https://scholars.lib.ntu.edu.tw/handle/123456789/402015
標題: | Differences in N loading affect DOM dynamics during typhoon events in a forested mountainous catchment | 作者: | JR-CHUAN HUANG | 關鍵字: | Dissolved organic matter; Hydrologic extremes; Nutrient dynamics; Terrestrial-aquatic continuum; Typhoon event | 公開日期: | 八月-2018 | 來源出版物: | Science of The Total Environment | 摘要: | The dissolved organic matter (DOM) and nutrient dynamics in small mountainous rivers (SMRs) strongly depend on hydrologic conditions, and especially on extreme events. Here, we investigated the quantity and quality of DOM and inorganic nutrients during base-flow and typhoon events, in a chronically N-saturated mainstream and low N-loaded tributaries of a forested small mountainous reservoir catchment in Taiwan. Our results suggest that divergent transport mechanisms were triggered in the mainstream vs. tributaries during typhoons. The mainstream DON increased from 3.4 to 34.7% of the TDN pool with a static DOC:NO3-N ratio and enhanced DOM freshness, signalling a N-enriched DOM transport. Conversely, DON decreased from 46 to 6% of the TDN pool in the tributaries and was coupled with a rapid increase of the DOC:NO3-N ratio and humified DOM signals, suggesting the DON and DOC were passively and simultaneously transported. This study confirmed hydrology and spatial dimensions being the main drivers shaping the composition and concentration of DOM and inorganic nutrients in small mountainous catchments subject to hydrologic extremes. We highlighted that the dominant flow paths largely controlled the N-saturation status and DOM composition within each sub-catchment, the effect of land-use could therefore be obscured. Furthermore, N-saturation status and DOM composition are not only a result of hydrologic dynamics, but potential agents modifying the transport mechanism of solutes export from fluvial systems. We emphasize the importance of viewing elemental dynamics from the perspective of a terrestrial-aquatic continuum; and of taking hydrologic phases and individual catchment characteristics into account in water quality management. © 2018 The Authors |
URI: | https://doi.org/10.1016/j.scitotenv.2018.03.177 http://scholars.lib.ntu.edu.tw/handle/123456789/402015 |
DOI: | 10.1016/j.scitotenv.2018.03.177 | SDG/關鍵字: | Biogeochemistry; Biological materials; Forestry; Hurricanes; Land use; Nutrients; Organic compounds; Quality management; Reservoirs (water); Runoff; Water conservation; Water management; Water quality; Catchment characteristics; Dissolved organic matters; Hydrologic conditions; Hydrologic extremes; Mountainous reservoir; Nutrient dynamics; Small mountainous rivers; Terrestrial-aquatic continuum; Catchments; dissolved organic carbon; dissolved organic matter; dissolved organic nitrogen; nitrate; nitrogen; organic compound; total dissolved nitrogen; unclassified drug; dissolved organic matter; extreme event; forested catchment; hydrological response; loading; mountain region; nutrient dynamics; solute transport; typhoon; water quality; Article; catchment; chemical composition; concentration (parameters); controlled study; hurricane; hydrology; inorganic nutrient; land use; nutrient loading; priority journal; solute; Taiwan; Taiwan |
顯示於: | 地理環境資源學系 |
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