共查询到19条相似文献,搜索用时 359 毫秒
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水环境容量是解决水环境问题的重要支撑,是开展流域综合整治的科学依据。以南充市西充县九龙潭水库为研究对象,运用一维水环境容量模型、湖库均匀混合型模型等方法,研究水库建成前后水文情势变化对水环境容量的影响,并基于水质、污染负荷排放情况对结果进行验证。结果表明:(1)根据水环境容量核算结果分析,研究区河流控制单元地表水环境容量成库后变化差异不大,水库控制单元地表水环境容量增加。(2)研究区在水库建成后污染源较水库建成前污染源减少。(3)研究区上游河流控制单元在成库前后水质状况基本无变化。水库控制单元成库后水质功能区变更,水质较好,基本满足Ⅱ类标准限值要求。总体上区域内地表水环境容量有所增多。 相似文献
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以浙江省台州市黄岩区4处控制断面所在河道为例,建立了该区域水环境数学模型,并对模型进行率定验证。通过率定验证得到水位相对误差在10%以内,氨氮和总磷降解系数相对误差分别在18.2%与18.6%以内,模型计算值和实测值吻合较好。以黄岩区永宁江为例,基于已建立的模型对研究区域的规划年最大允许入河量进行计算并分配至各控制单元,从而指导区域水环境整治。 相似文献
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分区达标法是计算水环境容量有效且合理的方法,其中贡献度系数是分区达标法的重要概念,在项目实际应用中贡献度系数偏向于理论假设而难以与实际相结合,据此对贡献度系数进行了详细研究,采用MIKE11模型计算贡献度系数,再通过MATLAB拟合得出其与污染源浓度、流量以及距离之间的定量化关系。结果表明,贡献度系数与距离和浓度呈线性关系,与流量呈指数关系。以此为基础提出单位负荷贡献度系数的概念,给出其计算表达式,并应用于新安涌黑臭治理中。应用结果表明,单位负荷贡献度系数可有效体现出流域排口污染贡献大小,量化流域现状污染,为后续计算水环境容量及总量分配提供计算依据。 相似文献
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为分析沱江干流自贡段航电枢纽建设前后对河道水质的影响,针对沱江干流污染现状,以沱江干流主要污染物COD、氨氮、TP为指标,应用MIKE 11模型建立能客观反映模拟河段水动力、水质时空演变规律的模型,分析了银蛇溪枢纽建库前后对沱江干流水质的影响。模拟结果表明:在污染负荷不增加的情况下,李家湾、黄葛浩、银蛇溪断面在建库后枯水年枯水月COD预测浓度月均值有所超标;枯水年NH3-N预测浓度较建库前增加率最高,平水年次之,丰水年最低;枢纽建设后,各断面TP浓度进一步升高。本研究以沱江自贡段航道建设工程为例,分析不同典型年下航电枢纽建设前后水质情况,研究结果可为沱江干流航电枢纽建设项目水质影响预测提供科学依据。 相似文献
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以西宁经济技术开发区高新技术产业园区建设为背景,针对北川河和湟水河下游水环境中度污染的状况,根据已有水质水文监测资料和沿岸排污情况,选取污染物中所占比例最大的化学需氧量和氨氮作为河段的主要污染控制因子,以一维水质模型为基础,进行水环境容量的计算,并以水环境容量为依据明确河段及园区水污染物排污控制量和削减量。 相似文献
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隧道建设相当于在地下增加一条新的地下水排泄通道。隧道排放的施工涌水如果不加控制,将会造成区域地下水水位下降,使得影响半径范围内地下水露头减少,井泉、溪流水量等不同程度的减小或消失,从而影响当地居民的生活和生产用水。文章以五陂石隧道为例,根据隧址区地质构造、地层岩性及其水文地质条件,通过对隧址区涌水量计算,定量分析隧道建设对地下水环境的影响。分析得出,隧道建设在一定程度上改变隧址区原有的地下水径流及排泄条件,涌出的地下水以地表径流形式流失和浪费,使地下水系统失去平衡。最后,提出保护地下水环境的对策和措施。 相似文献
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Wetland conservation is a critical environmental management issue. An emerging approach to this issue involves the construction
of wetland environments. Because our understanding of wetlands function is incomplete and such projects must be monitored
closely because they may have unanticipated impacts on ecological, hydrological, and geomorphological systems. Assessment
of project-related impacts on stream channel stability is an important component of riverine wetlands construction and operation
because enhanced erosion or deposition associated with unstable rivers can lead to loss of property, reductions in channel
capacity, and degradation of water quality, aquatic habitat, and riparian aesthetics.
The water/sediment budget concept provides a scientific framework for evaluating the impact of riverine wetlands construction
and operation on stream channel stability. This concept is based on the principle of conservation of mass, i.e., the total
amount of water and sediment moving through a specific reach of river must be conserved. Long-term measurements of channel
sediment storage and other water/sediment budget components provide the basis for distinguishing between project-related impacts
and those resulting from other causes. Changes in channel sediment storage that occur as a result of changes in internal inputs
of water or sediment signal a project-related impact, whereas those associated with changes in upstream or tributary inputs
denote a change in environmental conditions elsewhere in the watershed. A geomorphic assessment program based on the water/sediment
budget concept has been implemented at the site of the Des Plaines River Wetlands Demonstration Projection near Chicago, Illinois,
USA. Channel sediment storage changed little during the initial construction phase, suggesting that thus far the project has
not affected stream channel stability. 相似文献
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朱悦 《环境保护与循环经济》2021,41(1):62-67
新常态下,亟须开展辽河流域水环境承载力评估,以指导流域生态文明建设.针对辽河流域特点,以招苏台河铁岭市控制单元为例,采取目标—准则—指标层级关系框架建立水环境承载力指标体系,并结合主客观赋权综合法对该控制单元水环境承载力进行评估.结果表明,该控制单元水环境承载力指数介于0.1750~0.5302之间,总体呈超载状态.水... 相似文献
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1997年建成的"新疆环境保护"网站是全国第一家环保门户网站,也是新疆第一家政府类网站,新疆环保网站建设与发展已经历风雨兼程的10a,现在正进入一个崭新的发展阶段.回顾、总结和展望新疆各级环保网站的发展,吸取发展中的经验与教训,探索新疆各级环保网站建设中的规律,对新疆环保电子政务的"理性建设、快速推进"大有裨益. 相似文献
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让江河湖泊休养生息,就是要实行最为严格的污染物排放总量控制制度,以水环境容量确定发展方式和发展规模;就是要尊重自然规律,充分发挥水生态系统的自我修复能力,逐步改变环境恶化状况;就是要综合运用工程的、技术的、生态的方法,加大治理水环境的力度,促进水生态系统尽快步入良性循环的轨道;就是要充分运用法律、经济和必要的行政手段,既要形成严格排放、合理开发的强大压力,又要形成主动治理水环境的积极动力,用高效的办法解决长期积累的环境问题。 相似文献
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The Aging of America's Reservoirs: In‐Reservoir and Downstream Physical Changes and Habitat Implications
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Kyle E. Juracek 《Journal of the American Water Resources Association》2015,51(1):168-184
Reservoirs are important for various purposes including flood control, water supply, power generation, and recreation. The aging of America's reservoirs and progressive loss of water storage capacity resulting from ongoing sedimentation, coupled with increasing societal needs, will cause the social, economic, environmental, and political importance of reservoirs to continually increase. The short‐ and medium‐term (<50 years) environmental consequences of reservoir construction and operation are well known and include an altered flow regime, lost connectivity (longitudinal, floodplain), an altered sediment regime, substrate compositional change, and downstream channel degradation. In general, reservoir‐related changes have had adverse consequences for the natural ecosystem. Longer term (>50 years) environmental changes as reservoirs enter “old” age are less understood. Additional research is needed to help guide the future management of aging reservoir systems and support the difficult decisions that will have to be made. Important research directions include assessment of climate change effects on aging and determination of ecosystem response to ongoing aging and various management actions that may be taken with the intent of minimizing or reversing the physical effects of aging. 相似文献
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长江上游水电建设与环境影响研究若干问题 总被引:1,自引:1,他引:1
长江上游是我国水能资源富集区,对其开发具有全国战略意义,但开发会引起若干重大的生态与环境问题,需要尽早组织对上游地区环境本底研究,移民环境容量研究,生物物种保护研究,水资源综合利用研究,环境地质评价研究和水电工程的社会经济影响研究。 相似文献