نتایج جستجو برای: vegetation cover maps

تعداد نتایج: 249983  

Journal: :Int. J. Applied Earth Observation and Geoinformation 2010
Katrin Meusburger Nadine Konz Monika Schaub Christine Alewell

The focus of soil erosion research in the Alps has been in two categories: (i) on-sitemeasurements, which are rather small scale point measurements on selected plots often constrained to irrigation experiments or (ii) off-site quantification of sediment delivery at the outlet of the catchment. Results of both categories pointed towards the importance of an intact vegetation cover to prevent soi...

Journal: Desert 2016

In the present study, in order to calculate the movement of sand dunes in the period between 2001 and 2010, the ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) images were used. The training samples were obtained from the field, and the images of the years 2001 and 2010 were classified using maximum likelihood algorithm and decision making tree. The study area was classi...

Journal: :Journal of environmental management 2014
Sébastien Rapinel Bernard Clément Sylvie Magnanon Vanessa Sellin Laurence Hubert-Moy

Identification and mapping of natural vegetation are major issues for biodiversity management and conservation. Remotely sensed data with very high spatial resolution are currently used to study vegetation, but most satellite sensors are limited to four spectral bands, which is insufficient to identify some natural vegetation formations. The study objectives are to discriminate natural vegetati...

2012
Roberto Carlà Leonardo Santurri Katia Fontanelli

Remotely sensed data are widely used to gain information about biophysical parameters characterizing the Earth surface. Among the others, the Soil Adjusted Vegetation Index (SAVI) is commonly used to monitor the distribution and the health of the green cover. The vegetation usually shows a certain level of spatial correlation, that is expected to be present also in the related SAVI maps. Moreov...

Journal: :caspian journal of environmental sciences 2009
m. ajorlo h. ahmad husni mohd h. ridzwan abd

empirical models are important tools for relating field-measured biophysical variables to remotely sensed data. regression analysis has been a popular empirical method of linking these two types of data to estimate variables such as biomass, percent vegetation canopy cover, and bare soil. this study was conducted in a semi-arid rangeland ecosystem of qazvin province, iran. this paper presents t...

ژورنال: علوم آب و خاک 2008
باغستانی , ناصر , ثواقبی, محمد حسین , رحیمیان , محمد حسن , عبداللهی, جلال ,

The present study discusses a method used to produce updated information about vegetation cover in arid and semi-arid zones, using RS data and GIS technique. In this method, Landsat ETM+ data in 2002 was collected in an area of about 60000 ha in Nodoushan basin, Yazd, Iran. To collect the necessary ground data, 50 sites of different vegetation types were selected and the percentage of vegetatio...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Juan Carlos Laso Bayas Carsten Marohn Gerd Dercon Sonya Dewi Hans Peter Piepho Laxman Joshi Meine van Noordwijk Georg Cadisch

In a tsunami event human casualties and infrastructure damage are determined predominantly by seaquake intensity and offshore properties. On land, wave energy is attenuated by gravitation (elevation) and friction (land cover). Tree belts have been promoted as "bioshields" against wave impact. However, given the lack of quantitative evidence of their performance in such extreme events, tree belt...

2003
Chris J. Johnson Nancy D. Alexander Roger D. Wheate Katherine L. Parker

Woodland caribou (Rangifer tarandus caribou) are sensitive to changes in understory vegetation resulting from forest harvesting and are, therefore, of special concern for foresters and habitat biologists. Effective management of this species requires reliable habitat inventories which, because of the large heterogeneous areas over which caribou range, can be costly. We used Landsat Thematic Map...

2004
Nektarios Chrysoulakis Iphigenia Keramitsoglou Constantinos Cartalis

Digital Elevation Models (DEMs) and land cover products are primary inputs for hydrologic models of surface runoff that affects infiltration, erosion, and evapotranspiration. DEM and land cover play important role in determining the runoff characteristics of specific catchment areas. Recently, at local level, a number of data sources have been used to derive land cover products for high resolut...

2006
Leonardo F. Peres Carlos C. DaCamara

Retrieval of land-surface temperature (LST) using data from MSG/SEVIRI requires adequate estimates of land-surface emissivity (LSE). In this context LSE maps for SEVIRI channels IR3.9, IR8.7, IR10.8, and IR12.0 were developed based on the vegetation cover method. A broadband LSE map (3-14 μm) was also developed for estimating long-wave surface fluxes that may prove to be useful in both energy b...

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