This study examines the Carolina Bays and Nebraska Rainwater Basins,using high-resolution LiDAR elevation models to analyze their unique shapes.The research reveals that well-preserved Bays exhibit precise elliptical ...This study examines the Carolina Bays and Nebraska Rainwater Basins,using high-resolution LiDAR elevation models to analyze their unique shapes.The research reveals that well-preserved Bays exhibit precise elliptical geometry,distinguishing them from various oriented lakes they are often compared to.While the timing of their formation is discussed,the primary goal of this paper is to establish a repeatable method for quantifying the elliptical nature of these dominant geomorphic landforms.By applying the least squares method to points selected along the perimeters of these extraordinary basins,the study confirms their elliptical geometry with an error margin of less than 3%.This rigorous mathematical approach sets a high standard for any hypothesis attempting to explain the origin of these depressions using natural environmental conditions.Notably,the long axes of these elliptical basins converge near the Great Lakes region,and since ellipses can be described as conic sections,this finding supports the plausibility of a cosmic impact origin.The study suggests that these basins may be secondary impact features formed during a past glacial cycle of the Laurentide Ice Sheet.This research establishes a strong mathematical foundation to support future studies on the possible impact origin of the Carolina Bays and Nebraska Rainwater Basins.展开更多
The exchange of inorganic nutrients at the coastal sediment-water interface(SWI)plays a crucial role in regulating the nutrient budget in overlying water.The related studies mainly focus on the mid-to high-latitude re...The exchange of inorganic nutrients at the coastal sediment-water interface(SWI)plays a crucial role in regulating the nutrient budget in overlying water.The related studies mainly focus on the mid-to high-latitude regions,leaving a significant gap in the quantitative assessment of nutrient exchange and environmental controls at the SWI in lowlatitude coastal regions.We quantitatively assess the exchange of inorganic nutrients at the SWI in three tropical bays(Dongzhai Harbor,Xiaohai Lagoon,Qinglan Harbor).Sediments act as a source of ammonium,phosphate,and silicate,but for nitrate,sediments can be both a source and sink,although with substantial spatial and temporal variations in their fluxes.Labile organic matter is a critical regulator for the fluxes of inorganic nutrients at the SWI.The sedimentary nutrients input with high N/P molar ratio will alter the nutrient stoichiometry to mitigate the nitrogen limitation in coastal waters.However,the internal sediment release in these tropical bays plays a relative weak role in contributing to the nutrient addition in comparison with the other external nutrient sources including riverine input,submarine groundwater discharge,and atmospheric deposition.According to the global compilation on SWI nutrient fluxes,we propose that water column primary production and external inputs to interpret the variation in exchange and fluxes of nutrients at the SWI in different ecosystems.Such a conceptual understanding of these chain biogeochemical processes involving external nutrient input,primary production,particulate organic matter settling,and the accumulation and release of inorganic nutrients in sediments will be helpful for the scientific-based pollution prevent and control in coastal waters.展开更多
Eutrophication caused by inputs of excess nitrogen(N) has become a serious environmental problem in Hangzhou Bay(China),but the sources of this nitrogen are not well understood.In this study,the August 2019 distributi...Eutrophication caused by inputs of excess nitrogen(N) has become a serious environmental problem in Hangzhou Bay(China),but the sources of this nitrogen are not well understood.In this study,the August 2019 distributions of salinity,nutrients [nitrate(NO_(3)^(-)),nitrite,ammonium,and phosphate],and the stable isotopic composition of NO_(3)^(-)(δ^(15)N and δ^(18)O) were used to investigate sources of dissolved inorganic nitrogen(DIN) to Hangzhou B ay.Spatial distributions of nitrate,salinity,and nitrate δ^(18)O indicate that the Qiantang River,the Changjiang River,and nearshore coastal waters may all contribute nitrate to the bay.Based on the isotopic compositions of nitrate in these potential source waters and conservative mixing of nitrate in our study area,we suggest that the NO_(3)^(- )in Hangzhou B ay was likely derived mainly from soils,synthetic N fertilizer,and manure and sewage.End-member modeling indicates that in the upper half of the bay,the Qiantang River was a very important DIN source,possibly contributing more than 50% of DIN in the bay head area.In the lower half of the bay,DIN was sourced mainly from strongly intruding coastal water.DIN coming directly from the Changjiang River made a relatively small contribution to Hangzhou Bay DIN in August 2019.展开更多
In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical e...In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical elements are obvious. The distribution of silicate in Hangzhou Bay and contents of dissolved oxygen and nutrient in the Xiangshan Bay are found to be unusual in winter. Correlations among the elements are complex. The content of nutrient in the Hangzhou Bay is higher than that in Xiangshan Bay and the content of nutrient in the Xiangshan Bay is higher than that in the Leqing Bay . The variation of the ratio of N/P is obvious. This reflects the aquatic chemical characteristics in the bay. Finally, this paper also discusses the reason why the aquatic chemical characteristics in the bays are unusual.展开更多
由中国科学院海洋研究所沈志良研究员主编的《Studies of the Biogeochemistry of Typical Estuaries and Bays in China》将由Springer出版社出版。这是一部专门论述中国典型河口、海湾生物地球化学研究的书籍,以长江口和胶州湾为主要...由中国科学院海洋研究所沈志良研究员主编的《Studies of the Biogeochemistry of Typical Estuaries and Bays in China》将由Springer出版社出版。这是一部专门论述中国典型河口、海湾生物地球化学研究的书籍,以长江口和胶州湾为主要研究区域,研究内容包括营养盐、悬浮颗粒物、浮游植物、重金属等,涉及生物地球化学、生态学、环境科学、海洋化学、海洋生物学等多个学科。展开更多
With available survey data and 237surface sediment samples,the modern sedimentation in Qingdao bays is studied.The research result shows that the east area is shallower(16.4 m) than that in the west(45.8 m).The geogra...With available survey data and 237surface sediment samples,the modern sedimentation in Qingdao bays is studied.The research result shows that the east area is shallower(16.4 m) than that in the west(45.8 m).The geography was formed by a symmetric wave in a sequence of bank-offshore depression-platform-tidal channel-platform-offshore depression-foreshore from south to north.Flood sedimentary systems were formed from inlet of the Jiaozhou Bay in the west to the barrier bar in the east.Lateral sedimentation includes mainly tidal current ridges in two tidal channels.Gravel sandy sediments formed by wave lie in midland of from seashore to wave base.Dynamic functions are mainly tide and wave.Tidal current moves sediment in vertical and horizontal directions,sorting sediments and providing materials for coastwise beaches.The sources of sediment are mainly from eroded headland rocks.In general,grain sizes in this area from the inlet of the Jiaozhou Bay in the west(120°17') to the barrier bar outside in the east(120°35') are coarse-fine-coarse,forming gravel-gravelly sand(G-S),sand(S),gravel clay silt(G-YT),clay silt(YT),gravelly silty sand(G-TS),silty sand(TS),gravelly sandy silt(G-ST),and sandy silt(ST) in turn.展开更多
There are many papers on red tide occurrences and eutrophication. Here, we use these data to examine the relationship between dam construction and red tide occurrence in Kesennuma Bay, Dokai Bay and the small bays of ...There are many papers on red tide occurrences and eutrophication. Here, we use these data to examine the relationship between dam construction and red tide occurrence in Kesennuma Bay, Dokai Bay and the small bays of the Seto Inland Sea, Japan. Here, for the first time, differences in mechanisms of red tide occurrences in these small bays are demonstrated. Mud overflowing from dams likely induces red tides in these areas as the mud flows out from the mouth of the rivers, is carried along the coast by the longshore current, and then enters and is deposited into small bays. Red tide is considered to be induced by the accumulation of mud and siltation. From data on the locations and year of red tide occurrences in the Gulf of Mexico, the same mechanism as for the occurrence of red tide in small bays of Japanwas found to be applicable.展开更多
Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study ai...Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study aims to develop a unique high-resolution modeling system to accurately predict the coastal inundation in the ungauged coastal areas of Saco-Casco Bays and map the flood risk zones to potential sea level rise due to these storms.Hindcasts of five classic WS in 2014-2015 were studied.The inundation models are based on FVCOM that uses unstructured grid to capture the minor to significant flooding near the shallow areas of the bays,harbor entrance and river banks.In this study,topography has been generated from the NOAA’s integrated dataset of Portland,ME 1/3 arc-second MHW digital elevation model.The model runs were driven by two different sets of meteorological(NECOFS WRF and NOAA’s NAM WRF)forcing to examine the effect of spatial resolution on the predicted inundation.The study reveals that among the five storm surge cases,WS-III produces a maximum surge of 0.7 m and WS-II cause a minimum surge of 0.3 m.In all scenarios,southward wind-driven coastal current flowing towards Biddeford Pool,Pine Point and Camp Ellis forms a small-scale eddy which causes significant inundation however strength of the current varies accordingly.Sensitivity experiments have been carried out using NECOFS WRF simulation products with varying parameters of marshland elevation and bottom friction to understand the influence of intertidal storage on the predicted flooding.展开更多
Ecosystem service values(ESVs)of bays and their response to sea reclamation are of great practical importance for forming bay eco-compensation policy and extension of blue economic space.Based on land use information ...Ecosystem service values(ESVs)of bays and their response to sea reclamation are of great practical importance for forming bay eco-compensation policy and extension of blue economic space.Based on land use information of bays collected during the period of 1990–2015,the spatiotemporal evolution of ESVs of 12 main bays in East China Sea and their response to sea reclamation activities over the past 25 years were quantitatively analyzed.The analysis results indicate that ESVs of bays in East China Sea showed a continuous downward trend and the whole ecosystem was continuously degraded,in which the degradation degree of ESV in the southern bays was higher than that in the northern bays.Spatial zoning of ESVs of bays in East China Sea was remarkable,showing a continuous downward trend from low-value to high-value zone.Spatial variation of ESVs of each bay was also significant,expanding from a city and from inland to the coast,which suggests that human activities,mainly reclamation,have become main agents for ESV evolution of bays in East China Sea.ESVs of bays have a significant response to sea reclamation,manifested as a significant negative correlation between ESV and reclamation intensity.The correlation in the southern bays was stronger than that in the northern bays,which was caused by different effects of sea reclamation modes on ESV evolution of muddy and bedrock bays.A negative effect of sea reclamation activities on bay ecosystem was hysteretic.Therefore,an attention should be paid to dynamic monitoring and early warning of development status in offshore areas,ecosystem-level reclamation control policy,and coastal wetland reserves planning.Moreover,the spatial coupling mechanism study between bay ecosystem service demand and its service supply capacity should be strengthened to realize systematic regulation of bay ecological security pattern.展开更多
The seasonal variations in phytoplankton community structure were investigated for the Sanggou Bay （SGB） and the adjacent Ailian Bay （ALB） and Lidao Bay （LDB） in Shandong Peninsula,eastern China.The species comp...The seasonal variations in phytoplankton community structure were investigated for the Sanggou Bay （SGB） and the adjacent Ailian Bay （ALB） and Lidao Bay （LDB） in Shandong Peninsula,eastern China.The species composition and cell abundance of phytoplankton in the bay waters in spring （April 2011）,summer （August 2011）,autumn （October 2011）,and winter （January 2012） were examined using the Uterm6hl method.A total of 80 taxa of phytoplankton that belong to 39 genera of 3 phyla were identified.These included 64 species of 30 genera in the Phylum Bacillariophyta,13 species of 8 genera in the Phylum Dinophyta,and 3 species of 1 genus in the Phylum Chrysophyta.During the four seasons,the number of phytoplankton species （43） was the highest in spring,followed by summer and autumn （40）,and the lowest number ofphytoplankton species （35） was found in winter.Diatoms,especially Paralia sulcata （Ehrenberg） Cleve and Coscinodiscus oculus-iridis Ehrenberg,were predominant in the phytoplankton community throughout the study period,whereas the dominance of dinoflagellate appeared in summer only.The maximum cell abundance of phytoplankton was detected in summer （average 8.08 × 103 cells L-1） whereas their minimum abundance was found in autumn （average 2.60 x 103 cellsL-1）.The phytoplankton abundance was generally higher in the outer bay than in the inner bay in spring and autumn.In summer,the phytoplankton cells were mainly concentrated in the south of inner SGB,with peak abundance observed along the western coast.In winter,the distribution of phytoplankton cells showed 3 patches,with peak abundance along the western coast as well.On seasonal average,the Shannon-Wiener diversity indices of phytoplankton community ranged from 1.17 to 1.78 （autumn 〉 summer 〉 spring 〉 winter）,and the Pielou＇s evenness indices of phytoplankton ranged from 0.45 to 0.65 （autumn 〉 spring 〉 summer〉 winter）.According to the results of canonical correspondence analysis,phosphate level was the major factor that limited the occurrence of P.sulcata and C.oculus-iridis,whereas optimal temperature and low salinity were responsible for Prorocentrum blooms in summer.The detailed description of seasonal variations in phytoplankton community structure in the three bays provide reference data for future studies on marine ecosystems and mariculture in adjacent areas.展开更多
The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads...The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads and water quality responses, which is crucial for developing eutrophication control strategies, is not well studied. In this study, the riverine fluxes of nutrients were quantified and integrated with nutrient cycling and phytoplankton dynamics by using box models for Guangxi coastal bays. The model concepts and biogeochemical equations were the same; while most model parameters were specific for each bay. The parameters were calibrated with seasonal observations during 2006–2007, and validated with yearly averaged measurements in 2009. The general features of nutrient and phytoplankton dynamics were reproduced, and the models were proved feasible under a wide range of bay conditions. Dissolved inorganic nitrogen was depleted during the spring algal bloom in Zhenzhu Bay and Fangcheng Bay with relatively less nutrient inputs. Phosphorus concentration was high in spring, which decreased then due to continuous phytoplankton consumption. Chlorophyll-a concentration reached its annual maximum in summer, but was the minimum in winter. Eutrophication was characterized by both an increase in nutrient concentrations and phytoplankton biomass in Lianzhou Bay. Either about 80% reduction of nitrogen or 70% reduction of phosphorus was required to control the algal bloom in Lianzhou Bay. Defects of the models were discussed and suggestions to the environmental protection of Guangxi coastal bays were proposed.展开更多
The Hangzhou Bay（HZB） and Xiangshan Bay（XSB）, in northern Zhejiang Province and connect to the East China Sea（ECS） were considerably affected by the consequence of water quality degradation. In this study, we an...The Hangzhou Bay（HZB） and Xiangshan Bay（XSB）, in northern Zhejiang Province and connect to the East China Sea（ECS） were considerably affected by the consequence of water quality degradation. In this study, we analyzed physical and biogeochemical properties of water quality via multivariate statistical techniques. Hierarchical cluster analysis（HCA） grouped HZB and XSB into two subareas of different pollution sources based on similar physical and biogeochemical properties. Principal component analysis（PCA） identified three latent pollution sources in HZB and XSB respectively and emphasized the importance of terrestrial inputs, coastal industries as well as natural processes in determining the water quality of the two bays. Therefore, proper measurement for the protection of aquatic ecoenvironment in HZB and XSB were of great urgency.展开更多
The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the an...The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the annual primary productions of benthic microalgae on tidal flats in the two bays are 2 532 and 7 542 tons carbon, which would be able to support 3.1 x 103 and 9.2 x 103 tons shellfish meat, respectively. The nature of sediment is essential for governing the biomass and primary production of benthic microalgae on tidal flats. The biomass and primary production of benthic microalgae on tidal flats with muddy sediments are higher than those with sandy sediments, which resulted from higher nutrient concentration and lower grazing pressure. That is the reason why in comparison with Xiangshan Bay the standing crop and production of benthic microalgae on tidal flats of the Sanggou and Jiaozhou Bays are low. Light was a key factor controlling vertical distribution of biomass and production of benthic microalgae on tidal flats of the two bays, resulted in appearance of maximum chlorophyll a and primary production at the surface layer and sharply decreased with depth of sediment.展开更多
The Haizhou and Daya bays are chosen as basins for seiche research in this paper. By reducing the astronomical tide, we obtain residuals which include seiches from the original observed tide curve of two representativ...The Haizhou and Daya bays are chosen as basins for seiche research in this paper. By reducing the astronomical tide, we obtain residuals which include seiches from the original observed tide curve of two representative gauges of the Haizhou and Daya bays, with a time resolution of 1min. We have further made a statistical analysis of the characteristics of the seasonal distribution of seiches and by making a comparative analysis of the seiches and the corresponding weather system, studied the origin of seiches. The research findings are of important reference value for the ocean engineering design and the storm surge forecast.展开更多
文摘This study examines the Carolina Bays and Nebraska Rainwater Basins,using high-resolution LiDAR elevation models to analyze their unique shapes.The research reveals that well-preserved Bays exhibit precise elliptical geometry,distinguishing them from various oriented lakes they are often compared to.While the timing of their formation is discussed,the primary goal of this paper is to establish a repeatable method for quantifying the elliptical nature of these dominant geomorphic landforms.By applying the least squares method to points selected along the perimeters of these extraordinary basins,the study confirms their elliptical geometry with an error margin of less than 3%.This rigorous mathematical approach sets a high standard for any hypothesis attempting to explain the origin of these depressions using natural environmental conditions.Notably,the long axes of these elliptical basins converge near the Great Lakes region,and since ellipses can be described as conic sections,this finding supports the plausibility of a cosmic impact origin.The study suggests that these basins may be secondary impact features formed during a past glacial cycle of the Laurentide Ice Sheet.This research establishes a strong mathematical foundation to support future studies on the possible impact origin of the Carolina Bays and Nebraska Rainwater Basins.
基金The Major Science and Technology Plan of Hainan Province under contract No.ZDKJ2021008the Hainan Provincial Natural Science Foundation of China under contract No.623RC456+1 种基金the Hainan Province Science and Technology Special Fund under contract Nos ZDYF2021SHFZ064 and ZDYF2022SHFZ056the Collaborative Innovation Center of Marine Science and Technology in Hainan University under contract No.XTCX2022HYC19.
文摘The exchange of inorganic nutrients at the coastal sediment-water interface(SWI)plays a crucial role in regulating the nutrient budget in overlying water.The related studies mainly focus on the mid-to high-latitude regions,leaving a significant gap in the quantitative assessment of nutrient exchange and environmental controls at the SWI in lowlatitude coastal regions.We quantitatively assess the exchange of inorganic nutrients at the SWI in three tropical bays(Dongzhai Harbor,Xiaohai Lagoon,Qinglan Harbor).Sediments act as a source of ammonium,phosphate,and silicate,but for nitrate,sediments can be both a source and sink,although with substantial spatial and temporal variations in their fluxes.Labile organic matter is a critical regulator for the fluxes of inorganic nutrients at the SWI.The sedimentary nutrients input with high N/P molar ratio will alter the nutrient stoichiometry to mitigate the nitrogen limitation in coastal waters.However,the internal sediment release in these tropical bays plays a relative weak role in contributing to the nutrient addition in comparison with the other external nutrient sources including riverine input,submarine groundwater discharge,and atmospheric deposition.According to the global compilation on SWI nutrient fluxes,we propose that water column primary production and external inputs to interpret the variation in exchange and fluxes of nutrients at the SWI in different ecosystems.Such a conceptual understanding of these chain biogeochemical processes involving external nutrient input,primary production,particulate organic matter settling,and the accumulation and release of inorganic nutrients in sediments will be helpful for the scientific-based pollution prevent and control in coastal waters.
基金The Zhejiang Provincial Natural Science Foundation of China under contract No.LZ22D060002the Key R&D Program of Zhejiang under contract No.2022C03044the National Key Research and Development Program of China under contract No.2021YFC3101702。
文摘Eutrophication caused by inputs of excess nitrogen(N) has become a serious environmental problem in Hangzhou Bay(China),but the sources of this nitrogen are not well understood.In this study,the August 2019 distributions of salinity,nutrients [nitrate(NO_(3)^(-)),nitrite,ammonium,and phosphate],and the stable isotopic composition of NO_(3)^(-)(δ^(15)N and δ^(18)O) were used to investigate sources of dissolved inorganic nitrogen(DIN) to Hangzhou B ay.Spatial distributions of nitrate,salinity,and nitrate δ^(18)O indicate that the Qiantang River,the Changjiang River,and nearshore coastal waters may all contribute nitrate to the bay.Based on the isotopic compositions of nitrate in these potential source waters and conservative mixing of nitrate in our study area,we suggest that the NO_(3)^(- )in Hangzhou B ay was likely derived mainly from soils,synthetic N fertilizer,and manure and sewage.End-member modeling indicates that in the upper half of the bay,the Qiantang River was a very important DIN source,possibly contributing more than 50% of DIN in the bay head area.In the lower half of the bay,DIN was sourced mainly from strongly intruding coastal water.DIN coming directly from the Changjiang River made a relatively small contribution to Hangzhou Bay DIN in August 2019.
文摘In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical elements are obvious. The distribution of silicate in Hangzhou Bay and contents of dissolved oxygen and nutrient in the Xiangshan Bay are found to be unusual in winter. Correlations among the elements are complex. The content of nutrient in the Hangzhou Bay is higher than that in Xiangshan Bay and the content of nutrient in the Xiangshan Bay is higher than that in the Leqing Bay . The variation of the ratio of N/P is obvious. This reflects the aquatic chemical characteristics in the bay. Finally, this paper also discusses the reason why the aquatic chemical characteristics in the bays are unusual.
文摘由中国科学院海洋研究所沈志良研究员主编的《Studies of the Biogeochemistry of Typical Estuaries and Bays in China》将由Springer出版社出版。这是一部专门论述中国典型河口、海湾生物地球化学研究的书籍,以长江口和胶州湾为主要研究区域,研究内容包括营养盐、悬浮颗粒物、浮游植物、重金属等,涉及生物地球化学、生态学、环境科学、海洋化学、海洋生物学等多个学科。
基金Supported by the National Natural Scientific Foundation of China (No 40506013)
文摘With available survey data and 237surface sediment samples,the modern sedimentation in Qingdao bays is studied.The research result shows that the east area is shallower(16.4 m) than that in the west(45.8 m).The geography was formed by a symmetric wave in a sequence of bank-offshore depression-platform-tidal channel-platform-offshore depression-foreshore from south to north.Flood sedimentary systems were formed from inlet of the Jiaozhou Bay in the west to the barrier bar in the east.Lateral sedimentation includes mainly tidal current ridges in two tidal channels.Gravel sandy sediments formed by wave lie in midland of from seashore to wave base.Dynamic functions are mainly tide and wave.Tidal current moves sediment in vertical and horizontal directions,sorting sediments and providing materials for coastwise beaches.The sources of sediment are mainly from eroded headland rocks.In general,grain sizes in this area from the inlet of the Jiaozhou Bay in the west(120°17') to the barrier bar outside in the east(120°35') are coarse-fine-coarse,forming gravel-gravelly sand(G-S),sand(S),gravel clay silt(G-YT),clay silt(YT),gravelly silty sand(G-TS),silty sand(TS),gravelly sandy silt(G-ST),and sandy silt(ST) in turn.
文摘There are many papers on red tide occurrences and eutrophication. Here, we use these data to examine the relationship between dam construction and red tide occurrence in Kesennuma Bay, Dokai Bay and the small bays of the Seto Inland Sea, Japan. Here, for the first time, differences in mechanisms of red tide occurrences in these small bays are demonstrated. Mud overflowing from dams likely induces red tides in these areas as the mud flows out from the mouth of the rivers, is carried along the coast by the longshore current, and then enters and is deposited into small bays. Red tide is considered to be induced by the accumulation of mud and siltation. From data on the locations and year of red tide occurrences in the Gulf of Mexico, the same mechanism as for the occurrence of red tide in small bays of Japanwas found to be applicable.
文摘Coastal inundation along the northeast coast of the United States is usually caused by strong winter storms(WS).However,the accurate prediction of coastal inundation due to the WS is challenging.Therefore,our study aims to develop a unique high-resolution modeling system to accurately predict the coastal inundation in the ungauged coastal areas of Saco-Casco Bays and map the flood risk zones to potential sea level rise due to these storms.Hindcasts of five classic WS in 2014-2015 were studied.The inundation models are based on FVCOM that uses unstructured grid to capture the minor to significant flooding near the shallow areas of the bays,harbor entrance and river banks.In this study,topography has been generated from the NOAA’s integrated dataset of Portland,ME 1/3 arc-second MHW digital elevation model.The model runs were driven by two different sets of meteorological(NECOFS WRF and NOAA’s NAM WRF)forcing to examine the effect of spatial resolution on the predicted inundation.The study reveals that among the five storm surge cases,WS-III produces a maximum surge of 0.7 m and WS-II cause a minimum surge of 0.3 m.In all scenarios,southward wind-driven coastal current flowing towards Biddeford Pool,Pine Point and Camp Ellis forms a small-scale eddy which causes significant inundation however strength of the current varies accordingly.Sensitivity experiments have been carried out using NECOFS WRF simulation products with varying parameters of marshland elevation and bottom friction to understand the influence of intertidal storage on the predicted flooding.
基金NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization,No.U1609203National Natural Science Foundation of China,No.41976209,No.71874091+1 种基金Natural Science Foundation of Zhejiang Province,No.LQ15D020001Scientific Research Foundation of Graduate School of Ningbo University,No.G19077。
文摘Ecosystem service values(ESVs)of bays and their response to sea reclamation are of great practical importance for forming bay eco-compensation policy and extension of blue economic space.Based on land use information of bays collected during the period of 1990–2015,the spatiotemporal evolution of ESVs of 12 main bays in East China Sea and their response to sea reclamation activities over the past 25 years were quantitatively analyzed.The analysis results indicate that ESVs of bays in East China Sea showed a continuous downward trend and the whole ecosystem was continuously degraded,in which the degradation degree of ESV in the southern bays was higher than that in the northern bays.Spatial zoning of ESVs of bays in East China Sea was remarkable,showing a continuous downward trend from low-value to high-value zone.Spatial variation of ESVs of each bay was also significant,expanding from a city and from inland to the coast,which suggests that human activities,mainly reclamation,have become main agents for ESV evolution of bays in East China Sea.ESVs of bays have a significant response to sea reclamation,manifested as a significant negative correlation between ESV and reclamation intensity.The correlation in the southern bays was stronger than that in the northern bays,which was caused by different effects of sea reclamation modes on ESV evolution of muddy and bedrock bays.A negative effect of sea reclamation activities on bay ecosystem was hysteretic.Therefore,an attention should be paid to dynamic monitoring and early warning of development status in offshore areas,ecosystem-level reclamation control policy,and coastal wetland reserves planning.Moreover,the spatial coupling mechanism study between bay ecosystem service demand and its service supply capacity should be strengthened to realize systematic regulation of bay ecological security pattern.
基金supported by the National Program on Key Basic Research Project of China (Grant Nos. 2011CB409804 and 2015CB954002)Program for New Century Excellent Talents in University (NCET-12-1065)the National Natural Science Foundation of China (Grant No.41176136) to J. Sun
文摘The seasonal variations in phytoplankton community structure were investigated for the Sanggou Bay （SGB） and the adjacent Ailian Bay （ALB） and Lidao Bay （LDB） in Shandong Peninsula,eastern China.The species composition and cell abundance of phytoplankton in the bay waters in spring （April 2011）,summer （August 2011）,autumn （October 2011）,and winter （January 2012） were examined using the Uterm6hl method.A total of 80 taxa of phytoplankton that belong to 39 genera of 3 phyla were identified.These included 64 species of 30 genera in the Phylum Bacillariophyta,13 species of 8 genera in the Phylum Dinophyta,and 3 species of 1 genus in the Phylum Chrysophyta.During the four seasons,the number of phytoplankton species （43） was the highest in spring,followed by summer and autumn （40）,and the lowest number ofphytoplankton species （35） was found in winter.Diatoms,especially Paralia sulcata （Ehrenberg） Cleve and Coscinodiscus oculus-iridis Ehrenberg,were predominant in the phytoplankton community throughout the study period,whereas the dominance of dinoflagellate appeared in summer only.The maximum cell abundance of phytoplankton was detected in summer （average 8.08 × 103 cells L-1） whereas their minimum abundance was found in autumn （average 2.60 x 103 cellsL-1）.The phytoplankton abundance was generally higher in the outer bay than in the inner bay in spring and autumn.In summer,the phytoplankton cells were mainly concentrated in the south of inner SGB,with peak abundance observed along the western coast.In winter,the distribution of phytoplankton cells showed 3 patches,with peak abundance along the western coast as well.On seasonal average,the Shannon-Wiener diversity indices of phytoplankton community ranged from 1.17 to 1.78 （autumn 〉 summer 〉 spring 〉 winter）,and the Pielou＇s evenness indices of phytoplankton ranged from 0.45 to 0.65 （autumn 〉 spring 〉 summer〉 winter）.According to the results of canonical correspondence analysis,phosphate level was the major factor that limited the occurrence of P.sulcata and C.oculus-iridis,whereas optimal temperature and low salinity were responsible for Prorocentrum blooms in summer.The detailed description of seasonal variations in phytoplankton community structure in the three bays provide reference data for future studies on marine ecosystems and mariculture in adjacent areas.
基金supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2010BAC69B00)Basic Scientific Research Fund of the Second Institute of Oceanography, SOA (JG1210, JG1209 and JT1005)+1 种基金National Basic Research Program of China (2011CB409803)Special Expenses Program of Scientific Research in Marine Commonweal Industry (201205015)
文摘The increasing riverine pollutants have resulted in nutrient enrichment and deterioration of water quality in the coastal water of Guangxi Province, China. However, the quantitative relationship between nutrient loads and water quality responses, which is crucial for developing eutrophication control strategies, is not well studied. In this study, the riverine fluxes of nutrients were quantified and integrated with nutrient cycling and phytoplankton dynamics by using box models for Guangxi coastal bays. The model concepts and biogeochemical equations were the same; while most model parameters were specific for each bay. The parameters were calibrated with seasonal observations during 2006–2007, and validated with yearly averaged measurements in 2009. The general features of nutrient and phytoplankton dynamics were reproduced, and the models were proved feasible under a wide range of bay conditions. Dissolved inorganic nitrogen was depleted during the spring algal bloom in Zhenzhu Bay and Fangcheng Bay with relatively less nutrient inputs. Phosphorus concentration was high in spring, which decreased then due to continuous phytoplankton consumption. Chlorophyll-a concentration reached its annual maximum in summer, but was the minimum in winter. Eutrophication was characterized by both an increase in nutrient concentrations and phytoplankton biomass in Lianzhou Bay. Either about 80% reduction of nitrogen or 70% reduction of phosphorus was required to control the algal bloom in Lianzhou Bay. Defects of the models were discussed and suggestions to the environmental protection of Guangxi coastal bays were proposed.
基金The National Marine Ecoenvironment Assessment Program of State Oceanic Administration
文摘The Hangzhou Bay（HZB） and Xiangshan Bay（XSB）, in northern Zhejiang Province and connect to the East China Sea（ECS） were considerably affected by the consequence of water quality degradation. In this study, we analyzed physical and biogeochemical properties of water quality via multivariate statistical techniques. Hierarchical cluster analysis（HCA） grouped HZB and XSB into two subareas of different pollution sources based on similar physical and biogeochemical properties. Principal component analysis（PCA） identified three latent pollution sources in HZB and XSB respectively and emphasized the importance of terrestrial inputs, coastal industries as well as natural processes in determining the water quality of the two bays. Therefore, proper measurement for the protection of aquatic ecoenvironment in HZB and XSB were of great urgency.
基金This study was supported by EC Project under contract No.ERB3514PL97 2439 with the contract No.ERB IC18-CT98-0291.
文摘The standing crop and primary production of benthic microalgae on tidal flats have seasonally been observed in the Sanggou and Jiaozhou Bays of the northern China coast during 1999 - 2000. The results show that the annual primary productions of benthic microalgae on tidal flats in the two bays are 2 532 and 7 542 tons carbon, which would be able to support 3.1 x 103 and 9.2 x 103 tons shellfish meat, respectively. The nature of sediment is essential for governing the biomass and primary production of benthic microalgae on tidal flats. The biomass and primary production of benthic microalgae on tidal flats with muddy sediments are higher than those with sandy sediments, which resulted from higher nutrient concentration and lower grazing pressure. That is the reason why in comparison with Xiangshan Bay the standing crop and production of benthic microalgae on tidal flats of the Sanggou and Jiaozhou Bays are low. Light was a key factor controlling vertical distribution of biomass and production of benthic microalgae on tidal flats of the two bays, resulted in appearance of maximum chlorophyll a and primary production at the surface layer and sharply decreased with depth of sediment.
文摘The Haizhou and Daya bays are chosen as basins for seiche research in this paper. By reducing the astronomical tide, we obtain residuals which include seiches from the original observed tide curve of two representative gauges of the Haizhou and Daya bays, with a time resolution of 1min. We have further made a statistical analysis of the characteristics of the seasonal distribution of seiches and by making a comparative analysis of the seiches and the corresponding weather system, studied the origin of seiches. The research findings are of important reference value for the ocean engineering design and the storm surge forecast.
