Assuming the length of the channel is 1 m, the velocity of water coming from below the channel may be twice or even more than that of the river. However, if the length of the channel is very short, such as tens of centimeters or less, the increase of water velocity may be small, or even there may be no obvious change.
If water flows through both sides of the river, the flow rate may slow down. Because the obstacles on both sides of the channel will make the water flow resistant, the flow rate will slow down. The specific flow rate depends on the shape of the channel, the shape of the obstacle and the density of the water.
Therefore, it is necessary to consider the length and shape of the channel and the density of water when determining the degree to which the water flow rate will become faster or slower. In addition, it is necessary to consider the flow pattern of water in the channel, such as whether there is vortex or turbulence, which will also affect the flow rate of water.
In order to measure the flow rate of water more accurately, a speedometer or other measuring tools can be used. These tools can help you measure the flow velocity of water more accurately and help you determine the flow pattern of water in the channel.
In addition, if you want to measure water flow more accurately, you need to consider the accuracy of measuring time and measuring position. For example, the measurement time is too short, or the measurement position is not accurate enough, which may lead to errors in the measurement results. Therefore, attention should be paid to ensure the accuracy of measurement.