Antecedent rainfall and land use controlling the fate of nitrogen in karst urban rivers, elucidated by an isotopic approach
| Autor: | Ping Zhang, Cheng Yang, Xiao-Zheng Li, Fu-Jun Yue, Liu Taoze, Sai-Nan Chen, Xiao-Dan Wang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Pollutant
Pollution Hydrology geography Denitrification geography.geographical_feature_category 010504 meteorology & atmospheric sciences media_common.quotation_subject 0207 environmental engineering 02 engineering and technology Urban area Karst 01 natural sciences chemistry.chemical_compound Isotopic signature Nitrate chemistry Environmental science Ecosystem 020701 environmental engineering 0105 earth and related environmental sciences Water Science and Technology media_common |
| Zdroj: | Journal of Hydrology. 592:125803 |
| ISSN: | 0022-1694 |
| DOI: | 10.1016/j.jhydrol.2020.125803 |
| Popis: | Combined with human activities, rainfall events have become an important factor affecting the urban ecological environment, particularly in karst areas, where the ecosystem is fragile and more affected by pollution due to the frequent water exchange. To understand the fate of nitrogen in karst urban rivers, samples were collected under various rainfall events classified in four different hydrological conditions. The concentration of nitrogenous species, water isotopes and nitrate dual isotopes were measured. The results showed that nitrate was the primary inorganic nitrogen (>70%) in most of the samples. The nitrate isotopic signature and hydrochemistry suggested that volatilization and denitrification enriched the isotopic composition during low flow conditions (20.0 ± 8.0‰), while a high isotopic signature during high flow conditions suggested an anthropologic source, e.g. domestic waste. A response between accumulated rainfall and nitrate concentration in the studied urban karstic river suggested that antecedent conditions and sources accumulated in an urban area can affect N pollution in an urban area. This study highlighted that careful management in urban areas is required to understand the knowledge of transport flow paths of pollutant during rainfall events. |
| Databáze: | OpenAIRE |
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