The agricultural and livestock activities surrounding the rivers flowing into the lakes have caused non-point source pollution, leading to excessive amounts of nutrient salts in downstream rivers. Introducing river wa...The agricultural and livestock activities surrounding the rivers flowing into the lakes have caused non-point source pollution, leading to excessive amounts of nutrient salts in downstream rivers. Introducing river water into constructed wetlands along river course has proven to be an effective solution for decreasing nitrogen(N) and phosphorus(P) loads. This paper reports 9 years of monitoring the Yong’an River and its surrounding constructed wetlands in the upper reaches of Erhai Lake, located in Yunnan Province, China. This study analyzed the main types of pollutants in the river, and evaluated the removal efficiency of pollutants by the constructed wetlands. The findings indicate that total nitrogen(TN) and nitrate nitrogen(NO_(3)^(–)-N) are the primary pollutants in the Yong’an River, which exhibit variation throughout the year corresponding to the alternating wet and dry seasons. Although constructed wetlands are effective in removing NO_(3)^(-)-N and P, their efficacy in removing ammonium nitrogen(NH_(4)^(+)-N)and organic pollutants is limited. This limitation can be attributed to the lack of timely disposal of aquatic plant residues. This research contributes to the understanding of the potential issues that may arise during the extended use of constructed wetlands and provides solutions to address them.展开更多
Classification of groundwater conditions at the watershed scale synthesizes landscape hydrology, provides a mapped summary of groundwater resources, and supports water management decisions. The application of a recent...Classification of groundwater conditions at the watershed scale synthesizes landscape hydrology, provides a mapped summary of groundwater resources, and supports water management decisions. The application of a recently developed watershed-scale groundwater classification methodology is applied and evaluated in the 100,000 hectare lower Ruby Valley watershed of southwestern Montana. The geologic setting, groundwater flow direction, aquifer productivity, water quality, anthropogenic impact to water levels, depth to groundwater, and the degree of connection between groundwater and surface water are key components of the classification scheme. This work describes the hydrogeology of the lower Ruby Valley watershed and illustrates how the classification system is applied to assemble, analyze, and summarize groundwater data. The classification process provides information in summary tables and maps of seamless digital overlays prepared using geographical information system (GIS) software. Groundwater conditions in the watershed are classified as low production bedrock aquifers in the mountainous uplands that recharge the moderate productivity basin-fill sediments. Groundwater levels approach the surface near the Ruby River resulting in sufficient groundwater discharge to maintain stream flow during dry, late summer conditions. The resulting classification data sets provide watershed managers with a standardized organizational tool that represents groundwater conditions at the watershed scale.展开更多
基金supported by National Key Research and Development Program of China(2021YFD1700400)Yunnan Fundamental Research Projects(202201AU070001)Startup Fund for Young Faculty at SJTU(22X010500256).
文摘The agricultural and livestock activities surrounding the rivers flowing into the lakes have caused non-point source pollution, leading to excessive amounts of nutrient salts in downstream rivers. Introducing river water into constructed wetlands along river course has proven to be an effective solution for decreasing nitrogen(N) and phosphorus(P) loads. This paper reports 9 years of monitoring the Yong’an River and its surrounding constructed wetlands in the upper reaches of Erhai Lake, located in Yunnan Province, China. This study analyzed the main types of pollutants in the river, and evaluated the removal efficiency of pollutants by the constructed wetlands. The findings indicate that total nitrogen(TN) and nitrate nitrogen(NO_(3)^(–)-N) are the primary pollutants in the Yong’an River, which exhibit variation throughout the year corresponding to the alternating wet and dry seasons. Although constructed wetlands are effective in removing NO_(3)^(-)-N and P, their efficacy in removing ammonium nitrogen(NH_(4)^(+)-N)and organic pollutants is limited. This limitation can be attributed to the lack of timely disposal of aquatic plant residues. This research contributes to the understanding of the potential issues that may arise during the extended use of constructed wetlands and provides solutions to address them.
文摘Classification of groundwater conditions at the watershed scale synthesizes landscape hydrology, provides a mapped summary of groundwater resources, and supports water management decisions. The application of a recently developed watershed-scale groundwater classification methodology is applied and evaluated in the 100,000 hectare lower Ruby Valley watershed of southwestern Montana. The geologic setting, groundwater flow direction, aquifer productivity, water quality, anthropogenic impact to water levels, depth to groundwater, and the degree of connection between groundwater and surface water are key components of the classification scheme. This work describes the hydrogeology of the lower Ruby Valley watershed and illustrates how the classification system is applied to assemble, analyze, and summarize groundwater data. The classification process provides information in summary tables and maps of seamless digital overlays prepared using geographical information system (GIS) software. Groundwater conditions in the watershed are classified as low production bedrock aquifers in the mountainous uplands that recharge the moderate productivity basin-fill sediments. Groundwater levels approach the surface near the Ruby River resulting in sufficient groundwater discharge to maintain stream flow during dry, late summer conditions. The resulting classification data sets provide watershed managers with a standardized organizational tool that represents groundwater conditions at the watershed scale.
