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1.
Theoretical relationships between first flush of roof runoff and influencing factors 总被引：1，自引：0，他引：1
Considering the short length of building roofs, a theoretical analysis of the first flush of roof runoff was conducted based on the kinematic wave and pollutant erosion equations. This mathematical derivation with analytical solutions predicts pollutant mass first flush （MFF）, mean concentration of initial runoff （MCIF）, mean concentration of roof runoff （MCRR） with diversion of initial portion and residual mass available on the bed surface （RS） after the entire runoff under the condition of constant excess rainfall. And the effects of the associated influencing factors （roof length, roof gradient, roof surface roughness, rainfall intensity, rainfall duration, and erosion coefficients） on them were discussed while the values of parameters referred to the previous studies. The results showed that for roofs whose length is shorter than 20 m, both the increase in roof length and roof gradient and the decrease in roof surface roughness result in larger MFF and MCIF and smaller MCRR and RS, which is beneficial to water reuse and pollution reduction. The theoretical relationship between the first flush and the influencing factors may aid the planning and design of roof in terms of rainwater utilization or diffuse pollution control. 相似文献
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为评估降雨路面径流汞(Hg)污染状况,对南京绕城高速公路马群段11场降雨路面径流进行了监测,分析了汞(Hg)的事件平均浓度(EMC)以及降雨特性对径流中Hg污染的影响.结果表明,不同赋存状态的Hg的污染程度均较为严重,总Hg(THg)、溶解态汞(HgD)和颗粒态汞(HgP)含量分别为0.173~3.347,0.069~0.862和0.104~2.485μg/L.THg的EMC超过了中国《地表水环境质量标准(GB 3838—2002)》中5类水的限值.雨水径流中Hg主要以颗粒态存在,络合态Hg(Hgre,0.250~2.821μg/L)的含量远大于挥发性Hg(Hg0,0.023~0.215μg/L)和活性Hg(Hg2+,0.026~0.359μg/L).各种降雨特性对径流中Hg污染的影响顺序为前期晴天数径流时间降雨历时降雨强度降雨量. 相似文献
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南方丘陵地区降雨径流和泥沙输出特征 总被引：1，自引：0，他引：1
张玉珍 《福建工程学院学报》2006,4(3):323-326
在南方丘陵地区选择了2个小流域。进行野外9场降雨事件径流量、泥沙量随时问变化的试验。结果表明：受季节差异影响，不同月份径流量差异明显；低强度的降雨，当降雨过程停止后，径流流量反而有增大的趋势，强度较大的降雨。在中间时段降雨停止后。径流流量仍保持在一个稳定的值；在连续的低强度降雨后土壤含水量已经接近饱和，当遇到大强度的降雨后，地表径流在径流中所占比例较大；降雨量与悬浮泥沙含量相关程度较高。最大悬浮泥沙含量出现时间明显落后于径流流量出现峰值的时间。下降幅度要比径流流量下降幅度大。 相似文献
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华南地区城市道路径流污染特性:以深圳市为例(英文) 总被引：1，自引：0，他引：1
为了解析华南地区道路径流污染特性及其影响因素,对华南地区典型城市深圳市道路进行了4场降雨的径流样品采集及分析.结果显示道路径流水质劣于地表水4类环境质量标准,说明道路径流已经成为影响城市水环境质量的重要威胁.同时研究发现初期冲刷效应受到降雨类型和污染物种类的双重影响,因此在针对道路径流处理设施特别是初雨截流装置的设计时,需要同时考虑降雨类型与污染物种类.另外,建议华南地区的初雨截流量为3~5 mm的初期降雨.这些研究结果能为有效的道路径流处理设施设计提供有用的建议. 相似文献
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Phosphorus transport with runoff of simulated rainfall from purple-soil cropland of different surface conditions 总被引：5，自引：0，他引：5
We investigated the patterns of phosphorus transport from purple-soil cropland of 5° and 10° slopes with bare and vegetated surfaces, respectively. Each type of land was tested under a simulated moderate rainfall of 0.33 mm/min, a downfall of 0.90 mm/min, and a rainstorm of 1.86 mm/min. Runoff dynamics and changes in the export amount of phosphorus are influenced by the rainfall intensity, the slope and surface conditions of cropland. The vegetation diverts rain water from the surface into soil and helps the formation of a subsurface runoff, but has little influence on runoff process at the same sloping degree. Vegetated soil has a smaller phosphorous loss, particularly much less in the particulate form. A heavier rainfall flushes away more phosphorous. Rainwater percolating soil carries more dissolved phosphorous than particulate phosphorous. Understanding the patterns of phosphorous transport under various conditions from purple soil in the middle of Sichuan basin is helpful for developing countermeasures against non-point-source pollution resulting in the eutrophication of water bodies in this region that could, if not controlled properly, deteriorate the water quality of the Three Gorges Reservoir. 相似文献
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为了探讨雨水水质对雨水利用工程的影响,以沈阳市浑南新区的雨水水质为研究对象,对单体建筑屋面、小区径流及市政排出口的雨水进行为期一年的检测与分析.研究结果表明,影响雨水水质的主要污染物是COD和SS,特别是在降雨初期比较明显,随着降雨时间的延续,水质逐渐好转.市政排出口雨水COD和SS的含量最高,变化范围分别为167~249,119~332 mg/L,小区径流雨水COD和SS的变化范围分别为27~85和106~269 mg/L,建筑屋面雨水COD和SS的变化范围分别为15~80和50~153 mg/L.3个取样点的氨氮含量分别为1.7~5.2,3.7~18.2和5.2~25.6 mg/L. 相似文献
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为了实现屋面雨水利用系统量化评估中径流系数的精确取值,通过连续3年(2010—2012年)对河北省邯郸市不同屋面类型(屋面坡度和材料)及降雨特征(降雨深度和强度)的屋面径流进行实地监测,得到了各场实际降雨屋面径流系数的不同取值.研究结果表明,屋面径流系数的取值分布与各降雨事件的降雨深度相关性较强,其他影响因素对其影响较小.场次径流系数的取值与降雨深度呈显著的分段线性关系.根据1960—2008年的日降雨数据资料,计算得出邯郸市年均屋面径流系数可近似按照0.62这一常数进行取值.该研究成果可用于屋面雨水利用系统的量化评估及运行分析. 相似文献
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本文以城市住宅小区为例,基于DEM提取的小区水文信息,设计了小区降雨入渗条件的调控模型及实施方案,并结合现有条件计算了同等暴雨强度下的实际径流量和可调控径流量。计算结果表明,如果能按照本文提出的小区降雨入渗条件调控模型,将小区径流系数从现在的0.85调控至0.30,调控前后在相同降雨历时,相同降雨总量的情况下,径流量将相应减少554093.88升。 相似文献
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江淼华 《广西大学梧州分校学报》2010,(1):7-11
该文运用坡面径流小区法研究闽北裸露坡地水土流失与降雨量的关系。研究结果表明：径流量与降雨量呈极显著线性相关（P〈0．01）,径流量随降雨量增加而增大,拟合方程为y=-6．1447＋0．5125x;降雨量是引起土壤流失量的关键因素之一,降雨量与土壤流失量的关系与土地利用方式、人为干扰、降雨强度、降雨历时、前期降雨和下垫面性质等多种因素有关：土壤流失量受环境因素的影响远比径流量更为复杂。 相似文献
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在广州城市快速路代表性路段选择3个监测点开展路面径流监测．结果表明,广州城市快速路路面径流悬浮固体、化学需氧量和石油类等污染物浓度较高,氮、磷营养盐浓度较低;不同监测点路面径流污染浓度差异较大,主要受降雨特征、日交通量和道路周边土地利用等因素的影响．路面径流中的石油类、化学需氧量、五日化学需氧量、总氮、总磷、铅和锌等污柒物已超过我国地表水环境质量标准Ⅲ类标准限值,若不经处理直接排入地表水,则可能造成受纳水体的水质污染．城市快速路道路旁径流排水口附近的土壤已明显受路面径流污染的影响,表层土壤有碱化、养分含量增加和重金属积累的趋势,路面径流污染给道路沿线土壤带来潜在的土壤理化性质不平衡和重金属污染的威胁． 相似文献
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闽北不同土地利用方式水土流失与降雨量的关系研究 总被引：1，自引：0，他引：1
运用径流小区法研究了闽北不同土地利用方式水土流失与降雨量的关系.结果表明：相同降雨类型下不同土地利用方式的水土流失量具有很大差异.裸露地（对照）小雨时也可能产生水土流失,而大雨以上降雨会产生严重水土流失;具有一定植被覆盖且采取水土保持措施的果园和锥栗林的径流量和泥沙量大幅度减少;而植被覆盖良好的杉木林即使大雨以上降雨也仅产生极轻微的水土流失.降雨量与径流量均呈极显著线性相关,降雨量越大,径流量越大;而降雨量与土壤流失量的相关性明显小于降雨量与径流量的相关性,影响土壤流失量的因素比径流量复杂. 相似文献
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改革开放以来,有关我国城市社区体育的研究大多关注城市社区体育现状、对策以及发展模式等应用性问题,对社区体育基本理论问题的探讨还不够深入,还未形成符合我国国情的社区体育理论体系,原创性、有影响的研究成果不多。 相似文献
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利用2007年中国城市社会经济统计资料对中国241个地级及以上城市的建成区绿地面积进行分析。结果显示:①建成区绿化覆盖率分布走向由东南至西北逐渐降低,该分布情况与我国的城市化程度、经济发展及人口密度分布方向基本一致。②建成区绿化覆盖面积与建成区土地面积、地区生产总值和人口数量呈正相关,以建成区绿化覆盖面积受建成区土地面积影响最大,地区总产值次之。 相似文献
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大湖口水文站枯水流量小,枯季径流占全年径流的比重一般小于5％。为了解决枯季测验和整编难的问题,在对多年资料进行分析论证的基础上,提出了在控制年径流总量的前提下,对枯季流量进行监测与停测,采用多年单值化综合线进行整编的构想,对水文巡测进行了有益探索。 相似文献
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为提高城市绿道的雨洪调节功能,在文献研究和案例分析基础上,首先对城市绿道与低影响开发、绿色雨水基础设施的关系进行了分析.然后,提出了基于雨洪调节功能的城市绿道分类系统,总结适用于不同类型绿道的雨洪控制利用技术措施.结合中国城市规划体系,提出了与城市排水系统相结合的绿道规划方法,以及绿道雨水系统和单项雨水设施的设计方法,探讨了绿道雨水系统在入流、竖向、溢流等方面与其他系统的衔接关系.最后,介绍了上述规划设计方法在嘉兴滨水绿道和道路绿道示范项目中的应用,结果表明雨洪控制利用系统对年径流总量和年均污染物总量(TSS)的削减率分别不低于30%和40%. 相似文献
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屋顶绿化能充分利用城市空间,增加城市的绿化面积,改善城市的生态环境,已成为城市园林绿化的重要组成部分。通过分析屋顶绿化的发展历史、植物选择、种植基质、建筑施工要素及植物的养护管理,发现在政策、技术和资金等许多方面都还存在一些问题,应在吸收发达国家屋顶绿化成功经验的基础上,根据国情和地方实际,制定和完善相应的法律法规,并从政府、开发商和户主三方筹集建没资金,还应加强屋顶绿化专门人才的培养,在高等和中职业院校涉及建筑、园林等方向的专业开设相关的专业课程,才能使我国的屋顶绿化起到应有的作用。 相似文献
18.
The impacts of rainfall direction on the degree of hydrological response to rainfall properties were investigated using comparative rainfall-runoff experiments on a small-scale slope (4 m×1 m), as well as canonical correlation analysis (CCA). The results of the CCA, based on the observed data showed that, under conditions of both upstream and downstream rainfall movements, the hydrological process can be divided into instantaneous and cumulative responses, for which the driving forces are rainfall intensity and total rainfall, and coupling with splash erosion and wash erosion, respectively. The response of peak runoff (P r) to intensity-dominated rainfall action appeared to be the most significant, and also runoff (R) to rainfall-dominated action, both for upstream- and downstream-moving conditions. Furthermore, the responses of sediment erosion in downstream-moving condition were more significant than those in upstream-moving condition. This study indicated that a CCA between rainfall and hydrological characteristics is effective for further exploring the rainfall-runoff-erosion mechanism under conditions of moving rainfall, especially for the downstream movement condition. 相似文献
19.
Characterization of suspended solids and particle-bound heavy metals in a first flush of highway runoff 总被引：1，自引：0，他引：1
To investigate the dynamic characteristics of total suspended solids （TSS） and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound heavy metals, such as Zn, Pb, and Cu. Results show that the wash offbehavior of TSS under varying runoffrate condition can be explained by different antecedent dry weather period （ADWP）. Contribution of fine fraction （〈45 μm） to TSS was generally higher than that of coarse fraction （〉45 μm）. When the runoff flow increased obviously, a significant contribution of the coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more significant compared with that in the fine fraction. The results will assist in the development of effective control strategies to minimize heavy metals and solids in highway runoff. 相似文献
20.
陕西省渭河流域水沙变化分析 总被引：3，自引：0，他引：3
从流域概况、降雨、径流、输沙等方面,对90年代以来渭河降水减少、人类活动影响以及入境水量减少等因素的统计分析,提出了渭河流域水沙变化的特性及影响水沙减少的因素. 相似文献