三江平原挠力河流域湿地生态特征变化研究

经过近半个世纪的垦荒,挠力河流域湿地生态特征发生了明显的改变,大量湿地被垦殖,湿地面积逐年减少;湿地资源的破坏,造成环境污染严重,土壤有机质含量大大降低;土地沙化、盐碱化面积不断扩大;灾害性气候发生频率增加;动植物等多样性资源急剧减少。挠力河流域作为“北大荒”的重要组成部分,生态环境的剧烈变化也就很具有代表性了。伴随着新千年“北大荒”停止一切垦殖湿地、草地和林地的措施出台,挠力河流域也迎来了退耕还林、还牧、还湿的调整时期。     

潜流式人工湿地基质堵塞问题对策研究

基质堵塞是人工湿地长期稳定运行最关键的问题.针对滇池湖滨福保人工湿地运行后潜流湿地基质严重堵塞的问题,分析造成基质堵塞的原因,从工艺路线、碎石床结构、填料径粒和布水方式等方面对原有人工湿地进行分析研究,找出堵塞原因,提出技术改造方案,并经过工程模型实验进行验证,在此基础上确定"预处理-潜流湿地(垂直流)-调节池-潜流湿...     

基于InVEST模型的鄱阳湖湿地生物多样性情景分析

生态系统服务与功能的评估越来越多地被应用到自然资源管理政策制定中。通过参与式评估框架(FoPIA)方法建立鄱阳湖湿地到2020年的不同土地利用情景,以此作为参数应用到生态系统服务与功能的评估权衡模型(InVEST),以鄱阳湖湿地指示性生物(越冬候鸟)的栖息地为研究对象,定量和空间化评估典型村落未来土地利用情景下候鸟栖息地质量和空间分布特征。结果表明:在生态保育情景下,受生态退耕等因素的影响,栖息地规模增加,人类胁迫活动减少,鄱阳湖湿地典型村落候鸟栖息地的平均质量提高到0.89,比现状水平提高27.0%;在经济发展情景下,人类活动范围的扩张使得候鸟栖息地受到的胁迫增强,栖息地的平均质量下降为0.57,比现状水平低14.0%;在自然增长情景下,候鸟栖息地平均质量为0.66,比现状水平增加了1.5%。     

论我国滨海湿地综合性法律调整机制的构建

滨海湿地是我国湿地的重要组成部分,具有多种生态功能。随着风险社会的到来,各种开发利用行为造成滨海湿地严重的环境资源问题,滨海湿地的保护管理和法制建设成为当务之急。法律调整机制是应对滨海湿地问题的各类调整机制中最重要的部分,但我国现行法律调整机制无法有效解决滨海湿地利用中的“公地悲剧”和利益平衡问题,应该根据社会发展的需要,采取行政调整、市场调整和社会调整相结合的综合性法律调整机制。环境治理理论的兴起和我国第三部门的发展为滨海湿地综合性法律调整机制的构建提供了理论依据和社会基础,应该通过发展滨海湿地区域的环保产业、建立生态补偿制度、完善公众参与环境影响评价的途径、构建滨海湿地的社区共管模式,综合运用行政指导、经济激励、公众参与等各种法律手段完善我国滨海湿地的保护管理     

洞庭湖湿地景观格局变化以及三峡工程蓄水对其影响

通过对近20 a遥感影像的解译分析,结果表明：洞庭湖湿地景观格局变化较为迅速,在几种湿地景观类型中,芦苇分布面积稳定增长,由475 km²增至751 km²,年均增加13.1 km²,湖草的分布面积比较稳定,而水面与泥滩的分布面积则大幅减少。湿地格局演变总体上呈现芦苇挤占湖草的分布空间、湖草挤占水面泥滩的态势。分析认为泥沙淤积和湖泊水情变化改变了洲滩的淹水历时,引起植被分布的变化,是影响洞庭湖湿地景观格局的主要因素。2000年后,随着泥沙淤积减缓,湖泊水情变化对湿地景观格局影响更为重要,其中三峡水库的运行使洞庭湖中、低位洲滩提前出露,淹水历时缩短,导致湖草的分布界线明显向下延伸     

山地小微湿地生态修复探讨 ——以梁平区猎神村梯塘小微湿地为例

小微湿地是乡村景观的组成部分,是乡村重要的水土基础设施.湿地的功能已经得到广泛认同,但过去多关注大面积成片分布的沼泽、湖泊、滨海湿地及大型河流湿地等,而对于那些数量众多、分散分布的小型和微型湿地却缺少关注.2018年10月,《湿地公约》第十三届缔约方大会通过了中国政府提交的《小微湿地保护与管理决议草案》,小微湿地的保护...     

外源氮、硫添加对闽江河口湿地CH4、CO2排放的短期影响

于2015年4月在闽江河口鳝鱼滩湿地原位开展氮、硫添加实验,研究外源氮、硫添加对河口湿地CH_4、CO_2排放通量的短期影响,并同步观测相关环境因子.结果表明,NH_4Cl(NH)和NH_4NO_3+K_2SO_4(NS)添加显著促进了河口湿地CH_4平均排放通量(P0.01),NS耦合添加显著促进了湿地CO_2平均排放通量(P0.05);KNO_3(NO)和K_2SO_4(S)处理在实验期间对CH_4、CO_2排放通量表现为促进与抑制作用的交互影响,并且影响均不显著(P0.05).与对照(CK)相比,NH和NS添加使CH_4平均排放通量分别提高了(286.36%、122.73%),使CO_2平均排放通量分别提高了(39.92%、34.24%).氮、硫添加对河口潮滩湿地CH_4、CO_2排放的影响具有明显的时间变异性,改变了短叶茳芏湿地生长季CH_4排放时间变化规律,但未改变CO_2排放时间规律.相关分析显示,NH和NS添加处理下河口湿地土壤CH_4、CO_2排放通量主要受土温、EC、DOC以及NH+4-N的控制(P0.05或P0.01),NO和S处理主要受土温、EC、pH、DOC、NO_3~--N的控制(P0.05或P0.01),CK处理则主要受土温的影响(P0.01).温度、盐度、氮有效性是影响河口湿地CO_2、CH_4排放的主要因素.     

WETLAND DESIGN METHODS FOR RESIDENTIAL WASTEWATER TREATMENT1

ABSTRACT: Constructed wetlands have recently gained popularity as an alternative method for wastewater treatment. This paper compares two design methodologies currently used for constructed wetlands; Tennessee Valley Authority (TVA) and the Environmental Protection Agency (EPA) methods. A discussion of parameters for both methods is given and a wetland treatment system is designed for an individual residence with typical BOD5 loads and flow rates. Calculation results revealed significant discrepancies in the required constructed wetlands volume, and thus detention time, stemming from inherent differences in the design methodologies. The EPA method relies heavily on plug flow kinetics, and is therefore sensitive to changes in the reaction rate constant and media porosity. Conversely, TVA determines the surface area by sizing in accordance with a recommended hydraulic loading criterion and is affected only by the hydraulic flow rates. This study concluded that a constructed wetland is a viable option under design considerations that are not favorable for traditional on-site wastewater treatment methods. However, it is recommended that conservative values for flow and loading rates be assumed to assure complete treatment for either of the design methods.     

A combined hydrologic simulation and landscape design model to prioritize sites for wetlands restoration

Most landscape design models have been applied to the problem of maximizing species richness in a network of nature reserves. This paper describes a combined hydrologic simulation and landscape design model designed to prioritize sites for wetlands restoration, where the objective is to maximize the amount of nutrients in non-point-source runoff attenuated in the restored wetlands. Targeted site selection in four small watersheds in the Central Valley resulted in predicted levels of nitrogen attenuation two to eight times greater than that from maximizing wetland area without consideration of the location of the restoration sites. Disclaimer  The views expressed in this paper are those of the author and do not necessarily represent those of the US Environmental Protection Agency. No official Agency endorsement should be inferred.     

ECONOMIC ANALYSIS OF WETLAND RESTORATION ALONG THE ILLINOIS RIVER1

Creating and restoring wetland and riparian ecosystems between farms and adjacent streams and rivers in the Upper Mississippi River Basin would reduce nitrogen loads and hypoxia in the Gulf of Mexico and increase local environmental benefits. Economic efficiency and economic impacts of the Hennepin and Hopper Lakes Restoration Project in Illinois were evaluated. The project converted 999 ha of cropland to bottomland forest, backwater lakes, and flood‐plain wetland habitat. Project benefits were estimated by summing the economic values of wetlands estimated in other studies. Project costs were estimated by the loss in the gross value of agricultural production from the conversion of corn and soybean acreage to wetlands. Estimated annual net benefit of wetland restoration in the project area amounted to US$1,827 per ha of restored wetland or US$1.83 million for the project area, indicating that the project is economically efficient. Impacts of the project on the regional economy were estimated (using IMPLAN) in terms of changes in total output, household income, and employment. The project is estimated to increase total output by US$2,028,576, household income by US$1,379,676, and employment by 56 persons, indicating that it has positive net economic impacts on the regional economy.