缺资料流域水污染物总量分配方法研究

流域水污染物总量分配对流域水环境管理至关重要。但在缺资料流域,污染负荷的计算分析往往因水文资料匮乏而变得非常困难。本文以赣江袁河流域为例,在划分流域控制单元的基础上,利用SWAT模型对袁河流量进行模拟,再结合LDC(负荷历时曲线)法,实现了袁河流域分区(控制单元)、分期(丰水期、平水期、枯水期)、分类(点源和非点源)和分级(不同水质目标)的总量分配方案。结果表明,SWAT径流模拟精度较为满意,可以为LDC法提供控制单元内部的流量;新余工业区及其下游的保留区是袁河污染物超标最为严重的区域,超标污染物主要以点源为主,其中新余工业区削减量最大。研究结果说明SWAT模型结合LDC方法可以较好地应用于资料匮乏流域的水污染物总量分配。     

青山湖水库流域内水环境质量问题原因分析

青山湖水库调整为备用饮用水源,但水质为IV类水质,不符合备饮用水水源地Ⅲ类水质的要求.文中通过在水库上游及库区流域内现场调研和资料收集,分析了库区及上游污染源现状、库区存在的主要环境问题以及水质现状,并对流域内污染源进行分类和现状污染负荷核算.通过对水环境质量问题原因的分析,为下一步水环境整治提供了数据支撑和依据,此次水污染源负荷计算也为同类型水源地整治提供技术参考依据.     

辽河流域清河水环境容量计算方法探究

以辽河流域铁岭段一级支流清河为例,按照全河段水质达标的考核方法,重新划定河段水质目标,采用一维水质模型计算在水功能区划水质目标约束条件下清河的CODCr和NH4-N的水环境容量。计算结果表明:研究河段枯、丰两种水文条件下CODCr的水环境容量为2 012、4 111 t/a,氨氮的水环境容量为46、80 t/a。由流域点源及非点源污染负荷现状确定研究区域所需污染削减量的取值范围,CODCr月削减699～874 t、NH4-N月削减406～441 t,即可满足水功能区水质要求。     

基于补水配置情景的河流水质及环境容量研究——以汾河干流为例

汾河流域是山西省的政治文化中心和重要农业产区,也是全国的主要能源基地分布区域,该流域目前面临严重的水生态问题,而生态补水是改善水生态质量的一项重要举措。为定量评价生态补水对流域水质与水环境容量的影响,本文构建了汾河水质水量联合模拟平台,以污染源负荷和生态补水配置情景为基础,考虑2种不同补水方案,评价了汾河干流30个主要断面的水质状况与水环境容量。结果表明,现状水资源条件下汾河COD和氨氮容量分别为2.67万和0.14万t/a;生态补水方案可有效改善水质,低生态补水方案补水2.5亿m3,由于考虑了生态需水,对水环境容量影响不大;高补水方案补水3.9亿m3,可相应提高汾河干流COD8%和氨氮12%的水环境容量。     

淮南采煤沉陷区水环境影响分析

水质模型是预测评价建设项目对水环境影响的重要手段之一.在研究水利工程建设的水环境影响时,往往需要二维动态模型进行分析研究.近几十年来,国内外许多学者已做了大量研究工作,提出了各种方法的水质模型,包括有限差分法、有限单元法、特征线法及有限体积法等等.笔者建立了二维非稳态FVS格式水流水质模型,对淮南潘谢矿区采煤沉陷区不同蓄水条件下的水流水质过程进行了数值模拟,计算了采煤沉陷区在2020年积水面积和治理措施条件下库区水质浓度场分布,对水质可达性进行了研究.     

分担率法在洱海水环境容量计算中的应用

为了研究进入洱海河流污染物对洱海的影响,利用分担率法构建了洱海水动力水质模型,结合洱海污染负荷、水文气象特征,计算了洱海水环境容量。结果表明:在Ⅱ类水质目标下,平水年(2004年)中部湖区作为控制点时入湖河流可承担的COD、TN、TP水环境容量总和分别为16 338.11、11 643.84、620.39 t/a,其中弥苴河的水环境容量最大。同一特征水位、同一水平年条件下,洱海中部水环境容量最大,南部次之,北部最小;同一特征水位下,同一区域的主要污染物水环境容量随水文条件呈现出"丰水年>平水年>枯水年"的态势。     

潼关-三门峡段水质浓度及污染物削减量计算

针对黄河潼关-三门峡河段有机污染的突出特点,确定了河段水体功能及水质目标.根据水质模型,计算了河段在不同设计流量、设计含沙量条件下各断面的BOD5和CODMn的浓度值.根据水环境容量模型计算出在不同设计流量、设计含沙量条件下该河段的污染物削减量.指出加大上游来水污染物治理力度是提高该河段水环境容量,改善水环境质量的有效措施和途径.     

城市大型缓流景观水体水环境容量总量动态控制研究

针对缺水城市大型缓流景观水体水环境容量小、水质易恶化问题,提出了利用水环境容量总量动态控制模型进行水质管理的方法。以天津渤龙湖景观水体为研究对象进行实例研究。水环境容量计算结果表明：渤龙湖自然水环境容量无法容纳污染物输入总量的要求,而水体循环净化系统按照设计负荷运行时,会产生较大的剩余水环境容量。利用模型对渤龙湖水环境容量总量动态控制结果表明,在水体达到IV类水质标准的同时,优化后水体循环净化设施水量负荷可降低46.1%,且水环境容量得以充分利用。     

雁栖河流域点源氮磷污染负荷量的计算与分析

在大量野外调查和监测数据的基础上,通过流域污染负荷评估模型分析评价了雁栖河流域内主要污染负荷产生量与人河污染负荷量,建立河道水质模型计算分析了雁栖河流域的水环境容量,以流域水环境容量为约束条件,分别考虑不同污染源控制方案下的流域水环境承载能力与规模。研究结果表明：流域入河污染负荷中,餐饮企业占2％,自然村占12％,鱼场养殖约86％,是流域最主要的污染源。流域污染负荷远远超过了流域水环境容量,流域系统处于超负荷状态,需要通过削减鱼场排污以及提高自然村生活污水处理率的环境治理措施降低污染入河量;对于严重污染河段,需同时采用多种生态修复措施,提高流域的水环境承载力,维持流域社会一经济的可持续发展。     

河流泥沙与磷作用情景模拟及分析

泥沙是河流水环境系统的重要组成部分,泥沙运动过程和泥沙吸附解吸作用对河流水质具有显著的影响。天然河流中泥沙运动状态存在一定的变化,尤其是河流上修建大坝蓄水后,库区泥沙运动过程的变化更加明显,相应也会引起水环境条件的改变。本文采用挟沙水流水质一维数学模型,以磷为代表污染物,在一定的水流、泥沙和水质的计算条件下,对泥沙稳定吸附、泥沙淤积、床沙冲刷和不同冲刷位置等4种情景对水环境的影响进行了模拟和分析。通过模拟说明了特定条件下泥沙运动状态和吸附特性变化对水环境的影响,从而为进一步认识天然河流中泥沙对水环境的影响提供支持。     

Regression Kriging Analysis for Longitudinal Dispersion Coefficient

Prediction of longitudinal dispersion coefficient (LDC) is still a novel topic for both environmental and water sciences due to its practical importance. In this study, the appraisal of LDC is considered as a spatial modelling problem and the analyses are carried out by regression kriging. Since LDC prediction includes some geometrical (spatial) parameters, the analyses have been performed such that it takes spatial variability of data into account. The modelling procedure consists of two stages. In the first stage, spatial variables are analyzed via multi-linear regression technique and deterministic relationships are identified. In the second stage, based on the spatial auto-correlations of the residuals, the regression-based kriging procedure is applied. The capacity and accuracy level of the method has been compared with former models. As a consequence, the applications revealed that analyzing hydraulic and geometrical parameters with spatially correlated errors is a convenient approach for evaluating LDC in a hydrological system.     

Receiving More Accurate Predictions for Longitudinal Dispersion Coefficients in Water Pipelines: Training Group Method of Data Handling Using Extreme Learning Machine Conceptions

Water Resources Management - Longitudinal dispersion coefficient (LDC) is known as the most remarkable environmental variables which plays a key role in evaluation of pollution profiles in water...     

Water Quantity Operation to Achieve Multi-Environmental Goals for a Waterfront Body

This paper presents a water quantity operation scheme to resolve series of environmental problems which some waterfront bodies are faced with, such as frequent water-level fluctuation, sediment deposition, water quality degradation, water transparency depravation, and submerged aquatic plant disappearing. Neijiang, which is a typical tide-influenced waterfront body located within the Changjiang Delta, China has been considered as the research area. A 2-D environmental and ecological model coupled with water current, water quality, suspended sediment, algae growth, and water transparency is established and validated against the field investigated data, and the model can well reflect the dynamic processes of these factors in Neijiang. Three water quantity operation modes including self-introducing, pumping, and keeping quiescence are proposed. Based on different kinds of water demand of Neijiang and the actual water exchange ability, detailed water quantity operation schemes under different hydrologic conditions are studied with the established numerical model, and the changes of some living condition factors after water operation are forecasted and evaluated. Results show that water exchange and sediment deposition in Neijiang are apparently reduced after water operation in different level years. In addition, the water quality and transparency in Neijiang can keep a good status, and the living environment is improved for submerged aquatic plant restoration. This study provides an example to resolve environmental problems, improve living conditions and keep a healthy ecosystem for similar waterfront bodies.     

清潩河流域河流环境流量计算与应用

针对北方地区河流环境流量短缺和污染并存的现状,在综合考虑水质保护与水量维持的情况下界定了河流环境流量的概念和内涵,并探讨不同功能目标下河流环境流量的组成。通过分析河流水系特征及河段的空间结构特征,建立了改善河流水质所需环境流量计算模型,同时建立了Tennant和湿周模型计算河流生态系统所需环境流量。利用临颍高村桥的水文水质数据,对清潩河为改善河流水质和生态系统所需环境流量进行了初步评价,为河流应急补水提供了调控建议,并提出了河道应常年保持的流量水平。     

山区性河道水环境容量及合理配置研究

山区性河道具有单向流的特点,往往跨越多个行政区域。排入河道的污染物随水流稀释、降解后,多余的污染物进入下游河段,导致跨界水污染纠纷事件。河道水环境容量的分析与计算是水环境保护、污染物总量控制、排污权分配的理论依据。本文分析了影响水环境容量的主要因子及常见问题。提出在满足水质目标的前提下,应允许地方政府对排放流量作动态调整,以适应河道流量的变化。提出环境容量是有价值的环境资源,必须合理配置,并可以通过市场手段进行有偿转让。指出了水环境容量配置原则、转让补偿机制、标准等需要进一步研究的问题。     

Institutional Arrangements to Improve Water Quality in Irrigated Agriculture 1

Irrigated agriculture is closely linked to water quality problems throughout the western United States. In this paper it is argued that the market failure paradigm is not adequate as an environmental policy guide, especially for water quality problems involving individual irrigators. An alternative stewardship paradigm is developed and applied to nitrate pollution of groundwater in central Nebraska. This paradigm holds that producers are not profit maximizers, that information is imperfect and that producers care enough about the environment to voluntarily substitute some environmental quality for income. The analysis suggests that education can produce significant improvements in environmental quality, and that in some circumstances education may be more effective than regulations or incentive-based strategies.     

QUAL2Kw模型在新安江干流黄山段水质模拟中的应用

针对新安江干流当前水质状况与水生态功能分区要求不协调的问题,首先通过对流域内的12个监测站点多年水质监测数据进行模糊综合评价分析,确定水质现状并识别出各水质指标的污染贡献度矩阵。然后使用一维、稳态水质模型QUAL2Kw对河道水质进行模拟,在遗传算法校准得到参数集的基础上,对模型进行验证,最后根据水功能区划计算目标河道的环境容量。结果表明:QUAL2Kw模型可以很好地模拟现实水质状况,但模拟结果显示,新安江干流各河段的TN环境容量大部分为负值,污染现状不容乐观;水体对于TP则仍有少量的环境容量,但由于TP为限制因子,因此基于环境容量的营养盐污染控制亟需加强。     

Mitigating Socio-Economic-Environmental Impacts During Drought Periods by Optimizing the Conjunctive Management of Water Resources

Multi-period optimization of conjunctive water management can utilize reservoirs and aquifer carry-over to alleviate drought impacts. Stakeholders’ socio-economic and environmental indices can be used to minimize the socio-economic and environmental costs associated with water shortages in drought periods. The knowledge gap here is the evaluation and inclusion of the socio-economic and environmental value of conjunctive water management in terms of its drought mitigation capability. In this paper, an integrated water quantity-quality optimization model that considers socio-economic and environmental indices is developed. The model considers and integrates reservoir and aquifer carry-over, river-aquifer interaction and water quality with stakeholders’ socio-economic indices of production, net income and labor force employment to evaluate the socio-economic and environmental value of conjunctive water management. Total dissolved solid (TDS) is used as the water quality index for environmental assessments. The model is formulated as a multi-period nonlinear optimization model, with analysis determining the optimal decisions for reservoir release and withdrawal from the river and aquifer in different months to maximize the socio-economic indices of stakeholders within the environmental constraints. The proposed model is used in Zayandehrood water resource system in Iran, which suffers from water supply and pollution problems. Model analysis results show that conjunctive water use in the Zayandehrood water basin reduces salinity by 50 % in the wetland and keeps water supply reduction during a drought under 10 % of irrigation demand.     

Ecologically based standards for nutrients in streams and ditches in The Netherlands

General and specific water quality standards were formulated on a national scale in The Netherlands in the eighties of this century. A general environmental quality was defined as the minimum acceptable water quality level for all inland waters. For this quality level, standards for total phosphorus and total nitrogen were derived from measurements in shallow lakes sensitive to eutrophication for this quality level. No standards were developed for specific environmental quality.In this study we tested whether single nutrient standards are sufficient to guarantee the minimum quality level in streams and ditches. We also investigated whether specific environmental quality requires specific standards. We, therefore, analyzed data collected by regional waterboards in The Netherlands.The results show that nutrient standards for the general quality are not sufficient to guarantee the minimum quality for all water types. They do not provide appropriate protection for aquatic life. More specific standards should be set to protect and preserve the full biodiversity of ditches and streams.Setting a single standard for general environmental quality and one for specific environmental quality for all types of water is not defendable. Different types of water have different aquatic communities and different nutrient levels. It is therefore recommended that water type dependent standards should be developed. In this study, standards for both general and specific environmental quality in respect to nutrients are proposed for six stream types and for six ditch types.