نتایج جستجو برای: desertification intensity

تعداد نتایج: 182836  

ژورنال: علوم آب و خاک 2015
آزادنیا, فرزاد, خسروی, حسن, ممبنی, مریم, کرمشاهی, عبدالعلی, گرایی, پرویز,

Desertification is currently a big problem in many countries, especially in developing countries, and includes natural processes and improper human activities. The present study was conducted to evaluate the potential of desertification with an emphasis on water, climate and soil criteria using IMDPA Model in Abbas plain, Ilam province with an area about 18028.8 hectare. Geometric averages for ...

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...

Journal: Desert 2017
M. Ownagh S.A. Arami

About 80 percent of Iran is arid and semi-arid and about 35 percent of this area is susceptible to desertification hazard. Therefore desertification assessment and identification of the most important criteria for the assessment of risk and a basis for development of management plans is essential. This research was conducted in the semi-arid region of Agh-Band in the Golestan province, Iran wit...

Journal: :international journal of advanced biological and biomedical research 2014
nasrollah aslinezhad ahmad pahlavanravi nasrollah basirani mahdiye ebrahimi rasoul kharazmi

objective: more than 75 percent of iran is located in arid and semi-arid then land degradation and desertification are one of the crises ecological. we require a proper understanding of causes and processes of desertification to control the huge phenomenon on the global and regional situation. because southeast of iran located in arid land then assessment of desertification is very importance f...

Journal: :Environmental management 2014
C Kosmas Or Kairis Ch Karavitis C Ritsema L Salvati S Acikalin M Alcala P Alfama J Atlhopheng J Barrera A Belgacem A Solé-Benet J Brito M Chaker R Chanda C Coelho M Darkoh I Diamantis O Ermolaeva V Fassouli W Fei J Feng F Fernandez A Ferreira C Gokceoglu D Gonzalez H Gungor R Hessel J Juying H Khatteli N Khitrov A Kounalaki A Laouina P Lollino M Lopes L Magole L Medina M Mendoza P Morais K Mulale F Ocakoglu M Ouessar C Ovalle C Perez J Perkins F Pliakas M Polemio A Pozo C Prat Y Qinke A Ramos J Ramos J Riquelme V Romanenkov L Rui F Santaloia R Sebego M Sghaier N Silva M Sizemskaya J Soares H Sonmez H Taamallah L Tezcan D Torri F Ungaro S Valente J de Vente E Zagal A Zeiliguer W Zhonging A Ziogas

An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification risk, a total of 70 candidate indicators was s...

Journal: :مرتع و آبخیزداری 0
سید هدایت پروری اصل دانش آموخته کارشناسی ارشد رشته بیابان¬زدایی، دانشکده منابع طبیعی، دانشگاه زابل، ایران احمد پهلوانروی استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران علیرضا مقدم نیا استادیار، دانشکده منابع طبیعی، دانشگاه زابل، ایران

desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. arid and semi-arid areas have occupied most parts of iran. sistan region is one of arid areas of iran where wind erosion is an important factor of land degradation and soil deterioration. for classification of desertification intensity, several methods h...

Journal: :desert 0
h. azarnivand associate 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. joneidi assistant professort, university of kurdestan, sanandaj, iran

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...

2005
Y. CHEN H. TANG

Desertification in north China is ongoing despite the endeavours to mitigate it over the past 50 years. Overall examination of the context of desertification and defects of desertification-combating programmes is a prerequisite for desertification control, which is now attracting general concern in China. The physiographic circumstances of north China, including the dry, continental, mid-latitu...

Introduction: Desertification refers to the decreased biological potentials in the ecosystem of hyper-arid, arid, semi-arid, and humid semi-arid regions because of climate change and human activities. The phenomenon occurs due to a combination of direct and indirect factors whose intensity varies according to time and place, making the scientific, replicable, and systematic evaluation of desert...

Journal: :Proceedings. Mathematical, physical, and engineering sciences 2016
Karna Gowda Yuxin Chen Sarah Iams Mary Silber

A particular sequence of patterns, 'gaps→labyrinth→spots', occurs with decreasing precipitation in previously reported numerical simulations of partial differential equation dryland vegetation models. These observations have led to the suggestion that this sequence of patterns can serve as an early indicator of desertification in some ecosystems. Because parameter values in the vegetation model...

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