The Influence of Raised Field on Eutrophication in Baiyangdian Lake

In this paper, the impact of raised field on Baiyangdian Lake eutrophication was analyst according to the TROPHIC LEVEL INDEXES (TLI) calculated with the monitored water quality data and raised field structure index-raised field\´s scope", "canal\´s length", "canal\´s width by SPASS and Excel software. Results of the study show that the key stage of TLI reduction in a canal is 0-30m, which is the stage water in the canal exchanges with external water frequently. Canal\´s length affects the degree raised field reduces TLI of water in the canal. The TLI of 0m influences the range of TLI reduction in the canal. There is relationship between raised field\´s scope and TLI reduction range of breakthrough canal. The lowest TLI of water in breakthrough canal is closer to canal\´s entrance than non breakthrough canal. It is advised that it is better to reconstruct breakthrough canal and the advised raised field index is that canal\´s length is 160-180m", "canal\´s width is 6-8m and raised field\´s scope is 20-30°. The reconstructed canal should be different in structure according to the trophic state level.