نتایج جستجو برای: particularly for arid and semi

تعداد نتایج: 19058505  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی مهندسی 1385

acknowledge the importance of e-commerce to their countries and to survival of their businesses and in creating and encouraging an atmosphere for the wide adoption and success of e-commerce in the long term. the investment for implementing e-commerce in the public sector is one of the areas which is focused in government‘s action plan for cross-disciplinary it development and e-readiness in go...

Journal: :journal of agricultural science and technology 2009
s. javadi m. s. kiapasha k. mohammadi

reservoir dams are among the main storage systems employed in agriculture for the several past decades. proper operation of these reservoirs is important for irrigation espe-cially in such arid and semi-arid areas like iran, and particularly during dry years. a computational framework for reservoir simulation and flood routing is hereby presented. a key aspect of the reservoir simulation is the...

2009
A.W.T. Muigai A. M. Okeyo A. K. Kwallah D. Mburu O. Hanotte

Indigenous sheep of Kenya are very important to resource-poor farmers and pastoralists. They have over time adapted to the harsh environmental conditions of the arid and semi-arid lands where they are faced with challenges of persistent droughts, diseases, conflicts and poor nutrition, yet show resistance to gastrointestinal nematodes. In recent years, these indigenous sheep populations have be...

2000
KEVIN SMITH CHRISTOPHER B. BARRETT

Ð This paper introduces a systematic but simple approach to classifying and ordering sources of risk faced by subject populations. By distinguishing between the incidence and severity of subjective risk perceptions, this method enhances understanding of the nature and variation of risks faced within a population. We demonstrate the usefulness of the method as applied to pastoralist communities ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1390

in current study, 63 samples of bat populations collected from differ regions were used for evaluating the geographic variations. twenty cranial and dental characters for traditional morphometric and landmarks method on the ventral, dorsal skull and mandible for geometry morphometric studies were used. statistical analyses of traditional morphometric and geometry morphometric data indicated low...

2005
G. S. Okin J. E. Herrick

Aeolian processes are tightly linked to soil and vegetation change in arid and semi-arid systems at multiple spatial and temporal scales. Wind influences patterns of vegetation and soil within the landscape, and these patterns control wind erosion at patch to landscape scales. Aggregated at larger scales, patterns in soil and vegetation distributions influence global distributions of dust and i...

2015
Taijun Li Bowen Ren Dahui Wang Guobin Liu

Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China's Loess Plateau to assess the variation in C stocks and age-related dynamics...

2012
Clare Duncan Aliénor L. M. Chauvenet Louise M. McRae Nathalie Pettorelli

Droughts can have a severe impact on the dynamics of animal populations, particularly in semi-arid and arid environments where herbivore populations are strongly limited by resource availability. Increased drought intensity under projected climate change scenarios can be expected to reduce the viability of such populations, yet this impact has seldom been quantified. In this study, we aim to fi...

2012
Chunxiang Hu Brian A. Whitton

12.2 Biological Crusts of Arid Regions ............................. 346 12.2.1 Characteristic Species ................................................... 346 12.2.2 Taxonomic Problems in Describing Crust Cyanobacteria ...................................................... 347 12.2.3 Environmental Factors .................................................. 348 12.2.3.1 Light .......................

Journal: :محیط زیست طبیعی 0
سمیه حدادی نیا کارشناس ارشد محیط زیست، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران افشین دانه کار دانشیار گروه محیط زیست، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران کورش عشقی استاد دانشکدۀ صنایع، دانشگاه صنعتی شریف، تهران، ایران علی اصغر درویش صفت استاد دانشکدۀ منابع طبیعی، دانشگاه تهران، تهران، ایران محمد کابلی دانشیار دانشکدۀ منابع طبیعی، دانشگاه تهران، تهران، ایران

tourism as a growing industry needs special attention in developing countries. during last decades, nature based tourism has been growing faster than other tourism fields and it seems to grow even faster. ever growing demand for nature based tourism emphasizes the necessity of a holistic planning for preserving environment against degradation. objective of this study is to present a nature base...

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