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981.
上海青浦区不同用地类型河流滨岸带生境及植物群落组成   总被引:1,自引:0,他引:1  
按照工业用地、农业用地、交通用地、居住用地、绿地和荒地等6类不同用地类型,于上海青浦区选取河流滨岸带样点48个,研究不同用地类型对滨岸带生境及植物群落组成的影响。研究发现:(1)目前该地区河流滨岸带生境优劣程度为:荒地>绿地>农业用地>交通用地>居住区>工业用地。这主要是由于在不同用地类型下人们对河岸类型、滨岸带几何形态以及原有植被的影响所造成。(2)目前该地区河流滨岸带有植物51科118种,平均丰富度水平绿地最高,工业用地最低。从植物的生活型与来源方面看,6类用地类型下的河流滨岸带植物群落组成存在显著差异。工业用地受人为影响强度较大,外来入侵植物比例高达27.22%;农业用地草本平均数量11.75种,为6类用地类型中最高水平;交通用地与居住用地表现出较大人工引种植物比例,分别为37.77%和49.97%;绿地有相对均衡的乔灌草比例,人工引种植物占所有植物的64.05%;荒地缺乏乔木与灌木类型,自然分布植物比例最高,为69.94%。
  相似文献   
982.
李磊 《环境与发展》2020,(2):177-178
如今城市河道水环境的污染问题越来越严重,已经严重影响了人类的生活以及城市的建设,因此加强城市河道水环境的生态修复已经成为目前急需进行的重要工作之一。本文针对城市河道水环境生态修复的相关问题展开了探讨,首先探讨了关于城市河道水环境生态修复的价值以及在修复过程中应该持守的各方面原则,并根据几种先进的水环境生态修复措施进行了详细的探讨,以期为城市河道水环境修复工作提供参考。  相似文献   
983.
In recent decades, public and private environmental entities have been purchasing or leasing water rights across the Western United States (U.S.) in efforts to restore river flows and aquatic ecosystems. The need to pay for flow restoration arises from the fact that state governments did not begin to reserve water for instream purposes until the 1970s, long after water rights had become over‐appropriated and flows were substantially depleted in most rivers. As a consequence, flow depletion has become the leading cause of fish endangerment in the U.S., including the imperilment of two‐thirds of all native fish species in the Colorado River system. This paper takes stock of the progress made in buying water for the environment, specifically by reviewing and analyzing more than 50 transactions executed by public and private entities and the sources of funding underpinning these transactions. We conclude that nongovernmental actors — such as environmental organizations and state water trusts — are integral to regional efforts to restore river flows; these nongovernmental actors executed more than two‐thirds of the transactions we documented. However, we also conclude that the long‐term success of these nongovernmental actors depends upon the availability of sustained public funding that enables them to build capacity and engage in the large number of transactions needed to restore flows across each state.  相似文献   
984.
上海城市水环境质量改善历程与面临的挑战   总被引:2,自引:0,他引:2  
上海市排污总量大,污染负荷重.历史上,黄浦江曾经黑臭,苏州河则在20世纪70~90年代终年黑臭,地表水污染一度成为困扰上海环境的一个主要问题.20世纪80年代以来,上海加大了对城市受污染河流的治理力度,开展了一系列工作,其中苏州河修复是最具代表性的一项.苏州河治理耗资157亿元,历时20年.在实施了苏州河污水合流一期、苏州河环境综合整治一、二、三期项目后,苏州河黑臭现象消失,水质持续改善,滨河风貌明显改观,受到各方面高度评价.与此同时,上海城市水环境质量总体趋好,而要进一步稳定和持续改善全市水环境质量,深化整治势在必行,水环境工作者面临新的挑战.  相似文献   
985.
We argue that the environment, broadly construed, has a profound effect on human cognition, action, and well-being. If this is true, then the field of environmental psychology has a far larger potential to aid humanity than is generally realized. We suggest that the field would be more likely to achieve this potential if it viewed environments from the perspective of human informational needs, and focused on environmental/informational patterns that have the potential to make it easier for people to help themselves. Further, achieving such benefits could be greatly enhanced by taking advantage of the many opportunities available for collaborating with researchers in other areas of psychology. The reasonable person model is offered as a perspective that could facilitate moving in these various new directions while taking advantage of the considerable existent knowledge about human–environment interactions that is currently underappreciated.  相似文献   
986.
A method was developed to score the ecological condition of first- to third-order stream reaches in the Auckland region of New Zealand based on the performance of their key ecological functions. Such a method is required by consultants and resource managers to quantify the reduction in ecological condition of a modified stream reach relative to its unmodified state. This is a fundamental precursor for the determination of fair environmental compensation for achieving no-net-loss in overall stream ecological value. Field testing and subsequent use of the method indicated that it provides a useful measure of ecological condition related to the performance of stream ecological functions. It is relatively simple to apply compared to a full ecological study, is quick to use, and allows identification of the degree of impairment of each of the key ecological functions. The scoring system was designed so that future improvements in the measurement of stream functions can be incorporated into it. Although the methodology was specifically designed for Auckland streams, the principles can be readily adapted to other regions and stream types.  相似文献   
987.
Densmore, Roseann V. and Kenneth F. Karle, 2009. Flood Effects on an Alaskan Stream Restoration Project: The Value of Long‐Term Monitoring. Journal of the American Water Resources Association (JAWRA) 45(6):1424‐1433. Abstract: On a nationwide basis, few stream restoration projects have long‐term programs in place to monitor the effects of floods on channel and floodplain configuration and floodplain vegetation, but long‐term and event‐based monitoring is required to measure the effects of these stochastic events and to use the knowledge for adaptive management and the design of future projects. This paper describes a long‐term monitoring effort (15 years) on a stream restoration project in Glen Creek in Denali National Park and Preserve in Alaska. The stream channel and floodplain of Glen Creek had been severely degraded over a period of 80 years by placer mining for gold, which left many reaches with unstable and incised streambeds without functioning vegetated floodplains. The objectives of the original project, initiated in 1991, were to develop and test methods for the hydraulic design of channel and floodplain morphology and for floodplain stabilization and riparian habitat recovery, and to conduct research and monitoring to provide information for future projects in similar degraded watersheds. Monitoring methods included surveyed stream cross‐sections, vegetation plots, and aerial, ground, and satellite photos. In this paper we address the immediate and outlying effects of a 25‐year flood on the stream and floodplain geometry and riparian vegetation. The long‐term monitoring revealed that significant channel widening occurred following the flood, likely caused by excessive upstream sediment loading and the fairly slow development of floodplain vegetation in this climate. Our results illustrated design flaws, particularly in regard to identification and analysis of sediment sources and the dominant processes of channel adjustment.  相似文献   
988.
Abstract: The effects of natural flow restoration on metals fate and transport in the Upper Tenmile Creek Watershed, Montana, were modeled using the Water Quality Analysis Simulation Program developed by the U.S. Environmental Protection Agency (USEPA). This 50‐km2 watershed has over 150 historic abandoned mines, including mine waste rock and tailings, as well as adits discharging acid mine drainage, and is the primary drinking water supply for the City of Helena. Water supply diversions almost completely dewater some stream reaches during summer low flows, but the city is considering a new drinking water source and restoration of natural flows in Tenmile Creek as part of acid mine drainage remediation and broader aquatic habitat restoration. One dimensional steady‐state simulation of total recoverable cadmium, copper, lead, and zinc in the mainstem was performed, and the model was calibrated to June 2000 base‐flow data. Representative low‐flows in August and high‐flow snowmelt conditions in June were modeled using mean monthly natural flow estimates from the U.S. Geological Survey and representative USEPA metals concentrations data. The modeling showed that total recoverable metals concentrations, and especially loads, can vary significantly among input locations and over time in the watershed. Some data gaps limit evaluation of variability and increase uncertainty in several locations. Model results indicated, however, that natural low‐ and high‐flow restoration by itself can reduce some metals concentrations in the mainstem compared to June 2000 values, which were influenced by significant water diversion. Some values (such as Zn) may still exceed standards during natural August low flow due to the remaining high concentrations and loads in the primary inputs to the mainstem. Others (such as Cu) can increase during high flow due to remaining mine waste sources and loading of particulate Cu associated with erosion and transport of solids. Greater than 50% reduction in concentrations and loads from some of the main tributaries may be necessary to meet all standards, especially for potential particulate loads with higher flows in June.  相似文献   
989.
官厅水库库滨带非点源污染控制效应的遥感分析   总被引:3,自引:0,他引:3  
选取官厅水库库滨带为研究区域,应用SPOT5遥感数据对其结构进行了解析,建立了高分辨率的Quick Bird遥感数据与SPOT数据的尺度转化关系,对SPOT信息提取结果进行了校核,以提高SPOT卫星对库滨带结构的解译精度;最后结合点上的实验结果对流域尺度上的库滨带的环境效益进行了分析.研究结果表明:(1)官厅水库陆相库滨带的结构不利于非点源污染的防治,应该适当增加林地的比例,同时提高林地、草地的植被覆盖度;(2)按照官厅水库流域非点源区年均TN量为188.1×104 t、TP量为101.2×104 t计算,库岸库滨带对TN、TP的去除率分别为11.6%和0.4%;(3)为了有效地防止官厅水库流域的非点源污染,必须加强水库流域的农业管理和库岸库滨带的科学建设与管理.  相似文献   
990.
富营养化水体生态修复中水生植物的应用研究   总被引:19,自引:1,他引:18  
文章论述了水生植物修复富营养化水体的机理,并按不同生活型综述了不同水生植物在富营养化水体生态修复中的应用,指出了富营养化水体生态修复中水生植物选择依据,并展望了其研究应用前景。  相似文献   
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