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紫色丘陵区典型小流域暴雨径流氮磷迁移过程与通量   总被引:8,自引:1,他引:7  
对紫色丘陵区盐亭截流小流域2007年3次暴雨径流的全过程进行了连续监测,测定了径流量及降雨—径流过程中氮、磷的形态、浓度与通量变化。结果表明,N、P各形态浓度变化曲线与流量曲线趋势大致相同,总氮(TN)浓度迅速达到峰值后缓慢下降,而后期又略呈上升趋势,硝态氮(NN)浓度变化总体呈上升趋势,颗粒态氮(PN)与颗粒态磷(PP)浓度在径流过程中迅速达到峰值后陡然下降,氨态氮(AN)及磷酸盐(PO43-P)含量较低且波动较小。暴雨径流前期氮素迁移以PN为主,主要来源于地表径流,受降雨强度控制。后期以NN为主,来源于土壤硝酸盐随壤中流淋失。磷素主要以地表径流迁移的PP为主。暴雨径流导致的N、P流失负荷巨大,说明初期冲刷效应明显。  相似文献
2.
城市降雨径流污染初始冲刷效应对BMPs选择的启示   总被引:5,自引:1,他引:4  
指出城市降雨径流污染初始冲刷效应(FFE)在城市非点源污染的研究中占有重要地位。综述FFE的判定及大小定量化方法、季节性FFE的概念和污染物的相态对FFE的影响。FFE初中期雨水径流污染物浓度高的特性,为选择经济高效的最佳管理措施(BMPs)提供了理论依据和重要启示。结合FFE及冲刷过程中污染物的形态提出的工程BMPs,能使资源配置和污染控制效果达到最优化,为城市公共管理部门的决策和实践提供建议。  相似文献
3.
以新乡市城区屋面作为汇水区域,开展试验对雨水管网中场次降雨径流水文水质过程进行研究,可为有效利用城市雨水、控制非点源污染等提供依据。水质指标包括SS、COD和TN。结果表明:水质指标中SS、COD变化趋势基本一致,随着降雨过程的持续浓度逐渐降低并趋于一个稳定值;TN随着雨量的累积浓度逐渐降低,但在降雨结束前有反弹趋势;指标标准差率呈SS>COD>TN的趋势;径流初期屋面冲刷效应明显,初期径流量可定义为前1~3mm的降雨量;径流中SS与COD、TN之间的相关性较好,在控制径流污染时可采取措施同时去除;径流污染物直接通过城区排水管网汇入受纳水体后对其水质影响较大,尤以SS、COD的变化最为明显。  相似文献
4.
First flush of stormwater runoff plays an important role in water quality management. Since stormwater runoff during the initial period of precipitation events carries a greater portion of pollution loads, appropriate strategies are needed for effectively controlling the non-point source loads (NPS). In the present study, case studies were performed in two industrial parks for correlating the relationship between pollutant mass and the runoff volume. Three precipitation events were used for calibration and verification of a deterministic model, Storm Water Management Model. The model was then used to simulate all rainfall events in a particular hydrological year to determine the relationship between interceptive amounts of initial runoff and their corresponding reduced portion of annual NPS loads. The results indicate that the first 6–8 mm of a storm runoff depth includes more than 60% NPS loads. If the depth is increased to 10 mm, 80% NPS loading can be contained. The interceptive volume for eliminating 80% NPS loading in Guan-Tian and Yong-Kong industrial areas are 7 and 12 mm, respectively.  相似文献
5.
Communities throughout the United States are developing and implementing watershed management plans to address nonpoint sources of pollution and meet Total Maximum Daily Load (TMDL) requirements. Once a TMDL is established, a watershed management plan is developed and implemented to reduce contaminant sources and attain TMDL goals. Developing an effective TMDL and remediation plan should take into account fluctuation of pollution loadings and the timing of first-flush events. The objective of this study is to investigate the effect of hydrological conditions on microbial pollutant levels at a TMDL site during spring and summer storm events. A total of 64 water samples were collected from Sloan Creek in mid-Michigan in the spring/summer of 2015. All samples were analyzed to quantify concentrations of E. coli, bovine-associated Bacteroides (BoBac) gene markers, and human-associated Bacteroides (HuBac) gene markers. Discharge was the driving force of microbial contaminant loading in the studied water body. E. coli concentrations had significant strong correlation with precipitation and discharge, and BoBac concentrations were positively related to discharge. E. coli, BoBac and HuBac patterns suggested first-flush phenomena occurred during summer storms. E. coli permit exceedance rates increased from 31% before first-flush, to 100% during and after first-flush in the summer. The resulting information may help develop a plan for restoring impaired waters and establish the maximum amount of pollutants that the body of water can receive during different hydrological conditions.  相似文献
6.
Temporary streams expand and contract seasonally, forming a complex mosaic of aquatic, amphibic and terrestrial habitats. We studied the terrestrial arthropod fauna at the surface of the dry river bed as well as the fauna of Coarse Particulate Organic Matter (CPOM) deposits 0, 5 and 10 days after first flush events (years 2004–2006) along the Pardiela stream (SE Portugal). During the dry period, large amounts of organic material accumulated at the surface of the dry bed, colonized by abundant terrestrial arthropods (mean density: 13.3 ± 15.29 Ind g DM (Dry Mass of CPOM)). Arthropod density peaked in fresh flood deposits (mean density: 35.8 ± 33.4 Ind g DM), and subsequently decreased within time. Concurrently, the relative composition of the arthropod community changed from Day 0 to Day 10. The present results demonstrated that the dry bed of temporary streams served as a major habitat for terrestrial arthropods. During the first flush events, a mass dispersal of terrestrial arthropods, rafting on floating CPOM, occurred, subsequently forming distinct deposits along the channel margin. These deposits may constitute critical habitats, refugia and food resources for local and regional terrestrial arthropod assemblages. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献
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