FAQ/ Downstream water level at the end of the drainage station with a time of 0 seconds¶
Please tell me about the downstream water level of the river where the end-of-flow drainage station is installed at 0 seconds.
A river was created and a drainage machine was installed at its downstream end. The operating mode is[Pump + Himon] . This river was set not to merge. The downstream end water level was designated for this river.
However, at 0 seconds, the downstream water level of the river did not reach the specified downstream water level. Why?
response¶
This is normal.
IF A DRAINAGE STATION IS INSTALLED IN A RIVER THAT DOES NOT HAVE A MERGING DESTINATION, (A) THE DOWNSTREAM WATER LEVEL OF THE RIVER OBTAINED IN THE SIMULATION HAS A DIFFERENT MEANING FROM (B) THE DOWNSTREAM WATER LEVEL OF THE RIVER SPECIFIED BY THE USER. The figure shows an image of the downstream water level.
- Simulation of downstream water level of river (water level A): Water level upstream of the gutter gate of the end-of-stream drainage station
- User-specified downstream water level of the river (water level B): The water level downstream from the gutter gate of the end-of-flow drainage station
For example, think of water level A as the downstream water level of the river and water level B as the tide level. Between the water level A and the water level B, there is a gutter gate of the drainage station at the end of the stream.
At time 0 seconds, the water level A is the same as the riverbed height. This is because, by default, DioVISTA calculates the river depth from 0 meters. When water level A is higher than water level B, the gutter gate opens. This ensures that after some time, water level A becomes the same value as water level B.
When water level A is lower than water level B, the gutter gate closes. In this case, even after some time, water level A will not be the same as water level B. If you want to prevent this, initialize it with unequal flow. Alternatively, give the flow rate to achieve the desired water level [Upstream flow rate] as . This flow rate is continued to flow for example, for 3 hours, and the values after 3 hours are referred to as the simulation results.