نتایج جستجو برای: vegetation degradation

تعداد نتایج: 196873  

2009
MARTIN Arnaud

Human activities greatly affect the environment causing its degradation. Urban development and road networks construction cause main impacts on ecosystems and particularly on vegetation cover: road constructions induce complete degradation of the vegetation cover and often leaves a bare land, sometimes without even a soil cover. Reconstitution of vegetation cover is necessary to limit superfici...

Over the past two decades, degradation damage has increased in natural ecosystems. This research focuses solely on the degradation of soil and vegetation cover in Sorkheh Eshpar National Park. For this purpose, some physical properties of the soil (specific gravity and true porosity, moisture content, a percentage of pebbles, acidity and conductivity and soil texture) were measured. Also, the d...

Journal: :Remote Sensing 2015
Sergio Vicente-Serrano Daniel Cabello Miquel Tomás-Burguera Natalia Martín-Hernández Santiago Beguería Cesar Azorin-Molina Ahmed El Kenawy

We analyzed potential land degradation processes in semiarid regions worldwide using long time series of remote sensing images and the Normalized Difference Vegetation Index (NDVI) for the period 1981 to 2011. The objectives of the study were to identify semiarid regions showing a marked decrease in potential vegetation activity, indicative of the occurrence of land degradation processes, and t...

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...

2015
Emmanuel N. Mill'an Silvana Goir'an Julieta N. Aranibar Leonardo Forconesi Carlos Garc'ia Garino Eduardo M. Bringa

In the Monte desert, increasing population density, changing land rights and infrastructure may encourage livestock activity, with unknown consequences on ecosystems. Factors that influence livestock settlement distribution may affect ecosystem degradation. We hypothesize that surface and groundwater availability influence livestock settlements distribution. We evaluated this hypothesis with a ...

Journal: :desert 2012
h. azarnivand m.a. zare chahouki h. joneidi

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

2010
Toshpulot Rajabov

Since livestock production in Uzbekistan in arid and semi-arid zones is based on rangeland vegetation, contemporary studies have focused on improvement of low productive grazing lands and rehabilitation of degraded rangelands. Less interest has been given to the driving factors of land degradation and their interaction with other ecosystem components, e.g. response of vegetation to grazing indu...

جباری, سمیه , جعفری, رضا, خواجه‌الدین, سید جمال‌الدین , سلطانی, سعید,

The objective of the present study was to investigate the pasture vegetation changes using satellite data in Semirom, Isfahan province. This study was conducted in 2004 as a wet year and 2009 as a dry year. The WiFS and AWiFS satellite images were acquired and used for the year 2004 and 2009, respectively. First, the vegetation percentage was simultaneously measured in the two years. Then, cons...

2004
F. Dahdouh-Guebas J. G. Kairo S. Cannicci N. Koedam

Gazi Bay, Kenya, covers an area of 18 km2, and its mangroves are degraded. We present a quantitative and qualitative evaluation of the degradation of vegetation structure and dynamics of mangrove communities over a period of 25 yr, using aerial photography in a geographical information system (GIS), combined with ground-truth data for different vegetation layers, and with faunal and environment...

2015
Yihe Lü Liwei Zhang Xiaoming Feng Yuan Zeng Bojie Fu Xueling Yao Junran Li Bingfang Wu

Ecological conservation and restoration are necessary to mitigate environmental degradation problems. China has taken great efforts in such actions. To understand the ecological transition during 2000-2010 in China, this study analysed trends in vegetation change using remote sensing and linear regression. Climate and socioeconomic factors were included to screen the driving forces for vegetati...

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