变化环境下的钱塘江河口潮位特性及其影响因素  

Characteristics and effecting factors of the tidal level in the Qiantangjiang River Estuary under changing environment

作　　者：尤爱菊[1] 韩曾萃[1] 何若英[1] 

机构地区：[1]浙江省水利河口研究院,浙江杭州310020

出　　处：《海洋学研究》2010年第1期18-25,共8页Journal of Marine Sciences

基　　金：水利部公益性行业科研专项经费资助项目(200801072)

摘　　要：利用钱塘江河口沿程的闸口、七堡、仓前、盐官、澉浦和乍浦等7个潮位站的实测资料,分析了1953～2007年各站年最高潮位、年平均高潮位、年平均低潮位的不同变化特性,并对主要的影响因素进行了分析。线性拟合结果表明,自20世纪50年代以来,钱塘江河口沿程各潮位站年最高潮位抬升幅度达0.57～1.05m,其中七堡站年最高潮位抬升值最大;年最高潮位显著抬升的时间主要发生在20世纪90年代后,该时段年最高潮位抬升值占年最高潮位总抬升值的70.5%～92.6%,极值潮位出现频率显著增加。分析表明,1990年后钱塘江围垦面积仅占总围垦面积的21.6%,因此河口围垦不是造成年最高潮位抬升的唯一因素,而影响浙江的台风频次增多及围垦造成的潮波反射加剧是造成高潮位抬升的主要原因。钱塘江河口年平均高潮位的沿程变化出现趋势性的抬升现象,各站年平均高潮位抬高幅度接近,为0.43～0.49m,但不同潮位站因与围垦河段的相对位置不同,年平均高潮位抬升的历史过程存在明显差异。河口下游段的澉浦、乍浦站年平均高潮位呈现单一的抬升趋势,且与河口逐年累计围垦面积存在很好的相关关系(相关系数大于0.95);而河口上游段的闸口—盐官河段则以1970年为界,年平均高潮位明显有两次抬升过程,受围涂进程影响的机制比较复杂。钱塘江河口年平均低潮位多年来维持在一个相对稳定的水平上,但沿程年际间平均低潮位的变化却不相同。河口上游段的潮位站受径流丰枯及其引起的江道冲淤影响,年平均低潮位年代际呈现出波动的特性;澉浦以下的潮位站年平均低潮位受潮汐控制为主,年代际变化幅度甚微。钱塘江河口不同河段因受径流、潮流、治江围垦等因素的影响程度不同,其潮位特征值沿程的变化特点也不同,需要在河口工程设计、防洪减灾与河口治理等方面引起重视。As a result of intensifying human activities such as reclamation, global warming and sea level rise, the tidal level of the Qiantangjiang River Estuary presented a trend variation in recent 55 years, which would have a profound influence on the life and socio-economic development of the estuarine zone. Based on the observed data of Zhakou, Qibao, Cangqian, Yanguan, Ganpu and Zhapu tidal stations from 1953 to 2007, characteristics and change trend of the annual maximum tidal level, annual mean high tidal level and annual mean low tidal level were analyzed, of which the results could be the reference for making the strategy of disaster prevention and mitigation, estuary development and engineering design and construction. Linear fitting shows that there is an evident rising trend of the annual maximum tidal level along the Qiantangjiang River Estuary with a rise value of up to 0.57~1.05 m and the maximum at Qibao station. The rise mainly occurred after 1990, which makes up 70.5%~92.6% of the total and the extreme value appeared more frequently in this period. But the reclamation area in the same period only makes up 21.6% of the total, which means that reclamation is not the director factor for the rise of the maximum tidal level rise. Relevant study shows that increased occurrence of typhoon and intensified reflection of the tidal wave resulted from reclamation should be one of the main causes. The annual mean high tidal level is also rising up, and the raise range is similar at different stations during the last 55 years, that is 0.43~0.49 m. However, the historic rising process of the upper reaches of the estuary is obviously different from that of the down reaches. Sole rise presented at Ganpu and Zhapu stations on the lower reaches and has good relationship with the accumulated reclamation area with the correlation coefficient no less than 0.95, while that of the upper reaches from Zhakou to Yanguan has two raising stages before and after 1970, and the relationship with reclamation is more complicated. The ann

关 键 词：年最高潮位 年平均高潮位 年平均低潮位 潮位特性 钱塘江河口 

分 类 号：P731.23[天文地球—海洋科学]