نتایج جستجو برای: desertification intensity

تعداد نتایج: 182836  

Journal: :desert 0
m.s. ziaei associate professor, faculty of management, univ. of tehran, tehran, iran r. masoudi ph.d. student, faculty of natural resources, university of tehran, karaj, iran m. ghodsi ph.d. student, faculty of geography, university of tehran, tehran, iran h. khosravi ph.d. graduate, faculty of natural resources, university of tehran, karaj, iran

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...

2006
ZENG Xiaodong Robert E. DICKINSON Xubin ZENG Samuel S. P. SHEN

This paper investigates the hydrological interactions in the atmosphere-evegetation-soil system by using the bucket model and several new simplified intermediately complex models. The results of mathematical analysis and numerical simulations show that these models, despite their simplicity, can very clearly reveal the essential features of the rather complex hydrological system of atmosphere-e...

2014
Guang-Lei Gao Guo-Dong Ding Bin Wu Yu-Qing Zhang Shu-Gao Qin Yuan-Yuan Zhao Yan-Feng Bao Yun-Dong Liu Li Wan Ji-Feng Deng

BACKGROUND Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. METHODOLOGY/PRINCIPAL FINDINGS To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of succe...

2011
A. L. COWIE T. D. PENMAN L. GORISSEN M. D. WINSLOW J. LEHMANN T. D. TYRRELL S. TWOMLOW A. WILKES R. LAL J. W. JONES A. PAULSCH K. KELLNER M. AKHTAR-SCHUSTER

The United Nations Convention to Combat Desertification and its sister conventions, the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity, all aim to halt or mitigate the deterioration of the ecological processes on which life depends. Sustainable land management (SLM) is fundamental to achieving the goals of all three Conventions. Changes in land ...

2012
YinPing CHEN YuQiang LI Tala AWADA JuanJuan HAN YongQing LUO

Horqin Sandy Land is a fragile, seriously desertified region located in Inner Mongolia of China. Overgrazing is one of the primary drivers of desertification in this region. We investigated whether the establishment of grazing exclosures in areas with active sand dunes enhances soil carbon (C) sequestration and benefits soil recovery. The results showed that soil organic C storage was 1.4, 1.9,...

Journal: Desert 2013
H. Ahmadi M. Jafari M. Naghiloo M. Tahmoures

Desertification is recognized as a serious environmental threat in Iran because of its climatic-geomorphologicconditions. Desertification and land degradation in arid, semi-arid, and dry sub-humid regions, is a globalenvironmental problem. Accurate assessment of the status and trend of desertification is instrumental in developingglobal strategies to prevent and reverse this problem. The goal o...

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 ...

Journal: Desert 2012
Ahmadi H. Gh. Chamanpira Gh.R. Zehtabian M. Ekhtesasi

In recent years, the topic of desertification has been discussed in different ways in scientific areas. This event occurred globally, regionally and nationally and many steps were taken to stop it. Desertification is challenged universally and its destructive effects are unavoidable and its consequences do endanger the life of inhabitants. The identification of sensitive regions and prevention ...

2009
Rattan Lal

Desertification, a natural process, is exacerbated by anthropogenic activities. It reduces soil productivity, jeopardizes food security, impairs environment quality, accelerates global warming and exacerbates global security risks. Degradation of soil and vegetation aggravates the emission of greenhouse gases into the atmosphere. The biophysical processes of soil and vegetation degradation are ...

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...

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