https://scholars.lib.ntu.edu.tw/handle/123456789/510504
標題: | Shifts in stream hydrochemistry in responses to typhoon and non-typhoon precipitation | 作者: | Chang, C.-T. Huang, J.-C. Wang, L. Shih, Y.-T. Lin, T.-C. JR-CHUAN HUANG |
公開日期: | 2018 | 卷: | 15 | 期: | 8 | 起(迄)頁: | 2379-2391 | 來源出版物: | Biogeosciences | 摘要: | Climate change is projected to increase the intensity and frequency of extreme climatic events such as tropical cyclones. However, few studies have examined the responses of hydrochemical processes to climate extremes. To fill this knowledge gap, we compared the relationship between stream discharge and ion input-output budget during typhoon and non-typhoon periods in four subtropical mountain watersheds with different levels of agricultural land cover in northern Taiwan. The results indicated that the high predictability of ion input-output budgets using stream discharge during the non-typhoon period largely disappeared during the typhoon periods. For ions such as Na+, NH4+, and PO43ĝ', the typhoon period and non-typhoon period exhibited opposite discharge-budget relationships. In other cases, the discharge-budget relationship was driven by the typhoon period, which consisted of only 7ĝ€% of the total time period. The striking differences in the discharge-ion budget relationship between the two periods likely resulted from differences in the relative contributions of surface runoff, subsurface runoff and groundwater, which had different chemical compositions, to stream discharge between the two periods. Watersheds with a 17-22ĝ€% tea plantation cover showed large increases in NO3ĝ' export with increases in stream discharge. In contrast, watersheds with 93-99ĝ€% forest cover showed very mild or no increases in NO3ĝ' export with increases in discharge and very low levels of NO3ĝ' export even during typhoon storms. The results suggest that even mild disruption of the natural vegetation could largely alter hydrochemical processes. Our study clearly illustrates significant shifts in hydrochemical responses between regular and typhoon precipitation. We propose that hydrological models should separate hydrochemical processes into regular and extreme conditions to better capture the whole spectrum of hydrochemical responses to a variety of climate conditions. © Author(s) 2018. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/510504 | DOI: | 10.5194/bg-15-2379-2018 | SDG/關鍵字: | chemical composition; climate change; climate conditions; discharge; extreme event; land cover; mountain environment; precipitation (climatology); stream; subtropical region; tropical cyclone; typhoon; water chemistry; watershed; Taiwan |
顯示於: | 地理環境資源學系 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。