Storage in channel routing and the factors affecting it

Channel routing is the process of determining the flow of water through a river or stream channel over time. It is important in water resources management for flood forecasting, flood control, and water supply planning. One of the key variables in channel routing is storage, which is the amount of water held in the channel at any given time. Storage is affected by several factors, including:

Inflow discharge: This is the amount of water entering the channel from upstream sources, such as tributaries or precipitation. It is typically measured in cubic meters per second (m3/s) and can vary depending on weather conditions, runoff characteristics, and land use practices.

Outflow discharge: This is the amount of water leaving the channel and flowing downstream. It is also measured in m3/s and can be affected by factors such as channel geometry, slope, roughness, and sediment transport.

Channel storage: This is the volume of water held in the channel itself, which can vary depending on the cross-sectional area of the channel, the depth of water, and the shape of the channel bed and banks. Channel storage can be affected by factors such as vegetation, erosion, deposition, and sediment transport.

The relationship between inflow discharge, outflow discharge, and channel storage is governed by the continuity equation, which states that the rate of change of water storage in the channel is equal to the difference between inflow and outflow discharges. In other words, if inflow exceeds outflow, the channel storage will increase, while if outflow exceeds inflow, the channel storage will decrease.

Therefore, in case of channel routing, the storage is a function of both inflow discharge and outflow discharge. Option 'B' is the correct answer.