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1.
沱江是长江流域上游最重要的支流之一,为了明晰沱江流域水质时空变化特征和防治重点,根据2010—2017年沱江流域36个监测断面水质监测数据,采用单因子评价法和秩相关系数法,从年份、月份、季度和水期4个时间段进行了分析.结果表明:沱江流域水质状况总体上污染较重,但有向好趋势,总磷(TP)为首要污染物,流域断面达标率呈先上升后下降复上升的趋势;水质指标浓度年内变化显著,水质指标浓度丰水期达到最小值,枯水期达到最大值;沱江干流监测断面水质类别好于支流;TP和氨氮(NH3-N)浓度空间变异性较弱,化学需氧量(COD)和生化需氧量(BOD5)浓度则存在较强空间变异性.虽然沱江流域水质有变好趋势,但沱江流域面临的污染问题依然严峻,今后要高度重视污染源治理,尤其是TP的防治工作. 相似文献
2.
Alicia Kirschbaum Jesica Murray Emilce López Ahinoam Equiza Marcelo Arnosio Geraldo Boaventura 《Environmental Earth Sciences》2012,65(2):493-504
The Yacoraite River and its tributaries run down the eastern slope of the Aguilar Range. It is one of the tributaries of the
Rio Grande, located in Quebrada de Humahuaca, a UNESCO World Heritage site. The Aguilar underground mine (Pb–Ag–Zn) is located
in the upper reaches of the Yacoraite River drainage basin. The aim of this work is to characterize the presence of heavy
metals in water and sediments of the Yacoraite River and to identify their sources. The analysis shows the seasonal variation
of heavy metals concentration in water and their relation with the World Health Organization (WHO) limits established for
human consumption. The Yacoraite basin is naturally anomalous in some metals and some elements, such as As which is controlled
by the chemical composition of regional lithology. During the wet season, Al, Co, Mo and Pb concentrations in water samples
are higher than during the dry season; in addition, these metals are also higher than WHO limit values. High enrichment factors
for Ba, Mo, Pb, Zn and Cd were found in Casa Grande stream, indicating the direct influence of the mining activities. Cd,
Pb and Zn are present in the Aguilar ore minerals, such as sphalerite and galena. Sediments collected during the dry season
show a drastic increase in the concentration of As, Pb, Ba, Zn, Cd and Mn. The Müller geo-accumulation index in Casa Grande
indicates that it is a highly polluted stream. The concentrations of As, Pb, Ba, Zn, Cd are also high in Yacoraite River: Security Quality Guidelines indicates
toxicity. A decrease in enrichment factors and geo-accumulation indices observed in sediments indicates the occurrence of precipitation/adsorption
processes in the river to restore the equilibrium composition. Strict environmental controls in Aguilar Mine are necessary
to avoid the uncontrolled input of toxic metals in Casa Grande stream and Yacoraite River. 相似文献
3.
The purpose of this study is to evaluate the benthic macroinvertebrate distribution in the Ke?ap Stream (in the Eastern Black Sea Region of Turkey) for the summer period using biotic index. The water quality was assessed through the application of the Belgian biotic index. For this purpose, benthic macroinvertebrate sampling was performed in six sites along the Ke?ap Stream in the summer period, in July 2007. The distribution of dominant genera of the sites was evaluated according to water quality. According to the Belgian biotic index, II, III and IV water quality classes (slightly, moderately and heavily polluted, respectively) were determined in the stream. In addition, diversities of benthic macroinvertebrates in six sites were calculated. The biotic index values are found also consistent with the diversity values. Especially, in areas of the stream after industrial facilities water quality decreased. However, very heavy pollution was not observed accord to the biotic index values. It was found that Ephemeroptera was the dominant major taxon in all sampling sites. As a result of this biological evaluation, Ephemeroptera were concluded to be the most common taxa in the stream and the ephemeropterans, Potamanthus, Baetis and Ephemerella were dominant genera in the conditions of slightly, moderately and heavily polluted. 相似文献
4.
5.
G. Machender Ratnakar Dhakate M. Narsimha Reddy I. Panduranga Reddy 《Environmental Earth Sciences》2014,71(6):2885-2910
Groundwater and surface water samples from 47 locations (28 groundwater, 10 tanks and 9 stream channel) were collected during the pre-monsoon (May–June) and post-monsoon season (November) from Chinnaeru River basin. Chinnaeru River basin is situated 30 km east of Hyderabad City and its area covers 250 km2 and falls in the Survey of India Toposheet No. 56 K/15. The extensive agricultural, industrial and urbanization activities resulted in the contamination of the aquifer. To study the contamination of groundwater, water samples were collected from an area and analyzed for major cations and anions. Various widely accepted methods such as salinity, sodium absorption ratio, Kelly’s ratio, residual sodium carbonate, soluble sodium percentage, permeability index and water quality index are used to classify groundwater and surface water (tank and stream) for drinking as well as irrigation purposes. Besides this, Piper trilinear diagram, Wilcox diagram, Doneen’s classification and Gibb’s plot were studied for geochemical controls, and hydrogeochemistry of groundwater and surface water samples were studied. 相似文献
6.
清道光二十九年（1849年）长江中下游地区的大水灾,对民生造成了严重的影响。作者系统收集了档案、方志、日记和文集资料中关于该年份水灾的记载,以县级成灾分数资料为基础,重建了此次水灾的时空分布,并分析了形成这次水灾的天气气候特征。研究认为,该年度水灾基本在N28°～N33°间呈条状东西向分布,而以N31°一线的灾情最为严重;连续性的降水开始于5月18日左右,到7月18日才结束,中间还有3次持续各达10余天的强降雨过程;这次大水灾是全流域性的,涝灾大于洪灾,降水最集中区域为东部的太湖流域,这和有器测记录的几次长江全流域大洪水并不一致;本次大水灾的直接天气成因是梅雨期提前并超长,雨量明显偏大,持续时间长达62天左右,比有器测记录的更早、更长;当年夏季风应偏弱,副热带高压脊线位置异常偏南,且西风分支明显,经向环流发展,西风南支位置应该也异常偏南;夏季冷空气异常活跃可能是雨带长期在长江沿岸徘徊的真正原因。 相似文献
7.
《Applied Geochemistry》2005,20(8):1571-1586
87Sr/86Sr ratio variations were analyzed in rainfall, shallow ground water and base flow collected from 4 Piedmont streams within the Middle Oconee River basin in northeastern Georgia during the period between March, 2003 and March, 2004. They Sr isotope ratio analyses were accompanied by measurements of stream discharge, rainfall, stable O isotope ratios and major ion and 3H concentrations. The average Sr ion concentration and 87Sr/86Sr ratio for the terminal stream basin (the Middle Oconee River) were 23.6 μg/L and 0.7172, respectively. The average 87Sr/86Sr ratios of the rainwater and shallow ground water were below 0.7125, indicating that most of the Sr in this stream water is input by weathering reactions in deeper ground water, rather than by ion exchange in shallow soil horizons. This is consistent with the higher alkalinity concentrations (∼23–47 mg/L) and specific conductance values (60–113 μS/cm) that characterize stream base flow. Piedmont streams are characterized by lower concentrations of Sr and higher 87Sr/86Sr ratios than average global stream flow.Base flow rates decreased by a factor of 2–3 during the summer months and this is accompanied by increased alkalinity concentrations. 87Sr/86Sr ratios, however, were temporally invariant for a given stream basin and were independent of season, antecedent rainfall, and discharge. 87Sr/86Sr ratios were unique for each of the 4 basins and a general trend toward higher ratios with increasing basin area was apparent. The inferred contribution from minerals with high Rb contents such as K feldspar and muscovite may have resulted from the greater integration of flow from mineralogically diverse pathways afforded by a larger basin area. The basin specificity and temporal or seasonal invariability make 87Sr/86Sr ratios an invaluable hydrological tracer that can be readily employed in mass balance studies of stream flow within the Piedmont Province. 相似文献
8.
Ankara Creek is often subjected to overflowing of sewage caused by rainfall or direct discharge of raw sewage. Alluvial aquifers
adjacent to Ankara Creek and its tributaries have considerable groundwater potential. The present status of groundwater quality
is far from drinking water standards. Groundwater contamination in Ankara is suspected to be caused by Ankara Creek which
is heavily polluted by raw sewage discharge, surface runoff and other common sources. In order to investigate the influence
of heavily polluted Ankara Creek on the groundwater contamination in the adjacent alluvial aquifers, five sampling stations
on Ankara Creek and 25 water wells were monitored during 1996. At five different sampling periods, water samples were collected
from both surface water and groundwater. Chemical analyses of basic ions, pollution parameters and heavy metals in natural
waters were carried out. The organic pollution prevails in Ankara Creek whereas total dissolved solids (TDS) and heavy metal
concentrations are considerably low. Starting from the idea that Ankara Creek somewhat influences the groundwater quality
and the contaminants in groundwater should attenuate with respect to distance, a series of water wells in a certain area,
each having different distance from the creek, were examined using four pollution parameters. It is concluded that Ankara
Creek barely influences the aquifer systems in connection. This is attributed to two reasons: rapid attenuation of contaminants
due to dilution in groundwater and a blanket of very fine sized materials covering the bottom of Ankara Creek.
Received: 28. April 1997 · Accepted: 23. February 1998 相似文献
9.
以金矿开发影响的黄河二级支流太峪水系沉积物为研究对象,沿河采集16个表层沉积物样品,分层采集垂向剖面10件水库沉积物样品,测定了样品中重金属元素Hg、Pb、Cd、Cr、As、Cu和Zn的含量,采用Hakanson潜在生态指数法和Tomlinson污染负荷指数法评价重金属元素污染程度和潜在生态风险。结果表明,矿业活动是太峪水系沉积物重金属元素污染的主要因素;变异系数、富集系数和最高污染系数均反映Hg、Pb、Cd是太峪水系沉积物的特征污染重金属元素,Cr和As的质量分数接近地区背景值;太峪水系表层沉积物受到重金属元素的极强污染,山区段污染较山外更严重;整个流域的Hg、Pb、Cd具有很强的潜在生态危害,Cr、As、Zn的潜在生态危害轻微;太峪水系沉积物垂向各层沉积物都受到重金属元素的极强污染,生态问题以Hg、Pb、Cd的潜在生态危害为主,其污染和生态危害程度都高于流向上的沉积物。潜在生态危害指数评价突出了不同元素的毒性和危害程度,而污染负荷指数法侧重于样本空间上的污染程度,二者互补使用有利于实际问题的全面评价。 相似文献
10.
Water and bed sediment samples collected from the Damodar River and its tributaries were analysed to study elemental chemistry
and suspended load characteristics of the river basin. Na and Ca are the dominant cations and HCO3 is the dominant anion. The water chemistry of the Damodar River basin strongly reflects the dominance of continental weathering
aided by atmospheric and anthropogenic activities in the catchment area. High concentrations of SO4 and PO4 at some sites indicate the mining and anthropogenic impact on water quality. The high concentration of dissolved silica,
relatively high (Na+K)/TZ+ ratio (0.2–0.4) and low equivalent ratio of (Ca+Mg)/(Na+K) indicate that dissolved ions contribute significantly to the weathering
of aluminosilicate minerals of crystalline rocks. The seasonal data show a minimum ionic concentration in the monsoon season,
reflecting the influence of atmospheric precipitation on total dissolved solids contents. The suspended sediments show a positive
correlation with discharge and both discharge and suspended load reach their maximum value during the monsoon season. Kaolinite
is the mineral that is possibly in equilibrium with the water. This implies that the chemistry of the Damodar River water
favours kaolinite formation. The concentration of heavy metals in the finer size fraction (<37 μ m) is significantly higher
than the bulk composition. The geoaccumulation index values calculated for Fe, Mn, Zn, Ni and Cr are well below zero, suggesting
that there is no pollution from these metals in Damodar River sediments.
Received: 21 January 1998 · Accepted: 4 May 1998 相似文献
11.
12.
新疆阿尔泰山区克兰河上游水文过程对气候变暖的响应 总被引：17，自引：7，他引：10
额尔齐斯河支流克兰河上游发源于西风带水汽影响的阿尔泰山南坡,主要由融雪径流补给,年内积雪融水可占年径流量的45%.年最大月径流一般出现在6月份,融雪季节4~6月径流量占65%.流域自20世纪60年代开始明显升温,年平均温度从50年代的1.4℃上升到90年代的5.2℃;年降水总量也呈增加趋势,尤其是冬季和初春增加最多.随着气候变暖,河流年内水文过程发生了很大的变化,主要表现在最大月径流由6月提前到5月,月径流总量增加约15%,4~6月融雪径流量也由占年流量的60%增加到近70%.在多年变化趋势上,气温上升主要发生在冬季,降水也以冬季增加明显,而夏季降水呈下降趋势;水文过程主要表现在5月径流呈增加趋势,而6月径流为下降趋势;夏季径流减少而春季径流增加明显.冬春季积雪增加和气温上升,导致融雪洪水增多且洪峰流量增大,使洪水灾害破坏性加大.近些年来气候变暖引起的年内水文过程变化,已经对河流下游的城市供水和农牧业生产产生了影响. 相似文献
13.
The significance of morphometric analysis for obtaining groundwater potential zones in a structurally controlled terrain 总被引：5，自引：0，他引：5
Watershed development and management plans are more important for harnessing surface water and groundwater resources in arid and semi-arid regions. To prepare a comprehensive watershed development plan, it becomes necessary to understand the topography, erosion status and drainage patterns of the region. This study was undertaken to determine the drainage characteristics of Pageru River basin using topographical maps on a scale of 1:50,000. The total area of the Pageru River basin is 480 km2. It was divided into X sub-basins for analysis. The drainage patterns of the basin are dendritic and include a sixth order stream. The quantitative analysis of various aspects of a river basin drainage network characteristics reveals complex morphometric attributes. The streams of lower orders mostly dominate the basin. The development of stream segments in the basin area is more or less affected by rainfall. The elongated shape of the basin is mainly due to the guiding effect of thrusting and faulting. The erosional processes of fluvial origin have been predominately influenced by the subsurface lithology of the basin. 相似文献
14.
Zhongwu Li Yong Fang Guangming Zeng Jianbing Li Qi Zhang Qingshui Yuan Yamei Wang Fangyi Ye 《Environmental Geology》2009,58(1):101-107
Selecting the Liuyanghe River watershed as an example, using monitoring data of water quality of nearly 10 years and the improved
synthesis pollution index method to evaluate the water quality, the research studied the temporal and spatial characteristics
of surface water quality of a typical basin in the red soil hilly region, and analyzed reasons for the surface water quality
change. The results indicated the improved synthesis pollution index had a better serviceability than other methods, such
as, Pollution Index method, Fuzzy Evaluation method, Grey-System method etc. As for the temporal characteristic, because of
no-point source pollution, the water quality of Liuyanghe River watershed had become a more and more serious problem over
a ten-year period. The spatial characteristic indicated that the pollution degree increased from upstream to downriver. Water
quality upstream was better, and the content of the heavy metals was higher in the middle of the river, and the pollution
of ammonia nitrogen intensified downriver. The result suggested the improved universal pollution index could be used in the
assessment of the water environment. 相似文献
15.
《China Geology》2019,2(2):169-178
A comparative comparative study on the detrital mineral composition of stream sediments of the Yangtze River (Changjiang) and Yellow River (Huanghe) shows that, light minerals of the Yangtze River basin were mainly quartz, feldspar, and detritus, the compositional characteristics of light minerals differed among tributaries, the main stream had a generally higher maturity index than tributaries; heavy mineral content tended to decrease progressively from the upper stream to lower stream of the Yangtze River, the primary assemblage was magnetite-hornblende-augite-garnet-epidote, and diagnostic minerals of different river basins were capable of indicating the nature and distribution of the source rock. Detrital mineral assemblages in sediments of tributaries and the main stream of the Yellow River were basically similar, Primary heavy mineral assemblage was opaque mineral-garnet-epidote-carbonate mineral and alteration mineral. Variations in the contents of garnet, opaque mineral, and hornblende mainly reflected the degree of sedimentary differentiation in suspended sediment and the hydrodynamic intensity of a drainage system. The heavy mineral differentiation index F revealed sedimentary differentiation of diagnostic detrital mineral composition due to changes in regional hydrodynamic intensity and can serve as an indicator for studying the dynamic sedimentary environment of a single-provenance river and the degree of sedimentary differentiation of its detrital minerals. Changes in detrital mineral content of the Yellow River was not completely controlled by provenance but reflected gravity sorting of the detrital mineral due to variations in the ephemeral river hydrodynamic intensity and sedimentary environment, however the index changing of Yangtze River were mainly influenced by the complex sediment sources. Therefore caution must be exercised in using the detrital mineral composition of marginal sea to determine the contribution of the Yangtze River and Yellow River.© 2019 China Geology Editorial Office. 相似文献
16.
潮白河流域土壤重金属生态风险评价方法研究 总被引：1，自引：0，他引：1
为了研究潮白河流域某段土壤重金属环境质量现状及潜在生态风险评价,系统采集了42件土壤样品,对其7种重金属(Cu、Pb、Zn、Cr、Ni、Cd和As)进行了测试分析,利用《土壤环境质量标准》评价土壤重金属污染现状,并参考北京市土壤重金属背景值,采用环境质量指数与环境潜在生态危害指数、内梅罗综合指数法相结合的方法,探讨土壤中7种重金属的累积污染现状及潜在生态风险。研究表明,土壤样品中Cu、Zn、Cr含量超标分别为97.62%、100%、100%;Cu、Zn、Cr含量重度污染等级以上的分别占2.38%、2.38%、4.76%;潜在生态危害指数法评价表明,Cu、Zn、Cr含量处于轻微生态危害等级分别占97.62%、100%、100%,Cu含量2.38%处于强生态危害等级。内梅罗综合指数法评判表明,所有样点均已污染,其中达到轻度污染、中度污染、重度污染的样点分别占28.57%、42.86%、28.57%;而潜在生态危害指数法评价显示土壤样品点中97.62%处于轻微生态风险等级,根据悲观原则可以判断该段流域重金属污染均处于轻度污染以上。 相似文献
17.
长江沉积物环境地球化学特征及生态风险评价 总被引：1，自引：0，他引：1
为了进行长江流域沉积物生态风险评价,对长江流域干流以及主要支流的沉积物统一进行采样分析。首先对其元素的组成特征及重金属元素的富集特征进行分析。常量元素含量在流域空间上的变化主要受其携带矿物含量变化的影响;Cu、Pb、Cd、As、Hg 5种微量元素富集程度较大,存在异常。同时采用潜在生态风险指数法对长江沉积物Cr、Mn、Co、Ni、Cu、Zn、Pb、Cd、As、Hg 10种元素进行了评价研究。结果表明,潜在生态风险指数较大的地区分布在湖南湘江、安徽铜陵等地区,中等的地区分布在四川、重庆及江西等地区,这些潜在污染指数与矿产的开采冶炼以及工业的布局有一定的关系,很大程度上是由人为因素造成的。从元素的潜在污染程度看,长江流域Cd、As、Hg污染程度较重,Cu、Zn、Pb次之,而Cr、Mn、Co、Ni基本没有污染。本研究为探讨长江流域沉积地球化学过程和环境保护提供了科学依据。 相似文献
18.
Evaluation of the water resource reproducible ability on Tarim River Basin in south of Xinjiang,northwest China 总被引：1，自引：1，他引：0
With the over-exploitation of water resources, water pollution and poor management of water infrastructures are exacerbated.
Ecosystem degradation is apparent at the basin level. The Tarim River Basin in northwest China has seen intensive confrontation
between environmental protection and economic development over the past five decades. Ambitious agricultural development and
land reclamation projects implemented by the Chinese government in the early 1960s led to several influences. For example,
the construction of dams like the Daxihaizi Reservoir disrupted the stream-flow to the lower reaches. Water resource reproducible
ability (WRRA) refers to the ability of water resources to be continually added by the natural water cycle. It includes the
supplementation of water quantity and the self-purification of water quality in the natural cycle of water resources. This
study discusses the WRRA index and introduces the computational method for calculating the WRRA index for the Tarim River
Basin. The following conclusions are observed: (1) from 1956 to 2005, the indices of WRRA in the Hotan River Basin, Yarkand
and Aksu River Basin are 0.26, 0.55, 0.58, respectively, which are between 0 and 1. The results indicate that the hydrological
cycle in these three sub-basins is in a reproducible state. (2) The WRRA index in the Kaidu-Kong River Basin is 1.23 > 1,
which indicates that floods may occur in the Kaidu-Kong River Basin. (3) The index of WRRA in the main stream is 0, which
indicates that the WRRA is very weak at this location, and zero-flow may occur. Calculating the WRRA of a basin can provide
a basis for corresponding basin water resources management. 相似文献
19.
The Pecos River, situated in eastern New Mexico and western Texas, receives water from a drainage area of 91 000 km2. There are primarily two major water inputs, namely snowmelt from winter storms in the headwater region of the southern Rocky Mountains and runoff from warm-season monsoonal rainfall in the lower valley. The Pecos River suffers from high levels of total dissolved solids (TDS >5000 mg L−1) under normal flow conditions. This not only poses serious problems for agricultural irrigation and safe drinking water supply, but also results in a permanent loss of biodiversity. This study examines changes in stream flow and water chemistry of the Pecos River over the last 70 a to better understand the long-term variability in stream salinity and the role of agricultural practices in salt transfer. A TDS record from the lower Pecos River near Langtry (Texas) back to 1935 was extracted to show a distinct pattern of decadal variability similar to the Pacific Decadal Oscillation (PDO), in which stream salinity is overall above average when the PDO is in positive (warm) phase and below average when the PDO is in negative (cold) phase. This is due to: (1) the dissolved salts contributed to the river are largely from dissolution of NaCl and CaSO4-bearing minerals (e.g., halite and gypsum) in the upper basin, (2) the amount of the dissolved salts that reach the lower basin is mainly determined by the stream flow yield in the upper basin and (3) the stream flow yield from the upper basin is positively correlated with the PDO index. This further attests that large-scale climatic oscillation is the major source of long-term changes in stream flow and salinity of the Pecos River. On the other hand, there is also a strong indication that the rate of salt export has been affected by reservoir operations and water diversions for agricultural practices. 相似文献
20.
三峡库区澎溪河消落带土壤中重金属形态分布与迁移特征研究 总被引：2，自引：0，他引：2
消落带是水域与陆地的过渡地带,对水环境有着至关重要的影响。本文以三峡库区消落带面积最大的澎溪河流域作为研究区域,采集消落带土壤及其沿岸土壤样品,分析重金属形态分布特征,并使用地质累积指数法和风险评价准则(RAC)对重金属污染程度及生态风险进行评价。研究表明,消落带土壤中Pb、Cu、Cr、Cd、Zn和Ni平均含量分别为68.70、36.96、55.10、0.68、108.26、31.68 mg/kg,污染程度依次为CdPbZnCuNiCr,以Cd和Pb污染较为突出,普遍高于长江干流土壤,远高于重庆地区土壤。Cd的RAC值为20.62%,呈中等环境风险;其形态稳定性最差,以可还原态和酸提取态为主。Pb、Cu、Cr、Zn、Ni的RAC值为5.45%~10.0%,环境风险较低;且均以残渣态为主,占总量的54.69%~83.05%。以消落带沿岸土壤为对照,消落带形成后土壤中各重金属总量均有不同程度升高,且不同重金属在其增量部分的形态存在差异,Cr和Ni的增量部分以残渣态为主,Cd、Pb、Zn的增量以非残渣态为主。研究发现,由于受到水域与陆地污染源的双重影响,澎溪河流域重金属具有由沿岸向消落带沉积富集的趋势。 相似文献