Provenance analysis of surface sediments in the Holocene mud area of the southern coastal waters off Shandong Peninsula,China

The sedimentary record of mud areas is an important carrier of information on the Holocene evolution of marine environments. Based on fine interpretations of the shallow stratigraphic section data, a small mud deposit area has been found in the southern coastal waters off Shandong Peninsula. This mud area is mainly distributed in coastal waters north of Laoshantou to the vicinity of Rushan Estuary. Overall, it is parallel to the coastline and spreads in a banded pattern, gradually thinning from offshore to the sea. The isopach map of depth distribution is parallel with the shoreline, and the depocenter lies in coastal waters of the Aoshan Bay where the maximum thickness is up to 22.5 m. Accelerator mass spectrometry（AMS） ^（14）C dating shows that the mud area was formed in the Holocene. The test data of surface sediments from the mud area, including particle size, mineral characteristics, and rare earth element contents, are used in comparisons with the composition of materials from the major surrounding medium and small rivers flowing into the sea and the Huanghe（Yellow） River. In this paper, the sedimentary characteristics and provenance of the mud deposit area are discussed. The results show that the formation of this mud area resulted from the joint action of the Huanghe River and surrounding rivers flowing into the sea.

Urban surface water system in coastal areas: A comparative study between Almere and Tianjin Eco-city

In the purpose of defining typical urban water management challenges in coastal lowlands in the context of global climate change, a comparative study was conducted between two coastal new towns respectively located in the Netherlands and Northern China. Comparative method is applied to define main functioning patterns of urban water systems in the two cases, then computer simulations were used to furthercompare drainage capacity in order to reveal the trends of urban water management. Major resulthas shown that Almere in the Netherlands generally more advanced in urban water management asmultiple functioning patterns are available.Strong dykes maintain competence for land subsidence and sea level rise. Open water system decreases local runoff and increaseswater retention level. Systematic control ofsluicesand locks which serve for shipping and waterfront landscaping are simultaneously isolating contaminants from outer water body. Tianjin Eco-city in China has shown both strengths and weaknesses. It takes large amount of reclaimed water as main landscaping water source, which adapts to local water pollution and shortage while requires highly centralized facilities. Large water body is reserved and huge scale underground drainage system built, but it is still vulnerable to heavy storms due to the lack of efficient surface water drainage system. Coastal line control does not adequately prevent from increasing storm surge risks in the future. SWMMsimulations have supported the viewpoint ofdistributed surface water with a higher efficiency for storm drainage. Meanwhile, surface water system returns more added values to urban development. The study is corresponding well with the theory of water sensitive city. As a conclusion, urban water system should always incorporate methods to achieve higher system resilience based on multiple functioning patterns.

Assessing the Impact of Industrial Zones on the Environmental Pollution in Hai Phong’s Coastal Areas, Vietnam

Pollution in the coastal areas negatively affects biochemical indicators of seawater, human health and marine organisms. Hai Phong is a coastal city of Vietnam with the development of socio-economic activities, representing through an increasing number of industrial zones. This study is to evaluate the pollution of large industrial zones in Hai Phong city using numerical models. The numerical simulation (MIKE 21 SW, FM, ECO Lab) models were applied to simulate the wave propagation, hydraulic regime, water quality in coastal Hai Phong area. The MIKE 21 ECO Lab model was used to evaluate sources of waste from the large coastal industrial zones to some aquaculture zones. The calibration and validation results of wave propagation and the hydrodynamic models were resonably good, with Nash coefficient ranging from 0.65 to 0.90 and a percent bias (PBIAS) from 5.6% to 9.4%. The simulation results of water quality and concentration of pollutants (DO, BOD5, COD, TSS, Fe, and Coliform) in 2023 at the aquaculture locations show that the BOD5, COD, and TSS concentrations were higher than the allowable limits stated in the national technical regulation on surface water quality (QCVN 08:2023/BTNMT) and lower than the allowable limits stated in the national technical regulation on marine water quality (QCVN 10:2023/BTNMT). The outcomes of this study will provide more information to support managers to come up with a better socio-economic development plan for Hai Phong city to achieve sustainable development.

Refined Modeling of Water Temperature and Salinity in Coastal Areas

The prediction of water temperature and salinity in coastal areas is one of the essential tasks in water quality control and management. This paper takes a refined forecasting model of water temperature and salinity in coastal areas as a basic target. Based on the Navier-Stokes equation and k-epsilon turbulence model, taking the characteristics of coastal areas into account, a refined model for water temperature and salinity in coastal areas has been developed to simulate the seasonal variations of water temperature and salinity fields in the Hakata Bay, Japan. The model takes into account the effects of a variety of hydrodynamic and meteorological factors on water temperature and salinity. It predicts daily fluctuations in water temperature and salinity at different depths throughout the year. The model has been calibrated well against the data set of historical water temperature and salinity observations in the Hakata Bay, Japan.

Overall-effective Measures for Sustainable Water Resources Management in the Coastal Areas of Shandong Province, China——Case Study: the Huangshuihe River Catchment of Longkou City

In the coastal catchments of Shandong Province the water scarcity is aggravated due to saltwater intrusion, reducing the usability of water resources available. Such a situation calls for sustainable integrated water resources management (IWRM). The idea for the objectives and implementation of the IWRM are explained in this paper. The general objective of the planned project disscussed in the present study is to bring together German traditional expertise in water resources management and newer developments in the context of the European Water Framework Directive; the research efforts aim to relieve the desperate water scarcity situation in the costal area of Shandong Province.

The Influence of Land-Use on Water Quality in a Tropical Coastal Area: Case Study of the Keta Lagoon Complex, Ghana, West Africa

The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surrounding fresh water aquifers. In this study, a water quality index (WQI), indicating the water quality has been adopted. The WQI was determined on a basis of various physico-chemical parameters like pH, conductivity, turbidity, dissolved oxygen, calcium, magnesium, chloride, nitrates, ammonium and sodium. The index was used both for tracking changes at one site over time, and for comparisons among sites. The WQI was also employed to wells used for irrigation on farms along the Keta Sand Spit as well as that of the Keta Lagoon Complex and its surrounding floodplains, in order to ascertain the quality of water for public and livestock consumption, irrigation, recreation and other purposes. The WQI of the wells, Keta lagoon and its floodplains showed various degrees of poor water quality and therefore considered unsuitable for drinking and recreation. By WHO standards, this calls for intensive physical and chemical treatment of the water for human consumption.

Upwelling and anthropogenic forcing on phytoplankton productivity and community structure changes in the Zhejiang coastal area over the last 100 years

Phytoplankton productivity and community structure in marginal seas have been altered significantly during the past three decades, but it is still a challenge to distinguish the forcing mechanisms between climate change and anthropogenic activities. High time-resolution biomarker records of two 210Pb-dated sediment cores（#34： 28.5°N, 122.272°E; CJ12-1269： 28.861 9°N, 122.515 3°E） from the Min-Zhe coastal mud area were compared to reveal changes of phytoplankton productivity and community structure over the past 100 years. Phytoplankton productivity started to increase gradually from the 1970 s and increased rapidly after the late 1990 s at Site #34; and it started to increase gradually from the middle 1960 s and increased rapidly after the late 1980 s at Site CJ12-1269. Productivity of Core CJ12-1269 was higher than that of Core #34. Phytoplankton community structure variations displayed opposite patterns in the two cores. The decreasing D/B（dinosterol/brassicasterol） ratio of Core #34 since the 1960 s revealed increased diatom contribution to total productivity. In contrast, the increasing D/B ratio of Core CJ12-1269 since the 1950 s indicated increased dinoflagellate contribution to total productivity. Both the productivity increase and the increased dinoflagellate contribution in Core CJ12-1269 since the 1950–1960s were mainly caused by anthropogenic activities, as the location was closer to the Changjiang River Estuary with higher nutrient concentration and decreasing Si/N ratios. However, increased diatom contribution in Core #34 is proposed to be caused by increased coastal upwelling, with higher nutrient concentration and higher Si/N ratios.

Nitrogen and Phosphorus Diffusive Fluxes Across the Sediment-Water Interface in Estuarine and Coastal Tidal Flats

Nitrogen and phosphorus contents are analyzed in the overlying waters and pore waters taken from the Changjiang Estuary and Shanghai coastal tidal flats in this study. In addition, the diffusion fluxes of nitrogen and phosphorus across the sediment-water interface in tidal flats are estimated according to the nutrient concentration gradients at the interface. It has been indicated that the concentrations of ammonium, nitrite, nitrate and dissolved phosphorus in overlying waters range from 0.0082～2.56, 0.03～0.58, 0.69～5.38 and 0.035～0.53 mg/L, respectively, while 0.0025 ～ 1.35 mg/L for NH4+-N, 0. 0055 ～ 0.20mg/L for NO2--N, 0.61～1.14 mg/L for NO3--N and 0.11～0.53mg/L for DP insurface pore waters.The findings have revealed that ammonium, nitrite, nitrate and dissolved phosphorus diffusion fluxes across the sediment-water interface are between -0.024～0.99, -0.39～ -0.0019, -3.09～the source of phosphorus and an important sink for nitrogen in the waters.

饱和溶液电导率法在滨海高盐土壤水盐运移规律分析中的应用

分析海涂围垦区土壤水盐运移规律对改良滨海区域盐碱地有着重要意义。而在高盐土壤中实现含水率和可溶解盐分浓度的连续测量是掌握海涂围垦区土壤水盐运移规律的关键,因此以江苏如东海涂围垦试验区内的重度盐土为研究对象,利用耐盐度较好的土壤水分—盐分传感器连续监测土壤含水率、表观电导率变化,以土壤饱和溶液电导率(E_(C_(sat)))为盐分当量指标,分析受降雨、蒸发影响的水盐运移规律。结果表明,E_(C_(sat))可用以指示土壤中最大可溶解盐分含量。此外,土壤盐分在年内呈显著的季节性变化,即在冬季土壤中盐分较高,春季土壤脱盐,夏季土壤盐分波动剧烈,秋季土壤积盐明显。在蒸发和降雨过程中,E_(C_(sat))可有效指示不同埋深处土壤盐分的变化特征,结合土壤水分运移规律可直观佐证“盐随水走”的运移特征。

临江滨海强透水环境建筑工程载水减浮关键技术研究

结构抗浮设计是确保临江滨海强透水环境建筑工程安全的关键。依托广州某临江建筑工程,提出“载水减浮”概念。载水减浮新技术借助疏水、泄水等手段自主控制水位自溢泄流、均匀泄压,消除部分水浮力,充分利用有利荷载抵抗超出部分水浮力。搭建集地下水疏导、排泄、观测等多功能于一体的载水减浮系统。详细介绍载水减浮技术的施工步骤、要点、需妥善处理的问题及运维要求等。结果表明,载水减浮新技术具有成本低、工期短、环境影响小、施工便利等显著优势;解决了传统抗浮技术运用于临江滨海强透水环境建筑工程造价高、工期长、耐久性差的难题,最大程度实现依靠结构自身抵抗地下水浮力的目标,达到经济和安全的平衡。该抗浮新技术经验证后可推广至后续类似临江滨海强透水环境建筑工程的设计中。

滨海核设施核安保威胁分析及应对策略

当前世界格局加速变化,国内外安全形势日趋复杂,同时滨海地区环境复杂,核设施面临着更多的威胁。本文针对滨海核设施现阶段面对的威胁形势,分析陆域、水域、低空、网络等方面的威胁,并给出一些应对措施和方法,为在新形势下开展核安保工作提供参考。

厄尔尼诺事件对中国沿海地区水汽变化周期的影响

厄尔尼诺事件导致极端天气频发,中国沿海城市较多,分布有不同的气候类型。该文开展厄尔尼诺事件对中国沿海地区水汽变化以及变化是否存在空间差异的分析。基于CMONOC中国沿海地区的GNSS水汽时间序列,综合厄尔尼诺事件(I EP、I_(CP))指数,利用快速傅里叶变换和小波变换方法,从频域和时域开展GNSS水汽时序变化分析,分析东部型与中部型厄尔尼诺事件对中国沿海地区水汽变化的影响。研究发现:GNSS水汽异常值的出现与相应时段的厄尔尼诺事件存在对应。东部型厄尔尼诺(I_(EP))与大部分GNSS站点水汽的相关性为正相关;中部型指数(I_(CP))与GNSS站点水汽的相关性为负相关。厄尔尼诺事件对水汽变化周期的影响,日周期变化较小,在5 d和10 d周期,东部型厄尔尼诺与中部型厄尔尼诺事件影响下的水汽周期小于正常时段的水汽周期。

Tidal analysis in the venturi-shaped area between Zhenhai and Shenjiamen in the East China Sea

In order to better understand the general tidal features in the venturi-shaped area between Zhenhai and Shenjiamen in the northern coastal region of Zhejiang Province in the East China Sea, the tidal data were obtained from both the three permanent tide stations of Zhenhai, Dinghai and Shenjiamen, and four temporary tide stations of Mamu, Chuanshan, Guoju and Liuheng, along with the current speed being observed at Luotou Waterway. Results from harmonic analysis show that: (1) The area was dominated by shallow water tides with irregular semi-diurnal features, and the smallest tidal range occurred in the area near a crossing line between Zhenhai and Dinghai stations, indicating that a tidal node existed in the southern Hangzhou Bay; (2) Formulae, HS2/HM2 >0.4 and gM2-(gK1+gO1)=270° (where H and g are harmonic constants), could be used as judging criteria for high and low tidal level diurnal inequalities; (3) The duration difference between ebb and flood tides could be roughly assessed by the ratio of HM4 vs. HM2; and the larger the ratio is, the bigger the duration difference is. At the same time, the duration period could be assessed by 2gM2-gM4, the epoch difference between M2 and M4 tidal constituents. If 2gM2-gM4 <180°, then the ebb duration is longer than the flood duration; if 180°< 2gM2-gM4 <360°, the result is reversed; (4) Taking Dinghai station as a center point, the highest tidal levels and the average high tidal levels, as well as the average tidal ranges at all stations became higher and larger both southeastwards and northwestwards, while the lowest tidal levels and the average low tidal levels appeared to be lower both southeastwards and northwestwards; and (5) The tidal patterns were not all in line with the tidal current patterns. As a conclusion, the smallest tidal range occurred in the narrow part of the venturi-shaped area. Along the both sides of the area, the highest tidal level and tidal range became higher and larger, while the lowest tidal level became lower with the increase of the distance from the narrow throat area. This is somehow different from the theory that the tidal level increases gradually when it moves towards the top narrow area of a V-shaped bay or estuary.

Impact of Sand Mining and Sea Reclamation on the Environment and Socioeconomic Activities of Ikate and Ilubirin Coastal Low Income Communities in Lagos Metropolis, Southwestern Nigeria

Land reclamation is gradually posing negative impact on man due to unplanned urbanization. A study was carried out on impact of land reclamation through sand mining of coastal communities in Ikate and Ilubirin in Lagos, Nigeria. Ten waters (8 surface and 2 groundwater sources), 10 soil samples and air were collected and taken for analysis. Results of water revealed concentrations lower than WHO (2017) and SON (2007) standards. Soil/sediment with average crustal value revealed Pb and Cd above standard values, which is attributed to anthropogenic influence on soils. Quality of air in the study was mainly particulate matter arising from the sea and reclaimed land in the surroundings of the environment with the highest Total Suspended Particulate of 0.8 mg/m3 in sulfur dioxide. This explains corrosion found on the roofs of the communities. Therefore, in the development planning adequate precautions should be put in place to avert environmental degradation.

江苏沿海地区农业水土资源匹配及其效益差异分析

[目的]探究江苏沿海地区农业水土资源与效益的时空匹配差异。[方法]采用基尼系数与泰尔指数相结合的方法,分析了2009—2020年江苏沿海地区农业水土资源匹配及其效益的差异构成,采用耦合协调度评价各指标之间的协调发展水平。[结果]江苏沿海地区垦殖率高于全省平均水平,农业水土资源匹配系数低于全省平均水平,且在空间分布上存在错位现象。农业水土资源匹配系数及其效益基尼系数特征为“耕地效益基尼系数<农业水土资源匹配系数基尼系数<农田灌溉水效益基尼系数”,与泰尔指数结果一致。耦合协调度在0.35~0.40之间波动变化。[结论]江苏沿海地区农业水土资源呈“耕地资源丰富,农田灌溉水资源短缺”的特点,耕地对农业产值的匹配程度显著优于农田灌溉水资源,有限的水资源制约了江苏沿海地区的农业经济发展。各项指标差异主要来源于沿海3市的内部差异,且耦合协调发展水平由比较均衡状态向一般失衡状态转变。

海滨电厂温排水对附近海域生态环境的影响

本文基于2019年10月对湛江湾海滨电厂温排水受纳海域的采样调查,对比分析了温排水排放口附近站位(S9)和其他站位温度、溶解氧、营养盐和浮游植物群落结构的变化特征及影响因素。结果表明:排放口附近站位S9的表层温度受到了温排水的影响,其他站位几乎没有影响,温排水对于温度的影响主要集中在排放口附近的表层水体;排放口附近站位S9的溶解氧含量略高于其他站位,说明温排水的排放能提高排水口附近溶解氧含量;调查海域营养盐的分布主要受到湾内养殖区和湾外干净海水的共同影响,温排水仅对排放口附近(S9)营养盐含量造成局部影响;浮游植物群落调查结果表明,电厂附近站位S9的浮游植物群落结构与湾内其他站位群落结构差别不大,温排水对附近海域浮游植物群落结构的影响很小。综上所述,湛江滨海电厂温排水对附近海域生态环境影响较小。

厦门近岸海域营养盐时空变化特征分析及其富营养化评价

本研究根据2016—2020年厦门近岸海域15个航次的监测数据,对该区域营养盐的时空分布特征、影响因素及营养盐限制状况进行综合分析,并评估各海区的富营养化状态。结果表明,空间上,营养盐的分布特征表现为从近岸向远岸逐渐下降的趋势,溶解无机氮(Dissolved Inorganic Nitrogen,DIN)平均浓度排序为:九龙江口>西海域>同安湾>南部海域>东部海域>大嶝海域,溶解无机磷(Dissolved Inorganic Phosphorus,DIP)平均浓度排序为:同安湾>西海域>九龙江口>东部海域>南部海域>大嶝海域;时间上,营养盐浓度总体呈逐年下降趋势;枯水期最高,平水期次之,丰水期最低。研究海域平均DIN/DIP摩尔比值为40,总体表现为磷限制。2016—2020年厦门近岸海域富营养化指数(E)基本呈逐年下降的趋势;从空间分布上看,九龙江口和西海域富营养化较为严重。富营养化指数与盐度呈显著负相关关系,说明陆源输入对研究海域富营养化存在重要影响。

Effectiveness of vegetation on phosphorus removal from reclaimed water by a subsurface flow wetland in a coastal area

This work was conducted to evaluate the effectiveness and influence factors of vegetation on phosphorus （P） removal from reclaimed water in constructed wetlands. Comparisons were conducted between one pilot scale subsurface flow wetland （P-SSFW） and two demonstration subsurface flow wetlands, which were series-wound and named as first subsurface flow wetland （F-SSFW）, and second subsurface flow wetland （S-SSFW）, respectively. The three wetlands had the same vegetation and substrate, but different pH values, total dissolved solids （TDS） and P loads. Results showed that the P content in the vegetation shoots of the F-SSFW was 2.16 rag/g, while 2.31 mg/g in the S-SSFW and 2.69 mg/g in the P-SSFW. These differences were likely caused by the higher pH and TDS in the reclaimed water. The P content also differed among the tissues of the plant, which were 5.94-6.44 mg/g, 2.20-2.77 mg/g, 1.31-1.46 mg/g and 1.53-1.88 mg/g in the flowers, leaves, stems, and roots, respectively. The greatest discrepancy was observed in the leaves, indicating that the environment of the wetlands had the greatest influence on the leaves. When the total phosphorus （TP） load was lower, the proportion of P removed by vegetation assimilation was 16.17% in the P-SSFW, 12.90% in the F-SSFW and 13.29% in the S-SSFW. However, the relative removal efficiency by vegetation among the three wetlands did not vary greatly from that observed in other studies. Moreover, the influence of pH, TDS and TP load was not as great as the influence of the vegetation species, type of substrate, influent style or climate.