天津市路面雨水径流重金属污染特征

对天津市3条典型主要交通干线雨水径流中的Cr、Cd、Fe、Cu、Hg 5种重金属进行了取样监测,重点探讨了路面径流重金属的平均质量浓度、冲洗特征、重金属之间以及重金属与悬浮物之间的相关关系,并用聚类分析方法对降雨特征对重金属污染的影响进行了研究。结果表明,天津市路面雨水径流重金属污染严重,Fe、Cr和Cd质量浓度较高,污染贡献率大,为径流主要重金属污染物;重金属污染水平高于国内外城市研究结果,反映出天津市在道路路面环境维护和管理上与其他城市的差距。路面径流的重金属具有明显的径流初期冲洗效应,在径流的初始阶段,重金属质量浓度达到最大值,随着降雨和径流的延续,污染物质量浓度呈波浪性锯齿状下降,至降雨结束,重金属质量浓度最终趋于稳定。径流中不同种类重金属具有同源性,且与径流中的悬浮固体具有明显的相互依存关系,重金属主要以悬浮固体吸附的形式或重金属颗粒形式存在。通过聚类分析可知,重金属污染受降雨强度和前期晴天积累影响显著,其次是降雨量和降雨历时。     

贵阳地区雨水化学与Sr同位素地球化学

对贵阳地区22个雨水样品的化学组成和Sr同位素的研究表明,贵阳地区大部分雨水样品的pH值小于56(pH=453).雨水中Ca2 是最主要的阳离子,平均值为57μmol·l-1(12—164μmol·l-1),占阳离子组成的64%—87%;Mg2 是次要的阳离子,平均值为13μmol·l-1(5—47μmol·l-1),Ca2 和Mg2 之和占了阳离子组成的78%—96%;K 平均值为11μmol·l-1(2—44μmol·l-1);Na 最少,其平均值为4μmol·l-1(1—8μmol·l-1).SO2-4是最主要的阴离子,平均值为94μmol·l-1(34—279μmol·l-1),占阴离子组成的28%—94%;NO-3是次要的阴离子,平均值为48μmol·l-1(1—252μmol·l-1),SO2-4和NO-3是决定雨水酸度最主要的离子,SO2-4和NO-3之和占阴离子组成的77%—99%;Cl-最少,平均值为20μmol·l-1(1—128μmol·l-1).贵阳地区雨水中Sr的浓度为002—033μmol·l-1,87Sr/86Sr比值较小(0707934—0709080),非海盐来源的87Sr/86Sr比值为0707820—0709078.元素比值及Sr同位素组成辨识出贵阳地区雨水溶质主要来源于人为活动,岩石/土壤化学风化次之,海相输入很小或可以忽略不计.     

城市旅游区暴雨径流污染过程中的不透水面效应

选取武汉市动物园4种典型的不透水面暴雨径流污染特征进行了系统的研究,以期为旅游区面源污染危害评价和治理提供基本的依据.结果表明,动物园4种不透水面初期径流污染物浓度很高,COD最大值达1140 mg/L,下垫面类型及地表累积污染物是影响径流水质的主要因素.通过无量纲累积曲线的分析,表明旅游区不透水面径流初期冲刷严重,该曲线还为面源治理提供了重要的工程参数.     

沸石-茭白复合床技术脱氮中试研究

通过模拟农村暴雨径流水质 ,开展了沸石 茭白复合床技术处理农村暴雨径流的中试研究 ,分析了在不同工况下床体中各态氮的变化规律 ,结果表明 ,该项技术应用于暴雨径流氮的控制是可行的。     

以雨水为核心的城市水环境构建思路

在研究国内外利用雨水构建城市水环境的文献基础上,得出城市水环境构建要空中层、地表层和地下层综合构建三位一体的指导思想,以雨水为核心的城市水环境构建的思路是：从易到难,分步骤进行构建。     

Calibration and Verification of SWMM for Low Impact Development

The Storm Water Management Model was used to simulate runoff and nutrient export from a low impact development (LID) watershed and a watershed using traditional runoff controls. Predictions were compared to observed values. Uncalibrated simulations underpredicted weekly runoff volume and average peak flow rates from the multiple subcatchment LID watershed by over 80%; the single subcatchment traditional watershed had better predictions. Saturated hydraulic conductivity, Manning's n for swales, and initial soil moisture deficit were sensitive parameters. After calibration, prediction of total weekly runoff volume for the LID and traditional watersheds improved to within 12 and 5% of observed values, respectively. For the validation period, predicted total weekly runoff volumes for the LID and traditional watersheds were within 6 and 2% of observed values, respectively. Water quality simulation was less successful, Nash–Sutcliffe coefficients >0.5 for both calibration and validation periods were only achieved for prediction of total nitrogen export from the LID watershed. Simulation of a 100‐year, 24‐h storm resulted in a runoff coefficient of 0.46 for the LID watershed and 0.59 for the traditional watershed. Results suggest either calibration is needed to improve predictions for LID watersheds or expanded look‐up tables for Green–Ampt infiltration parameter values that account for compaction of urban soil and antecedent conditions are needed.     

Decreased Runoff Response to Precipitation,Little Missouri River Basin,Northern Great Plains,USA

High variability in precipitation and streamflow in the semiarid northern Great Plains causes large uncertainty in water availability. This uncertainty is compounded by potential effects of future climate change. We examined historical variability in annual and growing season precipitation, temperature, and streamflow within the Little Missouri River Basin and identified differences in the runoff response to precipitation for the period 1976‐2012 compared to 1939‐1975 (n = 37 years in both cases). Computed mean values for the second half of the record showed little change (<5%) in annual or growing season precipitation, but average annual runoff at the basin outlet decreased by 22%, with 66% of the reduction in flow occurring during the growing season. Our results show a statistically significant (p < 0.10) 27% decrease in the annual runoff response to precipitation (runoff ratio). Surface‐water withdrawals for various uses appear to account for <12% of the reduction in average annual flow volume, and we found no published or reported evidence of substantial flow reduction caused by groundwater pumping in this basin. Results of our analysis suggest that increases in monthly average maximum and minimum temperatures, including >1°C increases in January through March, are the dominant driver of the observed decrease in runoff response to precipitation in the Little Missouri River Basin.     

西南地区水资源及其评价

西南是我国水资源最丰富的地区,但供需矛盾十分突出:旱灾频繁不少城市供水不足中小河流污染较重径流式电站出力显著下降内河航运不断萎缩。分析其原因,与水资源的特点和演变规律分不开。① 来水与用水不协调:坝区地多水少、山区水多地少城市和工业集中区水量偏小、偏僻地区来水偏大用水季节来水少、非用水季节来水多岩溶分布广泛,水资源利用困难。② 枯季径流不断减少:西南水资源70％以上分布在雨季。旱季水很少,且在不断下降。如不改变径流的分配方式,用水危机将会到来。③ 水质不断恶化:西南水质是好的。随着城市化的发展,农药化肥的大量使用,水质变差。重视保护、防止污染是重要的战略措施。④ 水资源的开发必须因地制宜,重视蓄水和跨流域调水的作用。     

暴雨径流对非常规水源补给城市河流水质冲击研究

选择北运河流域典型非常规水源补给城市河流(凉水河)为研究对象,阐述暴雨径流对非常规水源补给城市河流水体物理化学特征的影响.结果表明,非暴雨期间,凉水河水体p H和DO平均值分别为7.67和3.88 mg·L-1;耗氧物质COD和氨氮(NH+4-N)平均质量浓度分别为47.41 mg·L-1和8.39 mg·L-1;富营养化元素总氮(TN)和总磷(TP)平均质量浓度分别为16.34 mg·L-1和1.45 mg·L-1.暴雨期间,雨水径流汇入收纳水体后,COD、NH+4-N、TP平均质量浓度明显上升,最高值分别达到108、14.24、3.02 mg·L-1.在空间分布上,COD、NH+4-N、TN和TP质量浓度变化趋势随土地利用类型变化特征趋于一致,从城镇区至农村区,均呈逐渐上升趋势.