Algae-ecological assessment of water quality and influence factors of algae growth in Songhuaba water source region of Yunnan

To make algae forecast,on-line warning and monitoring and algae control through ecological operation of reservoirs,this paper applies methods of hydrology,ecology,algae taxonomy and physiology to a general investigation of algae on the species level for the Songhuaba water source region of Yunnan,including algae community structure,spatial distribution,dynamic biomass and succession,etc.The results show that the algae in this region can be categorized into 7 phyla,11 classes,12 orders,18 families,30 genera and 48 species and that its structure and distribution are featured by obvious regionality with seasonal changes.Although most of the algae in the water is rinsing,potential risk of algae erupt remains.The algae that would probably cause water blooms is pyrrophyta and its erupt would occur in Gucangba between late May and early June.When the velocity exceeds(0.5-0.85)m/s,the water level has 0.05m changes,or the water temperature has 2℃ changes,the algae community structure and composition changes dramatically.By examining the impacts of water stage and velocity on algae growth,this study demonstrates the feasibility of algae removal and control by reservoir ecological operation and irrigation measures.