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

Journal Articles & Books
Dezembro, 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
Dezembro, 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
Dezembro, 2011
Estados Unidos

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
Dezembro, 2011
Suécia

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
Dezembro, 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
Dezembro, 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.

Monitoring the status of forests and rangelands in the Western United States using ecosystem performance anomalies

Journal Articles & Books
Dezembro, 2013
Estados Unidos

The effects of land management and disturbance on ecosystem performance (i.e. biomass production) are often confounded by those of weather and site potential. The current study overcomes this issue by calculating the difference between actual and expected ecosystem performance (EEP) to generate ecosystem performance anomalies (EPA). This study aims to delineate and quantify average EPA from 2000–2009 within the Greater Platte and Upper Colorado River Basins, USA.

Cross-evaluation of measurements of peatland methane emissions on microform and ecosystem scales using high-resolution landcover classification and source weight modelling

Journal Articles & Books
Dezembro, 2011

The methane exchange in an oligotrophic mire complex was measured on the ecosystem and microform scale with the eddy covariance (EC) and the closed chamber technique, respectively. Information about the distribution of three distinct microform types in the area of interest and in each 30min EC flux source area was derived from a high-resolution (1m²) landcover map in combination with an analytical source weight model (Kormann and Meixner, 2001).

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
Dezembro, 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
Dezembro, 2007
Mali

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
Dezembro, 2011
Japão

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
Dezembro, 2014
Alemanha

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.