共查询到19条相似文献,搜索用时 588 毫秒
1.
人工湿地是人为因素形成的湿地,由水体、基质、水生植被和微生物四个基本组成要素构成的,是一种生态治理污水的方法。皂河人工湿地是西安市为改善皂河入渭口水质而建设的人工湿地。经分析,皂河人工湿地对皂河污水中的主要指标均有明显去除效果,但是,对污水处理厂处理后的中水除氮、磷外,其他指标处理效果不明显。针对人工湿地净水植物随着年份增加,根系逐步板结、生长愈发缓慢、净水能力下降的问题,可以采取调整湿地整体功能、更新净水植物及创新管理运行方式等措施,更好发挥人工湿地的净化作用。 相似文献
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生态系统的破坏和环境的恶化使人们开始重新认识到湿地的重要功能,湿地生态系统的恢复和重建也开始得到广泛的重视,世界各国都在积极采取措施进行湿地的生态恢复。以单县嘉单河、东沟河人工湿地提升改造工程为例,分析了湿地提升改造的原理、施工方法等,认为新建湿地系统各个部分在地质结构和建造结构上存在不稳定性,加上人为的外界干扰,系统的结构容易遭到破坏,必须在系统结构上采用一定的检查与维护措施。同时,为积累湿地工程规划设计、维护、运行和管理的经验,获取科学的运行管理资料,需对湿地进出水进行水质和水量的监测和分析。 相似文献
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会仙湿地为中国最大的岩溶湿地,近半个世纪,由于人类不合理的开发利用,会仙湿地水域已严重萎缩,开展会仙湿地地下水动态和水均衡的研究,对维持湿地生态功能、湿地水资源管理和湿地保护等方面有极其重要的意义。根据会仙湿地的水文地质条件,将会仙湿地划分为两个地下水系统,即马面狮子岩地下河系统和睦洞河(湖)分散排泄系统,并分别分析了两个地下水系统的补给、径流、排泄特征和地下水动态特征,最后对两个地下水系统进行了地下水均衡计算。结果表明:会仙湿地水位波动受降雨影响明显,各监测点水位变幅不均且水位对降雨响应时间不一致。会仙湿地地下水系统的蓄存量为-6.19万m3,为负均衡,这与均衡期后期干旱有关;会仙湿地岩溶地下水主要补给来源为大气降水入渗,主要排泄方式为潜水径流和蒸发,其系统具有一定的储水调蓄功能,但调蓄能力有限。要长期维护会仙湿地的生态功能,应加强其调蓄能力,可从减少湿地蒸散发量和开采利用量入手,配合湿地生态环境恢复重建,提高水源涵养能力,使湿地水位维持在一个稳定的变化区间内。 相似文献
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湿地具有去除水中营养物质或污染物质的特殊结构和功能属性,在维护流域生态平衡和水环境稳定方面发挥巨大作用。提出了流域湿地是将流域中湿地看作一个整体,研究其水质净化功能。对国内外湿地净水功能的特殊属性、湿地系统各组分对污染物质的去除作用及湿地对污染物质的去除过程研究作了不同程度的探讨。在流域的尺度上,进行了流域湿地水质净化功能的环境因子、影响流域湿地水质净化功能的重要湿地类型和流域湿地整体水质净化功能的研究,总结了流域湿地水质净化功能。对流域湿地水质净化功能未来的研究进行了讨论与展望。 相似文献
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鄱阳湖水质污染对湿地生态系统生态功能的影响 总被引:8,自引:0,他引:8
湿她内部生物、物理、化学组份之间的相互作用过程,推动湿地的形成和发育,是其生态结构和生态功能的物质基础。水是鄱阳湖湖泊及其湿地的主体要素之一,各种形式的水是参与湿地生态过程的主体成分.贯穿融于生态形成和系统运作的生物、物理、化学过程的每一个环节,湖泊水质的变化直接影响着湿地的生态过程,影响水域生态系统、湖滩草洲生态系统、农牧与生态系统食物链和食物网的质量.所以水质变化及污染是湿地生态功能衰退研究的核心内容之一。 相似文献
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吉林西部向海湿地环境退化及驱动机制研究 总被引:10,自引:2,他引:10
向海湿地位于半干旱的吉林西部平原区,特殊的地理位置和水文条件决定了湿地处于动态变化之中.在自然和人为驱动影响下,系统结构和功能发生明显的退化趋势,湿地面积缩小、调节功能削弱,区域荒漠化发展迅速.通过对湿地发育的环境背景条件分析,剖析了湿地退化的现状及驱动机制,水陆界面的脆弱性是湿地退化的环境背景条件,而气候干旱化、上游水的大量截流、水利工程设施及土地资源的不合理开发利用等自然、人为因素的耦合作用,加速了湿地的退化过程.基于湿地退化的现状和驱动机制,河流湿地退化的恢复必须从湿地的水文功能出发,考虑水资源的循环和转化,制定水资源综合利用方案及生态技术和生态工程措施. 相似文献
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滨海湿地是上海的重要自然资源之一,在维持生态系统中发挥着重要作用。随着城市发展,上海滨海湿地面临面积缩小、功能减弱、生物多样性下降等严重胁迫,在人为活动的干扰下生态系统结构趋于破碎化,生态服务的调节能力减弱。本文探讨了其退化的自然因素和人为因素等原因,人工围滩造地加剧、滨海湿地资源过度发展、工业活动等导致了滩涂面积缩小、湿地退化甚至丧失的现象,分析了近自然生态恢复的修复方式,进一步针对外来物种管控措施、减缓湿地退化措施以及建立健全相关法制和管理体系等方面提出建议,可为滨海湿地修复的相关研究和实践提供参考。 相似文献
11.
Charles S. Hopkinson 《Estuaries and Coasts》1992,15(4):549-562
The effects of system closure on the dynamics of productivity and nutrient cycling are examined in four wetlands that differ in plant growth form and magnitudes and sources of water input and nutrient loading. Dynamics in relatively closed ombrotrophicCarex marsh andTaxodium swamp systems from Okefenokee Swamp are compared to those in open, rheotrophic riparian systems. The riparian systems examined includeZizaniopsis marshes along the tidal freshwater portion of the Altamaha River in Georgia and a matureTaxodium-Nyssa swamp along the Cache River in Illinois. Water budgets in the ombrotrophic systems are dominated by precipitation inputs while in the riparian wetlands they are dominated by overbank flooding. Nutrient loading to the open and closed systems differs by only two orders of magnitude, the former depending on atmospheric inputs and the latter depending on tidal and riverine inputs. Comparisons of nutrient import, export, and retention indicate that greater than 90% of inorganic nutrients are retained in the closed systems while less than 5% are retained in the open systems. Nutrient budgets for wetland vegetation, including aboveground uptake, root uptake, leaching, death, and translocation, are constructed. Strong differences in nutrient conservation within plant communities are found between marsh and forested closed systems and between open and closed systems as a whole. There is the indication that nutrients turn over more rapidly and nutrient cycles are less retentive and conservative as systems become more open and nutrient inputs increase. Nutrients turn over more rapidly in marshes with nonwoody vegetation than in swamp forests. This phenomena is partially attributable to the growth form of the vegetation as trees store vast amounts of high Canutrient ratio biomass in boles. Substituting space for time and marsh and swamp wetlands for young and mature ecosystems enables patterns of productivity and nutrient cycling for these wetlands to be compared with Odum’s (1969) predictions of ecosystem development. Patterns of ecosystem development in wetlands agree with those predicted for terrestrial systems in general, but there are many areas of contradiction. The degree of system closure appears to be a major factor controlling nutrient retention and cycling in wetland ecosystems. System closure is also likely to be important in determining the response of wetland systems to global increases in CO2 levels. 相似文献
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中国湿地科学的进展与展望 总被引:121,自引:3,他引:121
湿地学在国际上尚未形成完整的理论体系。在中国则处于初创时期,与国际水平差距较大。全面总结了中国湿地50年的主要成就:完成了全国沼泽调查;建成了若干研究基地,取得了一大批研究成果。在湿地生态系统及湿地与全球变化、湿地分类等方面的研究开始进入国际前沿。在此基础上提出8项未来研究与建设重点:湿地区域分异规律、湿地形成的多层圈作用过程与机制、湿地沉积动力学、内陆盐碱湿地与西部开发、湿地环境重建、湿地可持续发展、湿地保护理论与法规、建设数字湿地系统。 相似文献
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利用空间自相关模型,结合GIS技术,对别拉洪河流域不同尺度上湿地空间自相关的动态变化进行了研究。结果表明,自20世纪50年代至2000年,别拉洪河流域湿地面积逐渐减少,湿地全局空间自相关呈先增加后减小再增加的"N"字型趋势;别拉洪河流域湿地高-高自相关类型有逐渐减少并向流域下游扩张的趋势,而低-低自相关类型有逐渐增加并向流域上游扩张的趋势;湿地空间自相关表现出明显的尺度效应,随着研究尺度的增大湿地空间自相关性逐渐增强;别拉洪河流域湿地空间自相关的动态变化主要是由人类对湿地的开发造成的。 相似文献
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黄河三角洲进积与滨海湿地地质环境演替模式 总被引:1,自引:0,他引:1
本文通过对黄河三角洲5个钻孔岩芯的沉积学观测、微古分析、14C测年,同时结合历史记录及遥感资料,分析了本区末次冰后期以来的沉积序列,重建了近10ka以来古环境演变过程,分析了古环境演化对滨海湿地演替的控制作用。本文着重讨论了黄河三角洲进积与湿地形成演替规律,总结了从水生系统、浅海湿地系统、潮滩湿地直至上三角洲平原湿地向陆地生态系统的演替模式。同时通过对现代黄河三角洲与老黄河三角洲演化模式进行对比,提出气候变化、人类活动会加速和改变湿地地质环境演替进程和方向的一般规律。笔者等还进一步提出,由于人类活动的影响,1855年之后湿地演替速率明显加快,约达8~33倍。古环境的重建与滨海湿地响应机制研究可更清楚地理解湿地如何对未来环境变化进行响应,包括海平面上升,从而为滨海湿地保护与管理实践活动提供科学导向。 相似文献
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Ruifeng Zhao Yaning Chen Huarong Zhou Yiqing Li Yibing Qian Lihua Zhang 《Environmental Geology》2009,57(2):455-464
The wetlands in the middle and lower reaches of the Tarim River are a rich area of biodiversity and natural resources in the
inland arid region of China. However, this wetland area has decreased in size during the past several decades. Water quality
and biodiversity has declined due to expanded agricultural activities since 1960s. Using remote sensing (RS), geographic information
system (GIS) and global positioning system (GPS) techniques, we investigated the dynamics, spatial patterns and fragmentation
of the wetlands in the middle and lower reaches of the Tarim River from 1980 to 2000. We found that the total area of the
wetlands was reduced by 45.8% and the density of the patches increased four times from 1980 to 1990. From 1990 to 2000, though
the total area of the wetlands slightly increased the number of the patches increased three times and the density of the patches
doubled. Based on the analyses of transition matrixes, diversity and fragmentation indexes, and spatial distribution alternation
of the wetlands, we found the landscape diversity and fragmentation indices increased while wetland dominance index decreased
dramatically. Among the wetland types, the areas of the river-channel, reservoir and pond wetlands increased while the areas
of the lake and marsh wetlands decreased continuously. 相似文献
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Mark P. S. Krekeler Pete Probst Misha Samsonov Cynthia M. Tselepis William Bates Lance E. Kearns J. Barry Maynard 《Environmental Geology》2007,53(4):709-726
Subsurface flow constructed wetlands in the village of Akumal, Quintana Roo, Mexico were surveyed to determine the general
status of the wetland systems and provide baseline information for long term monitoring and further study. Twenty subsurface
flow wetlands were surveyed and common problems observed in the systems were overloading, poor plant cover, odor, and no secondary
containment. Bulk mineral composition of aggregate from two subsurface flow constructed wetlands was determined to consist
solely of calcite using bulk powder X-ray diffraction. Some soil structure is developed in the aggregate and aggregate levels
in wetlands drop at an estimated rate between 3 and 10 cm/year for overloaded wetlands owing to dissolution. Mineral composition
from fresh aggregate samples commonly is a mixture of calcite and aragonite. Trace amounts of Pb, Zn, Co, and Cr were observed
in fresh aggregate. Coefficients of permeability (k) varied from 0.006 to 0.027 cm/s with an average values being 0.016 cm/s. Grain size analysis of fresh aggregate samples
indicates there are unimodal and multimodal size distributions in the samples with modes in the coarse and fine sand being
common. Investigations of other geologic media from the Reforma region indicate that a dolomite with minor amounts of Fe-oxide
and palygorskite is abundant and may be a better aggregate source that the current materials used. A Ca-montmorillonite bed
was identified in the Reforma region as well and this unit is suitable to serve as a clay liner to prevent leaks for new and
existing wetland systems. These newly discovered geologic resources should aid in the improvement of subsurface flow constructed
wetlands in the region. Although problems do exist in these wetlands with respect to design, these systems represent a successful
implementation of constructed wetlands at a community level in developing regions. 相似文献
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水文过程在湿地形成、发育、演替直至消亡全过程中起重要作用.降水截流、径流和蒸散作用是湿地 大气界面水文过程研究的热点和重点,开发的模型较多但尚需进一步检验和完善.片流和明渠流是湿地主要地表径流,其中片流受地形坡度等因素影响而难以精确计算.湿地的地下水文系统对季节性积水湿地尤为重要,但是关于泥炭沼泽的垂向水力联系尚需进一步研究.可持续的湿地水文管理必须将人类活动和气候变化这两个因素纳入湿地综合水文模型,然而目前除少数几个综合模型外,大多数的湿地水文模型并非如此.加强湿地水文观测、多手段多技术相结合和开发综合湿地水文模型应是今后湿地水文学研究的主流. 相似文献
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黄河三角洲滨海湿地健康条件评价 总被引:3,自引:0,他引:3
以黄河三角洲滨海湿地系统为研究对象,基于描述滨海湿地健康条件的4项功能,充分考虑滨海湿地生态地质环境系统的特征及其健康响应因素,建立了黄河三角洲滨海湿地健康条件评价的概念模型和指标体系。以统计监测和遥感数据为基础,采用RS和GIS技术,通过栅格化实现分区评价及其结果的优化整合,探讨了黄河三角洲滨海湿地健康的时空分布规律。结果显示:黄河三角洲滨海湿地现状健康条件处于健康的占14.2%,亚健康的占61.9%,一般病态的占23.9%;近期(2010-2015年),河口三角洲湿地生境质量会逐步改善,向健康方向发展,而北部和南部部分滩涂区及神仙沟流路等局部地区在自然和人为因素的共同作用下,环境质量会有一定的降低;影响黄河三角洲滨海湿地健康条件的主要因素是全球气候变化背景下的区域水循环关键过程及其时空变化、湿地开发等人类负面干扰和黄河下游生态调度。应继续加大黄河下游生态调度的力度、积极实施生态修复工程,以促进黄河三角洲滨海湿地持续健康发展。 相似文献