نتایج جستجو برای: alluvial channels

تعداد نتایج: 142707  

ژورنال: :پژوهش های دانش زمین 0
مهران مقصودی دانشگاه تهران سید محمد زمان زاده دانشگاه تهران افسانه اهدائی دانشگاه تهران روح الله یوسفی زشک دانشگاه آزاد اسلامی واحد ورامین- پیشوا مجتبی یمانی دانشگاه تهران

ویژگی های محیط طبیعی، مهمترین عامل در جهت شکل گیری سکونت گاه های انسانی خصوصاً در ادوار باستانی می باشد و بهترین راه درجهت پی بردن به ویژگی های طبیعی سکونت گاه های باستانی در زمان برپایی آنها، بررسی های زمین باستان شناسی است. هدف از این پژوهش، بررسی نقش عوامل محیطی در مکان گزینی تپه باستانی چالتاسیان بوده است. این تپه باستانی، در دشت ورامین و در قسمت-های میانی مخروط افکنه جاجرود، واقع شده است. ا...

2011
E. V. RICHARDSON Thomas B. Nolan

Alluvial channel stage-discharge and depth-discharge relations were studied in a large sand-bed recirculating flume. From this study, it was found that the form of these relations are intimately related to: 1. Regime of flow 2. Form of bed roughness a. Characteristics of the bed material b. Concentration of fine sediment c. Temperature 3. Rate of change of discharge with time In the range of sh...

2004
Demetre P. Argialas Angelos Tzotsos

There is a need to automate terrain feature mapping so that to make the process more objective and less time consuming by using proper feature extraction techniques. The objective of this study was the use of object-oriented image analysis methods for the automatic extraction of alluvial fan terrain units. The study area was located in the Death Valley, Nevada, USA. The data used included an AS...

2016
Daniel Hunkeler

Alluvial aquifers in mountainous regions cover typically a limited area. Their contribution to catchment storage and outflow is rarely isolated; alluvial groundwater discharge under gauging stations is generally assumed negligible; and hydrological models tend to lump alluvial storage with other units. The role of alluvial aquifers remains therefore unclear: can they contribute significantly to...

Journal: :Tree physiology 2003
Stewart B Rood Jeffrey H Braatne Francine M R Hughes

Cottonwoods (Populus spp.) are adapted to riparian or floodplain zones throughout the Northern Hemisphere; they are also used as parents for fast-growing hybrid poplars. We review recent ecophysiological studies of the native cottonwoods Populus angustifolia James, P. balsamifera L., P. deltoides Marsh., P. fremontii S. Watson and P. trichocarpa T. & G. in North America, and P. nigra L. in Euro...

Journal: :پژوهش های جغرافیای طبیعی 0
وحید محمدنژاد آروق استادیار گروه جغرافیا، دانشگاه ارومیه

introduction iran forms a relatively compact zone of active continental deformation resulted from the northward collision of arabia with eurasia during late cenozoic times, which is continuing to the present-day at a rate of 25 mm/yrs (from gps data). evidences of active tectonic in different parts of iran, has been studied and identified. the arid climate, low rates of erosion, and minimal veg...

Journal: :تحقیقات جغرافیایی 0
علیرضا تقیان دانشگاه اصفهان

abstract alluvial fans are the most striking phenomena o fluvial geomorphology . these forms are found in frount of mountains and pediments of arid and semiarid zones . alluvial fans are affected by climate changes and tectonics . occurring of tectonic events lead to reaction of alluvial fans . some of these reactions appear on dissection of alluvial fans and displacement of depocenters on allu...

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