强降雨对胶州湾生源要素补充和分布的影响

发布时间：2019-03-09 09:54

【摘要】：台风带来的强降雨对地表的强烈冲刷作用可将大量淡水和生源要素从陆地输送到近海,从而在短时间内对近海的水文和生物地球化学过程造成显著影响。本文以胶州湾这一典型的半封闭海湾为研究对象,以2012年台风"达维"对青岛地区带来的强降雨事件为背景,通过降雨前后生源要素入湾河流和湿沉降输入及海上分布同步调查,考察了强降雨对胶州湾生源要素的输入、浓度及组成的影响。结果显示,在强降雨过程中,通过河流和湿沉降输入的生源要素DIN、SiO3-Si、PO4-P通量分别是降雨前的2.7、19.7和25.6倍。相应地,胶州湾表层海水中DIN、SiO3-Si、PO4-P平均浓度分别达到(37.90±26.72),(20.18±17.22)和(1.75±1.28)μmol·L-1,分别是降雨前的1.5、2.4和2.3倍;同时,胶州湾中生源要素的结构发生明显改变,N/Si/P的比例从降雨前的24∶8∶1变化为降雨后的19∶10∶1,更接近Redfield值和适宜浮游植物的生长。进一步运用富营养化指数(EI)分析表明,降雨后的富营养化程度加剧,整个海域EI指数平均值由降雨前的(4.35±6.40)升高到降雨后的(13.71±21.20),同时降雨后的EI5的严重富营养化区域面积占比达到50%。以上分析表明台风带来的强降雨提供了大量适宜浮游植物生长的生源要素,这可能是导致胶州湾富营养化程度加剧的原因。
[Abstract]:The heavy rainfall caused by typhoons can transport a large amount of fresh water and source elements from land to offshore, which will have a significant impact on the hydrologic and biogeochemical processes in the coastal waters in a short period of time. This paper takes Jiaozhou Bay, a typical semi-enclosed bay, as the research object, and takes the heavy rainfall event brought about by Typhoon "Davi" in 2012 as the background. The effects of heavy rainfall on the input, concentration and composition of source elements in Jiaozhou Bay were investigated by means of the input of source elements into the gulf and the input of wet subsidence and the synchronous investigation of marine distribution before and after rainfall. The results show that during heavy rainfall, the flux of source factor DIN,SiO3-Si,PO4-P input through river and wet deposition is 2.7, 19.7 and 25.6 times higher than that before rainfall, respectively. Accordingly, the average concentration of DIN,SiO3-Si,PO4-P in the surface seawater of Jiaozhou Bay reached (37.90 卤26.72), (20.18 卤17.22) and (1.75 卤1.28) 渭 mol 路L-1 respectively, which was 1.5, 2.4 and 2.3 times higher than that before rainfall, respectively. At the same time, the structure of source elements in Jiaozhou Bay changed obviously, and the ratio of N/Si/P changed from 24:8:1 before rainfall to 19 脳 10 ~ 1 after rainfall, which was closer to Redfield value and suitable growth of phytoplankton. Further analysis of eutrophication index (EI) showed that the eutrophication degree increased after rainfall, and the mean EI index increased from (4.35 卤6.40) before rainfall to (13.71 卤21.20) after rainfall. At the same time, the area of severe eutrophication area of EI5 after rainfall was up to 50%. The above analysis indicates that the heavy rainfall caused by typhoon provides a large number of biological elements suitable for phytoplankton growth, which may be the cause of the aggravation of eutrophication in Jiaozhou Bay.
【作者单位】：中国海洋大学海洋化学理论与工程技术教育部重点实验室;中国海洋大学化学化工学院;青岛市环保局;青岛市环境监测中心站;
【基金】：国家海洋局公益性课题项目(201205018) 中央高校基本业务费项目(201362014)资助~~
【分类号】：P734;X55

【相似文献】