IV. the analysis of reasons

1. the water pollution and eutrophication
In our research, we find that there are three animal husbandry factories, which discharge sewage directly into Jingmi Channel. The organic substance in sewage causes eutrophication.
2. lack of rain
The climate of recent years is lack of rain, which cause numerous production of lagae.
3. ecological disturbances
The eutrophication causes ecological disturbance of water, which leads to death of fish, shrimp, swan mussel and other species.