To investigate the influences of river bend geometry on flow structures, three-dimensional simulations were carried out. The influence of aspect ratio, channel sinuousness and curvature ratio were investigated. Simulation results show that with an increasing of channel aspect ratios, the streamwise variation of flow velocities decreases significantly, which is not the case for the spanwise direction. Simulation results also reveal the significant influence of the curvature ratio on the redistribution of primary flows. The streamwise variation of free-surface and bottom-wall velocities was compared and the phase differences between them was identified, which was described as anti-phase and out-of-phase patterns. Deep-water channels with an aspect ratio of 0.15 show significant phase-lag of flow velocities compared with channel geometry, this newly observed phenomenon implies the shift of the peak scouring point in fluvial river meanders. For the first time to our knowledge, the streamwise and spanwise variation of primary and secondary flow strength, as well as their spatial derivatives, are quantitatively provided, which are valuable for theoretical studies. It is also found that the widely adopted assumption that the streamwise velocity component is one order magnitude larger than the spanwise, is only valid for river bends with small curvatures and aspect ratios.
Accurate and Reliable Rainfall Measurements using Multiple X-band Compact Radars
IntroductionRecent serious threats to civilian lives due to localized heavy rains, larger typhoons and other meteorological events have been increasing. Many countries consolidate infrastructures that control rivers and sewage. They are creating systems to predict flow amounts and adding these capabilities to their existing weather observation and prediction systems. Each country deploys C-band and/or S-band radars to cover their nationwide area. Recent improvements include the addition of dual polarimetric...
Largest River Island in the United States Manages Flood Control with In-Siti^ System - Application ...
IntroductionSome of the most fertile agricultural lands in the United States are found in the Willamette Valley of Oregon. Sauvie Island, the largest river island in the United States, lies approximately 10 miles (16 km) northwest of downtown Portland. The Columbia River flows along the east, the Multnomah Channel lies to the west, and the Willamette River to the south. The 26,000-acre (105 km2) island provides rich farmland and a refuge for wildlife.
Utah’s Great Salt Lake in Jeopardy
Can irrigation efficiency and water reuse keep it from drying out? The Bear River’s circuitous course to the Great Salt Lake takes it through Utah, Wyoming, and Idaho, each of which is allotted a volume of its water under the Bear River Compact of 1958. Until now, the states have been unable to use all of their allotted water, and the agreement has not been amended since 1980. But, in an era of population and agricultural growth, and shrinking water supplies, hydrologists like Craig Miller of the Utah...
Tucson to Revive River with Recycled Wastewater
Plan will take advantage of existing water reuse facilities Traveler Julius Froebel once described the lush river valley that he encountered on his 1855 trip along the Santa Cruz River as: […] covered with poplars and willows, ash-trees and plantains, oaks and walnut trees […] Some portions of the valley are of such grand, rich and simple beauty […] that they would be remarkable in any part of the world. But that was before there ever was a city of Tucson, Arizona, on the site. Historic...
Live Webinar: OTT SVR 100 Radar Sensor - contact-free reliable and maintenance-free measurements
The measurement of the velocity at the water surface is one of the oldest hydrometric measuring methods, time-tested and easy to carry out with the aid of surface floats. While float measurements are only temporarily applicable and often error-prone, modern radar sensors can determine the surface velocity in real time and with a very high measuring accuracy around the clock. Learn more about the functional principle and the advantages of contact fee surface water velocity measurement with the OTT SVR 100 as...