نتایج جستجو برای: desertification assessment

تعداد نتایج: 562493  

2011
N. Juergens

Contents 1. Introduction 1.1. Arid Ecosystems 1.2. Desertification 2. Degradation of natural resources 3. Frame conditions: The importance of scale 4. Defining compartments for feasible approaches 5. Assessment and monitoring of the problem 6. Approaches to combating degradation in arid systems 6.1. Practical steps within the biophysical system 6.1.1 Water resources 6.1.2. Conservation of soils...

Journal: :مرتع و آبخیزداری 0
الهام السادات شکوهی دانش آموخته کارشناس ارشد مدیریت مناطق بیابانی، دانشکده منابع طبیعی، دانشگاه تهران، ایران. غلامرضا زهتابیان استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران. علی طویلی دانشیار دانشکده منابع طبیعی، دانشگاه تهران، ایران.

more than 80% of iran’s area has arid and semi arid climate. therefore, iran is exposed to desertification process. practical activities in controlling desertification must be based on current desertification situation and its severity. based on this theory, evaluating desertification rate indices in khezrabad region was done based on imdpa model. in this research two factors with 10 indices we...

Journal: :Environmental Conservation 1982

Journal: :EPL (Europhysics Letters) 2014

2014
Junhong Zhang

Karst rocky desertification is a geo-ecological problem in Southwest China because of nature and man-made factors, which restricts the development of local economic and social. Soil and water erosion is one of the most harmful form of rocky desertification, but the management methods still keep in the exploratory stage. Biological soil crust is the organic complexes of biotic components includi...

2016
Yunfa Miao Heling Jin Jianxin Cui

Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in ...

2008
L. LI A. H. WANG

Land desertification has become a significant issue of economy and ecological environment in global area. In this paper, we have applied the object-oriented method to the research of Zhenglanqi basin and the West of Badain Jaran Desert which present obviously different characters of china. On the basis of the multi-spectral images of Beijing-1 in June and September in 2006, under the standard c...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده زبانهای خارجی 1389

this study was conducted to investigate the impact of portfolio assessment as a process-oriented assessment mechanism on iranian efl students’ english writing and its subskills of focus, elaboration, organization, conventions, and vocabulary. out of ninety juniors majoring in english literature and translation at the university of isfahan, sixty one of them who were at the same level of writing...

2015
Shou-Li Li Fei-Hai Yu Marinus J. A. Werger Ming Dong Heinjo J. During Pieter A. Zuidema

Desertification is a global environmental problem, and arid dunes with sparse vegetation are especially vulnerable to desertification. One way to combat desertification is to increase vegetation cover by planting plant species that can realize fast population expansion, even in harsh environments. To evaluate the success of planted species and provide guidance for selecting proper species to st...

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