共查询到20条相似文献，搜索用时 140 毫秒
1.
由于湖泊生态问题日益突出,湖泊生态系统安全状态已经成为人们关注的热点问题,了解湖泊水生态系统的状况并根据湖泊生态系统健康状况开展精准治理和生态修复与保护尤为重要。本文基于对鄱阳湖及其流域生态环境的长期监测数据和资料收集,采用综合指标体系法,从物理形态、水文、水环境、水域生态、湿地生态和社会服务6个方面构建了鄱阳湖生态系统健康评估的指标体系,主要涵盖了湖泊口门状况、“五河”入湖径流变异程度、入湖河流水质达标率等26个指标。依据设置的阈值等级得到鄱阳湖生态系统健康评价各层次健康状况等级,通过对各湖泊生态系统各指标得分进行加权计算,得出生态系统健康评估准则层和目标层的得分,最终对鄱阳湖生态系统健康进行了客观的评价。结果表明,构建的湖泊生态系统健康评价体系针对性强、科学全面、具有可操作性,可为鄱阳湖及类似通江湖泊的生态系统健康评价提供案例和方法借鉴。评价结果表明鄱阳湖健康体征状况目标层得分为73.45分,评价结果为亚健康,鄱阳湖水生态系统健康主要受泄流能力、水文节律变化、富营养化程度和物种多样性的影响。最后根据鄱阳湖的水生态系统健康评分等级探讨了鄱阳湖水生态系统中亟需解决的问题,针对性地提出了... 相似文献
2.
济南市不同区域水生生物与水环境因子的响应关系 总被引：2，自引：2，他引：0
水生生物与水环境因子是水生态系统中重要的组成部分，研究水生生物与水环境因子的响应关系对制定水生态系统修复方案具有重要意义.于2014年5、8和10月，对济南市水生态系统进行野外采样调查.共设36个采样点，采集鱼类、底栖动物、浮游动物和浮游植物四种生物，并测定了26个水环境因子.采用Spearman相关分析法、小提琴图法和冗余分析法，筛选主要的水环境因子，分析济南市水生生物丰富度和主要水环境因子的分布特征，以及两者间的相互关系.结果表明，共筛选出6个主要的水环境因子，分别为流量（Flow）、溶解氧（DO）、栖息地质量指数（QHEI）、电导率（Cond）、化学需氧量（COD）和总氮（TN）.黄河区Flow、DO、QHEI和水生生物丰富度均较高，小清河区COD、TN、Cond和水生生物丰富度最低.黄河区Cond与鱼类丰富度呈显著相关，城区TN与底栖动物丰富度呈显著相关，小清河区COD、DO和QHEI对水生生物丰富度有显著影响，徒骇马颊河区TN对水生生物丰富度有显著影响.该研究为济南市水生态修复方案的制定提供参考，也为其他城市水生态文明建设提供一种思路. 相似文献
3.
大泊口位于滇池草海南部,水域面积0.52 km2,平均水深约2 m,作为滇池草海重富营养化水域生态修复示范区,大泊口分别于2015和2019年开展了两期生态修复工程,经过近年来的系统治理,大泊口水生态治理效果初步显现。为分析探究成功修复湖区水质改善、生态系统企稳向好的原因,本研究选择2015年2月—2021年12月共7年的连续监测数据,根据工程开展情况以及水生态状况将大泊口水域划分为4个部分(A1～A4水域),首先分析4个区域内主要的水质指标(悬浮物(SS)、化学需氧量(CODCr)、总磷(TP)、总氮(TN)和叶绿素a(Chl.a))的变化趋势和相关性,其次探究不同类型生态工程的修复效果,最后与草海和外海水域进行对比,分析大泊口的治理效果。结果表明,治理后大泊口A1～A4水域的CODCr、TP和Chl.a稳定下降,CODCr分别降低18.65、27.96、25.26、40.92 mg/L,TP分别降低0.11、0.10、0.11、0.14mg/L,Chl.a分别降低0.037、0.068、0.06... 相似文献
4.
湖沼学是研究内陆水体的多学科整合科学——兼论我国湖沼学发展面临的挑战与机遇 总被引：1，自引：0，他引：1
湖沼学是研究内陆水体的多学科交叉综合性科学,自从Forel F.A.于1892年首次对湖沼学做出定义以来已有近130年历史.湖沼学的主要分支学科包括地质湖沼学(包括古湖沼学)、物理湖沼学、化学(生物地球化学)湖沼学和生物湖沼学.湖沼学的关键自然属性是通过跨学科的整合,从水生态系统水平综合分析相关过程与机理,并对生态系统变化进行预测.因此,湖泊学也是支撑水资源与生态系统保护、管理与修复的核心科学.然而,目前我国湖沼学发展面临分支学科发展不平衡、研究碎片化等问题,而人类活动加剧和气候变化对内陆水体生态系统的影响及管理对策是湖沼学研究面临的挑战与机遇.我国湖沼学研究亟需围绕人类活动、气候变化的影响,重点开展以下几个方面的工作:1)水动力与水文地貌特征变化及其环境生态效应; 2)营养盐和有机质生物地球化学循环及其环境生态效应; 3)食物网结构与功能; 4)外来入侵物种的影响与控制对策; 5)与水环境有关的传染病防治; 6)地表水生态评价; 7)生态系统演变机理与退化生态系统修复等. 相似文献
5.
太湖河湖水系连通需求评价初探 总被引：3，自引：2，他引：1
水系连通需求分析是河湖水系连通战略研究的重要内容.水系连通需求指人类社会经济发展对水资源调配、防洪排涝、改善生态环境等方面的需求及对河湖水系健康的维护,它源于水系能够提供各种水生态系统服务功能的生态学特性.通过分析水系连通需求、水生态系统服务功能和水系连通工程之间的内在关系,认为水系连通需求评价可转化为对水生态系统服务功能的评价.运用水当量评价方法,建立了河湖水系连通需求评价的方法体系,并以河网地区的典型代表——太湖为例,定量评价了太湖在水资源调配、调蓄洪水、水环境净化和维持生境等方面的连通需求.结果表明,太湖水系年均连通需求最大的是净化入湖废污水需水量,其次为水资源调配需水量,而太湖调蓄洪水的需求减少;湖水自身净化需水量较大,且为一次性需水.水环境净化的需求需要通过降低污染物入湖量,进行湖泊生态修复等主要措施以及引清水增加环境容量这一辅助连通措施共同完成.水系连通需求的定量评价可为水系连通战略及工程的规划设计提供理论基础. 相似文献
6.
7.
湖滨带芦苇恢复过程中沉积物氮赋存形态及含量变化:以巢湖为例 总被引：1，自引：0，他引：1
水生植被对于维持水生态系统结构和功能稳定性具有举足轻重的作用,而重建水生植物被认为是污染湖泊生态修复的重要手段.氮素是水生态系统重要的限制性元素之一,根着挺水植物生长发育无疑将深刻地影响着沉积物氮的迁移转化过程,但水生植物不同生长阶段对沉积物氮的需求和植物代谢强度均不同,目前对挺水植物完整生长过程中沉积物氮组分及含量变化认识仍十分不足.本研究通过为期120d的沉积物柱芯培养和水槽模拟试验,探究巢湖芦苇恢复完整生长过程中沉积物总氮(TN)、无机氮(TIN)与可转化态氮(TF-N)的变化及其关键调控因子.结果表明,芦苇完整生长过程将持续激发沉积物氮活性,沉积物TIN与TF-N含量逐渐增加,而沉积物TN和非可转化态氮(NTF-N)含量显著降低.模拟试验期间,指数型增长的芦苇生物量提高了沉积物铵态氮(NH_4~+-N)和硝态氮(NO_3~--N)含量,但亚硝态氮(NO_2~--N)含量却逐渐降低;与第0天相比,第120天沉积物离子交换态氮(IEF-N)、碳酸盐结合态氮(CF-N)、铁锰氧化态氮(IMOF-N)和有机态及硫化物结合态氮(OSF-N)含量分别增加了 1.10、3.40、3.60和1.40倍,这主要受芦苇吸收利用、根系代谢强化根际沉积物氧化还原电势和改变pH微环境共同驱动.在第120天,沉积物NH_4~+-N和NO_3~--N含量急剧升高,分别是第90天的9.43和2.22倍,表明芦苇衰亡凋落过程将向沉积物释放大量的TIN,故需要综合采取湖泊物理—生态工程手段来有效管控芦苇枯落物,从而提升水生植被修复效果并构建长效稳态机制. 相似文献
8.
9.
10.
基于水生态改善的太湖分区分时动态水质目标制定方法 总被引：1，自引：0，他引：1
科学、合理地制定水体主要污染物浓度控制目标，即水质目标是实施河、湖"水质目标管理"的基础和前提.本文基于环境条件决定生态系统结构以及自组织适应生态学原理，提出一种可促进水生态改善的太湖分区分时动态水质目标制定方法.该方法在出入湖河道流量情景及分区污染物浓度情景设计的基础上，进行不同情境下水生态系统要素时空演化的数值试验；然后以藻类生物量减小、沉水植物生物量增加为判据，构造水质目标优化模型；最后将湖泊水生态模型与水质目标优化模型耦合，判断各污染物浓度情景下水生态系统健康状况，进而确定不同时间尺度下太湖各分区总氮、总磷、氨氮、高锰酸盐指数等主要污染物指标的动态控制目标.结果表明：本方法制定的太湖各湖区分时水质目标相比传统的"静态"目标更能促进太湖水生态系统健康发展，并为太湖水环境的精细化管理提供了可能. 相似文献
11.
用生态修复调控浮游植物种群局部控制富营养化——以贵州红枫湖水质生态修复工程为例 总被引：3，自引：1，他引：2
利用物理生态工程在水深10 m左右,水位变幅7 m左右的贵阳红枫湖/水库(正常水位时57.2 km2)右二湾富营养水体进行局部(围隔水体面积1.33 hm2)生态修复.对工程前后和内外水体浮游植物的群落结构、丰度、生物量等进行比较,结果表明,当植物浮岛覆盖率超过1/5～1/3时(可视为阈值),物理生态工程可以调控浮游植物种群结构和丰度,浮游植物优势种群由生态修复前的微囊藻属、角甲藻属及同期外环境的蓝藻门蓝纤维藻属转变为硅藻门的直链藻属.工程内与工程外比较,种属数减少了29.4%,特别是减少了蓝藻中可能释放藻毒素的微囊藻、鱼腥藻等属,蓝藻丰度和生物量分别减少了55.5%和57.9%;而硅藻的种属数则增多120.0%,且其丰度和生物量分别增加了56.4%和60.3%.从藻类总体统计资料看,工程内与工程外比较,藻类丰度减少53.6%,生物量减少39.1%,透明度提高了数十厘米以上,稳定在120～220 cm.当工程区外浮游植物优势种群是蓝藻,暴发蓝藻水华,且可释放藻毒素的种属有多次检出时,工程区内仍然以硅藻为优势种,未曾检测出可释放藻毒素的种属,从而在红枫湖局部水体实现了水质改善和富营养化控制.在目前高污染负荷下恢复浅水湖泊沉水植被时,本项目发展的可全年镶嵌式种植包括香根草、杞柳等高杆植物在内的多种水面植物的浮岛可作为防浪削浪、遏制蓝藻、改善水质、提高透明度的先锋性措施,以保障局部水面植被覆盖面积超过上述阈值,成为保护沉水植物生长、遏制暴发蓝藻水华的可操作途径. 相似文献
12.
13.
Kwokal Z Francisković-Bilinski S Bilinski H Branica M 《Marine pollution bulletin》2002,44(10):1152-1157
Anthropogenic mercury pollution was studied in Kastela Bay (Croatia), 10 years after chloralkaline plant (PVC) stopped production. The concentration of total mercury determined in sediments which are composed mainly of calcite and quartz, are in the range 14,280-30,400 ng/g. The values are higher than reported in the literature for Elbe and Seine estuaries and also above 25,000 ng/g used for criterion in remediation project in Minamata Bay. The concentration of methylmercury 6.05-36.74 ng/g are typical for slightly to highly contaminated estuarine sediments. The low ratio of methylmercury to total mercury found in sediments of Kastela Bay is in the range 0.04-0.18%. It can be explained that in this region predominate conditions which do not promote in-situ methylation. Sediments were found to be highly anoxic. Concentrations of total mercury in unfiltered surface waters are in the range 69-145 ng/l and in unfiltered bottom waters in the range 230-1,418 ngl(-1). High concentrations found in bottom waters suggest that either resuspension or partial dissolution of sediments takes place. An experiment performed on filtered and unfiltered waters showed that about 85% of total mercury in surface water and almost 100% in bottom water was retained on 45 microm filters. To demonstrate contrasts, two pristine estuaries from norths and south Europe were studied. Silicious sediments of Ore estuary (Sweden) and calcareous sediments of Krka estuary (Croatia) have total mercury concentrations close to accepted background level. The ratio of methylmercury to total mercury is < or = 1% in all samples with one exception. The highest observed ratio (2.70%) was in the surface sediment from E2 station in Krka estuary measured in March 2000. This location is suitable for studying methylmercury formation in pristine environment. 相似文献
14.
西藏羊卓雍错流域水体水质评价及主要污染因子 总被引：4，自引：1，他引：3
水质是流域生态系统的重要指标,水质评价则是开展流域水体污染防治等工作的基础.基于2010-2014年羊卓雍错流域湖泊、河流水质及2012-2014年流域居民饮用井水、自来水水质监测资料,结合单因子污染评价法和内梅罗污染指数法,对流域水质现状进行分析和评价.结果表明,12处地表水体中,羊卓雍错和巴纠错受中度污染,其他水体清洁或尚清洁,硒及氟化物为主要污染因子;9处居民饮用水体中,自来水水质明显好于井水,但也仅有3处自来水达清洁标准,硒、铝及硝酸盐为主要超标项.污染因子通过水-土-植被-动物系统破坏流域生态环境、阻碍农业生产发展,并直接或间接影响人类身体健康.因此,必须做好流域环境的综合整治、控制农业面源污染、完善饮用水基础设施建设,同时继续加强水质监测. 相似文献
15.
The aim of this paper is to show the concise chemico-physical adsorbent performance of water purification systems utilizing geo-(e.g., allophane, clinoptilolite, and smectite) and bio-polymer materials(e.g.,chitosan or cellulose nanocomposite materials) and to propose an optimal ground-water remediation technique. The performance of geo-materials is evaluated based on the individual sorption and immobilization capacities for various priority substances and pollutants(e.g., lead, zinc, cadmium, c... 相似文献
16.
17.
The occurrence of thermal/spa waters on Lesvos Island is related to the presence of a major faulting system. Thermal waters are the result of mixing of meteoric and infiltrating seawater at great depth, and their total salinity depends on the percentage of seawater in their composition. According to the diagrams of main elements, trace elements and environmental isotopes, most of the components that determine the chemical composition of thermal waters such as sodium, chloride and sulphates originate from seawaters. On the other hand, the concentration of calcium, magnesium, boron, lithium, etc., was affected by water–rock interaction under high temperature conditions. Moving towards the surface, thermal waters may become polluted by influx of recent seawater, allowing their chemical composition to become similar to that of seawater. The thermal waters of Lesvos Island present relatively high concentrations of ammonia and redox sensitive metals because they are hosted in a reducing environment. They also exhibit low nitrate concentrations due to their mixture with recent fresh water. Finally, they show increased radon concentrations, ranging from 20 to 60 kBq m?3 in the eastern and southern parts of the island, and about 230 kBq m?3 in the north, in the area of Eftalou–Argenos. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
18.
We have determined K, Rb and Sr concentrations and87Sr/86Sr ratios in fresh surface waters, a rain water sample and five geothermal waters from the Cantal volcanic area in the Massif Central, France. A comparison with appropriate rock types of the region showed no apparent chemical and isotopic fractionation occurring in the fresh water-surface rock system. The thermo-mineral water results suggest that all springs discharge dissolved Sr from the following contributors: Hercynian granito-metamorphic basement, lacustrian sediments underlying the volcano, Miocene-Pliocene volcanic rocks of basaltic to rhyolitic composition. 相似文献
19.
by Denis Cohen Mark Person Peng Wang Carl W. Gable Deborah Hutchinson ee Marksamer Brandon Dugan Henk Kooi Koos Groen Daniel Lizarralde Robert L. Evans Frederick D. Day-Lewis John W. Lane Jr. 《Ground water》2010,48(1):143-158
While the existence of relatively fresh groundwater sequestered within permeable, porous sediments beneath the Atlantic continental shelf of North and South America has been known for some time, these waters have never been assessed as a potential resource. This fresh water was likely emplaced during Pleistocene sea-level low stands when the shelf was exposed to meteoric recharge and by elevated recharge in areas overrun by the Laurentide ice sheet at high latitudes. To test this hypothesis, we present results from a high-resolution paleohydrologic model of groundwater flow, heat and solute transport, ice sheet loading, and sea level fluctuations for the continental shelf from New Jersey to Maine over the last 2 million years. Our analysis suggests that the presence of fresh to brackish water within shallow Miocene sands more than 100 km offshore of New Jersey was facilitated by discharge of submarine springs along Baltimore and Hudson Canyons where these shallow aquifers crop out. Recharge rates four times modern levels were computed for portions of New England's continental shelf that were overrun by the Laurentide ice sheet during the last glacial maximum. We estimate the volume of emplaced Pleistocene continental shelf fresh water (less than 1 ppt) to be 1300 km3 in New England. We also present estimates of continental shelf fresh water resources for the U.S. Atlantic eastern seaboard (104 km3 ) and passive margins globally (3 × 105 km3 ). The simulation results support the hypothesis that offshore fresh water is a potentially valuable, albeit nonrenewable resource for coastal megacities faced with growing water shortages. 相似文献
20.
The impacts of unconventional oil and gas production via high-volume hydraulic fracturing (HVHF) on water resources, such as water use, groundwater and surface water contamination, and disposal of produced waters, have received a great deal of attention over the past decade. Conventional oil and gas production (e.g., enhanced oil recovery [EOR]), which has been occurring for more than a century in some areas of North America, shares the same environmental concerns, but has received comparatively little attention. Here, we compare the amount of produced water versus saltwater disposal (SWD) and injection for EOR in several prolific hydrocarbon producing regions in the United States and Canada. The total volume of saline and fresh to brackish water injected into depleted oil fields and nonproductive formations is greater than the total volume of produced waters in most regions. The addition of fresh to brackish “makeup” water for EOR may account for the net gain of subsurface water. The total amount of water injected and produced for conventional oil and gas production is greater than that associated with HVHF and unconventional oil and gas production by well over a factor of 10. Reservoir pressure increases from EOR and SWD wells are low compared to injection of fluids for HVHF, however, the longer duration of injections could allow for greater solute transport distances and potential for contamination. Attention should be refocused from the subsurface environmental impacts of HVHF to the oil and gas industry as a whole. 相似文献