SOME ANALYSES OF RECENT CHINESE PROVINCIAL DATA

A complete set of Chinese provincial data has recently been published and may be employed to study the regional variations in China. Great regional inequalities are found in industrial outputs, provisions of university places and distribution of qualified doctors.     

江苏近岸海域水文气象要素的时空分布特征

2006～2007年在江苏近岸海域进行水文气象要素(气温、湿度、风速风向、波浪、透明度、水色和海水温盐度等)大面观测。数据分析表明,各水文气象要素具有较大的空间分异,四季变化显著。秋季气温明显高于春季,冬季气温较历史数据偏高。整个海域风速较大,风向受季风控制,有效波高与风速之间显著相关。如东附近海域波浪较大,废黄河口波浪较小;春、夏季有效波高较小,而夏、秋季近岸海域波高较小,离岸波高增大。夏季海水透明度最大,平均为2.3m;冬季透明度最小,平均只有0.6m;水色与透明度呈负指数相关。春、秋季水温分布与气温分布基本一致,冬季大致沿等深线分布。射阳河口与长江口为低盐区,辐射沙脊群外缘为高盐区。与20世纪80年代的调查结果相比,出现了一些新特点。这些新的调查成果可为江苏近岸海域的海洋环境保护和可持续发展提供科学依据。     

渤海风驱-潮致Lagrange余流的数值模拟与季相时空变异

The spatial distribution and seasonal variation of the tide-induced Lagrangian Residual Circulations (LRC hereafter), wind-driven LRC, and the coupling dynamic characteristics were simulated using ECOM, given the Hellerman and Rosenstein global monthly-mean wind stresses. The results showed that the tide-induced LRC of the harmonic constituent M2 bears an identical pattern in four seasons in the Bohai Sea: the surface one is weak with random directions; however, there exist a southeast current from the Bohai Strait to the Laizhou bay, and a weakly anticlockwise gyre in the south of the Bohai Strait for the bottom layer LRC. The magnitude of bottom layer tide-induced LRC is larger than the surface one, and moreover, it contributes significantly to the whole LRC in the Bohai Sea. Unlike the identical structure of the tide-induced LRC, the wind driven LRC varies seasonally under the prevailing monsoon. It forms a distinct gyre under the summer and winter monsoons in July and January respectively, but it seems weak and non-directional in April and September.     

2010-2011年胶州湾叶绿素a与环境因子的时空变化特征

2010年4、6、8、10月和2011年1、3月在胶州湾开展了6个航次的综合调查,研究了表层海水温度、盐度、营养盐和叶绿素a浓度的时空变化特征。调查期间,总无机氮(DIN)、磷酸盐(PO4)和硅酸盐(SiO3)多呈现东北部湾边缘高,而湾内和湾口低的空间分布特征。季节变化表明,DIN和PO4主要受养殖排放、河流径流输入和浮游植物生长消耗的影响,呈现初夏和秋季高,夏末和冬季低的特点;而SiO3主要受河流径流输入和浮游植物消耗的影响,呈现夏、秋高,而冬、春低的特点。营养盐浓度和结构分析表明,胶州湾存在PO4和SiO3的绝对和相对限制;SiO3限制尤其严重,是控制胶州湾浮游植物生长的主要环境因子。SiO3和PO4的限制主要表现在冬季,几乎遍布整个海湾;夏季降水可有效缓解海域的SiO3限制。叶绿素a浓度呈现春、夏季高,秋、冬季低的季节分布,温度、营养盐浓度与结构和季节性贝类养殖活动是控制胶州湾叶绿素a浓度时空分布的关键因素。     

Variation in Water Masses on Shelf of Northern Bering Sea in September 2016-2018

Abstract

Based on hydrological data obtained during the 7th to 9th Chinese National Arctic Research Expeditions in the summers of 2016–2018, the main water structure on the shelf of the northern Bering Sea and the volume and heat fluxes of the Bering Strait throughflow were analyzed. Distinct variability was identified in the three Pacific water masses feeding the strait - Anadyr Water (AW), Bering Shelf Water (BSW) and Alaskan coastal water (ACW). Overall, the temperature and salinity of the entire section increased each year, with 2018 showing significant anomalies, i.e., a temperature anomaly of up to 1?°C and a maximum salinity anomaly of 2. From 2016 to 2018, the extent of the ACW gradually narrowed in the eastern part of this section, while the AW expanded eastward each year. The net volume transport through each of the three sections increased poleward from 1.65?Sv to 2.76?Sv, with the AW increasing from 0?Sv to 1.03?Sv, the BSW varying between 0.52–1.65?Sv, and the ACW gradually decreasing from 1.04?Sv to disappearing completely. The net heat fluxes were also poleward, varying between 25.77 TW and 61.50 TW, and showing a significant increase. Significant variations in magnitude and extent were observed in each water mass of the Bering Strait throughflow, which could produce widespread effects in the Arctic Ocean and the global ocean beyond.     

Long-term stability of the fish assemblages in a warm-temperate South African estuary

Little is known about long-term changes in estuarine fish populations and related environmental variations. Fishes in the temporarily open/closed East Kleinemonde Estuary were sampled bi-annually, in summer and winter, using seine and gill nets between December 1994 and July 2005. A total of 18 families, represented by 33 species, were recorded. The 10 most abundant species caught were consistently recorded in catches each year, but CPUE of individual species varied on an annual basis and this can often be related to mouth state. Multivariate analyses of the annual marine fish community identified two distinct groups, with more species recorded during years that succeeded spring (September to November) mouth-opening events than in years following no mouth-opening events in spring. Interannual community stability (IMD) and seriation (IMS) also increased from the years following no opening events in spring to the years that succeeded spring opening events. These results highlight the importance of the timing of mouth opening to the marine fish community in a temporarily open/closed estuary. This study reinforces the importance of long-term studies to understanding community changes in estuaries caused by environmental variations over different time scales.     

钱塘江强潮河段江道缩窄治理研究

对钱塘江强潮河段江道缩窄治理进行研究。首先,回顾治理方案的比选,江道全线缩窄时河轴线线路和河道宽度的确定原则,以及不同河段的指数放宽率。然后,介绍了在涌潮汹涌、滩涂淤坍变化剧烈的强潮河段,实施筑堤所采取的工程措施的步序与要点。最后,分析论证了大规模江道缩窄治理后河床、潮汐、洪水位及涌潮高度等特征值的变化。可供进一步深入理论研究和工程施工参考运用。     

泸沽湖沉积物中磷累积的时空变化及其环境意义

湖泊沉积物中磷累积特征反映了流域人类活动影响下的磷入湖通量的变化,与湖泊生态环境密切相关。本研究分析了泸沽湖15根长17~27cm沉积短岩芯中磷的含量,评估了自然源与人为源磷的贡献,探讨了近140年来不同来源磷累积的时空变化特征及其与流域人类活动和湖泊生态环境的关系。结果表明,不同湖区沉积物中磷含量垂向变化趋势总体一致。以南部湖心区LGS岩芯为例,1960年前,沉积物中磷的含量与累积通量较低,为人类活动干扰较弱的准自然沉积;1960~2000年,自然源与人为源磷的含量和累积通量均逐渐增加,其中1960~1980年和1980~2000年人为源磷累积通量平均分别为4.9mg/(m²·a)和39.1mg/(m²·a)。2000年以来,沉积物中自然源磷的累积通量略有降低,但人为源磷的累积通量持续升高,平均为109mg/(m²·a)。空间上,南部湖区自然和人为源磷的累积通量总体上高于北部湖区,不同时期自然源磷的累积通量高值区均位于南部湖区东部,而沿岸居民点密集分布的南北湖区连接处和西北部湖区人为源磷的累积通量相对较高。不同来源磷累积通量的时空变化主要与农业和旅游业发展导致的土壤侵蚀和污染排放输入有关。沉积物中磷累积通量与硅藻、摇蚊等水生生物属种呈同步的历史变化趋势,指示了磷输入对湖泊生态环境变化的重要影响。

     

渤海的潮波系统及其变迁

采用二维非线性潮波微分方程对渤海M_2、S_2、K_1、O_1四个分潮进行数值模拟,得出四个分潮的潮波图,椭圆长短轴图,同潮流时图以及潮汐、潮流性质图和S_2与M_2、K_1与O_1的迟角差图。依此可以系统地了解渤海潮波系统的分布变化规律。依据30～40年代测得的渤海海图以及假设数十年后渤海的岸形对渤海进行数值模拟,从而了解过去和现在渤海潮波的变化情况,以及对未来潮波的变化作出判断。计算表明,从30年代到70年代以来,渤海南部的半日分潮波发生了很大的变化,而日分潮的潮波变化较小。     

2012—2016年象山近岸海域水质评价与模拟研究

为了解象山近岸海域水质污染状况,文章根据2012—2016年象山县近岸海域的水质监测结果,分析象山近岸海域水质现状及年际变化。应用灰色预测的模型来对象山近岸海域水质主要污染物的相关数据进行处理,得出主要污染物的预测结果。分析结果表明：象山近岸海域主要污染物为无机氮。用预测结果和实际数值通过残差验证,最后模拟出今后几年的监测值,为象山县近岸海域生态环境相关管理部门提供数据支撑和决策依据。