In order to emphasize that the 2009 was the year that had the lowest value of Microcystis
spp., along with having the highest cumulative value of solar radiation this year.
Therefore, it can be concluded that the most important factor is not the total value of
solar radiation, by contrast it determines how it is distributed throughout the year (Figure
3). Thus the year 2010, which had the highest values of Microcystis spp.(Figure 4), had a
steep and constant slope from early spring through August.