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1.
海水环境质量模糊-灰色关联评价及应用 总被引：1，自引：0，他引：1
根据灰色理论,提出对原始数据的初值化采用以水质评价标准为约束的极值化方法,构建了基于线性隶属函数初值化方法的模糊-灰色关联模型,采用水化学和生产力双重指标及可变权重,对深圳湾海域海水环境质量进行了综合评价,并将评价结果与模糊综合评判的评价结果进行比较。评价结果表明,深圳湾海水环境质量属于Ⅳ类水质标准,超出了深圳湾水质管理Ⅲ类水质标准的目标,深圳湾海水已受到严重污染。污染的总体趋势是湾内大于湾口;深圳一侧大于香港一侧;河口、码头处污染最严重,表明陆源活动是深圳湾海水环境质量受损的主要原因。此评价结果不仅与模糊综合评判的评价结果一致,而且还能进一步对评价对象的优劣进行排序,评价结果直观可靠,适用于海洋水环境质量的综合评价。 相似文献
2.
Comprehensive Assessment of Seawater Quality Based on an Improved Attribute Recognition Model 总被引：2，自引：0，他引：2
ZHANG Libing ) ) CHENG Jilin ) JIN Juliang ) * and JIANG Xiaohong ) ) College of Civil Engineering Hefei University of Technology Hefei P.R.China ) College of Hydraulic Engineering Yangzhou University Yangzhou P.R.China 《中国海洋大学学报(英文版)》2006,5(4):300-304
1IntroductionAssessment of environment quality,which plays ani mportant role in environmental science and engineer-ing,has shiftedfromtraditional qualitative analysis toquantitative calculation.Inrecent years,quite a num-ber of methods have been brought o… 相似文献
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SEAWATER INTRUSION TYPES AND REGIONAL DIVISIONS IN THE SOUTHERN COAST OF LAIZHOU BAY 总被引：1，自引：0，他引：1
The southern coast of Laizhou Bay, Bohai Sea, is one of the areas in China most seriously impacted by seawater intrusion. Based on the sources of intruding waterbedies, seawater intrusion can be divided into two types: intrusion of saline water derived from modern seawater, and intrusion of subsurface brine and saline water derived from paleo-seawater in shallow Quaternary sediments. There are some distinct differences in their formation, mechanism and damage. The subsurface brine intrusion is a special type, which can cause very serious disaster. The coastal landform and the Quaternary hydrogeological environment are predominant factors in the classification of seawater intrusion types. Various coastal environments in different coastal sections result in three types of intrusion: seawater intrusion, saline groundwater intrusion, and mixed seawater and saline water intrusion, in the southern coast of Laizhou Bay, which can be divided into four areas: the sea-water intrusion area in the northern Laizhou City coast, the mixed seawater and saline groundwater intrusion area in the Baisha River-Jiaolai River mouth plain area, the mixed seawater and saline groundwater intrusion area in the Weihe River mouth plain area northern Changyi county coast, and the saline ground-water intrusion area in the northern Shouguang plains. 相似文献
4.
Dike failure and marine losses are quite prominent in Laizhou Bay during the period of cold wave storm surges because of its open coastline to the north and flat topography. In order to evaluate the intensity of cold wave storm surge, the hindcast of marine elements induced by cold waves in Laizhou Bay from 1985 to 2004 is conducted using a cold wave storm surge–wave coupled model and the joint return period of extreme water level, concomitant wave height, and concomitant wind speed are calculated. A new criterion of cold wave storm surge intensity based on such studies is developed. Considering the frequency of cold wave, this paper introduces a Poisson trivariate compound reconstruction model to calculate the joint return period, which is closer to the reality. By using the newly defined cold wave storm surge intensity, the ‘cold wave grade' in meteorology can better describe the severity of cold wave storm surges and the warning level is well corresponding to different intensities of cold wave storm surges. Therefore, it provides a proper guidance to marine hydrological analysis, disaster prevention and marine structure design in Laizhou Bay. 相似文献
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基于指标规范值的海水水质评价的SVR模型 总被引：1，自引：0，他引：1
为了建立具有普适通用的海水水质评价的支持向量机模型,在设置各指标参照值和指标规范变换式,并对指标进行规范变换的基础上,应用免疫进化优化算法,建立基于指标规范值的海水水质评价的回归支持向量机模型。将优化好的模型用于珠江口海水水质的评价,其评价结果与BP神经网络的评价结果基本一致,从而表明基于指标规范值的支持向量机模型用于海水水质评价是可行的,且该模型较传统的支持向量机评价模型具有较好的普适性和通用性。 相似文献
7.
Application of an integrated methodology for eutrophication assessment: a case study in the Bohai Sea 总被引：1，自引：0，他引：1
An integrated methodology for eutrophication assessment,which integrates both water quality indicators(causative factors) and ecological response indicators(effect factors),is described.It is then applied to rank the eutrophication status of the years 2007 and 2008 in the southwest Bohai Sea.The assessment model identified that north Bohai Bay and west Laizhou Bay were the two areas with the most serious eutrophication problems in the southwest Bohai Sea.In addition,compared to that in the west Laizhou Bay,the eutrophication conditions in the north Bohai Bay was more serious in both years.Eutrophication problems such as harmful algal blooms(HABs) and low dissolved oxygen(DO) events in north Bohai Bay were frequent.The integrated method outmatched the currently used Chinese nutrient index method by definitely identifying areas with the most serious eutrophication problems,while the nutrient index method gave ambiguous results between the two years.Inclusion of both causative factors and effect factors,combining concentration,spatial coverage and frequency of indicators,as well as use of multi-season monitoring datasets in the methodology result in a more accurate,representative and useful assessment. 相似文献
8.
A preliminary study on the distribution and genesis of underground brine in the littoral plain of Laizhou Bay in the Bohai Sea 总被引：3，自引：1，他引：2
Quaternary underground brine in the littoral plain region of the Bohai coast is new type littoral facies evaporation ore deposit in liquid state . This model of " littorally- forming brine " is based on study of the distribution, depositional environment, forming / storing process, and genesis of underground brine in the coast of Laizhou Bay . Essential conditions for genesis of brine are arid and semiarid climate , abundant sources of ancient seawater, and geological and geomorphological environment of wide tidal beach along a coast. The process of underground brine genesis may be : seawater/tidal beach-evaporation and concentration-seeping and accumulation- brine/tidal beach - burial (evolution of the sea- land )- underground brine .Underground brine is characterized by high content of chemical elements, shallow burial depth and easy exploitation . The process of extracting salt from underground brine present in the tidal flat is incomparably superior to that of producing salt from seawater, and has b 相似文献
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Water quality assessment for Ulansuhai Lake using fuzzy clustering and pattern recognition 总被引：1，自引：0，他引：1
Water quality assessment of lakes is important to determine functional zones of water use. Considering the fuzziness during the partitioning process for lake water quality in an arid area, a multiplex model of fuzzy clustering with pattern recognition was developed by integrating transitive closure method, ISODATA algorithm in fuzzy clustering and fuzzy pattern recognition. The model was applied to partition the Ulansuhai Lake, a typical shallow lake in arid climate zone in the west part of Inner Mongolia, China and grade the condition of water quality divisions. The results showed that the partition well matched the real conditions of the lake, and the method has been proved accurate in the application. 相似文献
11.
红海湾水产养殖示范区水质综合评价 总被引：3，自引：0，他引：3
红海湾是广东省非常重要的海水养殖示范区。为了维系和保护红海湾规模化水产养殖示范区的优良生态环境 ,1 997年 4月至 1 998年 1 2月对红海湾水域水质的时空变化趋势和质量状况进行了研究与评价。结果表明 ,红海湾海水综合质量总体上处于相对清洁水平 ,但浅海养殖区和长沙湾养殖区有机污染明显 ,分别达富营养化和高富营养化程度。DIN和IP是水质富营养化的主要因素 ,而石油类、Cu、COD是重点控制的优先污染物。 相似文献
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赵建 《中国地理科学(英文版)》1999,9(2):151-158
１ＴＨＥＨＹＤＲＯＣＨＥＭＩＣＡＬＩＮＤＥＸＥＳＦＯＲＴＨＥＪＵＤＧＥＭＥＮＴＯＮＳＥＡＷＡＴＥＲＩＮＴＲＵＳＩＯＮＴｈｅｈｙｄｒｏｃｈｅｍｉｃａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｉｓｔｈｅｄｉｒｅｃｔｂａｓｉｓｆｏｒｔｈｅｊｕｄｇｅｍｅｎｔｏｎｓｅａ... 相似文献
13.
莱州湾瀰河三角洲滨海盐渍土,为近代松散沉积物。因海水入侵和蒸发浓缩作用,导致盐渍土(多属氯盐渍土)。根据土的物理力学性质指标,天然湿度下载荷试验和浸水载荷试验,认为:盐渍土是具有中等压缩性和湿陷性的土。盐渍土受水浸润后,土的压缩模量Es,承载力[R]明显下降,一般为浸水前的0.6倍。滨海盐渍土地区,地下水中硫酸根离子含量常大于3000毫克/升,具强结晶侵蚀性,应采取特殊防腐措施。 相似文献
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Strom surges are not only determined by the atmospheric forcing,but also influenced by the coastal geometry and bathymetry.The Bohai Sea,as one of China’s marginal seas,is seriously harmed by storm surges,especially those caused by cold-air outbreaks.As the coastline of the Bohai Sea has changed evidently these years,storm surges may have new characteristics due to the changes in the local geometry.This paper aims to find out these new characteristics by primarily investigating the influence of the changes in the local geometry on storm surges with numerical methods.20 scenarios were constructed based on the track and inten-sity of the cold-air outbreaks to describe the actual situation.By analyzing the model results of the control scenarios,it is found that the main changes of the maximum surge elevation occur in the Bohai Bay and the Laizhou Bay.At the top of the Bohai Bay,the maximum surge elevation is obviously decreased,while in the Laizhou Bay,it is enhanced by the growing Yellow River Delta.This,however,does not suggest that the storm surges in the Laizhou Bay become more serious.A comparison of the risk assessment of storm surges in the Tanggu,Huanghua and Yangjiaogou regions shows that the risk of storm surges in these coastal areas is lightened by the evolvement of the coastal geometry.Particularly near Yangjiaogou,though the maximum surge elevation becomes higher to subject more areas to risk,the risk is still reduced by the evolvement of the Yellow River Delta. 相似文献
15.
Laizhou Bay and its adjacent waters are of great importance to China's marine oil and gas development. It is therefore crucial to estimate return-period values of marine environmental variables in this region to ensure the safety and success of maritime engineering and maritime exploration. In this study, we used numerical simulations to estimate extreme wave height, sea current velocity and sea-level height in western Laizhou Bay. The results show that the sea-level rise starts at the mouth of the bay, increases toward west/southwest, and reaches its maximum in the deepest basin of the bay. The 100-year return-period values of sea level rise can reach 3.4–4.0 m in the western bay. The elevation of the western part of the Qingdong Oil Field would remain above the sea surface during extreme low sea level, while the rest of the oil field would be 1.6–2.4 m below the sea surface. The return-period value of wave height is strongly affected by water depth; in fact, its spatial distribution is similar to the isobath's. The 100-year return-period values of effective wave height can be 6 m or higher in the central bay and be more than 1 m in the shallow water near shore. The 100-year return-period values of current velocity is about 1.2–1.8 m s-1 in the Qingdong Oil Field. These results provide scientific basis for ensuring construction safety and reducing construction cost. 相似文献
16.
基于GIS的略阳县地质环境质量评价 总被引：11，自引：4，他引：7
基于地理信息系统(GIS)和多级模糊模式识别模型,建立了略阳县空间数据库和地质环境质量评价模型;综合考虑地形坡度、工程地质岩组、岩土体结构类型、地下水位、植被发育情况、月平均降雨量、人类工程活动强度等因素,用层次分析法确定各指标权值,应用评价模型对略阳县地质环境质量进行了综合评价,把略阳县地质环境划分为优、良、中、差4个质量级别。 相似文献
17.
Using fuzzy theory and variable weights for water quality evaluation in Poyang Lake,China 总被引：1，自引：0，他引：1
Achieving water purity in Poyang Lake has become a major concern in recent years, thus appropriate evaluation of spatial and temporal water quality variations has become essential. Variations in 11 water quality parameters from 15 sampling sites in Poyang Lake were investigated from 2009 to 2012. An integrative fuzzy variable evaluation(IFVE) model based on fuzzy theory and variable weights was developed to measure variations in water quality. Results showed that: 1) only chlorophyll-a concentration and Secchi depth differed significantly among the 15 sampling sites(P 0.01), whereas the 11 water quality parameters under investigation differed significantly throughout the seasons(P 0.01). The annual variations of all water quality variables except for temperature, electrical conductivity, suspended solids and total phosphorus were considerable(P 0.05). 2) The IFVE model was reasonable and flexible in evaluating water quality status and any possible ′bucket effect′. The model fully considered the influences of extremely poor indices on overall water quality. 3) A spatial analysis indicated that anthropogenic activities(particularly industrial sewage and dredging) and lake bed topography might directly affect water quality in Poyang Lake. Meanwhile, hydrological status and sewage discharged into the lake might be responsible for seasonal water quality variations. 相似文献
18.
Genesis of underground brine along south coast of Laizhou Bay： hydrochemical characteristics 总被引：1，自引：0，他引：1
1 INTRODUCTION Two large-scale concentration mechanisms, evaporation and freezing, have been proposed for marine origin brine production (Bein and Arad, 1992; Bottomley et al., 1999). There are three basic requirements for brine formation by seawater evap… 相似文献
19.
Yan Jiao Fei Huang Qingrong Liu Ge Li Yaru Li Qingxi Yu Yiding Zhao 《中国海洋大学学报(英文版)》2020,19(2):272-280
The Bohai Sea is one of the southernmost areas for sea ice formation in the northern hemisphere.Sea ice disasters in this body of water severely affect marine activities and the safety of coastal residents.In this study,we analyze the variation characteristics of the sea ice in the Bohai Sea and establish an annual regression model based on predictable mode analysis method.The results show the following:1)From 1970 to 2018,the average ice grade is(2.6±0.8),with a maximum of 4.5 and a minimum of 1.0.Liaodong Bay(LDB)has the heaviest ice conditions in the Bohai Sea,followed by Bohai Bay(BHB)and Laizhou Bay(LZB).Interannual variation is obvious in all three bays,but the linear decreasing trend is significant only in BHB.2)Three modes are obtained from empirical orthogonal function analysis,namely,single polarity mode with the same sign of anomaly in all of the three bays and strong interannual variability(82.0%),the north–south dipole mode with BHB and LZB showing an opposite sign of anomalies to that in LDB and strong decadal variations(14.5%),and a linear trend mode(3.5%).Critical factors are analyzed and regression equations are established for all the principal components,and then an annual hindcast model is established by synthesizing the results of the three modes.This model provides an annual spatial prediction of the sea ice in the Bohai Sea for the first time,and meets the demand of operational sea ice forecasting. 相似文献
20.
The phytoplankton reproduction capacity (PRC), as a new concept regarding chlorophyll-a and primary production (PP) is described. PRC is different from PP, carbon assimilation number (CAN) or photosynthetic rate ( P^B ) . PRC quantifies phytoplankton growth with a special consideration of the effect of seawater temperature. Observation data in Jiaozhou Bay, Qingdao, China, collected from May 1991 to February 1994 were used to analyze the horizontal distribution and seasonal variation of the PRC in Jiaozhou Bay in order to determine the characteristics, dynamic cycles and trends of phytoplankton growth in Jiaozhou Bay; and to develop a corresponding dynamic model of seawater temperature vs. PRC. Simulation curves showed that seawater temperature has a dual function of limiting and enhancing PRC. PRC‘s periodicity and fluctuation are similar to those of the seawater temperature. Nutrient silicon in Jiaozhou Bay satisfies phytoplankton growth from June 7 to November 3. When nutrients N, P and Si satisfy the phytoplankton growth and solar irradiation is sufficient, the PRC would reflect the influence of seawater temperature on phytoplankton growth. Moreover, the result quantitatively explains the scenario of one-peak or two-peak phytoplankton reproduction in Jiaozhou Bay, and also quantitatively elucidates the internal mechanism of the one- or two-peak phytoplankton reproduction in the global marine areas. 相似文献