نتایج جستجو برای: desertification hazard

تعداد نتایج: 66510  

More than one-third of the earth is characterized by arid and semi-arid climate and desertification phenomenon in these areas has been intensified in recent decades. This study aims to investigate the trend of desertification using vegetation indices and Iranian Model of Desertification Potential Assessment (IMDPA) in Abarkooh Plain, Yazd province, Iran. The satellite images (Landsat images in ...

ژورنال: علوم آب و خاک 2017

Appropriate criteria and methods are required to assess desertification potential in various ecosystems. This paper aimed to assess desertification levels in Segzi plain located in east part of Isfahan, with a focus on soil quality criteria used in MEDALUS model. Bayesian Belief Networks (BBNs) were also used to convert MEDALUS model into a predictive, cause and effects model. Soil samples were...

Journal: :مرتع و آبخیزداری 0
افشین جهانشاهی دانشجوی دکتری آبخیزداری، دانشگاه علوم کشاورزی و منابع طبیعی ساری علیرضا مقدم نیا دانشیار دانشکدة منابع طبیعی دانشگاه تهران حسن خسروی استادیار دانشکدة منابع طبیعی دانشگاه تهران

to assessment and preparation of desertification mapping, much research has been conducted ever within and outside the country that has led to numerous regional models. to provide a regional model and quantitative assessment of current state of desertification, shahrbabak plain with an area of 4112 square kilometers (km2) located in the northwest of kerman province were considered. in this stud...

Journal: Desert 2005
A. Rafiei Emam GH. Zehtabian, H. Ahmadi H. Khosravi

Desertification process as a great problem affects most of the countries in the world specially developing countries. This process has a high rate in arid and semi-arid countries such as Iran. The main objective of this research was to investigate land degradation status and desertification mapping of Kashan area. Different studies have been carried out in the world in order to assess desertifi...

2006
J. XIAO Y. SHEN

The grain size composition of topsoil characterizes the soil texture and other physical properties. The coarsening of topsoil grain size is a visible symbol of land degradation; thereby the change in topsoil grain size can be potentially used to monitor desertification using remote sensing. This study proposes a new index for detecting topsoil grain size composition through ground in situ soil ...

Journal: Desert 2012
H. Khosravi M. Ghodsi M.S. Ziaei R. Masoudi

Desertification is more related to social and anthropogenic issues than natural causes and it becomes moreimportant over the time. Human effects on desertification could be classified as direct and indirect factors. This studyhas focused on the effect of management factor, as a dominant case, on desertification of Kashan region based onIMDPA (IMDPA: Iranian Model of Desertification for Potentia...

Journal: Desert 2005
A. Golkarian E. Abrisham H. Ahmadi M. Ekhtesasi M. Jafari

There are different models for mapping and evaluation of desertification condition, such as global FAO_UNEP model. There are also several models for evaluation of desertification in Iran. In this study, tow fol/owing methods was used: 1-ICD method, (Iranian Classification of Desertification). 2- MICD method, (Modified Iranian Classification of Desertification). In this research, at first, these...

2002
Zhang Fengrong Wang Lixin Li Chao

YiJinHuoLuo Banner is a county of Inner Mongolia with obvious semiarid monsoon climate. Because of unsuitable land use, such as cultivating marginal land and over pasture, desertification was getting severer and severer before 1974. Since 1974, People have been doing their best to grow woods, shrubs and grasses for increasing the coverage of vegetation. People have taken suitable and available ...

Journal: :The New phytologist 2009
Sujith Ravi Paolo D'Odorico Scott L Collins Travis E Huxman

A common form of land degradation at the desert margins involves the rapid encroachment of woody plants into historic grasslands and the acceleration of soil erosion as a result of the loss of grass cover (Archer, 1989; Schlesinger et al., 1990). The conversion of perennial grasslands into desert scrublands has been documented worldwide (Van Auken, 2000; Ravi, 2008) and has important implicatio...

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