[Water Quality Characteristics and Distribution of Bacterial Communities During Thermal Stratification in the Miyun Reservoir].

As an important urban drinking water source, reservoirs are a special type of water body formed by artificial dams. Water quality of reservoirs directly affects the residents' drinking water safety. In order to reveal the characteristics of stratification and vertical changes of bacterial communities in the Miyun Reservoir, a drinking water source of Beijing, vertical stratified samples were collected during the stable stratified period of the reservoir (autumn).

[Dry and Wet Deposition of Atmospheric Nitrogen in Small Catchments].

Atmospheric nitrogen deposition is one of the important pathways for the transmission of terrestrial pollutants and nutrients to aquatic ecosystems. A considerable amount of nitrogen substances is delivered into the surface water environment via atmospheric deposition in the catchments, which are greatly affected by human activities, and have serious negative effects on the nutrient level and aquatic habitat environment. The Shixia Catchment north of the Miyun Reservoir was selected as study area.

[Spatial Distribution Characteristics and Source Analysis of Dissolved Organic Matter in Beiyun River].

Dissolved organic matter (DOM) in aquatic ecosystems has gained wide concern because of its influence on the light attenuation, nutrient availability and contaminant transport. Human activities strongly influence the DOM of rivers in different ways, including increased agricultural activities and industrial and domestic emissions. However, recent socio-economic development with rapid urban development has significantly enhanced the discharge of sewage, and has caused high loads of DOM, which in turn pose a great risk to aquatic ecosystems.