April 2, 2019
4:00PM - 4:30PM
Miss SHI Xiaoyan Department of Earth Sciences, HKU
Lake Taihu locates in the Yangtze River Delta (YRD) and is the third largest freshwater lake of China. It plays an important role on water supply, agriculture, aquaculture, fisheries and tourism. Unfortunately, Lake Taihu has suffered from serious environmental and ecological issues such as eutrophication and algae outbreaks. River input with anthropogenic sewage and fertilizer are thought to be responsible for these problems, and have been primarily targeted in traditional water resource remediation and improvement. However, the widely-distributed and well-developed groundwater around Lake Taihu may be another nutrition source, and groundwater and LGD may have potential influences on lake water quality.
Water samples from Lake Taihu were taken and analyzed, including lake water, river water and groundwater. Nutrition (NO3, NO2, NH4, PO4) are more concentrated in groundwater, indicating that groundwater should be regarded as the potential nutrition source. The nutrition distributions on lake reflect the influences from river as well as groundwater. Based on the Radon-222 balanced model, LGD is calculated to be 0.89×107 m3/d (3.78±2.07 mm/d), which is much smaller than the average river inflow of 3.15×107 m3/d, but the related nutrition inputs from the two sources are comparable because of the higher nutrition load in groundwater