نتایج جستجو برای: flood flow

تعداد نتایج: 502385  

2008
James Cullis JDS Cullis

To ensure a healthy and biodiverse ecosystem in cobble and boulder bed rivers, it is imperative that the channel bed is maintained. In pristine catchments this is achieved by the range of flows characteristic of the natural flow regime, which typically incorporates “maintenance” flood flows of different timing, duration and frequency. The construction of dams however, leads to a change in the f...

2004
J. H. Simpson N. R. Fisher P. Wiles

We report new measurements of the turbulent properties of the flow in a tidally energetic estuarine channel of almost uniform cross-section. A high-frequency (1.2 MHz), bottom-mounted Acoustic Doppler Current Profiler (ADCP) has been used to observe the velocity field at a sampling rate of 10 Hz in parallel with measurements of the surface elevation by tide gauges. Our data have been analysed u...

2006
Yan Ding

An optimal flow control methodology based on adjoint sensitivity analysis for controlling nonlinear open channel flows with complex geometries is presented. The adjoint equations, derived from the nonlinear Saint-Venant equations, are generally capable of evaluating the time-dependent sensitivities with respect to a variety of control variables under complex flow conditions and cross-section sh...

موسوی, سیدفرهاد, مهدوی, محمد, نکویی مهر, محمد ,

As unit hydrograph is an important item in flood estimation of the rivers and since flood hydrograph and simultaneous rainfall hyetograph is needed to derive a unit hydrograph, hydrologists recommend synthetic unit hydrographs for areas lacking these hydrometeorological data. A research was conducted in the Zayandehrud-dam watershed (Pelasjan sub-basin) to test the efficiency of synthetic unit ...

Journal: :PROCEEDINGS OF HYDRAULIC ENGINEERING 1993

2012
A. Zahiri A. A. Dehghani

Although many researchers have studied the flow hydraulics in compound channels, there are still many complicated problems in determination of their flow rating curves. Many different methods have been presented for these channels but extending them for all types of compound channels with different geometrical and hydraulic conditions is certainly difficult. In this study, by aid of nearly 400 ...

Journal: :تحقیقات آب و خاک ایران 0
وحید حق شناس دانشجوی دکتری سازه های آبی، گروه مهندسی آب، دانشگاه تربیت مدرس علیرضا وطن خواه دانشیار، گروه مهندسی آبیاری و آبادانی، پردیس کشاورزی و منابع طبیعی، دانشگاه تهران

side weir is a flow control structure that used extensively in irrigation and drainage as well as sewer networks. throughout the present research, a study comprised of 162 experiments was done on sharp-crested semi-circular side weir. since the height in this side weir varies along its length, this feature enables it to more properly control flood than rectangular side weirs in various flood co...

ستار چاوشی بروجنی, , سید سعید اسلامیان, ,

Numerous methods are used in the investigation of floods in catchments such as regional flood frequency analysis. Regional flood frequency analysis relies on physical, climatic and ecological characteristics of catchments and applies statistical methods to study flow records. Hosking and Wallis developed Probability Weighted Moments and presented L-moments statistics as a new tool for flood fre...

2014
A.M. Liu

Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River, Oncomelanias is the only intermediate host of schistosomiasis. Oncomelania entering into farmland or the residential zones through the flood discharge or irrigation system is the main reason of spreading schistosomiasis. Therefore it is most essential and effective way to control diffusion of oncomelanias a...

2016
Sebastian Schwindt Anton J. Schleiss

After a major flood with a peak discharge of 177 m3/s in the city of Martigny (Valais, Switzerland) by the alpine river Drance in October 2000, the local authorities are strengthening efforts for the protection of the urban area. The Drance has an annual average discharge of 10 m3/s and the most important floods occur in the late summer. Two lateral torrents potentially supply the Drance with d...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید