Tuesday 30 September 2014

Annual minimum flow


The annual minimum flow to date occurred on 24 September after a dry period of 5 days. Stage dropped to about 31 cm which is approximately 0.4 m3/s (0.0206 m3/s/km2) on the current stage-rating curve. A rainfall event of 37 mm around 25 September was enough to raise the baseflow level of the river by about 4 cm. This year's precipitation has been more evenly distributed than average which means that the annual minimum flow is also relatively high.


Friday 19 September 2014

September low flows


The first 9 days of September were very dry (just 3 mm of rainfall on the 5th), and we can see the water level falling to only about 32 cm. This might be the lowest water level for the water year, also known as the minimum annual flow. Today we measured the discharge to be 0.45 m3/s at a stage of 34.5 cm. With a basin area of 19.45 km2, the specific discharge becomes 0.0231 m3/s/km2.


Monday 1 September 2014

August rain


The hydrograph above shows that rains were quite frequent during August this year. Total precipitation for the month was 224mm at Miomote Amedas station, which is slightly above the average value of 209mm. The most notable storm event occurred on 11 August with a daily precipitation of 68mm (maximum intensity 15mm/h). Hot and dry weather around the week of 25 August saw the river level drop to near season-lows, and the daily fluctuations appear to show the influence of strong evapotranspiration during daytime. However, the dry first week of August does not show this diurnal pattern.