3 RESULTS
3.1 Physical and chemical
parameters
Monthly average data of all sampling
stations are presented for the three seasons
(Cool dry: CD, warm dry: WD and
warm wet: WW seasons) from 2009 to
2012 (Tab. III). For both water temperature
and pH, average values were
higher in the WD season. Water temperature
was approximately 8 °C higher
than in the coolest month (January)
whatever the year. The water was
slightly acid. No general annual trend
can be observed for conductivity. It was
relatively low ranging from 28.7 μS.cm-1
in January 2009 to 17.1 μS.cm-1 in June
2012. The nitrate concentrations (NO3
-N)
were generally low over the study
period. The highest values were found
after the impoundment and during the
WW season with an average of
0.36 mg.L-1. NH3-N concentrations were
under the limit of detection (