EHI showed that the dredging project caused negative effects on the lake health in the dredged region at first. Water chemistry and biomass returned to the initial state before dredging. However, these positive effects disappeared overtime. The monitoring results showed that the dredging project caused many short-term positive effects such as decreased total nitrogen, total phosphorus, permanganate index and phytoplankton biomass throughout the entire lake water, increased Secchi disk depth in the whole lake and increased benthonic animal biomass in the nondredged regions. To understand the variations of lake ecosystems before, during and after the project, water quality, phytoplankton, zooplankton and benthic animal biomass were monitored Four subindicators, including eco-exergy (Ex), structural eco-exergy (Ex st), buffer capacity of total phosphorus for phytoplankton (β (TP)(phyto)) and trophic level index (TLI) were calculated and developed to an integrated ecosystem health indicator (EHI). In this study, a dredging project was followed for 5 years. A lengthy and holistic assessment is important to understand the effects of a dredging project on a lake ecosystem. Sediment dredging is a controversial technology for lake eutrophication control.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |