نتایج جستجو برای: in semi arid area geomorphological impacts of dams are very major dams

تعداد نتایج: 24530842  

2012
Rakhshan Roohi John Webb

With the continuing pressure on Australia’s water resources and interand intra-annual rainfall variability, farmers, especially in rainfed agricultural and pastoral zones, have been developing farm dams as a mean of providing additional water sources for irrigation and stock. The density of farm dams has increased over time, and an accurate knowledge of the spatial distribution of farm dams is ...

Small sediment dams are the key structures for controlling sediment flow and improving the course of waterways in watersheds. In Kermanshah province, the efficiency of these structures in sediment accumulation has been less studied and evaluated. This study aimed to investigate the efficiency of these structures in sediment retention and flood control in three watersheds of the province. For th...

Journal: :پژوهش های زراعی ایران 0
مرجان قائمی علیرضا آستارایی سید حسین ثنایی نژاد

more than two third of the world lands are located in arid and semi arid area including iran. unfortunately there is lack of information and consequently poor scientific studies in these areas because of the difficulties which we face for collecting data and doing field studies in such a big areas under hard situations. however, in the recent decades there has been a great progress in using rem...

2011
Richard T. Kingsford

Dams, diversion of water, invasive species, overharvesting and pollution are degrading rivers and wetlands. Climate change may exacerbate impacts of these threats through predicted reductions in rainfall and increased temperature, decreasing flow and altering timing and variability of flow regimes. Papers in this special issue identify conservation-management strategies for wetlands and rivers ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد 1388

plagiarism in esl/efl learning contexts has been established as a dynamic and multi-layered phenomenon and has become a topic engaging many researchers in a heated debate in recent years. comparisons of student-generated texts with their source texts have shown that students rely on source texts in their writings and copying is a major strategy used by both l1 and l2 writers. in our country a...

Journal: Desert 2007
A. Esmaeili Nameghi A. Hassanli, M. Soufi

Abstract Spacing between check dams depends on the stream bed slope, effective height of check dams and slope of deposited sediments behind the check dams. The slope of deposited sediments is more important than the other two factors because of complications in the way of its occurrence and its measurement after several years of dam construction. This research presents the effective factors a...

Journal: :Aqua 2022

Abstract Anthropogenic interventions in the form of dams and barrages often alter fluvial functionality eco-geomorphological (geomorphology, hydrology, ecology) behaviour river systems. The present work examines environmental flow, channel metamorphosis, Damodar River context Valley Corporation (DVC) development. Structural (dams, barrages, weirs, etc.) non-structural (urban–industrial agricult...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان 1392

in the area of vocabulary teaching and learning although much research has been done, only some of it has led to effective techniques of vocabulary teaching and many language learners still have problem learning vocabulary. the urge behind this study was to investigate three methods of teaching words. the first one was teaching words in context based on a traditional method of teaching that is,...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مدیریت و حسابداری 1391

the application of e-learning systems - as one of the solutions to the issue of anywhere and anytime learning – is increasingly spreading in the area of education. content management - one of the most important parts of any e-learning system- is in the concern of tutors and teachers through which they can obtain means and paths to achieve the goals of the course and learning objectives. e-learn...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

armenias geopolitics and its historical experience have had a determining impact on the character of its foreign policy .present-day armenia is a small, landlocked country with _11,620 square miles area armenias landlocked nature makes it dependent on the benevolence of its neighbors for access to the outside world a fact that gives it a sense of isolation and vulnerability. as it was indic...

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