نتایج جستجو برای: vegetation degradation

تعداد نتایج: 196873  

Journal: Desert 2012
H. Azarnivand H. Joneidi M.A. Zare Chahouki

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...

1999
V. Blanfort P. Thomas G. Balent A. Michon

The use of a systemic approach allows us to analyse the interrelationship between the vegetation dynamic and the agricultural practices through three biological indicators which relate to one hundred paddocks in six cattle farms. Concerning the vegetation dynamics, it seems that some management practices lead to a nonreversable degradation stage. As regards the forage system, the measure of swa...

Journal: :مرتع و آبخیزداری 0
شفق رستگار استادیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری حسین بارانی دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان علی دریجانی استادیار دانشکده اقتصاد کشاورزی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان واحدبردی شیخ دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان جمشید قربانی دانشیار دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری محمد قربانی استاد دانشکده اقتصاد کشاورزی، دانشگاه فردوسی مشهد

vegetation cover as the main factor affecting the water erosion plays an important role in preventingsoil loss. to this end, for better understanding the impact of vegetation cover on soil erosion andsediment yield over the major existing geological formations in the summer rangelands of balade inthe mazandaran province, rainfall simulation studies have been carried out using a portable rainfal...

Journal: :Remote Sensing 2014
Cécile Dardel Laurent Kergoat Pierre Hiernaux Manuela Grippa Eric Mougin Philippe Ciais Cam-Chi Nguyen

Rain Use Efficiency (RUE), defined as Aboveground Net Primary Production (ANPP) divided by rainfall, is increasingly used to diagnose land degradation. Yet, the outcome of RUE monitoring has been much debated since opposite results were found about land degradation in the Sahel region. The debate is fueled by methodological issues, especially when using satellite remote sensing data to estimate...

2017
Ziqiang Du Xiaoyu Zhang Xiaoming Xu Hong Zhang Zhitao Wu Jing Pang

Variability in satellite measurements of terrestrial greenness in drylands is widely observed in land surface processes and global change studies. Yet the underlying causes differ and are not fully understood. Here, we used the GeogDetector model, a new spatial statistical approach, to examine the individual and combined influences of physiographic factors on dryland vegetation greenness change...

Journal: :Remote Sensing 2015
Jian Peng You Li Lu Tian Yanxu Liu Yanglin Wang

Vegetation is one of the most important components of the terrestrial ecosystem and, thus, monitoring the spatial and temporal dynamics of vegetation has become the key to exploring the basic process of the terrestrial ecosystem. Vegetation change studies have focused on the relationship between climatic factors and vegetation dynamics. However, correlations among the climatic factors always di...

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...

2013
Olena Dubovyk Gunter Menz Christopher Conrad Elena Kan Miriam Machwitz Asia Khamzina

Advancing land degradation in the irrigated areas of Central Asia hinders sustainable development of this predominantly agricultural region. To support decisions on mitigating cropland degradation, this study combines linear trend analysis and spatial logistic regression modeling to expose a land degradation trend in the Khorezm region, Uzbekistan, and to analyze the causes. Time series of the ...

2004
L. R. BASHER

Soil degradation has been implicated as a cause of the poor vegetation condition over much of the unimproved tussock grassland in the South Island high country and as a threat to the sustainability of extensive pastoralism (Parliamentary Commissioner for the Environment, 1991; South Island High Country Review Working Party, 1994). A key requirement for assessment of sustainability is an ability...

Journal: :Remote Sensing 2016
Manuela Domínguez-Beisiegel Carmen Castañeda Bernard Mougenot Juan Herrero

Inland saline wetlands are complex systems undergoing continuous changes in moisture and salinity and are especially vulnerable to human pressures. Remote sensing is helpful to identify vegetation change in semi-arid wetlands and to assess wetland degradation. Remote sensing-based monitoring requires identification of the spectral characteristics of soils and vegetation and their correspondence...

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