摘要
根据长江与黄河各一个完整水文年的调查数据,并结合历史资料分析了我国这两条大型河流活性硅((RSi,RSi=溶解硅(DSi)+生物硅(BSi))的入海通量及长时间序列的变化规律与影响因素.结果表明,长江与黄河RSi的组成存在显著的差异,二者水体中BSi/RSi的平均比值分别为0.22和0.49;黄河DSi的年平均浓度为长江的74%,而BSi年平均浓度却是长江的3倍.黄河水体中相对较高的BSi浓度反映了黄河流域水体浑浊度与土壤侵蚀程度较高,源自黄土高原高的泥沙输送量是导致黄河水体中BSi浓度较长江高的主要原因.长江与黄河下游RSi通量在丰水期、平水期与枯水期的比值分别为5.3∶3.1∶1.6与3.8∶3.4∶2.8,长江半数以上的RSi入海通量是在丰水期输出的,而黄河在3个时期的差异不明显.相比于径流的变化,1958-2014年间长江DSi通量变化主要是由DSi浓度的变化引起的,流域气候变化(如温度变化)是其浓度及其通量年代际变化的重要原因;而黄河1985-2001年间DSi通量下降是由于径流量与DSi浓度降低的双重原因引起的.气候变化,特别是温度的变化会对流域硅的风化速率与硅的产出产生重要影响,但其具体的影响有待进一步揭示.
Based on the monthly observation during a hydrological year and available historical data,fluxes,seasonal variations of reactive silica（ RSi,RSi = dissolved silicate（ DSi） ＋biogenic silica（ BSi）） in the Changjiang River and the YellowRiver were analyzed for their long-term changes and their controlling factors. The results showed that the compositions of RSi had a significant difference between the Changjiang River and the YellowRiver. During the sampling period,monthly average concentration of DSi in the YellowRiver accounted for 74% of that in the Changjiang River,while monthly mean concentations of BSi in the YellowRiver was three times higher than that in the Changjiang River. The atomic ratios of BSi/RSi were 0.22 and 0.49 in the Changjiang River and the YellowRiver,respectively. The relatively higher BSi concentrations in the YellowRiver reflected relatively higher degree of soil erosion and turbidity of the water in comparison with the Changjiang River. High sediment flux originated from the Loess Plateau is the main reason why BSi concentration was relatively higher in the YellowRiver than that in the Changjiang River in thesampling period. The shares of RSi among the wet season,normal season and dry season were 5.3 ∶3.1 ∶1.6 and 3.8 ∶3.4 ∶2.8 in the Changjiang River and the YellowRiver,respectively. More than half of RSi discharge occurred during the wet season in the Changjiang River. During 1958-2014,the variation of DSi concentration was of primary importance in affecting the change in DSi flux in comparison with the discharge in the Changjiang River,which is mostly caused by climatic change（ such as temperature variation）. Whereas,the combined effects of runoff and DSi concentrations resulted in the decreasing DSi flux in the YellowRiver during 1985-2001. Weathering rate and output of silicon in the river basin are largely affected by climatic change such as the temperature variation,and more studies need to do for comprehensively understanding the specific process.
作者
王昊
冉祥滨
臧家业
刘军
曹磊
刘森
马永星
WANG Hao;RAN Xiangbin;ZANG Jiaye;LIU Jun;CAO Le;LIU Sen;MA Yongxing(Research Center for Marine Ecology,First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,P R.China;Qingdao National Laboratory for Marine Science and Technology,Laboratory of Marine Geological Processes and Envi ronmental Functions,Qingdao 266237,P.R.China;Key Laboratory of Marine Sedimentology and Environmental Geology,First Institute of Oceanography,State Oceanic Ad ministration,Qingdao 266061,P.R.China;Deep Sea Research Center,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2018年第5期1246-1259,共14页
Journal of Lake Sciences
基金
国家自然科学基金项目(41776089
41706082)
中央级公益性科研院所基本科研业务费专项(2017S03
2017Q10)联合资助
关键词
长江
黄河
溶解硅
生物硅
气候变化
Changjiang River
the Yellow River
dissolved silicate
biogenic silica
climate change
