نتایج جستجو برای: desertification map

تعداد نتایج: 196664  

Journal: Desert 2011
Gh.R. Zehtabian H. Azarnivand H. Khosravi N. Shakerian

Desertification refers to land degradation phenomenon in arid, semi-arid and dry sub-humid areas, resulting from various factors including climate variation and human activities. For evaluation and mapping of desertification many research have been conducted leading to regional and local models. In this research, among different existing methods IMDPA‌ was selected and desertification intensity...

Journal: :desert 0
a. salehpour jam soil conservation and watershed management research institute, iran m. karimpour reihan geo science research dept., international desert research center (idrc), university of tehran

investigation of desertification trend requires an understanding of phenomena that create changes singly or action and reaction together in an area that these changes were led to the desertification and land degradation. in the investigation of pedological criterion affecting on land degradation in alluvial fans, first, the map of units was created by overlaying and crossing maps of slope class...

2016
Long Wan Jing Tong Jinxing Zhou Hongyan Guo Ming Cui Yuguo Liu Like Ning Fukai Tang

Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regio...

Journal: :desert 2014
hassan khosravi gholamreza zehtabian hassan ahmadi hossein azarnivand

desertification in arid, semi-arid and dry sub-humid regions is a global environmental problem. considering theincreasing importance of desertification and its complexity, the necessity of giving attention to desertification criteria andindices is essential. models and methods such as medalus, unep-fao, and others have been proposed on local andnational scales. in this research, imdpa was selec...

2004
Meixue Yang Shaoling Wang Tandong Yao Xiaohua Gou Anxin Lu Xuejun Guo

Desertification in Qinghai-Xizang (Tibet) Plateau is part of Chinese desertification. In the past decades, due to the climate warming, the climate condition in Qinghai-Xizang (Tibet) Plateau has been relatively dry. This has resulted in permafrost degradation and other environmental problems. In addition, the vegetation and the soil layer were also destroyed by unreasonable economic activities....

2015
Qi Feng Hua Ma Xuemei Jiang Xin Wang Shixiong Cao

Desertification is the result of complex interactions among various factors, including climate change and human activities. However, previous research generally focused on either meteorological factors associated with climate change or human factors associated with human activities, and lacked quantitative assessments of their interaction combined with long-term monitoring. Thus, the roles of c...

Journal: :Environmental monitoring and assessment 2003
Yansui Liu Jay Gao Yanfeng Yang

The farming and grazing interlocked transitional zone along the Great Wall in northern Shaanxi Province is particularly vulnerable to desertification due to its fragile ecosystem and intensive human activity. Studies reveal that desertification is both a natural and anthropogenic process. Four desertification indicators (vegetative cover, proportion of drifting sand area, desertification rate, ...

Journal: Desert 2014

Desertification in arid, semi-arid and dry sub-humid regions is a global environmental problem. Considering theincreasing importance of desertification and its complexity, the necessity of giving attention to desertification criteria andindices is essential. Models and methods such as MEDALUS, UNEP-FAO, and others have been proposed on local andnational scales. In this research, IMDPA was selec...

2015
Yongfang Wang Jiquan Zhang Enliang Guo Zhongyi Sun

Desertification is a typical disaster risk event in which human settlements and living environments are destroyed. Desertification Disaster Risk Assessment can control and prevent the occurrence and development of desertification disasters and reduce their adverse influence on human society. This study presents the methodology and procedure for risk assessment and zoning of desertification disa...

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...

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