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基于国际法的跨境水分配关键指标及其特征 总被引：1，自引：1，他引：0
基于《国际淡水条约数据库》及1999 年以来相关跨境水资源利用与管理的研究成果,通过综合分析1864-2002 年49 个跨境水分配条约中的6 类28 项分水指标的区域与演进特征,判识跨境水分配的关键指标,结果表明：分水指标在实践中存在着明显的区域差异,在欧美发达地区的分水主要指标首先是维持最小水量,其次是多年平均水量,而亚非及南美洲欠发达地区则反之;少水区河流水分配的主要指标是多年平均水量和维持最小水量指标,而多水区河流则是维持最小水量和最大取用水量指标;从1864-2002 年分水条约签订的4 个历史时期上看,条约数量呈现少-多-较少-持平的变化趋势,条约的区域分布呈现出从欧美地区向亚非地区转移特征;主要分水指标从最早的维持最小水量和多年平均水量指标,演变到维持最小水量和最大取用水量指标,再到水利设施运行和多年平均水量,至最近的维持最小水量和多年平均水量指标,主要指标具有变化往复特点.综合跨境水分配条约中主要指标在不同时期及不同地区应用特征,可确定跨境水分配的关键指标为维持最小水量指标. 相似文献
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玛纳斯河泥沙特征概述 总被引：2，自引：0，他引：2
本文通过玛纳斯河的泥沙资料，分析了玛纳斯河泥沙的一般特性，并对玛纳斯河红山嘴水文站县移质泥沙和推移质泥沙与其它水文要素之间的关系作了论证。 相似文献
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本文在分析我国东部季风区不同自然带年径流与气侯因子关系的基础上,揭示了径流深随纬度和经度变化的规律,并对不同自然带中人类活动对河川径流的干预强度进行了比较,指出半干旱区是人类活动对径流影响最严重的地区,在这里应加强水资源的保护并大力推行各种节水措施。 相似文献
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人为季节性河流的初步研究 总被引：14，自引：3，他引：11
由于人类引水量的激增,我国北方的一些天然常流河频繁断流,已经成为季节性河流。文中提出了人为季节河的概念,在分析天然常流河与天然季节河的形成条件的基础上,查明了人为季节河形成的敏感带和在这种敏感带中,常流河向季节河转化的条件。 相似文献
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黄河中游流域环境要素对水沙变异的影响 总被引：15，自引：7，他引：15
目前 ,黄河中游地区流域的水沙变化主要以水文法和水保法研究为主。由于黄河中游具有明显的自然地带性分布特征 ,流域系统的水沙过程受到环境要素的综合影响。本文根据黄河中游河口镇至龙门区间已控一级支流的测站资料 ,采用地理环境要素法分析水沙变异及成因。研究表明 ,河龙区间流域径流量和输沙量与地理环境因子的影响密切相关。 2 0世纪 70年代以来 ,降雨减水减沙作用不断减小 ,随着水土保持措施的提高 ,人类活动减水减沙所占比重不断增大。 70年代与 80年代气候波动和人类活动影响的平均减水减沙作用分别为5 3 4 %、 2 8 6 %和 4 6 6 %、 71 4 %。 相似文献
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历史时期西北干旱区生态环境演变过程和演变阶段 总被引：13，自引：4，他引：9
在历史时期,西北干旱区的生态环境演变过程是绿洲化与沙漠化并存,人进沙退和沙进人退皆有。灌溉绿洲是通过人工水系(渠、库、井)、栽培植物和耕作土壤,逐步替代自然水系、自然植被和土壤形成的。沙漠化则是由于人类活动改变了水资源的地域分配,使河流中下游地表水减少,地下水位下降,植被衰败向发展扩大。在受人类干扰很少的自然水系情况下,本区生态处自然平衡;在较强干扰下的半自然水系时,生态平衡失调;在强烈干扰的人工水系时期,河流上游生态改善,下游急剧恶化。 相似文献
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Rivers in drylands typically are characterized by extreme flow variability, with long periods of little or no flow interspersed with occasional large, sometimes extreme, floods. Complete adjustment of river form and process is sometimes inhibited, resulting in a common assumption that equilibrium conditions may rarely, if ever, exist in dryland rivers, and that transient and unstable (nonequilibrium) behavior is the norm. Examples from the Channel Country and the Northern Plains in central Australia challenge that notion. Along the middle reaches of these intermediate and large, low-gradient rivers, where long duration floods generate moderate to low unit stream powers and boundary resistance is high as a result of indurated alluvial terraces, cohesive muds or riparian vegetation, there is evidence that: (1) channels have remained essentially stable despite large floods; (2) sediment transport discontinuities, while present at a catchment scale, are largely insignificant for channel form and process in individual reaches; (3) there are strong correlations between many channel form and process variables; and (4) many rivers appear to be adjusted to maximum sediment transport efficiency under conditions of low gradient, abundant within-channel vegetation and declining downstream discharge. In these middle reaches, rivers are characterized by equilibrium conditions. However, in the aggradational lower reaches of rivers on the Northern Plains, where upstream terraces are buried by younger sediments and channels are less confined, nonequilibrium conditions prevail. Here, channels sometimes undergo sudden and substantial changes in form during large floods, sediment transport discontinuities are readily apparent, and landforms such as splays remain out-of-balance with normal flows. Hence, dryland rivers can exhibit both equilibrium and nonequilibrium conditions, depending on factors such as catchment size, channel gradient, flood duration, unit stream power, channel confinement, sediment cohesion, and bank strength. [Key words: dryland rivers, floods, equilibrium, nonequilibrium, central Australia.] 相似文献
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水电开发对河流水沙变化的综合影响评价新方法(英文) 总被引：1，自引：1，他引：0
The environmental impact assessment (EIA) of cascade dams building in international rivers has been widely discussed in China and ASEAN countries since the 1990s. In Southwest China, all the great mountainous rivers have been the major state base for large-scale hydropower development. Among these rivers, the environmental change and response of the watercourse under the cascade dams building in the upper Mekong (called Lancang River in China) has been the focus in recent 20 years. In this paper, the Lancang River, which has over 25 years of large-scale hydropower development, was chosen as a case study for establishing the affected evaluation indicators system and its regression model of runoff and sediment, determining the indicators weight by the hierarchy analysis method and factor analysis method, and setting up the quantitative evaluation models of indicators affected level based on the "marginal efficiency" principle. Using these methods and model established, the influence degree of runoff and sediment in the Lancang River from 1986 to 2007 were assessed. The major results are: (1) the impact of sediment transport change by the cascade development is much higher than that of the runoff change; (2) the years’ number with different impact levels respectively are 72.7% as the "smallest" level, 18.2% as "smaller", and 9.1% as "general"; (3) the change process of runoff and sediment shows a "U-shaped" pattern, which indicates the balance of sediment change because of the interaction of sediment reduction by Manwan reservoir storage and the increase by the Dachaoshan dam construction. 相似文献
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60年来洞庭湖区进出湖径流特征分析 总被引：2，自引：0，他引：2
采用集中度与集中期、M-K趋势检验法、变差系数法等方法对洞庭湖入湖径流河流（荆江三口、湖南四水）和出湖径流（城陵矶）年径流量序列进行分析。结果显示：① 洞庭湖区径流集中期为每年6~7月份,最大径流出现时间为6月底7月初;径流集中期合成向量方向介于103.2~190.2°之间,均能够反映各河流进出湖径流量最大值出现的月份。② 径流变差系数介于0.194~0.761之间,说明径流年际变率大。各河流径流极值比均在0.6以上,径流量衰减较为明显。③ 从径流的丰枯交替规律来看,湖南四水水量分配相对较为平均。荆江三口以藕池口丰水年和枯水年概率最大,分别占到32.79%和57.38%,径流年际变化较为剧烈,不利于水资源的合理利用。 相似文献
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皇甫川流域降水量和人类活动对径流量变化影响的定量评估(英文) 总被引：6，自引：1，他引：5
The runoff of some rivers in the world especially in the arid and semi-arid areas has decreased remarkably with global or regional climate change and enhanced human activities.The runoff decrease in the arid and semi-arid areas of northern China has brought severe problems in livelihoods and ecology.To reveal the variation characteristics,trends of runoff and their influencing factors have been important scientific issues for drainage basin management.The objective of this study was to analyze the variation trends of the runoff and quantitatively assess the contributions of precipitation and human activities to the runoff change in the Huangfuchuan River Basin based on the measured data in 1960-2008.Two inflection points(turning years) of 1979 and 1998 for the accumulative runoff change,and one inflection point of 1979 for the accumulative precipitation change were identified using the methods of accumulative anomaly analysis.The linear relationships between year and accumulative runoff in 1960-1979,1980-1997 and 1998-2008 and between year and accumulative precipitation in 1960-1979 and 1980-2008 were fitted.A new method of slope change ratio of accumulative quantity(SCRAQ) was put forward and used in this study to calculate the contributions of different factors to the runoff change.Taking 1960-1979 as the base period,the contribution rate of the precipitation and human activities to the decreased runoff was 36.43% and 63.57% in 1980-1997,and 16.81% and 83.19% in 1998-2008,respectively.The results will play an important role in the drainage basin management.Moreover,the new method of SCRAQ can be applied in the quantitative evaluation of runoff change and impacts by different factors in the river basin of arid and semi-arid areas. 相似文献
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内流河流域水资源利用对径流年际年内变化影响的分析——以塔里木河流域为例 总被引：10，自引：1，他引：9
以塔里木河流域为例,探讨了干旱区内流河流域近40年来,由于人口增长、灌溉面积扩大、河流水资源引用程度日益增加等原因所引起的河流径流多年变化及年内变化等水文效应及其变化的原因。 相似文献
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皇甫川流域降水和人类活动对径流量变化的贡献率分析——累积量斜率变化率比较方法的提出及应用 总被引：19，自引：1，他引：18
随着全球或区域气候的变化,加上渐强的人类活动的影响,世界上一些河流的径流量发生了明显减小的变化趋势,这在干旱及半干旱地区的河流中尤其明显。在我国,北方干旱及半干旱地区河流的径流量的减小已经引起了严峻的生活及生态方面的问题。因此查明流域径流量的变化特征、趋势及分析其原因,是流域管理中面临的重要科学问题。该研究以黄河中游一级支流皇甫川流域为例,利用1960-2008 年的数据资料,采用累积距平方法、年际累积量方法,分析了该流域径流量和降水量的变化趋势,识别出径流量变化过程中1979 和1998 为其两个突变年份,而降水量变化过程中仅存在唯一的突变年份1979。利用统计分析法分别分析了1960-1979、1980-1997 和1998-2008 三个时期的累积径流量与年份之间的线性关系,以及1960-1979、1980-2008 两个时期累积降水量与年份之间的线性关系。采用本文提出的新的计算方法——累积量斜率变化率比较方法,以1960-1979 为基准期,在不考虑蒸散总量的影响时,计算得出皇甫川流域径流量减小的降水量和人类活动的相对贡献率在1980-1997 年间分别为36.43%和63.57%,在1998-2008 年间分别为16.81%和83.19%。该研究结果揭示了皇甫川流域近半个世纪以来径流量的变化趋势及其主要影响因素的贡献率,对于该流域未来水资源的开发利用具有重要指导作用。同时,所提出的定量研究方法可以应用在干旱—半干旱地区河流径流量变化及其影响因素的定量评估中。 相似文献
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将污水排放口污染物质的实测值与河流中同种物质的量，通过各河段推求的参数Ｋ１建立起数学关系，利用这种数学模型来预测和模拟河流各河段的各种污染物质量，这是当前流域水质管理和污染治理规划最经济适用的办法。 相似文献