The influence of urbanization on karst rivers based on nutrient concentration and nitrate dual isoto

• 作者: Zhong-Jun Wang Fu-Jun Yue Jie Zeng Si-Liang Li
• 来源期刊: 地球化学学报(英文）
• 关键词: Urbanization Urban river Nitrate isotopes Southwestern China Chengguan River
• 年，卷（期）: 2017,（3）
• 页码范围: 446-451
• 页数: 5页
• 语种: 英文
• DOI: 10.1007/s11631-017-0188-9

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 that volatilization, 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.