نتایج جستجو برای: desertification assessment

تعداد نتایج: 562493  

Journal: :desert 0
m jafari professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran h. ahmadi professor, islamic azad university, science and research branch , tehran, iran h.r. abbasi research instructor, forest, range & watershed management organization, tehran, iran

one of the characters in iranian model of desertification potential assessment (imdpa) is soil. since soil is very important in the degradation of land, so some indices were determined for this character in order to evaluate desertification potential of arid, semi-arid and dry sub humid areas of iran. the indices included soil texture, deep gravel percentage, soil depth, and ec. to calibrate th...

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...

Journal: :Ecology letters 2009
Fernando T Maestre Matthew A Bowker María D Puche M Belén Hinojosa Isabel Martínez Pablo García-Palacios Andrea P Castillo Santiago Soliveres Arántzazu L Luzuriaga Ana M Sánchez José A Carreira Antonio Gallardo Adrián Escudero

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean ...

2013
Kazem Rangzan

Desertification is the reduction of ecologic and biologic on the earth surface, which might happen naturally or unnaturally (human). In this research, the TM and ETM images were used to study changes occurred in sand dunes during last 11 years and for determining the type of clay minerals. For evaluation of changes, maximum likelihood image classification and LMM, methods are carried out. Accor...

2000
Wang Quan

Arid and semi-arid areas occupy one third of the total area of the world. This vast region is rich in natural resources. In recent times, desertification has become a world-wide phenomenon, due to human activities. China also suffers from this problem. Desertification is especially severe in the southeastern part of the arid and semi-arid region of the country. In this paper, the use of remote ...

Mohammad rahimi Mohammadkia kianian Neda soleiman dehkordi Seyed Hassan kaboli Shima nikoo Zahra bayat,

Desertification could be traced back to one or many factors. Thus, to cope with such a phenomenon, there exists a need for a profound understanding of the processes and the causes. The study area of the current paper is the extent of Shahrekord’s Marghzar as an important case amongst the important ones of the province. In order to evaluate the roots of desertification in the area, the Iranian m...

Journal: :international journal of advanced biological and biomedical research 0
zahra bayat m.sc. student of desertification, faculty of natural resources, university of semnan, semnan, iran seyed hassan kaboli assistance professor of desertification, faculty of natural resources, semnan university, iran mohammad rahimi assistance professor of desertification, faculty of natural resources, semnan university, iran shima nikoo ph.d of desertification, faculty of natural resources, university of semnan, semnan, iran mohammadkia kianian instructor of desertification, faculty of natural resources, university of semnan, semnan, iran neda soleiman dehkordi m.sc. student of desertification, faculty of natural resources, university of semnan, semnan, iran

desertification could be traced back to one or many factors. thus, to cope with such a phenomenon, there exists a need for a profound understanding of the processes and the causes. the study area of the current paper is the extent of shahrekord’s marghzar as an important case amongst the important ones of the province. in order to evaluate the roots of desertification in the area, the iranian m...

2016
Emanuele Calabrò Salvatore Magazù

Background: This study investigates the connection between annual global solar radiation and ground albedo solar radiation due to desertification in line with previous research on the correlation between climatic changes and desertification. Methods: A simulation study was performed using an algorithm formulated by the authors and the typical albedo coefficient values of forested ground, green ...

Extended abstract 1-Introduction Desertification means land degradation in the arid, semi-arid and dry sub-humid regions because of natural or anthropogenic factors. Desertification is accounted as the third most important global challenge after the crisis of water shortage and drought in the 21st century. Desertification is a problem for many countries, especially the developing countries. I...

2003
Alfredo Huete Tomoaki Miura Xiang Gao Carlos Borghi Ricardo Ojeda

Land degradation impacts on several critical environmental issues such as food security, diminishing quality and quantity of fresh water resources, preservation of natural resources, loss of biodiversity, and global climate change. Land degradation is responsible for soil erosion and can eventually lead to desertification. The International Convention to Combat Desertification (CCD) defines des...

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