Flow rate - Discharge Vs Time/Distance

[Andre]

Yes, Im aware of that, the higher water flows easier over the obstacles, like pools, and rocky sections, so in practice, heavier flows, do cause a faster river.[/QUOTE]

[Andre s]

flow.jpg

Did this long ago, should give some indication of how long the increase takes to reach 15.54Km, but the time will change over distance, so i don't think it will be very accurate if you multiply this by 4.5 to get 70km and if the outflow peaked at 70cum and then started dropping the next day, 70cum wont reach Schoemans. unless the outflow was 70cums for a day.

Unfortunately, when i did this, the gauge at Schoemans was faulty, so i couldn't take the readings there which would have probably been able to answer the question and interesting.



BARRAGE DAILY LOGSHEET
Day: TUESDAY Barrage to Gbay = 15.54km
Date:- 22 NOVEMBER 2011
Time Disch (m³s) gbay flow time hours
09:00 15.091 15.03 23:00..........22 14hrs
22:00 20.214 20.025 14:48........23 16h48m
Time Disch (m³s) WEDNESDAYTUESDAY
07:00 25.262 25.43 20:12..........23 13h12m Date:- 23 NOVEMBER 2011
12:00 30.304 30.136 23:36.........23 11h36m
20:00 45.486 45.664 13:12..........24 15h12m
09:00 55.660 55.673 19:48..........24 10h48m
12:00 60.692 60.592 21:24..........24 9h24m
18:00 75.447 70.064 05:36.........25 11h36m Goose bay peaked at 70.064
Time Disch (m³s) DAY: FRIDAY
Time Disch (m³s) DAY: SATURDAY
14:00 62.184 62.279 17:00........26 5h
20:00 45.131 45.503 02:12.........27 6h12m
Time Disch (m³s) DAY: SUNDAY
07:00 40.061 40.96 09:36.......27 2h36m Date:- 27 NOVEMBER 2011
14:00 29.926 29.855 20:24.........27 6h24m

[Glans]

The only reason why you would like to know the question would be to save lives or equipment.
Or see if you can catch fish, obviously.
The farmers probably not all have some system where they know the time it takes for the raised water level from the barrage to reach them after the slues has been opened. Over years of experience of loosing a pump or animals farmers know or should know how long the increased water level would take to reach them. This should be close to the estimate calculated but would reflect the real time that it takes. Not sure if farmers would accurately make the link between volume released and time it would take to reach them?