Skip to main content

page search

Issuesland coverLandLibrary Resource
There are 2, 240 content items of different types and languages related to land cover on the Land Portal.
Displaying 1645 - 1656 of 2218

Genetic isolation of endangered bird populations inhabiting salt marsh remnants surrounded by intensive urbanization

Journal Articles & Books
December, 2014

Urbanization represents the most extreme form of land cover transformation and is expected to restrict dispersal of animals, both because of the structural unsuitability of the novel habitat, as well as through mechanisms associated with human activity, such as disturbance. Fragmentation of populations by urbanization is considered to be a significant threat to several endangered bird populations, although isolation has seldom been demonstrated genetically.

impacts of shrimp farming on land use, employment and migration in Tumbes, northern Peru

Journal Articles & Books
December, 2013
Peru

Export-oriented shrimp aquaculture appeared in the coastal landscape of Peru in the late 1970s. Its rapid development has entailed both positive and negative environmental and socioeconomic impacts across the newly emerging shrimp farming territory of the Tumbes river delta. Here we combine ground surveys and interviews with remote sensing analysis of the transformed environment in order to characterize and quantify the nature, origin and scale of the environmental and social impacts caused by the intrusion of aquaculture.

Patterns of vegetation cover/dynamics in a protected Mediterranean mountain area: Influence of the ecological context and protection policy

Journal Articles & Books
December, 2012
Italy

In Mediterranean mountains, the abandonment of traditional land-uses is promoting a rapid forest expansion. This trend may be exacerbated by nature reserves, which further limit human disturbance in mountain contexts. We investigated whether ecological parameters, landscape structure, and management policy influenced vegetation cover/dynamics over a 14-year period in the Pollino National Park, a large protected area in southern Italy. Based on remote sensed and field data we obtained land-cover maps referred to 2004, 1997, and 1990.

Impacts of Supplyshed-Level Differences in Productivity and Land Costs on the Economics of Hybrid Poplar Production in Minnesota, USA

Journal Articles & Books
December, 2015
United States of America

The joint effects of poplar biomass productivity and land costs on poplar production economics were compared for 12 Minnesota counties and two genetic groups, using a process-based model (3-PG) to estimate aboveground biomass productivity. The counties represent three levels of productivity which, due to spatial stratification, were analogous to three biomass supplysheds. An optimal rotation age (ORA) was calculated that minimizes the annualized, discounted per-dry megagrams biomass cost for each county, genetic group and land cover, and for two discount rates (5 and 10 %).

Environmental determinants of the spatial distribution of Alaria alata in Hungary

Journal Articles & Books
December, 2013
Hungary

Alaria alata is a potential zoonotic parasite, which is widely distributed in Eurasia. To assess the risk of human infection, it is important to know the spatial distribution pattern of the parasite and factors influencing this pattern. To investigate these relationships, 1612 red fox (Vulpes vulpes) carcasses were randomly collected from the whole Hungarian territory, and the intestines were examined by sedimentation and counting technique. The spatial distribution of the parasite was highly clumped.

Land Transitions in Northwest Vietnam: An Integrated Analysis of Biophysical and Socio-Cultural Factors

Journal Articles & Books
December, 2013
Vietnam

This paper discusses transitions in land use evidenced by the case of the Suoi Muoi catchment area in NW mountain of Vietnam. Land use transitions were detected from LANDSAT and SPOT satellite images taken over the last 40 years. The maps showing changes in land use were linked with biophysical properties of the land such as slope gradient, elevation and soil type, and cultural characteristic of various ethnic groups by means of logistic regression model.

2010 map estimate of annually tilled cropland within the conterminous United States

Journal Articles & Books
December, 2013
United States of America

A ca. 2010, 30m resolution map depicting annually tilled areas across the conterminous United States was developed. Input sources included fouryears, spanning 2008–2011, of annual national-level coverage Cropland Data Layer (CDL) land cover classifications as produced by the National Agricultural Statistics Service. Derived total land area under tillage from the aggregate CDL product equaled 112.8million hectares (278.7million acres).

Multiscale Environmental Influences on Fish Assemblage Structure of South Atlantic Coastal Plain Streams

Journal Articles & Books
December, 2015

South Atlantic coastal plain streams are unique and understudied freshwater environments that provide crucial habitats for a wide range of aquatic taxa. We investigated patterns in fish assemblages across South Carolina's coastal plain, and developed statistical models to identify the dominant multiscale abiotic environmental factors that influence assemblage structure.

Factors influencing vegetation cover change in Mediterranean Central Chile (1975–2008)

Journal Articles & Books
December, 2011

Questions: Which are the factors that influence forest and shrubland loss and regeneration and their underlying drivers? Location: Central Chile, a world biodiversity hotspot. Methods: Using land-cover data from the years 1975, 1985, 1999 and 2008, we fitted classification trees and multiple logistic regression models to account for the relationship between different trajectories of vegetation change and a range of biophysical and socio-economic factors.

hierarchical approach to Compact Airborne Spectrographic Imager (CASI) high-resolution image classification of Little Miami River Watershed for environmental modelling

Journal Articles & Books
December, 2012
United States of America

Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery was acquired over the Little Miami River Watershed in Ohio, USA, which was one of the largest hyperspectral image acquisitions. A hierarchical approach was employed using two different classification algorithms: ‘image object segmentation’ for level 1 and ‘spectral angle mapper’ (SAM) for level 2. This classification scheme was developed to overcome the spectral inseparability of urban and rural features and to deal with radiometric distortions due to cross-track illumination.

Spectral similarity-preserving hyperspectral band selection

Journal Articles & Books
December, 2013

Due to the high spectral resolution, hyperspectral images (HSI) have been widely used in land cover classification and material identification. Band selection is one of the necessary preprocessings to reduce the data volume and the redundancy therein for the subsequent analysis. Aiming at speeding up the search-based band selection process, this letter proposes a new technique from the perspective of spectral curve shape similarity.

subpixel mapping algorithm combining pixel-level and subpixel-level spatial dependences with binary integer programming

Journal Articles & Books
November, 2014
Global

A new subpixel mapping (SPM) algorithm combining pixel-level and subpixel-level spatial dependences is proposed in this letter. The pixel-level dependence is measured by the spatial attraction model (SAM) with either surrounding or quadrant neighbourhood, while the subpixel-level dependence is characterized by either the mean filter or the exponential weighting function. Both pixel-level and subpixel-level dependences are then fused as the weighted dependence in the constructed objective function.