Long description
Figure 20 shows the development of the algal bloom coverage in Lake Taihu, for the years 2000 to 2011. There twelve pictures that show the outline of Lake Taihu with areas that have an algal bloom on them coloured bright green. The extent of the algal bloom tend to increase year on year but the increase is not always smooth. For example the coverage in 2009 is fairly low and similar to that in 2004. The greatest coverage is shown in years 2006, 2007, 2010 and 2011.