青岛环胶州湾地区暴雨特征及暴雨灾害风险分析

通过37年(1971-2007年)的气候资料分析了青岛地区暴雨气候特征和暴雨发生概率及重现期分布特征。基于暴雨是对青岛地区城市建设和发展影响较大的气象灾害,结合1984-2007年的暴雨灾情普查资料,进行了暴雨气象风险评估。总的看来,青岛环湾地区暴雨灾害风险最高的地区在崂山区、胶南市和市北区。     

基于SCS法模拟的上海郊区农田地表产流特征及原因

利用上海市近8 a的日降雨数据,采用修正的SCS模型模拟得出上海地区农田地表径流流量,分析出了上海地区农田地表产流的特征。主要结论：（1）旱地在土壤湿度为干燥、几乎饱和、饱和条件下产生地表径流临界降雨量分别为847、358、141 mm;水田的土壤湿度几乎一直为饱和状态,产生地表径流的降雨临界值为026 mm。（2）旱地和水田产流量分布形状都呈极度右偏状,旱地和水田产流最大值分别为13559和18570 mm,但是9811%的天数中旱地产流量小于10 mm,9540%的天数中水田产流量小于20 mm。年产流量在月份中分布比例大体上是以6月和8月为峰的双峰分布,这个峰有从8月向6月前移的趋势。旱地产流量相对于水田的更加集中在5～9月。（3）旱地年产流总天数在50 d左右波动,水田年产流天数在120 d上下波动。旱地连续产流的天数一般不会超过5 d,水田连续产流天数一般不会超过7 d     

9月至翌年4月宜昌、大通来流趋势及两站流量关系初探

利用长江上、下游代表水文站宜昌、大通站1951~2008年逐月月均流量资料,采用线性倾向估计、非参数Mann Kendall检验、滑动t 检验等方法,对两站9月至翌年4月（三峡蓄水期及枯季）各月多年来的流量变化趋势进行探讨,分析了流量发生突变的时间,并对各月两站流量间关系进行初步的研究。研究表明：宜昌、大通各月流量多年变化趋势基本一致,多年来,两站9~10月流量减少,1~3月流量显著增加,流量突变大多发生在20世纪80年代,流量的变化主要与水利工程的建设及流域降雨量的变化有关;宜昌、大通站两站流量存在一定的内在关系,9~10月份两站流量间关系较好,其余月份宜昌、大通两站流量的比值与大通流量间关系较好,所得关系式可初步用于流量预测     

湖北省双季稻生长季降水及洪涝变化特征

利用1961～2008年湖北省双季稻区常规气象站资料,统计计算了双季稻产区在早晚稻生长季的降水量、暴雨量、暴雨日数以及洪涝发生次数,揭示了近50 a来双季稻区降水及洪涝的变化特征。结果显示：湖北省双季稻区在早晚稻生长季的降水量都有弱的增加趋势,尤其是鄂东北局部和江汉平原南部;在水稻抽穗扬花至成熟期间,早稻暴雨量大部有不显著的增加趋势,而晚稻则大部为弱减少趋势。早稻生长季内洪涝的发生次数总体呈增加趋势,局部地区严重洪涝发生次数加大;晚稻生长季洪涝总次数有略减少趋势,重度以上洪涝发生很少,但呈略增加趋势     

城市面源污染形成过程及其排放特征研究进展

随着城市的迅速发展,城市面源污染日益成为影响城市水体水质的重要因素。本文按照地表累积—降水—径流冲刷—输送这一城市面源污染的形成过程对次降雨径流平均浓度、初始冲刷效益等污染特征进行了研究,分析了不同下垫面及不同功能区的污染特性。     

Ability of Remnant Riparian Forests,With and Without Grass Filters,to Buffer Concentrated Surface Runoff1

Knight, Kris W., Richard C. Schultz, Cathy M. Mabry, and Thomas M. Isenhart, 2010. Ability of Remnant Riparian Forests, With and Without Grass Filters, to Buffer Concentrated Surface Runoff. Journal of the American Water Resources Association (JAWRA) 46(2):311-322. DOI: 10.1111/j.1752-1688.2010.00422.x Abstract: Riparian forest buffers established according to accepted conservation practice standards have been recommended as one of the most effective tools for mitigating nonpoint source pollution. The midwestern United States is characterized by many kilometers of narrow, naturally occurring forests along streams. However, little is known about the relative effectiveness of these remnant forests compared with these newly established buffers. This study compared the ability of naturally occurring remnant forests with and without adjacent planted grass filters to buffer concentrated flow paths (CFPs) originating in crop fields along first- and second-order streams in three northeast Missouri watersheds. Remnant forests breached by runoff through CFPs were narrower than those that dispersed 100% of the CFPs. Remnant forests with adjacent grass buffers were nearly twice the width as those without grass filters. We also found that CFPs, which developed within remnant forests and at the base of in-field grass waterways, were potential sources of sediments to streams. Methods to mitigate these CFPs warrant further investigation. Our study suggests that although these natural remnant forests provide substantial buffering capacity, both improved management and/or the addition of an adjacent grass filter would improve water quality by reducing sediment loss to streams. Inferences can be used to inform the design and management of similar conservation buffer systems within the region.     

Simulation of Combined Best Management Practices and Low Impact Development for Sustainable Stormwater Management1

Damodaram, Chandana, Marcio H. Giacomoni, C. Prakash Khedun, Hillary Holmes, Andrea Ryan, William Saour, and Emily M. Zechman, 2010. Simulation of Combined Best Management Practices and Low Impact Development for Sustainable Stormwater Management. Journal of the American Water Resources Association (JAWRA) 1-12. DOI: 10.1111/j.1752-1688.2010.00462.x Abstract: Urbanization causes increased stormwater runoff volumes, leading to erosion, flooding, and the degradation of instream ecosystem health. Although Best Management Practices (BMPs) are used widely as a means for controlling flood runoff events, Low Impact Development (LID) options have been proposed as an alternative approach to better mimic the natural flow regime by using decentralized designs to control stormwater runoff at the source, rather than at a centralized location in the watershed. For highly urbanized areas, LID practices such as rainwater harvesting, green roofs, and permeable pavements can be used to retrofit existing infrastructure and reduce runoff volumes and peak flows. This paper describes a modeling approach to incorporate these LID practices in an existing hydrologic model to estimate the effects of LID choices on streamflow. The modeling approach has been applied to a watershed located on the campus of Texas A&M University in College Station, Texas, to predict the stormwater reductions resulting from retrofitting existing infrastructure with LID technologies. Results demonstrate that use of these LID practices yield significant stormwater control for small events and less control for flood events. A combined BMP-LID approach is tested for runoff control for both flood and frequent rainfall events.     

不透水表面雨水径流污染物冲刷规律研究

针对雨水径流污染冲刷模型中降雨强度与污染物冲刷存在的时间差问题,采用有效降雨强度替代降雨强度,建立了径流污染物冲刷模型,并利用建立的模型对不透水表面雨水径流污染物冲刷进行了模拟。结果表明,模型对SS、COD、TN和TP模拟的相关系数R2平均为0.87、0.81、0.93和0.89,具有较高的模拟精度。SS、COD、TN和TP的冲刷系数分别为0.77、0.66、0.92和0.74 mm-1,TN的冲刷系数略高,但总体相差不大。SS、COD、TN和TP均显示了较强的初期冲刷效应,在有效降雨强度为4 mm时,截留初期雨水径流量的35%~40%,即可控制70%以上雨水径流污染物。建立的模型可应用于研究不透水表面的雨水径流污染物冲刷规律,为雨水径流污染物控制提供理论计算依据。     

梯级开发对河流径流过程和水温过程均化作用的研究

长江中上游干流及主要支流正在大规模地进行水电开发,随着这些梯级水库群的建设,自然河流中具有重要生态意义的流量过程和水热过程发生变化,导致流量和水温均化,引起了一些河流生态环境问题。根据现有资料统计,结合金沙江下游正在建设的溪洛渡和向家坝水电站,对比分析了梯级水电工程径流调节后与天然过程的差异程度,探讨了河流径流过程和水温过程均化现象对生境的影响。将均化系数λ引入,定量计算了水库调节对天然径流的均化作用;采用宽度平均的立面二维k-ε水温模型,初步分析了梯级水电工程对水温过程均化作用。最后提出减小梯级水库对长江生态环境影响的对策和建议.     

河水受百年一遇大旱后城市降雨径流的污染与治理

2009年入秋至2010年春,中国西南地区发生了百年一遇的特大旱灾。为探讨河水受百年一遇大旱后降雨径流污染的状况,对昆明典型交通干道路面的降雨径流和河水水质进行了监测,分析了大旱后降雨径流污染的严重性和对河水水质的影响,并考察了曝气塘—浮石床水平潜流人工湿地复合系统处理大旱后由城市降雨径流污染导致的重污染河水的效能。结果表明,大旱后的前3场降雨径流污染程度较正常雨季降雨径流污染程度严重,SS、COD、TN及TP浓度平均高出1.3倍。大旱后的前3场降雨径流溢流会对河流造成严重污染。该复合系统在塘调蓄—循环处理运行工况下能有效处理大旱后的重污染河水,对SS、COD、TP、TN和NH4+-N的平均去除率分别为98%、90%、96%、60%和90%,出水均达《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。