivers. We studied plant nitrogen (%N) and N stable isotopic composition (δ¹⁵N) in residential yards and paired native ecosystems in seven cities across the US that span major ecological biomes and climatic regions: Baltimore, Boston, Los Angeles, Miami, Minneapolis-St.

importance of wetlands in the energy balance of an agricultural landscape

Journal Articles & Books
Diciembre, 2014

Energy fluxes, including net radiation, latent heat flux and sensible heat flux were determined on clear days during the vegetative period in four types of land cover: wet meadow, pasture, arable field, and an artificial concrete surface. The average net radiation ranged between 123� W� m⁻² at the concrete surface and 164� W� m⁻² at the wet meadow. The mean maximum daytime latent heat ranged between 500 and 600� W� m⁻², which corresponds to an evapotranspiration rate of about 0.2� g� m⁻²� s⁻¹ under the prevailing conditions of the wet meadow.

Spatial and seasonal variations of polycyclic aromatic hydrocarbons in Haihe Plain, China

Journal Articles & Books
Diciembre, 2011
China

A dynamic fugacity model was developed to simulate the spatial and seasonal variations of PAHs in Haihe Plain, China. The calculated and measured concentrations exhibited good consistency in magnitude with deviations within a factor of 4 in air and 2 in soil. The spatial distributions of PAHs in air were mainly controlled by emission while the seasonal variations were dominated by emission and gas–particle partition. In soil, the spatial distributions of PAHs were controlled by the soil organic carbon content while the seasonal variations were insignificant.

Efficiency and Accuracy of Wildland Weed Mapping Methods

Journal Articles & Books
Diciembre, 2011

Land managers must set weed management priorities if limited resources are to be utilized effectively. Weed surveys and inventories assist land managers in this process by providing information regarding the identity, location, and relative abundance of weeds on their land. Although this information is vital, it can be challenging to select a method that provides the necessary data to meet management objectives while remaining accurate and cost effective. This paper critically evaluates four wildland weed mapping methods.

influence of watershed characteristics on nitrogen export to and marine fate in Hood Canal, Washington, USA

Journal Articles & Books
Diciembre, 2011
Estados Unidos de América

Hood Canal, Washington, USA, is a poorly ventilated fjord-like sub-basin of Puget Sound that commonly experiences hypoxia. This study examined the influence of watershed soils, vegetation, physical features, and population density on nitrogen (N) export to Hood Canal from 43 tributaries. We also linked our watershed study to the estuary using a salinity mass balance model that calculated the relative magnitude of N loading to Hood Canal from watershed, direct precipitation, and marine sources.

National Inventory of Landscapes in Sweden (NILS)--scope, design, and experiences from establishing a multiscale biodiversity monitoring system

Journal Articles & Books
Diciembre, 2011
Suecia

The landscape-level and multiscale biodiversity monitoring program National Inventory of Landscapes in Sweden (NILS) was launched in 2003. NILS is conducted as a sample-based stratified inventory that acquires data across several spatial scales, which is accomplished by combining aerial photo interpretation with field inventory. A total of 631 sample units are distributed across the land base of Sweden, of which 20% are surveyed each year. By 2007 NILS completed the first 5-year inventory phase.

Incorporating the uncertainty of linguistic-scale reference data to assess accuracy of land-cover maps using fuzzy intervals

Journal Articles & Books
Diciembre, 2013

The reference classifications that serve as the fundamental basis of accuracy assessment of land-cover maps are subject to uncertainty. A fuzzy interval approach is proposed in which linguistic-scale labels assigned to each land-cover class at each sample observation are converted to fuzzy intervals. These fuzzy intervals are then used to produce a fuzzy confusion matrix from which fuzzy thematic accuracy measures analogous to overall, user's, and producer's accuracy are produced.

Improved Band Selection Technique for Hyperspectral Data Using Factor Analysis

Journal Articles & Books
Diciembre, 2013

This paper discusses a statistical and band transformation based approach to select bands for hyperspectral image analysis. Hyperspectral images contain large number of spectral bands with redundant information about the spectral classes in the image scene. It is necessary to reduce the high dimensionality of the data for the processing of hyperspectral data. We report a feature selection technique that removes correlated spectral bands using band decorrelation technique and obtains maximum variance image bands based on factor analysis.

Testing the effect of site selection and parameter setting on REVEALS-model estimates of plant abundance using the Czech Quaternary Palynological Database

Journal Articles & Books
Diciembre, 2012
República Checa

REVEALS-based quantitative reconstruction of Holocene vegetation cover (expressed in plant functional types, PFTs) is used in the LANDCLIM project to assess the effect of human-induced land-cover change on past climate in NW Europe. Using the Czech Quaternary Pollen Database, this case study evaluates the extent to which selection of data and input parameters for the REVEALS model applications would affect reconstruction outcomes.

Tracking environmental dynamics and agricultural intensification in southern Mali

Journal Articles & Books
Diciembre, 2007
Malí

The Office de la Haute Vallée du Fleuve Niger (OHVN) zone in southern Mali is a small but important agricultural production region. Against a background of environmental degradation including decades of declining rainfall, soil erosion, and human pressure on forest resources, numerous farming communities stand out through the use of improved soil and water management practices that have improved agricultural and environmental conditions. Field surveys conducted in 1998-2001 indicated that environmental and agricultural conditions have improved in the past decade.

Evaluations of seasonal habitat variations of freshwater fishes, fireflies, and frogs using a habitat suitability index model that includes river water temperature

Journal Articles & Books
Diciembre, 2011
Japón

The habitats of aquatic organisms, including freshwater fishes (Oncorhynchus masou masou, Plecoglossus altivelis altivel, and Cyprinus carpio), fireflies (Luciola cruciata and Luciola lateralis), and frogs (Anura sp.), were evaluated dynamically in the Natori River basin in the central Miyagi prefecture in Japan using water temperature as an environmental index.

Sampling for landscape elements—a case study from Lower Saxony, Germany

Journal Articles & Books
Diciembre, 2014
Alemania

The estimation of coverage, i.e., the proportion of the total area in a study region covered by a given target class, is essential to many aspects of environmental monitoring. We analyze and compare the efficiency of different sample-based approaches for the estimation of coverage of different land cover classes from aerial imagery in a case study in Lower Saxony, Germany on the basis of the estimated standard errors.