نتایج جستجو برای: land cover vegetation

تعداد نتایج: 243729  

2017
Gregory P. Asner Jeffrey L. Privette Nazmi El Saleous Carol A. Wessman

Regional analyses of biogeochemical processes can benefit significantly from observational information on land cover, vegetation structure (e.g., leaf area index), and biophysical properties such as fractional PAR absorption. Few remote sensing efforts have provided a suite of plant attributes needed to link vegetation structure to ecosystem function at high spatial resolution. In arid and semi...

2008
T. Quaife S. Quegan M. Disney P. Lewis M. Lomas F. I. Woodward

[1] Large-scale bottom-up estimates of terrestrial carbon fluxes, whether based on models or inventory, are highly dependent on the assumed land cover. Most current land cover and land cover change maps are based on satellite data and are likely to be so for the foreseeable future. However, these maps show large differences, both at the class level and when transformed into Plant Functional Typ...

Abolghasem Dadrasi Sabzevar Ali Ariapour, Sara Toloee

Land use may be regarded as one of the most important factors affecting theenvironment with respect to human activities. So far, destroying the rangelands andchanging them into the waste lands and poor rangelands has been proposed as the mostsignificant variations of land use done by human beings. This paper has been conducted toevaluate the variations of vegetation percentage and land uses in ...

Journal: :ISPRS Int. J. Geo-Information 2012
Ronald C. Estoque Ria S. Estoque Yuji Murayama

Analysis of spatial and temporal changes of vegetation cover using remote sensing (RS) technology, in conjunction with Geographic Information Systems (GIS), is becoming increasingly important in environmental conservation. The objective of this study was to use RS data and GIS techniques to assess the vegetation cover in 1989 and 2009, in the barangays (smallest administrative units) of the cit...

Journal: :Remote Sensing 2010
Ignacio Melendez-Pastor Jose Navarro-Pedreño Magaly Koch Ignacio Gómez Encarni I. Hernández

Mediterranean coastal areas are experiencing rapid land cover change caused by human-induced land degradation and extreme climatic events. Vegetation index time series provide a useful way to monitor vegetation phenological variations. This study quantitatively describes Enhanced Vegetation Index (EVI) temporal changes for Mediterranean land-covers from the perspective of vegetation phenology a...

2013
Satoshi Tsuyuki

As landmass of the world is covered by vegetation, taking into account phenology when performing land cover classification may yield more accurate maps. The availability of no-cost Moderate Resolution Imaging Spectrometer (MODIS) NDVI dataset that provides high-quality continuous time series data is representing a potentially significant source of land cover information especially for detection...

2009
R Mathieu K Wessels G Asner D. Knapp J. van Aardt M Cho B. Erasmus I. Smit

Land degradation is one of the most significant environmental problems in the semi-arid and arid savannas of Southern Africa. Degradation affects vegetation structure, cover and patchiness and this result in the loss of vegetation resources used by rural populations (grazing, fuel wood, and other non-timber forest products) and wildlife. Land degradation processes are influenced by rainfall, la...

2002
S. Mugisha J. Huising

Due to increased availability and affordable cost of TM7 data, one envisages its widespread use for land cover mapping in many developing countries. There is need to establish not only the potential but also the limitations of TM data for land cover mapping in some natural ecosystems of the tropics. Uganda is a tropical country with well-distributed rainfall and its landscapes are characterised...

2002
A. LOTSCH Y. TIAN M. A. FRIEDL R. B. MYNENI

Land cover maps are used widely to parameterize the biophysical properties of plant canopies in models that describe terrestrial biogeochemical processes. In this paper, we describe the use of supervised classification algorithms to generate land cover maps that characterize the vegetation types required for Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation (FPAR) retrie...

2015
Sadroddin Alavipanah Martin Wegmann Salman Qureshi Qihao Weng Thomas Koellner Marc A. Rosen

The Urban Heat Island (UHI) is the phenomenon of altered increased temperatures in urban areas compared to their rural surroundings. UHIs grow and intensify under extreme hot periods, such as during heat waves, which can affect human health and also increase the demand for energy for cooling. This study applies remote sensing and land use/land cover (LULC) data to assess the cooling effect of v...

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