Fig. 2.

Seasonal variations of water quality and Tukey test at each site (Rz: Riverine zone, Tz: Transition zone, Lz: Lacustrine zone, BOD: biological oxygen demand (a–c), SS: suspended solids (d–f), TN: total nitrogen (g–i), COD: chemical oxygen demand (j–l), EC: electrical conductivity (m–o), TP: total phosphorus (p–r), CHL-a: chlorophyll-a (s–u), the first highest mean receives the letter “a”, and the second and third highest mean receives the letter “b”, and “c”, respectively, and means with no significant difference receive the same letter).