Three-dimensional refined modeling of water quality in Victoria Harbour

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唐山近海海域波浪要素特征分析

本文基于唐山近海海域1#、2#浮标2017年4月至11 月实时海浪观测数据及部分风速风向数据, 对唐山近海海域波浪有效波高、有效波向、有效波周期等波参数特征进行了统计分析, 并利用origin 软件对波参数与风速、风向相关性进行了研究。研究结果表明： 1#、2# 浮标海域常浪向为SSW、SW、SSE, 常浪向有效波高均以0.2 ～ 0.4 m 小浪及3 ～ 4 s 短周期为主,有效波高1 m 以上较大波浪极少出现; 该海域波浪以风浪为主, 波浪破碎速度较快, 有效波高与风速相关性较强, 相关系数r 为0.71, 风向与波向、有效波高与周期基本无相关性, 该研究资料可为海上活动及防灾减灾提供技术依据。     

酸气工厂附近地下污染影响自然水体的关键因素

Hydrocarbon contamination of lakes and rivers from subsurface discharge of ground-water is a common environmental problem in many countries. This source of contamination, particularly dissolved phase hydrocarbons, can significantly reduce the quality of natural waters. Laboratory results show that the aqueous solubility of benzene can be predicted by Raoul''s Law for BTEX mixtures and for gas condensate. In contrast, the solubility of total xylenes was up to three times higher than the calculated results using Raoul''s Law. A comparison of these finding with the composition of BTEX in groundwater at a sour-gas plant, indicated that the mole fraction and groundwater flow velocity were two principle factors affecting the discharge concentration of benzene and xylenes to natural waters.     

MODIS水色产品在中国黄、东海海域应用研究

An extensive study collected in situ data along the Yellow Sea(YS) and East China Sea(ECS) to assess the radiometric properties and the concentration of the water constituents derived from Moderate Resolution Imaging Spectroradiometer(MODIS). Thirteen high quality match-ups were obtained for evaluating the MODIS estimates of Rrs(λ), chlorophyll a(Chl a) and concentrations of suspended particulate sediment matter(SPM). For MODIS Rrs(λ), the mean absolute percentage difference(APD) was in the range of 20%–36%, and the highest uncertainty appeared at 412 nm, whereas the band ratio of Rrs(λ) at 488 nm compared with that at 547 nm was highly consistent, with an APD of 7%. A combination of near-infrared bands and shortwave infrared wavelengths atmosphere correction algorithm(NIR-SWIR algorithm) was applied to the MODIS data, and the estimation accuracy of Rrs were improved at most of the visible spectral bands except 645 nm, 667 nm and 678 nm. Two ocean-colour empirical algorithms for Chl a estimation were applied to the processed data, the results indicated that the accuracy of the derived Chl a values was obviously improved, the four-band algorithms outperformed the other algorithm for measured and simulated datasets, and the minimum APD was 35%. The SPM was also quantified. Two regional and two coastal SPM algorithms were modified according to the in situ data. By comparison, the modified Tassan model had a higher accuracy for the application along the YS and ECS with an APD of 21%. However, given the limited match-up dataset and the potential influence of the aerosol properties on atmosphere correction, further research is required to develop additional algorithms especially for the low Chl a coastal water.     

中国近海鲐鱼资源时空分布与海洋净初级生产力的关系研究

海洋净初级生产力影响了浮游动植物的空间分布和丰度,因此决定了海洋渔业的潜在产量。本文根据2006-2015年7-9月中国远洋渔业数据中心提供的中国近海鲐鱼捕捞数据和海洋净初级生产力遥感数据,以单位捕捞努力量渔获量（CPUE）表征资源丰度,以经度和纬度重心表征空间分布,分析研究了鲐鱼资源丰度和空间分布与海洋净初级生产力的关系。研究结果表明,2006-2015年鲐鱼产量、CPUE、经度和纬度重心呈现明显的月份和年际变化,7-9月渔场内净初级生产力空间分布模式不同。频率分布结果表明7-9月鲐鱼对应的适宜净初级生产力浓度范围分别为300~500 mg/（m2·d）（以碳计,下同）,300~400 mg/（m2·d）,300~400 mg/（m2·d）。相关分析结果表明,鲐鱼资源丰度与适宜净初级生产力海域范围比例呈显著正相关,且鲐鱼纬度重心与适宜净初级生产力海域平均纬度呈显著正相关关系,这表明渔场内的净初级生产力大小和分布模式显著影响鲐鱼的资源丰度和渔场重心位置。在鲐鱼主要分布海域25°~30°N,120°~130°E范围内,鲐鱼资源丰度与净初级生产力大小呈显著负相关关系。此外,不同气候条件下鲐鱼渔场净初级生产力大小变化不同,2007年和2010年强拉尼娜年份以及2009年中强厄尔尼诺年份鲐鱼渔场范围海洋净初级生产力降低,但适宜的海洋净初级生产力范围增大,导致鲐鱼资源丰度上升;而2015年超强厄尔尼诺年份鲐鱼渔场范围内海洋净初级生产力上升,但适宜的海洋净初级生产力范围显著减小,因此鲐鱼资源丰度相对降低。研究表明,中国近海鲐鱼资源时空分布与海洋净初级生产力具有显著关联。     

两类强度厄尔尼诺和拉尼娜事件对中国近海鲐鱼栖息地的影响

鲐鱼是中上层鱼类,具有较高经济价值,其种群受到气候和海洋环境的显著影响。本文根据2006-2015年7-9月中国远洋渔业数据中心提供的中国近海鲐鱼捕捞和海表温度以及海面高度两个关键环境因子的数据,构建了基于捕捞努力量的鲐鱼综合栖息地指数模型,分析研究了在不同强度厄尔尼诺和拉尼娜条件下鲐鱼栖息地适宜性的变动规律。通过计算和交叉验证,结果发现,基于算术平均法的栖息地模型能够较好地预测鲐鱼渔场栖息地适宜性指数。空间相关性结果表明,鲐鱼渔场主要作业海域范围内海表温度异常与栖息地指数值呈显著正相关关系,而海表面高度异常与栖息地指数值呈显著负相关关系。不同强度厄尔尼诺和拉尼娜事件对鲐鱼种群影响不同,具体表现为:相对于中强度厄尔尼诺事件（或中强度拉尼娜事件）,超强厄尔尼诺事件（或强拉尼娜事件）驱动鲐鱼主要作业海域内温度下降（或上升）,海面高度上升（或降低）,鲐鱼渔场适宜栖息地面积显著减小（或增大）,导致鲐鱼单位捕捞努力量渔获量骤减（或显著增加）。研究表明,中国近海鲐鱼栖息地适宜性与厄尔尼诺和拉尼娜事件显著相关,且随着异常气候事件强度的不同而发生变化。     

Two new species of medusae (Cnidaria) from the coastal waters of the northern Beibu Gulf

Medusae in 116 samples collected from the coastal waters of the northern Beibu Gulf during four seasonal oceanographic cruises from October 2017 to August 2018 were analyzed. In total, 34 species were identified. Two of the species are new to science, Proboscidactyla pentacanalis Xu, Chen & Yang sp. nov. and Helgicirrha apapillata Xu, Chen & Wang sp. nov., and three species are newly recorded in the Beibu Gulf, i.e., Hydractinia vacuolata Xu & Huang, 2006, Proboscidactyla flavicirrat...     

Direct Trace Element Determination in Oil and Gas Produced Waters with Inductively Coupled Plasma‐Optical Emission Spectrometry: Advantages of High‐Salinity Tolerance

Waters co‐produced during petroleum extraction are the largest waste streams from oil and gas development. Reuse or disposal of these waters is difficult due to their high salinities and the sheer volumes generated. Produced waters (PWs) may also contain valuable mineral commodities. While an understanding of produced water trace element composition is required for evaluating the associated resource and waste potential of these materials, measuring trace elements in brines is challenging due to the dilution requirements of typical methods. Alternatively, inductively coupled plasma‐optical emission spectrometry (ICP‐OES) has shown promise as being capable of direct measurements of trace elements within PWs with minimal dilution. Here, we evaluate direct ICP‐OES trace element quantification in PWs for seventeen trace elements (As, Al, Ba, Be, Cd, Cr, Co, Cu, Hg, Mo, Ni, Pb, Rb, Sb, U, V and Zn) within fifteen PWs from five U.S. continuous reservoirs. The total analytical uncertainties associated with the trace element levels determined using ICP‐OES were estimated to be better than ± 30% (2s) except for Rb, which could not be determined due to ionisation interferences. The ICP‐OES results are compared with trace element levels determined using inductively coupled plasma‐mass spectrometry from the same samples. Our results demonstrate the potential for direct analysis of high‐salinity waters using ICP‐OES with minimal dilution and provide trace element concentrations in waters from several important U.S. petroleum‐generating reservoirs where available data are sparse.     

Using unsteady-state water level data to estimate channel roughness and discharge hydrograph

A novel methodology for simultaneous discharge and channel roughness estimation is developed and applied to data sets available at three experimental sites. The methodology is based on the synchronous measurement of water level data in two river sections far some kilometers from each other, as well as on the use of a diffusive flow routing solver and does not require any direct velocity measurement. The methodology is first analyzed for the simplest case of a channel with a large slope, where the kinematic assumption holds. A sensitivity and a model error analysis are carried out in this hypothesis in order to show the stability of the results with respect to the error in the input parameters in the case of homogeneous roughness and to analyze the effect of unknown roughness heterogeneity on the estimated discharges. The methodology is then extended to the more general case of channels with mild slope and validated using field data previously collected in three Italian rivers: the Arno (in Tuscany), the Tiber (in Latium) and the Vallo di Diana, a small tributary of the Tanagro river (in Southern Italy). The performance of the proposed algorithm has been investigated according to three performance criteria estimating the quality of the match between the measured and the computed stage and discharge hydrographs. Results of the field tests can be considered good, despite the uncertainties of the field data and of the measured values.