نتایج جستجو برای: land cover vegetation

تعداد نتایج: 243729  

2010
Qian Li Yongkang Xue

The Tibetan Plateau (TP) is a key region of land–atmosphere interactions with severe eco-environment degradation. This study uses an atmospheric general circulation model, NCEP GCM/SSiB, to present the major TP summer climate features for six selected ENSO years and preliminarily assess the possible impact of land cover change on the summer circulation over the TP. Compared to Reanalysis II dat...

ژورنال: آبخیزداری ایران 2019
, , soufi, majid, yasrebi, banafshe,

Gully erosion is one of the important forms of soil degradation especially in semi-arid areas. Gullies are occupying 13 percent of Ilam Province area. This research focused on studying the, topographic threshold of gullies, dominant process of gully initiation and development as well, in agricultural and rangeland land uses. Ilam province with 2 million hac area is located in western Iran. Ilam...

2000
A. Lotsch

Land cover maps are widely used 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 LAI and FAPAR retrievals from MODIS and MISR. As part of this analysis, we examine the ...

Journal: :Remote Sensing 2014
Xiaoxiao Li Guofan Shao

There are growing demands for detailed and accurate land cover maps in land system research and planning. Macro-scale land cover maps normally cannot satisfy the studies that require detailed land cover maps at micro scales. In the meantime, applying conventional pixel-based classification methods in classifying high-resolution aerial imagery is ineffective to develop high accuracy land-cover m...

C. Jiang J. Cheng Q. Yu, X.Q. Rao Z.F. Wu,

Great changes in land use/land cover from rapid urbanization have occurred in the PearlRiver Delta, China. As the primary cause of land development in the urbanization process,urban expansion has mostly occurred on land with higher NPP, significantly impacting theregional ecosystems. The primary purpose of this study was to reveal the impacts of urbanexpansion on the regional NPP. The land cove...

2012
Priyakant Sinha Lalit Kumar

Due to seasonal spectral variability in land-cover of cool temperate climatic conditions, the method that suits best for seasonal land-cover change identification remains uncertain. The study tested 11 different binary change detection methods and compared their capability in detecting land-cover change/no-change information in different seasons. Multi-date Thematic Mapper (TM) data pertaining ...

2012
Prasanth MEIYAPPAN Atul K. JAIN

Earth’s land cover has been extensively transformed over time due to both human activities and natural causes. Previous global studies have focused on developing spatial and temporal patterns of dominant human land-use activities (e.g., cropland, pastureland, urban land, wood harvest). Process-based modeling studies adopt different strategies to estimate the changes in land cover by using these...

2017
Kevin P. Gallo Dan Tarpley Ken Mitchell Ivan Csiszar Timothy Owen Brad Reed

The land cover classes developed under the coordination of the International Geosphere-Biosphere Programme Data and Information System (IGBP-DIS) have been analyzed for a study area that includes the Conterminous United States and portions of Mexico and Canada. The 1-km resolution data have been analyzed to produce a gridded data set that includes within each 20-km grid cell: 1) the three most ...

Journal: :Environmental management 2007
Kristin B Byrd N Maggi Kelly Adina M Merenlender

Historical and recent remote sensing data can be used to address temporal and spatial relationships between upland land cover and downstream vegetation response at the watershed scale. This is demonstrated for sub-watersheds draining into Elkhorn Slough, California, where salt marsh habitat has diminished because of the formation of sediment fans that support woody riparian vegetation. Multiple...

2014
Jing Zhang Jianming Niu Alexander Buyantuev Jianguo Wu

Drylands, which occupy more than 40% of the Earth’s land surface, are highly susceptible to degradation. It is important to understand causes, mechanisms, and environmental consequences of dryland ecosystem degradation. Land use policies are known to play a critical role in driving land cover changes, as well as in mitigating land degradation and promoting sustainable development in drylands. W...

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