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我国农村水环境非点源污染研究进展 总被引：8，自引：0，他引：8
农业非点源污染是导致水质污染最主要原因之一。我国农村非点源污染研究之初采用的研究方法主要有两种，一种是应用与水文模型紧密相关的模型来模拟和估算非点源污染负荷；另一种是通用土壤流失法。最近又提出了一种简便易用的流域非点源污染负荷估算方法－平均浓度法。将农业非点源污染负荷与3S技术结合、与水质模型对接用于流域水质管理成为农业非点源污染研究的新生长点。近年来，农村非点源污染研究也开始探索非点源污染负荷与河流水质模型接口问题。 相似文献
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非点源污染是导致流域水体水质恶化的关键污染来源之一,为了估算流域非点源污染负荷,本文提出将一维水质模型应用于分离监测断面点源污染负荷和非点源污染负荷的方法,并结合了改进的输出系数法,以CODMn和NH3-N为代表性指标,将该模型应用于潮河下游流域,并与传统的水文分割法结合改进的输出系数法估算非点源污染负荷的结果进行对比。结果表明,一维水质模型结合改进的输出系数法估算流域非点源CODMn和NH3-N污染负荷模拟值的纳什系数均在0.800以上,具有良好的模拟精度,同时避免了水文分割法无法较好地模拟枯水期非点源污染负荷的弊端。该方法在运用SWAT（soil and water assessment tool）模型预测得到水文数据的情况下,能够预测流域非点源污染负荷,作为SWAT模型对COD模拟的补充。 相似文献
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渭河水质在较大程度上受非点源污染的影响,因此,有必要对其负荷和比重进行研究。2009年至2010年,对渭河干流关中段咸阳和临潼断面进行了洪水期和非洪水期水质水量同步监测。根据监测结果及水文站实测流量资料,分别采用改进的水文分割法和平均浓度法对两断面的非点源污染负荷进行了计算,分析了非点源污染的特点。结果表明:渭河干流关中段主要污染物为COD、NH3-N和TN,两断面洪水期间各指标的平均浓度基本都小于平时的平均浓度;各指标非洪水期浓度变化总体上小于洪水期浓度变化幅度,量级较大的洪水水质变化幅度相对较小;改进的水文分割法和已被检验并被广泛采用的平均浓度法计算结果符合良好。2009年(枯水年,P=68%)渭河咸阳和临潼站各指标非点源污染所占比例基本在20%～30%左右;2009年渭河干流咸阳-临潼河段污染以点源污染为主,构成比例在80%以上。对比2006年(枯水年,P=69%),2009年临潼站COD、NH3-N和TN年点源负荷分别减少11937t、791t和29t,渭河点源治理取得一定成效;此外,临潼站这两年的污染构成比例基本相同。非点源污染在渭河水污染中占较大比重,其对渭河水质的影响不容忽视。 相似文献
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依据祖厉河流域上下游(会宁、靖远站) 2个水质监测断面2008-2017年的地表水水质监测数据,采用层次分析法研究各指标,应用模糊综合评价法对流域水质进行综合评价。采用Tennant法、近10年最枯月流量法、90%保证率最枯月流量法、月年保证率设定法分别计算了流域内2个断面的生态环境需水量。结果表明:(1)祖厉河流域上下游水质评价标准隶属度分别为0.954(汛期0.967)、0.706(汛期0.546),均属于Ⅴ类水质。(2)上游会宁站生态环境需水量为0.039 m3/s,下游靖远站生态环境需水量为0.413 m3/s,满足多年平均流量的10%以上。 相似文献
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非点源污染负荷计算对水污染总量控制具有重要意义,为分析中国非点源污染负荷计算研究的现状与问题,在系统调研相关文献的基础上,将中国常用的非点源污染负荷计算方法总结为三大类:输出系数模型、实证模型和机理模型,阐述了各种模型的特点及其在中国的研究和应用情况;从非点源污染的界定、产污量和排污量的区别、国内和国外非点源污染产生环境的差异以及平原河网地区非点源污染负荷的计算4个方面分析了中国非点源污染负荷计算研究存在的主要问题;认为模型和计算方法适应研究区的环境特征是研究工作取得成功的关键,今后要加强实证研究、理论研究与模型开发的结合,逐步建立适应中国环境特点的非点源污染负荷计算方法体系。 相似文献
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基于平均浓度法原理,根据黄河中游降雨径流特点,将年内过程分为汛期和非汛期两个阶段,同时将高含沙水流中的污染负荷分为水体中的溶解态污染负荷、泥沙吸附态负荷两部分,提出了多沙河流非点源污染负荷估算模型;根据黄河干流潼关断面1950-2006年实测水沙资料,结合水体、泥沙污染物浓度测定试验,分别计算了潼关断面2006年以及丰水年(P=25%)、平水年(P=50%)、枯水年(P=75%)3种不同代表年型下的非点源污染负荷.结果表明:黄河干流潼关断面年污染负荷以汛期为主,汛期污染负荷以非点源为主;非点源污染负荷中,硝酸盐氮、氨氮以溶解态为主,总磷以吸附态为主;潼关断面非点源污染负荷占全年负荷比例:丰水年时,硝酸盐氮占63.09%,氨氮占61.32%,总氮占87.17%、总磷占89.83%;枯水年时,硝酸盐氮占26.92%,氨氮占24.62%,总氮占67.60%、总磷占71.73%.2006年,硝酸盐氮、氨氮、总氮和总磷非点源污染负荷占全年比例依次为:17%、14%、15%和41%. 相似文献
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为探讨闸坝工程对河流水生态环境的影响效应,进行实地闸坝调控实验,监测河流水质指标在不同调控(0 m3/s、20 m3/s、40 m3/s和60 m3/s)方式下的空间变化,并调查水生态指标,探析长期和短期的调控干扰对河流水生态环境的影响特征。结果表明:60 m3/s调控,有助于闸下污染物的氧化和分解,提高河流水体的自净作用;水体的强烈冲刷和扰动作用促进底泥中污染物向水体转化,极易造成闸下区域水体的突发性二次污染;短期频繁地开闸调控对浮游动植物的密度分布影响显著;长期的调控干扰导致水生生物群落和结构单一,水生态环境显著恶化,闸上区域负面影响更为严重。研究结果可为河流生态修护与可持续流域水环境管理提供科学依据。 相似文献
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利用《中国河流泥沙公报》数据,采用水沙动态图方法并按平衡水沙比相对应,分析中国主要河流2006年前实测水沙的变化。根据河流下游站历年水沙变化趋势,将中国主要河流大致分为4类:水量不变沙量降低、水量和沙量均降低、水量和沙量同步略降低、几近断流断沙。按地域看,中国淮河及其以南大多数河流年径流量无明显改变,而年沙量呈明显下降趋势;淮河以北地区河流水沙量均呈明显下降趋势,特别是黄河年径流量的近10年平均值仅为多年平均值的1/3,输沙量10年平均值仅为多年平均值的1/4,而海河水系的河流下游几乎是断流断沙。总体上,中国大多数河流的沙量明显下降。大多数河流入海水沙量的明显降低主要是人类活动造成的,淮河及其以南河流沙量的降低多与水库兴建、河道采砂和水土保持工程等有关;北方河流水沙量的降低主要是引水量的大幅增加、水库建设及其运行方式的改变以及水土保持工程的发挥效益等造成的。分析也表明,利用水沙动态图法分析河流的水沙长期变化具有一定的优越性。 相似文献
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西南岩溶地下河流量重复统计问题及对策探讨 总被引：2，自引：2，他引：0
西南岩溶区的地下河数量及总流量是有关职能部门和专业技术人员关心的两个重要数据。20世纪80年代对西南6省进行统计,结果为2 836条,流量1 482 m3/s;20世纪90年代对西南8省进行统计,并经过近年的数据库校核为2 523条,总流量1 321.7 m3/s;其中流量大于2 000 L/s有120条,合计流量699.7 m3/s,占总流量的52.94%;流量在50~500 L/s地下河最多,有1 311条,占总数的51.55%,其次为流量小于50 L/s的有723条,占总数的28.43%。文章针对上述统计方法存在岩溶地下河流量重复统计、与岩溶大泉流量交叉重复统计两种问题,以大小井和寨底地下河系统为例,给出了具体重复统计量。基于1∶20万水文地质普查资料,大小井和寨底地下河重复统计量分别占总出口流量的57.1%、7.1%;而基于最新调查资料,重复统计量则分别可增加到134.3%, 86.1%。因此,随着1∶5万水文地质调查面积越多,所发现的地下河出口越多,按传统的统计方法其重复统计量则越大。引起上述重复统计问题主要原因是把地下河系统和子系统混合在一起。文章最后讨论了地下河系统的空间属性,提出避免重复统计措施,对西南岩溶区地下河流量正确统计以及具有相同特征的岩溶大泉流量统计有一定指导意义。 相似文献
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柴达木盆地气候干旱,降水稀少,地下水补给来源主要为河流渗漏,如何计算河流渗漏量是地下水资源评价必须解决的首要问题。根据柴达木盆地河流渗漏特征,在河流渗漏量组成分析的基础上,建立了适用于自由渗漏型河流的渗漏率经验公式,并利用该公式对比计算了柴达木盆地格尔木河、塔塔棱河、鱼卡河的河流渗漏率,其结果与实测值相近,表明所建立的渗漏率公式具有一定的适用性和普遍性。同时,计算了柴达木盆地主要河流的渗漏率和渗漏量,结果表明,流量大于10m~3/s的河流,渗漏率为61.1%~78.3%;流量小于5m~3/s的河流,渗漏率为94.5%~99.9%,符合该地区河流渗漏的一般性规律。研究提出的渗漏率公式对水文地质条件相似区地下水资源评价具有借鉴意义。 相似文献
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Giasemi G. Morianou Nektarios N. Kourgialas George P. Karatzas Nikolaos P. Nikolaidis 《Earth Science Informatics》2018,11(2):205-216
The objective of this work was the estimation of time-space hydraulic (water depth, flow velocity) and morphological (sediment transport and bank erosion) characteristics in the downstream part of a Mediterranean stream under current and future climatic conditions. The two-dimensional hydraulic model MIKE 21C was used, which has been developed specifically to simulate 2D flow and morphological changes in rivers. The model is based on an orthogonal curvilinear grid and comprises two parts: (a) the hydrodynamic part and (b) the morphological changes part. The curvilinear grid and the bathymetry file were generated using a very high-resolution DEM (1 m × 1 m). Time series discharge data from a hydrometric station introduced in the hydrodynamic part of the model. Regarding the morphological part of the model, field measurements of suspended sediment concentration and of bank erosion were used. The model was calibrated and verified using field data that were collected during high and low flow discharges. Model simulation was in good agreement with field observations as indicated by a variety of statistical measures. Next, for predicting the riverbank change, future meteorological data and river flow data for the next 10 years (2017–2027) were employed. These data series were created according to a lower and a higher emission climate change scenario. Based on the results, an increase in rainfall intensity may cause significant changes in river banks after 10 years (more than 5 m of soil loss in river meanders). Using the obtained simulation results, extreme hydrological events such as floods transporting large sediment loads and changes in river morphology can be monitored. The proposed methodology was applied to the downstream part of the Koiliaris River Basin in Crete, Greece. 相似文献
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《Applied Geochemistry》2003,18(2):195-220
Samples of fine-grained channel bed sediment and overbank floodplain deposits were collected along the main channels of the Rivers Aire (and its main tributary, the River Calder) and Swale, in Yorkshire, UK, in order to investigate downstream changes in the storage and deposition of heavy metals (Cr, Cu, Pb, Zn), total P and the sum of selected PCB congeners, and to estimate the total storage of these contaminants within the main channels and floodplains of these river systems. Downstream trends in the contaminant content of the <63 μm fraction of channel bed and floodplain sediment in the study rivers are controlled mainly by the location of the main sources of the contaminants, which varies between rivers. In the Rivers Aire and Calder, the contaminant content of the <63 μm fraction of channel bed and floodplain sediment generally increases in a downstream direction, reflecting the location of the main urban and industrialized areas in the middle and lower parts of the basin. In the River Swale, the concentrations of most of the contaminants examined are approximately constant along the length of the river, due to the relatively unpolluted nature of this river. However, the Pb and Zn content of fine channel bed sediment decreases downstream, due to the location of historic metal mines in the headwaters of this river, and the effect of downstream dilution with uncontaminated sediment. The magnitude and spatial variation of contaminant storage and deposition on channel beds and floodplains are also controlled by the amount of <63 μm sediment stored on the channel bed and deposited on the floodplain during overbank events. Consequently, contaminant deposition and storage are strongly influenced by the surface area of the floodplain and channel bed. Contaminant storage on the channel beds of the study rivers is, therefore, generally greatest in the middle and lower reaches of the rivers, since channel width increases downstream. Comparisons of the estimates of total storage of specific contaminants on the channel beds of the main channel systems of the study rivers with the annual contaminant flux at the catchment outlets indicate that channel storage represents <3% of the outlet flux and is, therefore, of limited importance in regulating that flux. Similar comparisons between the annual deposition flux of specific contaminants to the floodplains of the study rivers and the annual contaminant flux at the catchment outlet, emphasise the potential importance of floodplain deposition as a conveyance loss. In the case of the River Aire the floodplain deposition flux is equivalent to between ca. 2% (PCBs) and 36% (Pb) of the outlet flux. With the exception of PCBs, for which the value is ≌0, the equivalent values for the River Swale range between 18% (P) and 95% (Pb). The study emphasises that knowledge of the fine-grained sediment delivery system operating in a river basin is an essential prerequisite for understanding the transport and storage of sediment-associated contaminants in river systems and that conveyance losses associated with floodplain deposition exert an important control on downstream contaminant fluxes and the fate of such contaminants. 相似文献
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V. I. Sinyukov V. A. Glukhov O. V. Rybas A. N. Makhinov V. I. Kim N. V. Berdnikov 《Russian Journal of Pacific Geology》2008,2(6):545-552
The dynamics of river channel processes were analyzed in the region of complex floodplain-channel branching of the Amur River near Khabarovsk using remote sensing data of the Earth’s surface. Zones of steady accumulation and long-term erosion of the river channel are established within the Khabarovsk water junction over the period of 1964–2004. The main problems related to restoring the Amur River back to its initial channel were distinguished in the course of these works. A map of individual streams formed in the Amur River channel under the influence of large tributaries (the Sungari and Ussuri rivers) was developed. The importance of this map for forecasting the spreading of anthropogenic pollution in the channel of the Amur River is shown using the example of the emergency situation that resulted from the explosion at the chemical plant in the Sungari River basin (Jilin, China; November 2005). 相似文献
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A total of 42 aquatic particulate sample:, (suspended matter and < 63 m surficial sediments) was collected from 11 large rivers in eastern China. Contents of both major elements (Al, Si, Ca, Mg, K, Na, Ti, Fe, Mn) and trace elements (Cu, Pb, Zn, Cd, Cr, Co, Ni, V) in the particulate samples were analyzed. The geographic variations of river particulate compositions were studied. The results showed that the Yellow River particulates contained a notably high content of Ca and a low content of Al. Except for the Yellow River, A1 contents in particulates increased from the northern rivers to the southern rivers, while K and Na decreased. Trace elements were relatively enriched in the southern river particulates. The geographic variations seemed to be related to the weathering types and geological background within the river basins. The average composition of river particulates in China was then estimated. Based on the Chinese river data from this paper, as well as on the literature data for other main world rivers, a new estimation of the global average particulate composition was reported. Since the earlier estimations in the literature were not concerned with or at best concerned only with few of the Chinese rivers which contribute a major proportion to the global load of river particulates, this new estimation may be more reasonable. 相似文献
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对同期降水、江河水和地下水的元素组成,使用中子活化分析方法作了对比试验。降水取自分布于8个气候带的11个站,其海拔高程为5～3659m,年平均降水量为50～1571mm。河水取自各主要江河包括内陆河和海岛的12个测站以及3个实验流域,并在其附近采集地下水。降水中共检出35种元素,各站有19～31种元素,同期均有空间分布。河水中共检出39种元素,各河分别有21～31种元素。地下水中共检出35种元素,各站有30～32种元素。对其浓度组成作了由大于1000μg/L至小于0.01μg/L的分级综合。有些元素含量超出所报道的世界淡水浓度范围,小于其最低值,甚或远大于其最高值。 相似文献
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The ability to detect hydrologic variation in large arctic river systems is of major importance in understanding and predicting effects of climate change in high-latitude environments. Monitoring uranium isotopes (234U and 238U) in river water of the Yukon River Basin of Alaska and northwestern Canada (2001?C2005) has enhanced the ability to identify water sources to rivers, as well as detect flow changes that have occurred over the 5-year study. Uranium isotopic data for the Yukon River and major tributaries (the Porcupine and Tanana rivers) identify several sources that contribute to river flow, including: deep groundwater, seasonally frozen river-valley alluvium groundwater, and high-elevation glacial melt water. The main-stem Yukon River exhibits patterns of uranium isotopic variation at several locations that reflect input from ice melt and shallow groundwater in the spring, as well as a multi-year pattern of increased variability in timing and relative amount of water supplied from higher elevations within the basin. Results of this study demonstrate both the utility of uranium isotopes in revealing sources of water in large river systems and of incorporating uranium isotope analysis in long-term monitoring of arctic river systems that attempt to assess the effects of climate change. 相似文献
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The article presents results of long-term monitoring, detailed studies and numerical simulation of hydrological hazards at the mouths of the Northern Dvina and the Pechora rivers. The Northern Dvina River discharges into the White Sea and the Pechora River flows into the Barents Sea. They are major rivers in northern European Russia. The main hydrological hazards at the mouths of these rivers include dangerous ice phenomena, inundations from both pure maximum stream flow and peak discharges with ice jams, surge-induced flooding, wind-induced down-surges, low-water periods and seawater intrusion into the delta branches. These hazards repeatedly caused significant socioeconomic loss and environmental damage to the riparian areas. Causes and characteristics of hydrological hazards have been evaluated and considered with respect to features, pattern and factors of their long-term, seasonal and spatial variability using statistic methods, remote sensing data and numerical simulation. Furthermore, the impact of regional climate change and economic activities is discussed. As a result, detailed information about the Northern Dvina river mouth is presented. It included the structure and the efficiency of measure for preventing ice jam formation and protecting from river discharge, ice jam and surge-induced inundations. The article also included fundamental and updated data on the structure, parameters and hydrological regime of the Northern Dvina and the Pechora river mouths and specifics of their changes in the twentieth and early twenty-first centuries. 相似文献