Friday 28 September 2018

September wetter than usual


Early September began wetter than usual and another powerful typhoon (#24) is due to arrive around 30th September. Today's discharge measurement was 0.975 m3/s at 0.425 m stage, which fit exactly on the current rating curve.


Wednesday 5 September 2018

Persistent rains during late August


As you can see from the hydrograph above, the drought finally broke on 16th August with a good sized flood, followed by unusually persistent rains (similar to rainy season) during the last week of August. This season normally has flash-floods with short-lived peak discharges. This kind of persistent rain will have done much to replenish the groundwater levels which were at extremely low levels through June and July.


The updated stage-rating curve below shows that recently measured high flows seem to plot well below the previous curves, while medium to low flows are similar. As always, further measurements are needed to confirm this apparent change in the shape of the stage-rating curve.