A positive surge is an unsteady open channel flow motion characterised by a sudden rise in water surface elevation. The surge propagation was a three-dimensional unsteady flow motion, resulting in a complicated transient secondary motion compared to positive surge propagating in rectangular canals.

in the midst of things

səˈlɛrəti) A rate that is rapid. Synonyms. speediness promptitude fleetness immediacy rapidness expedition dispatch rate despatch promptness expeditiousness rapidity quickness instancy immediateness instantaneousness pace. Antonyms. indirectness mediacy immediate mediate refrain.

Wave celerity – The speed at which an individual wave advances or “propagates” is known as the wave celerity. For a deepwater wave the celerity is directly proportional to the wave period, T. The formula for deepwater celerity, Co, is Co =1.56T m/sec = 5.12T ft/sec.

The open channel Surges due to sudden changes of flow depth creates Celerity (Wave Velocity) in the flow in addition to the normal water velocity of the channels. These waves travel in the downstream and sometimes upstream of the channels depending on the various situations.

Hydraulic surges are created when the velocity of a fluid suddenly changes and becomes unsteady or transient. Fluctuations in the fluid’s velocity are generated by restrictions like a pump starting/stopping, a valve opening/closing, or a reduction in line size.

Hydraulic jumps can be seen in both a stationary form, which is known as a “hydraulic jump”, and a dynamic or moving form, which is known as a positive surge or “hydraulic jump in translation”. They can be described using the same analytic approaches and are simply variants of a single phenomenon.

A hydraulic jump occurs when the upstream flow is supercritical (F>1). To have a jump, there must be a flow impediment downstream. The downstream impediment could be a weir, a bridge abutment, a dam, or simply channel friction. Water depth increases during a hydraulic jump and energy is dissipated as turbulence.

In biological oceanography, ‘Critical Depth’ is defined as a hypothesized surface mixing depth at which phytoplankton growth is precisely matched by losses of phytoplankton biomass within this depth interval. This concept is useful for understanding the initiation of phytoplankton blooms.

positive surge

When the depth is normal, which parameter is zero? Explanation: Normal depth is a depth of flow in the channel. It is created when the slope of the water surface and channel bottom is the same and the water depth remains the same throughout the entire flow.

Hydraulic jump usually maintains the high water level on the down stream side. This high water level can be used for irrigation purposes. Hydraulic jump can be used to remove the air from water supply and sewage lines to prevent the air locking.

The tailwater at a culvert is the depth of water at the downstream end of the culvert, as measured from the downstream invert of the culvert. The tailwater must be known or estimated prior to performing the culvert hydraulic calculations. There are various methods to estimate the tailwater at a culvert.

1 : water below a dam or waterpower development. 2 : excess surface water draining especially from a field under cultivation.

about 4 inches deep

We take the average depth multiplied by the average width to obtain the cross-sectional area and divide by four to determine the rough diameter of pipe needed to pass the average storm. The diameter of pipe(s) used must add up to the total diameter needed without using a pipe taller than the average depth.