The influence of urbanization on karst rivers based on nutrient concentration and nitrate dual isotopes： an example from southwestern China  

作　　者：Zhong-Jun Wang Fu-Jun Yue Jie Zeng Si-Liang Li 

机构地区：[1]State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry, Chinese Academy of Sciences,Guiyang 550081, China [2]University of Chinese Academy of Sciences, Beijing 100049,China [3]Puding Karst Ecosystem Research Station, Institute of Geochemistry, Chinese Academy of Sciences, Anshun 562100, China [4]School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK [5]Key Laboratory of Karst Environment and Geohazard,Ministry of Land and Resources, Guizhou University,Guiyang 550025, China [6]Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China [7]State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China

出　　处：《Acta Geochimica》2017年第3期446-451,共6页地球化学学报（英文）

基　　金：financially supported by National Natural Science Foundation of China(Grant Nos.41571130072 and41130536);the Ministry of Science and Technology of China through Grant Nos.2016YFA0601000 and 2013CB956700

摘　　要：China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area,indicating a response to different levels of urbanization.Measurements of nitrate dual isotopes suggest thatvolatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China.China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area,indicating a response to different levels of urbanization.Measurements of nitrate dual isotopes suggest thatvolatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China.

关 键 词：URBANIZATION Urban river Nitrate isotopes Southwestern China Chengguan River 

分 类 号：X52[环境科学与工程—环境工程]