10 June 2024, Volume 46 Issue 3

    

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• Research Paper
• Experimental study on the scour of the seabed around the tripod foundation under the combined action of wave and current

  WANG Rengang, ZHU Chenghao, SUN Yuan, LIU Hongjun, FU Yipeng, CHEN Da

  2024, 46(3): 1-11. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.001

  Abstract ( ) PDF ( )

  Under the action of waves and currents, offshore wind power foundations may experience local erosion, resulting in an increase in the length of the foundation cantilever, which seriously affects the stability and safety of the foundation. To investigate the local erosion characteristics of offshore wind power tripod foundations under the combined action of waves and currents, local erosion tests were conducted on tripod foundations with different installation angles in a wave current tank. The characteristics of local erosion depth, influencing factors, and the morphology of erosion pits were studied. The research results indicated that under the action of individual waves, the central column provided a certain protective effect on downstream piles, weakening the development of erosion. When waves and currents acted together, waves provided drag force on the bottom bed, while water flow provided sediment transport force, resulting in a significant increase in scouring depth. When the installation angle was 30°, the water blocking effect on the double pile side of the tripod was greater, and some water flow was directed towards the single pile side, resulting in an increase in the scouring depth. As the flow velocity, wave height, and KC increasing, the depth of erosion around the foundation gradually increased. An empirical formula using KC to predict the equilibrium scour depth had been proposed, which could accurately predict the equilibrium scour depth of local scour on a tripod foundation under wave action and wave current combined action.
• Studieson the influence of coastline change on tidal prism and water exchange of Laizhou Bay

  ZHU Jinlong, SUN Wei, CHEN Shaowei, FENG Yinyin, WEI Xiao, LIU Ning, XU Yandong, WANG Wanguan, LI Zimo

  2024, 46(3): 12-18. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.002

  Abstract ( ) PDF ( )

  Since the 21^st century, the coastline of Laizhou Bay has changed significantly due to coastal reclamation activities such as port dam construction and aquaculture dikes, which have caused the change of the hydrodynamic environment of the bay. In order to investigate the response of the tidal prism and water exchange capacity of Laizhou Bay to its coastline change during the past 20 years, the influence of the coastline change on tidal prism and water exchange capacity was analyzed with two-dimensional flow and advection-diffusion models for the two typical years, 2000 and 2020. The results showed that from 2000 to 2020, aquaculture dikes have caused an increase in the potential energy of tidal waves, and the maximum possible tidal range of Laizhou Bay also shows an increasing trend. The head of the bay between Weifang Port and Guangli Port increased significantly with the maximum increase of 8 cm. The spring tidal prism was decreased by 2.91%, the neap tidal prism by 1.42% and the mean tidal prism by 2.33%, and decreased bay area was the main reason for the decrease of tidal prism. The decrease in the sea area of the bay has led to a reduction in its self-cleaning capacity and water exchange, increasing the bay half-life time by 15 days. As for the local water exchange capacity, the water exchange capacity in the western part of the bay was decreased by port dam construction and a deposition trend of the Yellow River Estuary, resulting in an increase of half-life time in the western part of the bay by 40 d.
• Influence of the inclination angle on seawater intrusion in seaward-inclined unconfined aquifer

  LIN Guoqing, PING Yuwei, HUANG Zhuoxiong, LI Song, MO Weiming

  2024, 46(3): 19-27. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.003

  Abstract ( ) PDF ( )

  Seawater intrusion is a global environmental geological disaster, and the degree of intrusion is influenced by both geological and human factors. In the investigation of seawater intrusion, the inclination angle of the aquifer bedrock is a geological issue that cannot be disregarded. At present, there are few researches on the influence of the inclination angle of the aquifer bedrock on seawater intrusion systematically. In this study, a color tracing experiment in an indoor sand tank was used to examine how the inclination angle affected seawater intrusion in unconfined aquifers under various hydrodynamic conditions. The findings demonstrated an exponential function link between the inclination angle of the aquifer bedrock and the length of saltwater wedge. The phenomenon of seawater intrusion weakened with increasing the inclination angle under the conditions of constant-flow boundary and constant-head boundary. While the length and area of saltwater wedge and the time needed to reach steady state decreased and the fresh water discharge outlet increased. The length of the saltwater wedge decreased by 32.4%, the intrusion area decreased by 35.0%, the groundwater outlet increased by 27.1%, and the equilibrium time decreased by 40.7% when the freshwater boundary flow was 15 mL/min and the inclination angle raised from 0° to 10°. Additionally, the length of saltwater wedge was the most sensitive to freshwater discharge, followed by freshwater level and inclination angle. The research results provided scientific basis for quantitative evaluation and prevention of seawater intrusion.
• Seabed erosion mechanism and maximum scour depth in front of the Gudong seawall

  SUN Jian, XU Jishang, LI Guangxue

  2024, 46(3): 28-38. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.004

  Abstract ( ) PDF ( )

  Seawalls play an important role in preventing coastal areas from storm surges, but the seabed in front of seawalls usually suffers serious erosion after their construction, which would threaten the safety of seawalls. To analysis the scour problem in Gudong Seawall, we recovered the scouring process according to the water depth during the past 20 years, discussed the scour mechanism and calculated the maximum scouring depth. The results showed that: (1) Gudong seawall was under the erosion background in the abandoned sub-lobes of the underwater delta of the Yellow River Delta, and the seabed within 500 m offshore suffered more severe erosion, which was called background scouring and toe scouring respectively in this manuscript. The background water depth had deepened from 2-3 m in 2000 to the present depth of 6 m, and the maximum water depth at the toe of the seawall had exceeded 7 m. (2) Background scouring was mainly caused by the diversion of the river course and the reduction of sediment into the sea. Waves were the main driving factor for seabed scouring. Seawall toe scouring was caused by complex hydrodynamic processes in front of the Gudong Seawall, such as wave reflections, wave breaking, turbulence, coastal current, offshore current, etc. (3) It was predicted that the maximum scouring depth for background erosion in the Gudong Sea area was 7 m, whilst for toe scouring was 1.7-2.5 m, so the maximum water depth in front of the Gudong seawall was 8.7-9.5 m.
• Research on tidal missing data imputing with long and short term memory neural network

  MIAO Qingsheng, LIU Yulong, WEI Guanghao, YANG jinkun, YANG Yang, XU Shanshan

  2024, 46(3): 39-46. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.005

  Abstract ( ) PDF ( )

  Tidal data reflects changes in coastal sea level, and plays a very important role in various fields. The lack of tidal data brings inconvenience to the use of tide level data. Based on the tidal data of the Chongwu and Jinjiang ocean stations in 2017, this paper proposed a method of filling missing data based on the LSTM model (long short-term memory neural network model). Compared with traditional interpolation methods such as linear interpolation and spline interpolation, the LSTM method had stable performance, high accuracy and easy implementation. Especially when the lack of measurement time was long, the LSTM method was obviously better than the traditional interpolation method. At the same time, this method was also suitable for filling other missing data including water temperature.
• Numerical simulation study of typhoon waves caused by typhoon Lekima on the coast of Shandong peninsula

  YE Zuchao, MA Xin, FU Yucheng, LI Qingjie, SHI Hongyuan, LI Feng

  2024, 46(3): 47-54. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.006

  Abstract ( ) PDF ( )

  Disasters such as strong winds and huge waves caused by typhoons have a significant impact on the offshore area of Shandong peninsula. In this paper, by using the third-generation wave model SWAN, the driving field of the model was formed by ERA5 background wind field and the typhoon model wind field nested with Takahashi and Fujita. t formulas. The typhoon waves in the process of No. 9 typhoon "LIKEMA" in 2019 were simulated. According to the simulation results, the distribution of effective wave height, average period and wave age of typhoon wave was analyzed numerically, and the spatial distribution characteristics of typhoon wave during typhoon "LIKEMA" were preliminarily explored, which provided technical support for typhoon wave warning, disaster prevention and mitigation in Shandong province. The research results have certain scientific significance and application value.
• Wave study on the design schemes of marina in Colombo Port City

  XIANG Yinyu

  2024, 46(3): 55-64. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.007

  Abstract ( ) PDF ( )

  MIKE21 BW was applied to study the waves of four design schemes of marina in Colombo port city. The results showed that the layout of the breakwater near the entrance of the marina had a significant influence on the wave protection effect of the marina basin. The breakwater with linear shape near the entrance had the worst wave protection effect on the marina basin, which could not meet the requirement that the effective wave height of 50-year return period was less than 0.4m. The breakwater near the entrance was in the form of inward encircling, which had a good wave protection effect on the marina basin, and the protection effect of the inward encircling curvature of 0.0059 was better than that of the curvature of 0.005. The breakwater with outward flip at the end of the breakwater had the best wave protection effect.
• Identification andclassification of marine ranching fish based on the Faster-RCNN

  JIAO Menglu, ZHANG Haiyan, LI Xin

  2024, 46(3): 65-72. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.008

  Abstract ( ) PDF ( )

  Towards the problems of color distortion of the marine ranching observation video and low accuracy of traditional fish identification methods, a marine ranching fish identification and classification method based on Faster-RCNN was proposed. SDI (Serial Digital Interface) signal color compensation system was used first to improve the poor video quality caused by the particularity and complexity of the marine environments, and then the optimized video was applied to produce data sets with diverse qualities. The Faster-RCNN works following a deep learning model with the feature extraction network and region proposal network (RPN) optimized and used to identify and classify marine ranching fish. The tentative experimental results showed that the mean average precision (mAP) of this method reached 81.63%, significantly improved the accuracy of recognition compared with traditional machine learning target detection algorithms.
• Characteristics of suspended sediment transport and analysis of sedimentary dynamic environment in the coastal waters of Wanning Riyue bay

  LIN Jijiang, WANG Ping, ZHANG Zhuo, TANG Ling, WANG Lei, YOU Dawei, NIE Yuhua, NIU Jianwei

  2024, 46(3): 73-81. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.009

  Abstract ( ) PDF ( )

  Based on the synchronized data of suspended sediment and sea current, this paper analyzed the suspended sediment transport mechanism and the main mechanical control factors in study areas using sediment flux mechanism decomposition method. The sedimentary dynamic environment was divided into different zones using Flemming triangle diagram method on the basis of the distribution characteristics of the surface sediments in the study area. The results showed that the Lagrangian advection transport was the main governing factor in transport of suspended sediment and the vertical net circulation came second. And the transport direction of the tidal average single-width net sediment transport was in SW, which corresponds to the direction of the remaining flow in the study area. The average single tidal-width sediment transport at the outer station showed a decreasing trend from northeast to southwest, while the inner station showed the opposite, the average single tidal-width sediment transport increased from the northeast to the southwest. It was indicated that there was nearshore erosion or river sand transport. Observation showed that the study area was covered largely by sand and the local area was silty sand, gravel sand, and sandy gravel, with a small number of shells or coral reefs. The dynamic environment could be divided into zone S, zone A and zone B. The motion of surface sediments were three types: moving, jumping, and overhanging. The jumping was the main route of the surface sediment. The surface sediments had a lower content of transitional components in sediments and the increase of suspended-transition components with the hydrodynamic environment became weaker.
• Estimation of organic carbon content and carbon sequestration capacity of macroalgae in natural seaweed field-Take subtidal zone of Gouqi Island, Zhejiang, as an example

  ZHAO Xu, WANG Xiao, LI Xunmeng, CHENG Xiaopeng, HUANG Hong, ZHANG Shouyu

  2024, 46(3): 82-89. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.010

  Abstract ( ) PDF ( )

  In this paper, the species, distribution area and biomass per unit area of macroalgae in the subtidal zone of Gouqi Island, Zhejiang Province, were investigated through acoustic side scanning and SCUBA diving. At the same time, the organic carbon content of different macroalgae was detected, and based on the biomass per unit area, the biomass and carbon sequestration capacity of the subtidal algal field in Gouqi Island were estimated. The results showed that the distribution area of the subtidal zone algal field is about 22.33 hectares in Gouqi Island, and there were 19 species of 3 phyla of macroalgae are distributed. The content of organic carbon in different species ranged from 29.11% to 36.85%. Brown algae contain a special blue light effect and have the highest average organic carbon content (32.62%) which was followed by Chlorophyta (31.82%) and Chlorophyta (29.39%). The macroalgal carbon sequestration capacity per unit area was estimated to be 176.15g·C/m², and the total carbon sequestration in the sea area is about 38.28 tons, equivalent to about 129.07 tons of CO₂ emission reduction. The results of this study can accumulate basic data for the study of carbon sequestration capacity of macroalgae farms in coastal waters, and also provided a scientific basis for the study of negative emission reduction path in the ocean.
• Research Report
• Analysis on the linear relations about BOD₅, DO and COD in the water of marine outfalls

  JIN Xingliang, SUN Taotao, TANG Tianjun, LIAO Guowei, WANG Yu, DAI Zhiguang

  2024, 46(3): 90-96. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.011

  Abstract ( ) PDF ( )

  The relations about BOD₅, DO and COD were researched, which were acquired from water of marine outfalls near a coastal city, south China. The results indicated that preferable one-variable linearity existed between COD and BOD₅, but relatively weak linearity between BOD₅ and DO, as weakly between DO and COD. A binary linear function was established to express the relation about the three parameters, with a better linear determination coefficient and a larger F-test value. When COD ≥ 100mg/L, the fitting degree of the binary linear function was better than the one-variable linear function between COD and BOD₅. Monitoring data of BOD₅, DO and COD from water of marine outfalls of this city in 2015 year was used to verify the binary linear function. The relative error between COD values fitted by the binary linear function and COD values detected in a lab, was less than 25%, which accorded with the precession of quality control criterion, and verified the binary linear function reliable.
• Analysis on the change and driving factors of coastal wetland in Shantou city

  YI Jiaji, ZANG Yunzhong, WANG Yang, FENG Kecong, WANG Wanhu, YUAN Kun

  2024, 46(3): 97-106. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.012

  Abstract ( ) PDF ( )

  In this study, according to the human-computer interactive interpretation and GIS analysis, the distribution of coastal wetlands in Shantou city was obtained since 1980s by analyzing the multi-temporal landsat remote sensing image data. According to wetland classification system, Shantou coastal wetland was divided into natural wetlands and constructed wetlands (first classification), including 9 types. They were shallow sea areas, rivers, lakes, beaches/coastal, mangroves forest, reservoirs/ponds, water fields, salterns and aquaculture ponds (secondary classification). The variation characteristics and the influencing factors of coastal wetlands in Shantou city were analyzed by dynamic degrees of single wetland type, wetland transition matrix and correlation analysis. The results showed that: from 1982 to 2020, the coastal wetlands in whole area were increased slightly by 19.08 km². The natural wetlands shrank significantly with a total area loss of 51.18 km², while the constructed wetlands expanded significantly, with a total area increase of 70.26 km². The main driving force of the change came from a series of human activities such as tideland reclamation, land reclamation, sea reclamation and river aquaculture, construction of fishing port wharf and water conservancy facilities in the rapid urbanization process of Shantou city. Secondly, the changes of sediment discharge and sea level rise of the major rivers also played a certain role in the wetland change.
• Analysis of heavy metal content and potential ecological risk in surface seawater of Yangjiang offshore area of Guangdong province

  LI Yang, HE Jinxian, LIN Hai, GAN Huayang, CAO Wenjie, WANG Jian, XING Huitong, SHI Shuai, YANG Tiantian

  2024, 46(3): 107-113. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.013

  Abstract ( ) PDF ( )

  To understand Yangjiang, Guangdong nearshore sea surface water content and potential ecological risk of heavy metals, samples surface waters were collected at 14 stations. The content distribution characteristics of 7 kinds of heavy metals were analyzed in surface waters including Cr, Cu, Zn, Cd, Pb, As, and Hg. The Hakanson method was adopted to evaluate their ecological risk index and potential ecological harm. The results showed that the average concentrations of heavy metals Cr, Cu, Zn, Cd, Pb, As and Hg in the surface waters off Yangjiang were 1.10 μg/L, 5.25 μg/L, 9.91 μg/L, 0.027 μg/L, 0.945 μg/L, 1.06 μg/L and 0.027 μg/L, respectively. Among them, Cr, Zn, Cd, Pb, As and Hg met the quality standards for class I seawater, while Cu met the quality standards for class II seawater. There was a strong correlation among the 7 heavy metals, and each heavy metal also had a certain correlation with different environmental parameters. Based on the analysis of the potential ecological risk index, the average value of RI was calculated to be 6.59, which was a slight ecological hazard and the overall level of cleanliness.
• Contamination and assessment of potential ecological risk of heavy metals in sea water and sediment from aquaculture areas of Dongtou islands, Zhejiang

  LI Fei, TAO Jianbin, XIA Luyao, LIANG Xuan

  2024, 46(3): 114-120. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.014

  Abstract ( ) PDF ( )

  In order to assess the aquaculture environmental quality of Dongtou sea area, 24 sea water samples and 24 surface sediment samples were collected from aquaculture areas of Dongtou and the contents of heavy metals including Hg, As, Cu, Pb, Zn, Cd and Cr were determined. Then the levels of heavy metal pollution in sea water and surface sediment were evaluated by single factor method and comprehensive pollution index. The potential ecological risk of heavy metals in sediments were evaluated by Hankanson potential ecological risk index. The results showed that the contents of seven heavy metals in sea water of the aquaculture areas investigated were below the standard values by the national standard of mariculture sea water quality. The Hg, As, Pb, Cd and Cr quality in surface sediment conformed to the first grade by the national standard of marine sediment quality which was suitable for aquaculture. However, the single pollution index of Cu and Zn in sediment were a bit more than 1, it means that the sediment quality was slightly polluted. When the geochemical background values of sediments in the Yangtze estuary offshore marine areas were used as reference values, the degree of heavy metals potential ecological risks was in the order: Hg＞Cd＞As＞Cu＞Pb＞Zn＞Cr and Hg contributed the most to the total potential ecological risk. The potential ecological risk indexes (RI) of 7 heavy metals at all aquaculture areas were in the range of 129.31 and 157.45, and posed medium level potential ecological risks for the Dongtou sea area.
• Present situation of Chinese marine industry structure and its developmental prospects

  ZHANG Zuping, WU Liuxiang

  2024, 46(3): 121-128. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.015

  Abstract ( ) PDF ( )

  In order to further cultivate marine industry, promote the development of marine economy and build a powerful marine power, in this paper, we analyzed the current situation of Chinese marine industrial structure and its developmental prospects through deviation share, industrial structure deviation and grey correlation analyses. The results showed that (1) Chinse marine industry presents the "three two one" structure model, the development of marine secondary industry is slow, lagging behind the development of the second industry of national economy, and is in a weak position; (2) the employment structure and output structure of marine industry are asymmetric, and the industrial structure benefits are low; (3) the subdivision industry in the three marine industries needs to be further optimized and upgraded. We suggested to improve the structural benefit of the primary industry, enhance the competitiveness of the secondary industry and consolidate the dominant position of the tertiary industry.
• Impact of cage culture on regional surface sediment of Maniao Bay

  HUANG Hong, LIU Yilin, YU Jinchen, LAN Yan, ZHAO Xu, WANG Zuanyi, LI Yingdong, CHU Ming

  2024, 46(3): 129-140. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.016

  Abstract ( ) PDF ( )

  In recent years, the cage aquaculture industry has developed rapidly, but the impact of cage aquaculture on the regional environment, especially the scope of influence, is rarely reported. Large-scale fish production in cages has been carried out in Maniao Bay, Chengmai County, Hainan Province. Field surveys and sampling were conducted in March (Spring), July (Summer), October (Autumn), and December (Winter), 2019. The total nitrogen (TN), total phosphorus (TP) and total organic carbon (TOC) and other indicators in the sediments were detected and their temporal and spatial changes were analyzed as well as the fitting equations of TN, TP and TOC with the distance from the cage culture area were established. The results showed that the contents of TN, TP and TOC in the surface sediments of the Maniao Bay vary between 113.48 and 1265.10mg/kg, 287.90 and 760.05mg/kg and 0.03 and 1.14%, respectively. During the study period, the overall sedimentary environment was good. TN is significantly affected by seasonal changes, it is lower in summer, and tends to increase in autumn and winter. TP and TOC fluctuate up and down as a whole. TN is enriched at different degrees in spring, autumn and winter. TP is enriched in autumn, but TOC is not enriched. The content of TN in the surface sediments of Maniao Bay is high in S and A while the content in the control area (B, C) is low. The overall spatial distribution of TP and TOC content is similar to that of TN. Geographically, the content is high at the mouth of the northern gulf and low at the bottom of the southern bay. Possibly affected by the northeast and southwest reciprocating flow, the aquaculture waste generated from cage aquaculture was brout out of Maniao Bay. The overall trends of TN, TP, and TOC of the surface sediments in Maniao Bay are relatively consistent. The content in the space range of 0~1 km away from the cage culture area shows a certain increasing trend. A decreasing trend within the space range of 1 km~3 km from the cage culture area was shown. Based on this preliminary judgment, the impact range of cage culture in Maniao Bay on surface sediment TN, TP, TOC was estimated to be about 1 km.
• Distribution of Antarctic krill inhabiting Cosmonaut Sea

  LI Xu, WANG Jing, LU Kunyu, ZHAO Liang, FENG Jianlong

  2024, 46(3): 141-148. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.017

  Abstract ( ) PDF ( )

  It is of a great significance for the utilization and protection of Antarctic krill to study the distribution of and predict the suitable habitat of Antarctic krill in the Cosmonaut Sea. Using krill distribution data from the Krillbase and data from the global ocean data assimilation reanalysis system (GLORYS), the spatial distribution characteristics of krill in Astronaut Sea and the characteristics of sea surface temperature, sea surface salinity, chlorophyll and sea ice in krill collection points were analyzed. At last, the suitable habitat of Antarctic krill in Astronaut Sea was obtained. Results showed that the density of krill was high in the south and low in the north, and high in the west and low in the east of the Astronaut Sea. The high density was concentrated in the coastal area to the west of Enderby, and mostly located in the south of 65°S. Results showed that Antarctic krill prefers to habitat sea surface temperature of 271.4K-271.9K, salinity of 33.9-34.1, chlorophyll of 0.28 mg·m^-3~0.36 mg·m^-3, sea ice concentration of 0.67-0.81. The suitable habitat of the Antarctic krill distributed in the south of 65°S, and was paralleled to the coastline.
• Characteristics of phytoplankton communities along Qingdao coast and their relationship with environmental factors

  LI Xiaojiao, CUI Zhengguo, SUN Xuemei, JIA Jun, DING Dongsheng, CHEN Bijuan, CHEN Jufa

  2024, 46(3): 149-157. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.018

  Abstract ( ) PDF ( )

  A field survey was carried out in Qingdao coastal area in spring (May) and summer (August) in 2019. Variation characteristics of phytoplankton community structure in coastal areas of Qingdao and their relationship with environment were studied, and the reasons of variation were analyzed based on the historical data. The results showed that a total of 109 taxa which belong to 52 genera of 4 phyla were identified in spring and summer. Compared with the historical data, the survey results of the phytoplankton community in costal waters of Qingdao showed obvious species succession, and the dominance of predominant species, Skeletonema costatum, remarkably decreased. The cell abundance of phytoplankton in Jiaozhou Bay was significantly higher than that in Laoshan Bay, and the diversity index of Laoshan Bay was higher than that in Jiaozhou Bay in summer. Correlation analysis and redundancy analysis of phytoplankton community structure and environmental factors showed that the phytoplankton cell abundance showed a positive correlation with phosphate and DIN (P<0.01), the phytoplankton cell abundance showed a positive correlation with COD (P<0.05) while the phytoplankton cell abundance showed a negative correlation with salinity and pH (P<0.05).
• Diversity and ecological health assessments of aquatic plants inhabiting northern suburb wetland of Zhangye City

  WU Jiandong, LIU Yubing, TIAN Kun

  2024, 46(3): 158-166. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.019

  Abstract ( ) PDF ( )

  Aquatic plant diversity and ecological health assessment are of great significance to the integrity and stability of wetland ecosystem. Taking Zhangye northern suburb wetland as an example, the aquatic plant community, water quality index and wetland health status were studied by combining field investigation and observation, indoor measurement and analysis, numerical calculation and simulation. The results showed that the water quality of the wetland in the northern suburb of Zhangye was good, and the average contents of DO, TP, NH₃-N and NO₂-N were low, which was in line with Class Ⅰ or Class Ⅱ water quality. The contents of TN, NO₃-N and COD were high, which conformed to Class IV water quality, indicating that nitrogen and organic matter are the main pollutants in wetland water. There were 14 orders, 18 families, 21 genera and 26 species of aquatic plants, all of which belong to angiosperms. The monocotyledonous plants had 10 orders, 12 families, 15 genera and 20 species. Dicotyledonous plants consisted of 4 orders, 6 families, 15 genera and 20 species, among them Potamogetoncrispus, Schoenoplectus tabernaemontani and Phragmites australis have a wide distribution range. Among the 25 stations, 9 were in sick condition. There were 5 subpathological and critical stations. There were 4 sub-healthy stations. There were 2 healthy stations. From the eigenvalues and index weights of each subsystem level, we can see that the main factors affecting system health were water quality, hydrology and aquatic plant indexes. The results of this study are of a great significance for understanding the influence of different water environmental factors on aquatic plant diversity, and improving effective management measures and technical support for northern suburban wetlands through wetland ecosystem assessment.
• Research Review
• Research progresses in the application of vulnerability methodology in fishery

  ZHANG Yuqing, CHEN Xinjun

  2024, 46(3): 167-176. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.020

  Abstract ( ) PDF ( )

  Vulnerability represents a certain state of a system, and vulnerability analysis is an inevitable requirement for each system to respond to global changes and a necessary path to practice sustainable development. In order to make the fishery system better respond to external changes and maintain the sustainability of fishery resources and its economy, in this paper, we studied the vulnerability theories and methods and their application research progresses in fishery. Through the collation of relevant literature, it is found that vulnerability research has been applied and developed in multiple disciplines and fields, and the theoretical system such as conceptual methods is rich, but there is no unified standard ye. Fishery vulnerability research is still in its infancy, mainly about the vulnerability analysis of species, ecosystem, and coupled systems, with a relatively mature concept definition and a variety of evaluation methods. The literature mainly focuses on the quantitative research on the vulnerability of the coupled system and the qualitative and semi-quantitative research on the vulnerability of the species. Only a small amount of literatures studies the vulnerability of the ecosystem. The studies have been conducted on different scales and angles around inland, marine, and special fishery (especially coral reef fishery). Among them, there are more studies on marine fishery, and less on inland fishery, all of which focus on the vulnerability to climate change. The findings of this study can provide a reference for fishery vulnerability assessment in China.
• An exploration of typhoons and salty rains invading Taiwan and their response during the Dao-Han period of the Qing dynasty

  CAI Qinyu, LIU Zhen

  2024, 46(3): 177-184. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.021

  Abstract ( ) PDF ( )

  During the Dao-Han period of the Qing Dynasty, typhoons and salty rains were frequent in Taiwan, showing the suddenness and serious destructive nature of disasters, resulting in the collapse of houses, shriveling of crops, damage to land, injuries and deaths, the sinking of merchant ships, and even the destruction of public facilities. In the face of disasters, the central government adhered to the "inter-governmental cooperation" mechanism for disaster relief, in which local officials at all levels independently surveyed the disaster situation and cooperated with each other, giving full play to the governance strengths and values of the grass-roots government. In terms of material mobilization, under the coordination of the central government, local governments in disaster-stricken areas had been able to allocate materials close to each other, thus enhancing the efficiency and level of disaster relief. In terms of specific measures, local governments realized the cooperation between local governments and the private sector in disaster relief by mobilizing private donations and other measures. Through the effective governance of the central government during this period, Taiwan achieved good relief results. This idea of inter-governmental cooperation in disaster relief also provided valuable experience for the future relief model of typhoon salty rain disasters in Taiwan and even other regions.
• A review on the conservation of Acipenser sinensis in past 40 years based on bibliometrics

  WANG Xiaojun, LI Wenlu

  2024, 46(3): 185-191. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.022

  Abstract ( ) PDF ( )

  With the bibliometric method and the help of the literature analysis function of CiteSpace software, in this study, we took 662 literatures using key word combination of Acipenser sinensis and protection included in China National Knowledge Network (CNKI) as the data source, and collated and analyzed their annual distribution, publishing institutions and cutting-edge trends. The results showed that the academic research results on Acipenser sinensis showed a general trend of fluctuating upward in recent years. The number of papers published in the core journals of related literature was small. Fisheries research institutes and universities were the main publishing institutions. Current researched focus on the hot points such as the protection of the Yangtze River estuary and Yangtze River. The academic protection of Acipenser sinensis in China needs to be further studied, and multi-disciplinary interaction and communication should be carried out to expand research methods, so as to provide new ideas for the future research and protection of Acipenser sinensis.
• Construction of the operating mechanism of emission trading based on public-private partnership

  REN Hao, KONG Fanhong

  2024, 46(3): 192-199. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.023

  Abstract ( ) PDF ( )

  The emission trading system is an important measure for the government to use market mechanisms to control environmental pollution. The current operating mechanism of emissions trading under government control has problems such as insufficient trading market activity, high corporate transaction costs and weak monitoring of emissions trading. The PPP mode (Public-Private Partnership) is an institutional innovation that the government and social capital cooperate to solve the construction of public infrastructure. The introduction of the PPP mode into the operating mechanism of emissions trading has certain feasibility from the perspective of system, technology and organization. It can be substantively embedded in the licensing management, trading and verification, and evaluation of emissions trading. In order to ensure the smooth operation of the PPP mode, the government should also fully play the role of regulating the emission trading and the cooperation between the government and social capital by way of revising and enacting relevant laws and regulations, building a complete guarantee system. Follow the rules above, the construction of cooperation of the emission trading operation mechanism between the government and social capital can be realized.
• Social network analysis of cross-domain management of water environment in the middle and lower reaches of Yangtze River

  YANG Yang, LIU Xiushuang

  2024, 46(3): 200-206. https://doi.org/10.13984/j.cnki.cn37-1141.2024.03.024

  Abstract ( ) PDF ( )

  The restoration and protection of the water environment in the middle and lower reaches of Yangtze River require the coordinated management of the middle and lower reaches, the left and right shores and the main and tributaries, but the cross-administrative characteristics of the drainage basin make cross-domain governance more difficult. In this study, we used Social Network Analysis to reveal the link structure and cooperation status of cross-domain management of water environment in the middle and lower reaches of Yangtze River, the overall structure, network density and cohesion subgroups of 20-year water environment cross-regional governance. Although the cross-domain management of the water environment in the middle and lower reaches of Yangtze River has formed a complex and interlaced overall network, the participating subjects are greatly influenced by spatial geography factors. The three provinces and cities of Shanghai, Jiangsu and Anhui are in an absolute central position in the cross-domain management of the water environment in the middle and lower reaches of Yangtze River. It is necessary to establish and improve the information sharing, trust and benefit compensation mechanisms in order to break through the constraints of spatial geography, improve the level of mutual assistance and enhance cooperation among local governments.