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1.
A study on the distribution of Ephemeroptera, Plecoptera, Trichoptera and Odonata in relation of environmental interruptions was done at three different rivers tributaries of Bukit Merah Reservoir, Perak namely Sungai Jelai, Sungai Ara, and Sungai Kurau from October 2013 to January 2014. A total of 1 942 individuals were collected during the 4month of the study. The number of Ephemeroptera was highest, which was found at Sungai Jelai and Sungai Kurau and dominated by Baetis from family Baetidae while at Sungai Kurau dominated by Trichoptera, Hydropsyche from family Hydropsychidae. Ecological and biological indices have been used to evaluate the diversity of Ephemeroptera, Plecoptera, Trichoptera and Odonata at each river. The highest Simpson's diversity index(D=0.893) and Pielou's evenness index(E=0.803) were recorded at Sungai Jelai while Sungai Ara had the highest value of Margalef's richness index(MgR I=5.698). The variance for the assemblages of Ephemeroptera, Plecoptera, Trichoptera and Odonata influenced by9 chemical and physical variables was really a satisfactory with total variance explained of 57.2%. The results of canonical correspondence analysis(CCA) model showed that two groups of insects taxa characterized by water parameters.The first group from the CCA analysis clustered the Ephemeroptera, Plecoptera, Trichoptera and Odonata genera showed that deterioration in dissolved oxygen concentration, pH and nitrate while the second group showed dependence on total dissolved solids(TDS), conductivity, total suspended solid(TSS) and velocity. The study showed that the distribution of Ephemeroptera, Plecoptera, Trichoptera and Odonata taxa was affected by the environmental interruptions such as human residential area, agricultural plantation and river embankment.  相似文献   

2.
Forty middle and small rivers in three towns of Fengjing, Songjiang and Zhujiajiao of suburban Shanghai were chosen as sampling sites for water quality research. Measurement results of DO, CODCr, TP, TN and so on show that the rivers are under heavy eutropic conditions, which are several times greater than the critical values of the worst level (Type V) of water. Water pollution situation has different temporal and spatial characteristics. Non-point pollution, such as village domestic sewage, farmland runoff, livestock feces, has become the primary source of pollution of the middle and small rivers in suburban Shanghai.  相似文献   

3.
The study investigated the effect of urbanization, drought and pollution on the deterioration of water quality in the Tafila Basin in southern Jordan during the year 2000. Six representative springs were chosen, from which 84 water samples were analysed for their chemical and biological characteristics. In addition, 75 samples were analysed for their chemical characteristics during the period 1978–1999. The arid and semi-arid climatic characteristics, high population growth and the lack of sewer systems cause pollution. The infiltration of waste water from septic tanks into springs and ground-water resources is considered the most prominent cause. The primary evaluated parameters are EC, NO3, faecal coliform, total coliform and total count. Their concentration is accelerating, due to the increase of waste water in comparison to fresh water quantity. The fracture system associated with Upper Cretaceous carbonates allows the waste water to recharge the springs very quickly and without any purification. Connecting the scattered buildings with the Tafila Treatment Plant (TTP), built in 1988, will stop or decrease the pollution and allow the springs to refresh themselves. The TTP is under-loaded, and its effluent water can be used for irrigation.  相似文献   

4.
图们江地区水环境质量研究   总被引:7,自引:3,他引:7  
朱颜明  卢学强 《地理科学》1996,16(3):215-223
图们江地区5条河流18个断面水环境质量研究表明,本区地表水污染比较严重,大部分河流断面水质在Ⅳ、Ⅴ级水平,只有珲春河水质优于Ⅲ级,除布乐哈通河水质继续呈下降趋势外,其它河流污染水平基本得到了控制,河流污染物比较固定,主要是SS、COD、BOD、AR-OH、N-NHa。  相似文献   

5.
基于策勒绿洲78个取样点的地下水的观测资料,结合地理信息系统,运用地统计学方法和Sigmaplot10.0中的Piper模块,研究塔里木盆地南缘策勒绿洲区地下水TDS(Total Dissolved Solids)的时空变异,揭示地下水水化学特征及其演变的主要水化学过程。结果表明:①地下水TDS存在强烈的空间相关性,其空间相关距离为4.4 km,在步长为6 km范围之内,地下水TDS的空间变异是各向同性的,当步长大于6 km时,4个方向上的半变异函数发生了不同的变化;②绿洲南部区域为地下水TDS的低值区,最小值为551 mg·L-1,由南向北地下水TDS呈增加的趋势,在北部地下水埋深低值区的TDS最大值为7 192 mg·L-1;从地下水水流方向上看,即从绿洲西南的低值区向北,再转向东北区方向,地下水TDS逐渐增加,最大值为3 677 mg·L-1;③浅层地下水化学类型变化复杂,主要从Na-Ca—SO4-Cl-HCO3、Na-Ca—SO4-Cl型向Na—SO4-Cl-HCO3和Na—SO4-Cl型演化。  相似文献   

6.
Based on the synergetic development of new industrialization, rapid urbanization and agricultural modernization (IUAM), and from the viewpoint of interactive relationships between water resources and regional population, eco-environment, economy and society, the concepts of water resources intensity (WRI), water environment intensity (WEI), water resources relative efficiency (WRRE) and water environment relative efficiency (WERE) are defined with reference to energy intensity, resources efficiency and environment efficiency theory. On the basis of benchmarking theory, the quantitative characterization and evaluation method of “Three Red Lines” (the upper limit of water resources allocation, the baseline of utilization efficiency of water resources and the upper limit of sewage discharge) is proposed. According to these concepts and models, an empirical analysis of the Three Red Lines of water resources on the Chinese mainland between 2003 and 2012 was carried out. The results showed that total water consumption in eastern, central and western parts of China possesses “club convergence” characteristics, which means these areas have similar internal conditions appeared convergence in the development. Inter-provincial differences in water consumption continue to decrease, but the north–south differentiation characteristics in the eastern and central regions were still relatively obvious, while provincial differences in the eastern part were at a minimum and the central region had the largest. Water Resources Efficiency (WRE) of all four sectors in the Southwest rivers and Huaihe River basins were generally high. Industrial WRRE in the Songhua River, Yangtze River and Pearl River basins, agricultural WRRE in the Songhua River, Yellow River and northwestern river basins and domestic WRRE in the Liaohe River, Yangtze River and Pearl River basins were all low. Eco-environmental WRRE in the southeastern rivers and Yangtze River basins were low but showed an upward trend. Other river basins, except for the Northwestern rivers basin, had high eco-environmental WRRE with a downward trend. Western China, especially the northwestern part, had a low relative intensity of the water environment (WERI) and high integrated water environment management (IWEM) performance, but the relative intensities of the water resources (WRRI) were fairly high, and the comprehensive performance of integrated water resources management (IWRM) in these regions was low. In southern China, especially the southeastern part, the IWEM was fairly high, but the overall IWRM was lower.  相似文献   

7.
生化需氧量(BOD)测定方法进展   总被引:2,自引:0,他引:2       下载免费PDF全文
生化需氧量(BOD)是水质监测中最重要的指标之一。分析论述了BOD的传统测定方法、快速测定方法及在线分析检测仪器的发展,论述了各类方法的工作原理及各自的适用范围和局限性。  相似文献   

8.
1 Introduction Recently, some important international institutions, like the World Bank (WB) and the Asian Development Bank, have pointed out that there will exist water crises, water conflicts, and even water wars in the 21st century. The equitable utilisation and co-ordinated management of the shared freshwater resources in international watercourses (sharing rivers, lakes, and underground water layers) were particularly emphasised and are turning out to be the international hot point an…  相似文献   

9.
塔里木河中游典型绿洲盐渍化土壤的反射光谱特征   总被引:2,自引:0,他引:2  
研究盐渍化土壤的光谱特性是利用遥感技术实现在区域尺度上进行土壤盐渍化监测和评价的工作基础, 是建立地面数据和遥感数据关系的桥梁。本文以塔里木河中游典型绿洲--渭干河-库车河三角洲绿洲为研究对象, 采用光谱学技术以及多元统计相结合的方法, 研究干旱区典型绿洲盐渍化土壤的反射光谱特征。首先, 对光谱数据进行预处理(去噪、剔除水分吸收波段), 以便消除仪器本身噪声及外界条件的影响, 并且计算了部分盐渍地样本的光谱吸收特征参数, 说明相同程度的盐渍化土壤具有相似的吸收特征;其次, 研究盐渍化土壤的反射光谱与盐分因子(八大离子、电导率(EC)、含盐量(salt content)、pH、总溶解固体(TDS)等) 之间的关系, 并选择具有代表性的盐分因子与野外实测光谱数据建立定量回归模型, 通过多元线性回归分析得出含盐量、SO42-、TDS、EC与原始光谱数据的相关性分别是0.746、0.908、0.798 和0.933, 达到了理想的效果。本研究对于干旱区典型绿洲盐渍土的光谱特征研究有着重要指示意义, 为发展和完善中国盐渍土理化特征的可见光-近红外反射光谱分析理论奠定科学积累, 并进一步为干旱区土壤盐渍化、沙漠化灾害等环境恶化问题的解决提供新的科学技术手段。  相似文献   

10.
张嘉欣  朱秉启 《地理研究》2022,41(5):1437-1458
流域尺度上的水化学组成特征和来源会受到何种因素的影响和限制,是研究区乃至全球环境变化的焦点问题,需要综合考虑不同地表要素和环境下的天然水体来揭示其答案。本文选择北疆地区的三大水系(伊犁水系、准噶尔水系、额尔齐斯水系)开展水化学组成研究,以期认识中亚造山带中部干旱环境下典型水系的水化学组成特征、成因及其影响因素。本研究利用已采集的北疆三大水系天然水样品及其水化学组成分析数据,同时系统收集了北疆及其周边地区文献资料,并与其他中纬度地区和国际典型气候带地区进行了综合对比。综合数据分析结果表明,北疆水系的河流溶解性固体总浓度(TDS值)普遍高于中国季风区和湿润地区河流,也高于世界平均水平;水体的主要阴阳离子分别以Ca2+和HCO3-占主导地位;主量离子间相对浓度与中国东部季风区河流类似,也与世界大部分以碳酸盐岩风化为主导的河流相似。岩石风化作用在水化学成因上对北疆大部分地区都占据主导地位;进一步定量的结果发现,不同来源对天然水溶质贡献量大小的顺序为:蒸发岩溶解>碳酸盐岩风化>硅酸盐岩风化>大气降水,证明了蒸发岩溶解和碳酸盐岩风化的主导地位。对比硅酸盐岩风化与碳酸盐岩风化,北疆水系的中低地形区硅酸盐岩影响更大,海拔较高的山地地区则碳酸盐岩影响更大。区域降水、水热组合、径流、岩性等因素都对水化学过程产生重要的影响,但与温度的关系不明显,与流域物理侵蚀过程及其季节变化等的关系尚不明确,需要开展进一步的研究工作。  相似文献   

11.
利用Google Earth Engine遥感大数据云平台,以若尔盖县的弯曲河流为研究对象,以空间分辨率为10 m的Sentinel-2多光谱卫星遥感影像为数据源,选用归一化差分水体指数(NDWI)、改进型归一化差分水体指数(MNDWI)和自动水体提取指数(AWEI)相组合的方式,建立支持向量机模型,进行弯曲河流信息的提取;利用归一化差分水体指数、改进型归一化差分水体指数和自动水体提取指数,提取出弯曲河流信息,并与支持向量机模型提取的结果进行了比较。研究结果表明,利用归一化差分水体指数提取的弯曲河流的整体性和连续性最优;利用改进型归一化差分水体指数提取的地势复杂区域细小河流的精度较高;利用支持向量机模型提取的弯曲河流更为准确,并消除了山体和植物阴影对弯曲河流提取的影响;与利用3种指数提取的结果相比,支持向量机模型提取的弯曲河流的总体精度和用户精度都相对最高。  相似文献   

12.
Downstream hydrologic and geomorphic effects of large dams on American rivers   总被引:12,自引:4,他引:12  
William L. Graf   《Geomorphology》2006,79(3-4):336
The hydrology and geomorphology of large rivers in America reflect the pervasive influence of an extensive water control infrastructure including more than 75,000 dams. One hundred thirty-seven of the very large dams, each storing 1.2 km3 (106 acre feet) of water or more, alter the flows of every large river in the country. The hydrologic effects of these very large dams emerge from an analysis of the stream gage records of 72 river reaches organized into 36 pairs. One member of each pair is an unregulated reach above a dam, whereas the other is a regulated reach downstream from the same structure. Comparison of the regulated and unregulated reaches shows that very large dams, on average, reduce annual peak discharges 67% (in some individual cases up to 90%), decrease the ratio of annual maximum/mean flow 60%, decrease the range of daily discharges 64%, increase the number of reversals in discharge by 34%, and reduce the daily rates of ramping as much as 60%. Dams alter the timing of high and low flows and change the timing of the yearly maximum and minimum flows, in some cases by as much as half a year. Regional variation in rivers, dams, and responses are substantial: rivers in the Great Plains and Ozark/Ouachita regions have annual maximum/mean flow ratios that are 7 times greater than ratios for rivers in the Pacific Northwest. At the same time, the ratio of storage capacity/mean annual water yield for dams is greatest for Interior Western, Ozark/Ouachita and Great Plains rivers and least for Pacific Northwest streams. Thus, in many cases those rivers with the highest annual variability have the greatest potential impact from dams because structures can exert substantial control over downstream hydrology. The hydrologic changes by dams have fostered dramatic geomorphic differences between regulated and unregulated reaches. When compared to similar unregulated reaches, regulated reaches have 32% larger low flow channels, 50% smaller high flow channels, 79% less active flood plain area, and 3.6 times more inactive flood plain area. Dams also affect the area of active areas, the functional surfaces that are functionally connected to the present regime of the river. Regulated reaches have active areas that are 72 smaller than the active areas of similar unregulated reaches. The geomorphic complexity (number of separate functional surfaces per unit of channel length) is 37% less in regulated reaches. Reductions in the size of hydrologically active functional surfaces are greatest in rivers in the Great Plains and least in Eastern streams. The largest differences in geomorphic complexity are in interior western rivers. The shrunken, simplified geomorphology of regulated large rivers has had direct effects on riparian ecology, producing spatially smaller, less diverse riparian ecosystems compared to the larger, more complex ecosystems along unregulated reaches of rivers.  相似文献   

13.
额济纳盆地浅层地下水演化特征与滞留时间研究   总被引:2,自引:1,他引:1  
以地球化学和氚(3H)同位素测年技术相结合,通过额济纳盆地地下水、地表水地球化学及同位素的研究,探讨中国西北干旱区内陆河流域下游盆地地下水地球化学演化规律和平均滞留年龄.额济纳盆地浅层地下水状况主要受地表水补给状况的影响,离河道近的水样矿化度低;而离河道较远的戈壁区,地下水矿化度高.水体化学成分主要受岩盐、石膏、白云石等矿物的溶解及蒸发作用的影响.通过利用指数-活塞模型流模型(EPM),计算出额济纳浅层地下水年龄在13~58年之间.  相似文献   

14.
河湖水系连通特征及其利弊   总被引:9,自引:0,他引:9  
随着水资源以及水环境健康的恶化,河湖水系连通性作为河流健康以及提高水资源利用的一个重要指标在国家"十二五"战略规划中被着重提出。目前,中国对河湖水系连通特征及其对河流健康的影响缺乏足够的认识,本文主要对河湖水系连通的定义、分类、评判指标、影响因素及其对水环境健康的影响进行了一一阐述。分析表明:维持水系连通可以明显地改善...  相似文献   

15.
Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various dynamic flows and ecological functions of river-lake interconnected relationships. We then propose a novel method for the health assessment of river systems based on interconnected water system networks. In a healthy river system there is “material and energy exchange” and it is the first and foremost relationship of material and energy exchange between rivers and lakes. There are unobstructed various “flows” between rivers and lakes including material flows (water, dissolved substances, sediments, organisms and contaminants), energy flows (water levels, flow and flow velocity), information flows (information generated with water flows, organisms and human activities) and value flows (shipping, power generation, drinking and irrigation). Under the influences of nature and human activity, various flows are connected by river-lake interconnection to carry material and energy exchange between rivers and lakes to achieve river-lake interactions. The material and energy exchange between rivers and lakes become one of the approaches and the direct driving forces of changes in river-lake interconnected relationships. The benignant changes in river-lake interconnected relationship tend to be in relatively steady state and in ideal dynamic balance.  相似文献   

16.
南翼山油田卤水以高钙富锂等元素为特征,是柴达木盆地研究程度较高的油田卤水之一。本文根据南翼山构造区及其周边地区油田卤水、盐湖卤水、河水和潜水等不同水体的水化学及岩层的地球化学和矿物特征,研究了湖水的蒸发浓缩对Li+的富集作用,探讨了水岩反应对油田卤水Li+含量和δ7Li的影响。结果表明,埋藏之前的蒸发浓缩是Li+含量和总固溶物增大的主要原因;水岩反应对Li+含量和δ7Li有影响,但不会引起明显变化。南翼山油田卤水主要来源于古盐湖卤水,演化过程中曾受到水岩反应的影响。  相似文献   

17.
宁南地区地表特征参数及辐射平衡区域分布   总被引:1,自引:0,他引:1  
郭建茂  于强  王连喜  陆维松 《地理研究》2007,26(6):1127-1136
本文利用2001年6月30日LANDSAT-7 ETM+卫星遥感资料和宁夏南部及周边区域22个气象站气象观测资料,求得地表特征参数中NDVI、地表反射率、地表温度和地表辐射平衡各量中地表短波吸收辐射、地表长波辐射区域、大气逆辐射、净辐射的区域分布和分布直方图,将地表分成5类,分类别讨论了其各量分布特征。主要研究结果表明:地表特征参数及地表辐射平衡各量的分布均呈现明显的地带性,各区域分布图上山体、水体的轮廓很显著,主要原因是山上及河流附近生长着茂密的植被,说明植被的分布在相当程度上影响了辐射平衡各量和地表特征参数的分布。  相似文献   

18.
Previous studies have shown chironomids to be excellent indicators of environmental change and training sets have been developed in order to allow these changes to be reconstructed quantitatively from subfossil sequences. Here we present the results of an investigation into the relationships between surface sediment subfossil chironomid distribution and lake environmental variables from 42 lakes on the Tibetan Plateau. Canonical correspondence analysis (CCA) revealed that of the 11 measured environmental variables, salinity (measured as total dissolved solids TDS) was most important, accounting for 10.5% of the variance in the chironomid data. This variable was significant enough to allow the development of quantitative inference models. A range of TDS inference models were developed using Weighted Averaging (WA), Partial Least Squares (PLS), Weighted Averaging–Partial Least Squares (WA–PLS), Maximum Likelihood (ML), Modern Analogues Technique (MAT) and Modern Analogues Techniques weighted by similarity (WMAT). Evaluation of the site data indicated that four lakes were major outliers, and after omitting these from the training set the models produced jack-knifed coefficients of determination (r 2) between 0.60 and 0.80, and root-mean-squared errors of prediction (RMSEP) between 0.29 and 0.44 log10 TDS. The best performing model was the two-component WA–PLS model with r 2 jack = 0.80 and RMSEPjack = 0.29 log10 TDS. The model results were similar to other chironomid-salinity models developed in different regions, and they also showed similar ecological groupings along the salinity gradient with respect to freshwater/salinity thresholds and community diversity. These results therefore indicate that similar processes may be controlling chironomid distribution across salinity gradients irrespective of biogeographical constraints. The performance of the transfer functions illustrates that chironomid assemblages from the Tibetan Plateau lakes are clearly sensitive indicators of salinity. The models will therefore allow the quantification of long-term records of past water salinity for lacustrine sites across the Tibetan Plateau, which has important implications for future hydrological research in the region.  相似文献   

19.
天水及其南北地区地热水水化学特征及起源   总被引:1,自引:0,他引:1  
运用水化学和同位素示踪的原理追溯地热水的水岩相互作用和起源,得出武山和天水地热水为pH较高(7.94~9.06)的低TDS(226~255 mg/L)HCO3型水,通渭和清水地热水为pH较低(7.1~8.07)的较高TDS(915~1 793 mg/L)SO4型水,地热水的水化学特征主要受不同的围岩及与围岩相互作用的程度所控制。地热水的δD和δ18O值说明地热水起源于大气降水,且未受水-岩同位素交换明显影响。综合应用各种地热温标,估算地热水的热储温度为70~111℃,属于中低温地热资源。对年均降雨量约500 mm的天水及其南北地区,应采取采、停交替的地热水利用方式。  相似文献   

20.
Transboundary rivers have important geopolitical and geo-economic connotations, but riparian states of transboundary rivers are often driven by their own rapid population growth and economic development to be-come involved in regional conflicts about the development and use of water resources. Therefore, finding a balance between the need for fair and reasonable development of water resources and the effective protection of environment from an ecological perspective has become a major problem faced by the international community. This paper begins with consideration of international water laws related to transboundary rivers and then reviews advances in the research on benefit-sharing, ecological compensation mechanisms, and adaptive management systems. We believe that existing international water laws form a complete legal system and that more attention needs to be paid to transboundary cooperation and sustainable water resource use. With respect to how transboundary water conflicts are resolved, there is a trend to move away from single water resource allocation (a zero-sum game) to benefit-sharing in order to achieve a win-win situation for riparian states, but there are still some difficulties in transboundary ecological compensation. In China, the central government has paid attention to horizontal ecological compensation between upstream and downstream, offering guidance to promote establishment of inter-province ecological compensation. Based on existing practice, horizontal ecological compensations are still in their infancy, small in scale, supported by a weak legal system, lacking market mechanisms to encourage their use and relying on fiscal transfers as the method of payment. In the future, China will need to intensify its research on legal system development, international cooperation, and benefit-sharing as these impact transboundary water resources. Because government can be seen as a management department with multiple identities (enabler, regulator and buyer), to improve adaptive transboundary ecological compensation mechanisms, government must develop as soon as possible data sharing platforms, standards of water consumption behaviors and intergovernmental policies (or ordinances).  相似文献   

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