Formation and Evolution of Ancient Lakes on South Coast Plain of Laizhou Bay

1INTRODUCTIONAncient lakes are lakes that once existed in history,butnow have died out.As a kind of land water and geomorphicconfiguration,the formation and evolution of ancientlakes were closely linked with the variance of geographicenvironment.The south coast plain of Laizhou Bay is aplain extending from the estuary of the Xiaoqing Riverin the west to the estuary of the Jiaolai River in the east.There were once some lakes on the plain in history,suchas Judian Lake,Qingshuibo Lake,an…     

三峡工程对两湖的生态影响

长江干流的渔业捕捞量从1954年的43万t下降到2011年的8万t,降幅达81%,而两湖(洞庭湖和鄱阳湖)的渔业捕捞量分别在2~4万t之间波动。三峡大坝对洞庭湖三口径流量的影响有限,但使江水倒灌鄱阳湖的天数和水量进一步降低。长江来水占洞庭湖径流量的30%,而在鄱阳湖中仅有0.1%,因此,对维持长江干流的渔业资源(特别是产漂流性卵鱼类)来说,洞庭湖的重要性远超鄱阳湖。干流渔业资源的衰退主要是江湖阻隔的结果,虽然过度捕捞起到了推波助澜的作用,因此,即使在干流休渔十年,也未必能使长江的渔业资源大幅回升。如果在两湖建闸,长江渔业资源的衰退将会进一步加剧,江豚的灭绝可能难以避免,因此,维持两湖与长江的生态联系,对长江干流生物多样性的维持至关重要。     

洞庭湖、鄱阳湖白鱀豚和长江江豚的生态学研究

１９９７年至１９９９年对洞庭湖和鄱阳湖的湖区及其支流的白豚和长江江豚的分布、数量和活动规律进行了系统的调查。调查结果表明,白豚已在洞庭湖和鄱阳湖绝迹。长江江豚随着水位的变化,其分布范围、数量和活动规律也随之而变化。长江江豚在洞庭湖的分布范围主要集中在从城陵矾到鲶鱼口一带,其种群数量大致力１００～１５０头。洞庭湖各支流中已看不到江豚的踪迹。在鄱阳湖主要分布在湖口至龙口一带,老爷庙至小矶山是其集中分布区。赣江南北支、抚河下游及康山河在涨水季节也有少量江豚活动。洞庭湖和鄱阳湖大规模的围湖造田,湖区的迅速淤积变浅,大桥的修建,有害渔具渔法的大量使用,船舶数量的大量增加是长江江豚迅速减少的重要原因,两大湖泊中的长江江豚急待保护。     

Quantitative assessment of the long term behaviour of 90Sr in Lake Uruskul,Southern Urals,Russia

The present paper is aimed at assessing the long term behaviour of 90Sr migration from water to bottom sediments of Lake Uruskul, Southern Urals, Russia. The lake was contaminated following the nuclear accident at the Mayak nuclear complex in 1957 (the Kyshtym accident). Some transfer parameters relevant to the behaviour of 90Sr in the water-sediment system were evaluated: a) the radionuclide migration velocity from the water column to the bottom sediment, b) the radionuclide migration rate from bottom sediment to water, and c) the radionuclide migration rate from bottom sediment to deep sediment. The estimated values of the above parameters were 6.4 x 10(-1) m s(-1), 5.7 x 10(-10) s(-1) and 5.2 x 10(-10) s(-1), respectively. These values were compared with data obtained for some Italian lakes contaminated by 90Sr after the nuclear weapons tests fallout. The relatively low radionuclide migration from water to sediment of these lakes is reflected by the values of the ratio migration velocity/migration rate from sediment to water (4 m and 12 m) that are significantly lower than the corresponding value in the Russian lake (112 m). The peculiar hydrochemical conditions of Lake Uruskul (high pH, high mineralisation, etc.) are considered to be responsible for the high radionuclide migration from water to sediment.     

西洞庭湖鱼类物种多样性及其时空变化

洞庭湖是长江中游现存仅有的两大通江湖泊之一,研究其鱼类资源对了解湖泊通江的生态作用有着重要意义。为此,在2002年9月~2004年6月每月定期定点在西洞庭湖区开展鱼类调查,结果如下：① 实地调查到鱼类111种,隶属9目20科,包括中华鲟、胭脂鱼等珍稀物种;②鱼类物种数年动态波动较大,最高月份达69种,最低为26种,月均50±13种;③物种多样性指数年动态与物种数年动态大体一致,最高达3.34,最低为1.89,月均2.84±0.38;④空间分布上,位于入湖口的调查点物种数和多样性指数高于内湖,且差异有显著性(p<0.05);⑤在数量上,湖泊定居型鱼类占50%以上,其中,鲫数量最多,占16%左右。可见：西洞庭湖作为通江湖泊在鱼类多样性的保护上起到避难所和交流场所的作用;目前,西洞庭湖鱼类在生态组成上,湖泊定居型鱼类比重有逐渐增加的趋势。     

Research on the Variation of Population Distribution and Its Characteristics Based on Spatial Autocorrelation Method: A Case Study of Poyang Lake Region in Jiangxi Province

Abstract

According to Statistical Yearbook of Jiangxi Province (2001~2006), We analyze the time-space variation of population distribution of Poyang Lake region from the two points of view. The former is quality of population, which involves culture structure, occupational structure, age structure and sex structure of population. The latter is quantity of population, which only involves the amount of population. Furthermore, we can reveal the internal relations and action mechanism of variation of population distribution by analyzing the regional economic development, population urbanization, land use and ecological landscape of Poyang Lake region. It is important to provide help for region planning, ecological landscape planning and environmental protection by correct understanding the man-land relationship of natural-human ecosystem in Poyang Lake region.     

Relict Crustaceans under Conditions of Long-Term Pollution of Subarctic Lake Imandra: Results of Observations in 1930–1998

Changes in the role of relict crustaceans in the zoobenthic communities of large subarctic Lake Imandra are analyzed over the long period of economic development in its drainage area. To date, Mysis relicta as a species highly sensitive to anthropogenic pollution has apparently disappeared from the lake fauna. The currently recorded maximum values of Pontoporeia affinis abundance and biomass are more than 20 times as great as those between 1968 and 1986. As in other lakes with mass development of P. affinis, the populations of this crustacean inhibit chironomid larvae in the communities of Lake Imandra.     

Comparative study of 137Cs partitioning between solid and liquid phases in Lakes Constance, Lugano and Vorsee.

The methodology for estimating radiocaesium distribution between solid and liquid phases in lakes is applied for three prealpine lakes: Lake Constance (Germany), Lake Lugano (Switzerland) and Lake Vorsee (Germany). It is based on use of the exchangeable distribution coefficient and application of the exchangeable radiocaesium interception potential (RIPex). The methodology was tested against experimental data. Good agreement was found between estimated and measured 137Cs concentrations in Lake Constance and Lake Lugano, whereas for Lake Vorsee a discrepancy was found. Bottom sediments in Lake Vorsee are composed mainly of organic material and probably cannot be described in terms of the specific sorption characteristics attributed to illitic clay minerals.     

江湖阻隔对涨渡湖区鱼类资源的生态影响

长江中游两岸绝大多数通江湖泊自20世纪50年代以来因水利工程阻隔先后失去与长江的联系而产生一系列的生态问题。我们以涨渡湖为例开展江湖阻隔后对单个湖泊鱼类资源所产生的生态影响进行研究,结果表明：江湖阻隔导致湖泊生产经营方式改变,使得野生渔业产量的比例由1949年的95%,降低到2002年的不足5%;江湖阻隔后湖泊鱼类种类由50年代约80种下降到现在的52种,其中,洄游性和流水型鱼类比重由50%下降至不足30%;迷魂阵渔获物在单位产量、个体大小上极显著(p < 0.01)地高于通江湖泊,但在物种数和多样性指数上则要低得多(p < 0.01)。因此,江湖阻隔对湖泊渔业具明显影响,且正导致野生鱼类资源的进一步衰退。     

Environmental implications of changes in the levels of lakes in the Ethiopian Rift since 1970

The Ethiopian rift is characterized by a chain of lakes of various sizes and hydrological and hydrogeological settings. The rift lakes and feeder rivers are used for irrigation, soda extraction, commercial fish farming, and recreation, and they support a wide variety of endemic birds and wild animals. The levels of some of these lakes have changed dramatically over the last three decades. Lakes that are relatively uninfluenced by human activities (Langano and Abaya) remain stable except for the usual inter-annual variations, strongly influenced by rainfall. Some lakes have shrunk due to excessive abstraction of water; others have expanded due to increases in surface runoff and groundwater flux from percolated irrigation water. Lakes Abiyata and Beseka, both heavily impacted by human activities, show contrasting lake level trends: the level of Abiayata has dropped by about 5 m over three decades because of the extraction of water for soda and an upstream diversion for irrigation. Beseka has expanded from an area of 2.5 to 40 km² over the last three decades because of increased groundwater inputs from percolated irrigation water. Lake Awassa has risen slightly due to land use changes resulting in increased runoff in its catchment. This paper addresses these lake level changes and their environmental repercussions, based on evidence from hydrometeorological records, hydrogeological field mapping supported by aerial photography and satellite imagery interpretations, water balance estimation, and hydrological modeling. A converging evidence approach is used to reconstruct the temporal and spatial variations of lake levels. The results reveal that the major changes in the rift valley are mainly related to anthropogenic factors. These changes appear to have grave environmental consequences for the fragile rift ecosystem. These consequences demand the very urgent implementation of integrated basin wide water management practice.     

江苏天目湖表层沉积物中多环芳烃污染特征与来源

区别于长江三角洲地区众多的大型天然浅水湖泊，江苏天目湖是一个较深的水库型湖泊，也是重要的城乡生活及工农业水源地之一。为了解天目湖表层沉积物中多环芳烃（PAHs）污染状况， 2006年在天目湖全湖采集7个点位的表层沉积物样品，利用GC/MS分析了16种优控PAHs。结果表明：天目湖表层沉积物中16种优控PAHs总量介于28750~71393 ng/g（干重），平均值为45852 ng/g；在空间分布上，北部受污染程度高于南部，主要是北部旅游业快速发展导致污染物排放的影响；沉积物中总有机碳含量与PAHs总量呈显著相关；利用特征化合物指数对PAHs的来源进行判别，指示天目湖表层沉积物中PAHs的主要来源是木材、煤的不完全燃烧。与不同地区水体沉积物PAHs含量对比表明，天目湖PAHs污染处于一个低至中等程度。基于沉积物中多环芳烃的环境质量标准，仅有1个样点芴浓度超过风险效应低值，但远小于毒性风险效应中值，因此沉积物中多环芳烃的生态风险较小。然而天目湖表层沉积物中的PAHs的污染程度已超过南水北调东线所经过的南四湖，而且天目湖湖水较深，湖水交换周期比较长，其PAHs污染应引起重视，需制定切实措施保护江苏“最后一泓净水”。     

滇池流域水资源综合平衡管理研究

随着滇池治理的进展,在今后一个时期内,恢复滇池饮用水环境功能,成为滇池治理的首要目标和任务。围绕滇池流域水资源供求平衡,采用水资源全要素配置框架下的三次平衡分析理论,从整体上分析了滇池流域水资源供求平衡关系及存在的主要问题,提出了以需求为导向,建立滇池流域水资源综合平衡管理目标和措施。分析表明：在滇池治理的基础上,通过建立滇池流域水资源综合平衡管理体系,落实管理措施,从总量平衡的理论上能够充分发挥引水工程的作用,恢复滇池饮用水环境功能,实现水量、水质供求的综合平衡。建议进一步开展量化分析和模拟实验研究,为在滇池流域实施综合平衡管理提供可靠依据和建议     

Composition and Some Ecological Features of Winter Zooplankton in Deep Stratified Lakes

For the first time, zooplankton and environmental factors have been studied in winter in the deep stratified lakes Siverskoe, Borodaevskoe, and Vydogoshch. The zooplankton consists of 18–22 species of rotifers, copepods, and cladocerans, including 15–18 specifically winter, cryophilic and eurythermic forms. The populations of zooplankters reproduce actively: males and egg-bearing females (in copepods), females with embryos and eggs in brood pouches (in cladocerans), and females with attached eggs (in rotifers) are present. In lakes Siverskoe and Borodaevskoe (depth 20–24 m), where oxygen deficiency is observed only in the bottom water layer, the zooplankton populates the greater part of the water column and forms a large aggregation in the oxycline and near the bottom. The abundance of bacteria in these zones is high (up to 4–6 × 10⁶ cells/ml). In Lake Vydogoshch (depth 16 m), oxygen deficiency extends to the middle layers, and all zooplankton is distributed above the oxycline. The biomass of winter zooplankton in Lake Siverskoe in 1983 averaged 1.26 g/m³, with a maximum of 4 g/m³; in 1993, 1.4 and 8.04 g/m²; the respective values in Lake Borodaevskoe were 0.98 and 3.1 in 1983 and 0.14 and 1.6 in 1993; in Lake Vydogoshch, 0.15 and 0.24 in 1983 and 1.25 g/m³ in 1993. The development of winter zooplankton is limited by the size of the zone of oxygen deficiency and depends on the amount of food (bacterioplankton). The distribution of zooplankton in the water column and its biomass in individual layers is determined by the rate of methane formation and oxidation.__________Translated from Ekologiya, No. 3, 2005, pp. 201–214.Original Russian Text Copyright © 2005 by Rivier.     

城镇化对太湖平原河网的影响——以太湖流域武澄锡虞区为例

为探讨近年来城镇化快速发展等对太湖流域腹部地区平原河网水系的影响,选取城镇化快速发展且城镇化程度很高的武澄锡虞区为例开展了研究。以1960年代、1980年代和2003年水系为基础,依据河道宽度对水系分级,并从河流地貌学角度定量分析了河网密度、水面率、河网复杂度、河网结构稳定度、分维数等结构特征及长时间序列的水位变化。结果表明：研究区水系要素基本上都在减小;不同等级的河流长度和河湖面积除一级河流面积增加外,均呈减少趋势。河网密度、水面率、分维数均变小,河网复杂度、河网结构稳定度下降,河网演化趋于主干化、单一化,河湖连通性下降。城镇化前后变化显著,且1980年代以来变化加快。同时城镇化背景下的水系衰减对河网蓄泄功能也产生了较大影响,使得年平均水位和汛期水位呈现上升趋势,导致洪灾风险增大。故在城镇化过程中应遵循河网演变规律,促进水系的保护     

The Role of Floodplain Soils as a Barrier to Radionuclide Migration: An Example of the Techa–Iset' River System

The contents of ⁹⁰Sr and ¹³⁷Cs and the pattern of their redistribution in the soil and plant cover of floodplain ecosystems have been assessed. It is shown that the radionuclide distribution across the floodplain and along the river flow is determined by the formation of a barrier to their migration near the river channel, at which less mobile ¹³⁷Cs accumulates. The soil and plant cover of the central floodplain are enriched with ⁹⁰Sr. Differences in radionuclide migration in floodplain soils and their input into plants are determined by the relationship between the processes of their immobilization and migration with soil water.     

汉阳湖群底栖动物群落及其对环境质量的指示

汉阳地区湖汊纵横、水系丰富,是汉阳地区工业和生活废水的主要纳污水体,水质多为劣V类。底栖动物已被广泛用于监测湖泊有机污染,因此,为探明汉阳地区湖泊群（三角湖、墨水湖、龙阳湖、月湖、后官湖）的污染状况和污染分布格局,于2002~2005年全面调查了各湖泊的底栖动物群落,并分析了其对环境的指示作用。除后官湖发现软体动物外,其他各湖泊均以耐污的颤蚓科寡毛类(霍甫水丝蚓,苏氏尾鳃蚓)和摇蚊科幼虫(长足摇蚊、红裸须摇蚊、羽摇蚊)占绝对优势。统计分析表明,颤蚓类和摇蚊幼虫的密度与水体氮、磷、叶绿素含量呈显著正相关（〖WTBX〗p<005）,且颤蚓类密度对水体氮、磷水平的预测能力（R2）〖WTBZ〗优于摇蚊幼虫。K 优势曲线和多样性指数的污染评价结果显示,墨水湖和龙阳湖属重污染,月湖和三角湖属中度污染,后官湖属轻度污染,这与理化指标表征的营养状况基本吻合,特别是在受苯酚化工废料污染的龙阳湖东片没有采集到底栖动物,这是底栖动物能够监测污染物长期效应的例证。进一步应用颤蚓类密度的水平分布指示了各湖泊的沉积物污染分布,结合湖体周边环境分析论证了这种指示作用的可信度     

Residues of organochlorine pesticides in fish from the Egyptian delta lakes

The distribution and residue levels of BHC, Lindane, Endrin, o,p′-DDT, p,p′-DDE, and p,p′-DDD in Mugil and Tilapia species collected from Egyptian Delta lakes were evaluated. Residues of BHC and p,p′-DDT were found in most fish samples obtained from El-Manzala, El-Burullus, Edku, and Maryut lakes. Fish samples from Lake Edku showed the highest residue levels of the studied compounds. Residues of BHC and p,p′-DDT in Mugil and Tilapia species are within the range found in fish from the northwest Atlantic but lower than the levels reported for other fish species the United States. Mugil and Tilapia species could be used as indicator organisms for monitoring the residue levels of organochlorine pesticides and their distribution.     

鄱阳湖区氮磷污染物分布、转移和削减特征

根据入湖污染负荷监测、调查资料和不同水文条件下流场-水质同步监测资料,应用数理统计方法,研究了鄱阳湖氮磷营养物质分布、转移和削减特征。研究结果显示:(1)总磷、总氮是影响鄱阳湖水环境质量的主要污染物,入湖污染负荷与入湖径流水量紧密正相关。(2)鄱阳湖换水周期短,水流更换频繁,氮磷污染物在湖区不会充分混合;氮磷超标水域随着水体流动,逐步向下游转移、扩散;湖水位处于消落状态,通江水道部分水域氮磷浓度超标。(3)湖相状态水环境比河相好,湖相状态一般不会出现大面积的总氮和总磷同时超标。(4)鄱阳湖水环境勉强维持Ⅲ类标准,如果出现损害环境的人类活动,脆弱的水环境将会恶化。针对这些特征提出了保护鄱阳湖"一湖清水"的对策建议。     

南水北调东线湖群水体营养状态评价及其限制因子研究

湖泊富营养化问题是我国湖泊保护面临的紧迫问题,开展湖泊营养状态评价及其限制因子研究,对于富营养化湖泊治理和生态系统修复具有重要意义。该研究以南水北调东线工程调蓄湖群-高邮湖、洪泽湖、骆马湖、南四湖、东平湖为研究区域,于2018年4月非调水期和10月调水期对调蓄湖群109个样点开展了系统监测,采用综合营养状态指数法对调蓄湖群营养状态进行了评价,运用多元统计分析方法分析了湖群富营养化特征及其限制因子。结果表明:同一水期内调蓄湖泊间水质指标不尽相同,各调蓄湖泊非调水期水质优于调水期,影响水质达标的主要因子为总氮和总磷。调蓄湖群调水期均处于轻度富营养状态,非调水期均处于中营养状态,非调水期优于调水期。透明度和叶绿素a是决定调蓄湖群富营养化水平的限制性因子。     

Potential for the desalination of a brackish groundwater aquifer under a background of rising sea level via salt intrusion prevention river gates in the coastal area of the Red River Delta,Vietnam

Additional freshwater sources are required in many parts of the world, including the coastal areas of the Red River Delta (RRD), where the groundwater (GW) is generally brackish. Determining a feasible method for desalinating brackish aquifers would help provide additional freshwater sources. However, substantial desalination of brackish aquifers cannot be achieved under the natural conditions of GW flow and precipitation recharge. Although rainfall recharge to the shallow Holocene aquifer has occurred for hundreds of years, the aquifer still remains brackish since the natural hydraulic conditions do not allow a complete mixing between the fresh recharged water and aquifer salinized water or the discharging of the aquifer salinized water. The planned salt intrusion prevention gates in the Red River, Tra Ly River and Hoa River in the RRD coastal area, combined with increased GW abstraction and associated aquifer recharge with fresh river water, could result in the gradual desalination of the shallow Holocene aquifer. These effects would help improve the area’s resilience to freshwater shortages and sea level rises and would allow for the creation of a long-term sustainable water resource development plan to manage the salinization of water resources caused by sea level rises. Finite element (FE) modeling of GW flow, solute transport via GW flow and dynamic programming (DP) have been used to study the potential desalination of brackish aquifers, the magnitude of GW abstraction quantities and the spatial and temporal aspects of desalination. FE modeling of GW flow coupled with DP was utilized to identify the magnitude of sustainable abstraction quantities and the GW flow field, which is required in salt transport models. Multiple sizes of elements and time steps were used to adapt to the unsteady state of GW flow and hydraulic head variables between the elements in the FE meshes in order to ensure reasonable accuracy of numerical modeling. The GW flow and salt transport modeling and DP allowed determining quasi-steady-state GW abstraction rates and aquifer salinity levels for conditions that did and did not include the shallow Holocene unconfined aquifer recharge from rainfall. The aquifer modeled domain which is supposed to serve the pumping well field is 1.5 km². The results showed that the Holocene aquifer may provide a stable abstraction rate of 100 m³/day starting in the 6th year (for the worst-case scenario with zero aquifer recharge from rainfall) to 130 m³/day starting in the 3rd year (for the scenario with aquifer recharge equal to 3% of the rainfall levels). During the first years of GW abstraction, the desalination of the brackish upper Holocene aquifer will mainly occur in the area close to the river, and at the 18th year of abstraction, almost the entire area between the river and line of pumping wells would be desalinized. From the 10th year of abstraction, the abstracted water has a total dissolved solids content lower than 0.5 g/l for the worst-case scenario with zero aquifer recharge from rainfall and lower than 0.42 g/l for the scenario with aquifer recharge equal to 3% of the rainfall. The modeling results indicate the simulated process by which abstraction of groundwater adjacent to the Tra Ly River could desalinize the brackish aquifer via freshwater recharge from the river.