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Issuesland coverLandLibrary Resource
There are 2, 239 content items of different types and languages related to land cover on the Land Portal.
Displaying 1513 - 1524 of 2218

Modeling the radiation balance of different urban underlying surfaces

Journal Articles & Books
December, 2012

An urban net all-wave radiation parameterization scheme is evaluated using annual datasets for 2010 recorded at a Beijing urban observation site. The statistical relationship between observed data and simulation data of net radiation has a correlation coefficient of 0.98 and model efficiency of 0.93. Therefore, it can be used to simulate the radiation balance of Beijing. This study analyzes the variation in the radiation balance for different underlying surfaces. To simulate radiation balance differences, we set four pure land-cover types (forest, grass, roads, and buildings).

Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

Journal Articles & Books
December, 2011

This study has analyzed the global nitrogen loading of rivers resulting from atmospheric deposition, direct discharge, and nitrogenous compounds generated by residential, industrial, and agricultural sources. Fertilizer use, population distribution, land cover, and social census data were used in this study. A terrestrial nitrogen cycle model with a 24-h time step and 0.5° spatial resolution was developed to estimate nitrogen leaching from soil layers in farmlands, grasslands, and natural lands.

Multi-scale land cover dynamics of semiarid scrubland in Baja California, Mexico

Journal Articles & Books
December, 2014
Mexico

Land use and cover changes trigger multi-factorial responses with tangible and intangible effects. Driving forces governing changes are scale-, place- and time-dependent; because of their complexity, a multi-scalar analysis is required to determine conjoint causation. Studies using multi-scalar approach in semiarid scrubland ecosystems are scanty. This paper investigates land use changes on the largest semiarid scrubland ecosystem of Mexico, the Baja California Peninsula, using a multi-scalar analysis approach.

Carbon dioxide exchange of a Sitka spruce plantation in Scotland over five years

Journal Articles & Books
December, 2012

Scotland's 17% forested land cover sequesters 10% of Scotland's emissions of greenhouse gases. The expected rise of forested land cover to 25% by the middle of this century make forests an important component of the national carbon budget. This paper presents the carbon exchange measurement methodology, results, and modeling associated with a five-year experiment at a plantation forest in Scotland, UK, as part of a European initiative to develop and verify vegetation carbon-exchange models. We have developed a site specific correction for advective flux loses.

Acacia nilotica-based silvipastoral systems for resource conservation and improved productivity from degraded lands of the Lower Himalayas

Journal Articles & Books
December, 2014
India

High population density and unscientific land use practices have induced severe land degradation in the fragile Lower Himalayan ecosystem of India. Land cover management has been an effective strategy in managing land degradation through the reduction of water, soil and nutrient losses and improvement in soil fertility and quality.

mechanistic modeling system for estimating large-scale emissions and transport of pollen and co-allergens

Journal Articles & Books
December, 2011
United States of America

Allergic airway diseases represent a complex health problem which can be exacerbated by the synergistic action of pollen particles and air pollutants such as ozone. Understanding human exposures to aeroallergens requires accurate estimates of the spatial distribution of airborne pollen levels as well as of various air pollutants at different times. However, currently there are no established methods for estimating allergenic pollen emissions and concentrations over large geographic areas such as the United States.

Modelling catchment hydrological responses in a Himalayan Lake as a function of changing land use and land cover

Journal Articles & Books
December, 2013

In this paper, we evaluate the impact of changing land use/land cover (LULC) on the hydrological processes in Dal lake catchment of Kashmir Himalayas by integrating remote sensing, simulation modelling and extensive field observations. Over the years, various anthropogenic pressures in the lake catchment have significantly altered the land system, impairing, inter-alia, sustained biotic communities and water quality of the lake.

impact of land use and land cover changes on solute dynamics in seepage water of soil from karst hillslopes of Southwest China

Journal Articles & Books
December, 2011

Land use and land cover changes can cause variations in terrestrial energy, water balance and availability of nutrients. To understand the role of vegetation in regulating the hydrochemistry of karst hillslopes, overland flow and soil seepage water from two hillslopes covered with and without vegetation were studied in the Huanjiang Observation and Research Station for Karst Ecosystems, Guangxi, SW China. Dissolved major ions, as well as isotopic compositions of dissolved inorganic C (DIC) were examined.

Drought vulnerability drives land-use and land cover changes in the Rift Valley dry lands of Ethiopia

Journal Articles & Books
December, 2013
Ethiopia

The Ethiopian Rift Valley is a dry land zone where for a long time pastoral communities have made their living from acacia-based woodlands. But many pastoralists have changed from a pastoral way of life to mixed farming over time. The aim of this study was to evaluate land-use and land cover (LULC) changes in the Central Rift Valley dry lands of Ethiopia, and determine the role of drought vulnerability as a driver. A combination of GIS/remote sensing techniques, drought vulnerability analyses, field observation and surveying were employed.

Super-resolution mapping using Hopfield Neural Network with panchromatic imagery

Journal Articles & Books
December, 2011

Land-cover proportions of mixed pixels can be predicted using soft classification. From the land-cover proportions, a hard land-cover map can be predicted at sub-pixel spatial resolution using super-resolution mapping techniques. It has been demonstrated that the Hopfield Neural Network (HNN) provides a suitable method for super-resolution mapping. To increase the detail and accuracy of the sub-pixel land-cover map, supplementary information at an intermediate spatial resolution can be used.

Global albedo change and radiative cooling from anthropogenic land-cover change, 1700 to 2005 based on MODIS, land-use harmonization, radiative kernels and reanalysis

Journal Articles & Books
December, 2014
Global

Widespread anthropogenic land-cover change over the last five centuries has influenced the global climate system through both biogeochemical and biophysical processes. Models indicate that warming from carbon emissions associated with land cover conversion have been partially offset if not outweighed by cooling from elevated albedo, but considerable uncertainty remains partly because of uncertainty in model treatments of albedo.

Characteristics and landcover of estuarine boundaries: implications for the delineation of the South African estuarine functional zone

Journal Articles & Books
December, 2015
South Africa
Southern Africa

This study investigated whether the current lateral boundary for estuaries in South Africa, i.e. the estuarine functional zone (EFZ), includes all estuarine habitats. The EFZ covers 173 930 ha in 304 estuaries/outlets nationally. Field surveys and analysis of available aerial images showed that 82 (12 956.70 ha) of these estuaries (26%) had estuarine habitats occurring outside of this boundary. As a result of mapping scale, the National Vegetation Map does not represent habitats that are associated with small estuaries (approximately 50% of South Africa's estuaries).