نتایج جستجو برای: desertification

تعداد نتایج: 1803  

2018

Most of the issues regarding desertification are always related to soil fertility and water quality [1,2]. Hence United Nation Framework Convention on Climate Change (UNFCCC) seriously globalized the issues of desertification in 1992. The developed and developing including hilly mountainous countries are the conference of the parties and so as Nepal [3]. The catchments in hill and Himalayan reg...

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: :مرتع و آبخیزداری 0
علی اذره دانشجوی دکتری بیابان زدایی، دانشکدة منابع طبیعی، دانشگاه تهران غلامرضا زهتابیان استاد دانشکدة منابع طبیعی، دانشگاه تهران علی اکبر نظری سامانی دانشیار دانشکدة منابع طبیعی، دانشگاه تهران حسن خسروی استادیار دانشکدة منابع طبیعی، دانشگاه تهران

in management, the monitoring means systematic collection and storage of data from activities and strategies that provide assessment and report about the overall condition of the study area. in this research, among different existing methods, imdpa model was selected for monitoring desertification in garmsar plain. based on the study area two criteria including agriculture and water were select...

Journal: :environmental resources research 0
morteza akbari ph.d. candidate, gorgan university of agricultural sciences & natural resources, gorgan, iran. majid ownegh professor of department of arid region, faculty of range and watershed management, gorgan university of agricultural sciences & natural resources. hamidreza asgari assistant professor of department of arid region, faculty of range and watershed management, gorgan university of agricultural sciences & natural resources. amir sadoddin associate professor of department of arid region, faculty of range and watershed management, gorgan university of agricultural sciences & natural resources. hasan khosravi assistant professor of department of rehabilitation arid and mountainous, faculty of natural resources. tehran university, karaj.

early warning systems are key components of strategies to reduce risk. this research, by adopting a systematic approach in the management of the risk of desertification and by including previously developed models and systems, offers an integrated efficient structure in terms of early warning for the risk of desertification as a pilot system for semi-arid areas of west golestan province in iran...

Journal: Desert 2008
A. Malekian A.A. Mehrabi GH. Zehtabian N. Rostami

Undoubtly, land degradation causes apparent decrease of natural resources potential which are highly linked to desertification. Different countries and also international organization have realized a great number of projects to combat desertification. Unfortunately these projects have not reach to their goals. The experiences shows that the reason of these unsuccessful works is lack of consider...

ژورنال: علوم آب و خاک 2018

In this study, to study the status of water resources degradation in Kashan region, Isfahan Province, eight indices including: drop in groundwater, water salinity, irrigation efficiency, Well-to-Qanat development ratio, the pumping time, shortage of water supplies for animals and humans and the water negative balance were selected according to previous studies conducted on desertification in Ir...

Journal: :Frontiers in Physics 2023

In recent years, with the abnormal global climate change, problem of desertification has become more and serious. The vegetation pattern is accompanied by desertification, thus, study helpful to better understand causes desertification. this work, we reveal influences hydrotropism on based a vegetation–water system in form reaction–diffusion equations. Parameter ranges for steady-state mode obt...

2018

Most of the issues regarding desertification are always related to soil fertility and water quality [1,2]. Hence United Nation Framework Convention on Climate Change (UNFCCC) seriously globalized the issues of desertification in 1992. The developed and developing including hilly mountainous countries are the conference of the parties and so as Nepal [3]. The catchments in hill and Himalayan reg...

2006
Zhengyu Liu Yi Wang Robert Gallimore Michael Notaro Colin Prentice

[1] The abrupt desertification over the northern Africa in the mid-Holocene is studied in both a complex and a simple coupled climate-vegetation model. In contrast to the previous mechanism that relies on strong positive vegetation-climate feedback and the resulted multiple equilibria, we propose a new mechanism in which the abrupt desertification is caused by low frequency climate variability,...

1999
Martin Claussen Claudia Kubatzki Victor Brovkin Andrey Ganopolski Philipp Hoelzmann Hans-Joachim Pachur

Climate variability during the present interglacial, the Holocene, has been rather smooth in comparison with the last glacial. Nevertheless, there were some rather abrupt climate changes. One of these changes, the desertification of the Saharan and Arabian region some 4 6 thousand years ago, was presumably quite important for human society. It could have been the stimulus leading to the foundat...

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