暴雨条件下沙棘林减水减沙效益研究

造成黄土高原水土流失的降雨主要是短历时暴雨。根据这一特点，利用人工模拟降雨方法研究了短历时暴雨条件下沙棘林的减水减沙效益，以及不同郁闭度对产流产沙过程的影响。结果表明，沙棘林郁闭度越高，减水减沙效益越好。     

紫色土丘陵区典型生态-水文单元径流与氮磷输移特征

通过对紫色土丘陵区典型农业-集镇-林地复合型小流域3次降雨-径流全过程的连续监测，测定径流过程中泥沙含量和不同形态氮磷浓度，以期认识典型农村生态-水文单元降雨径流过程中氮磷迁移规律。结果表明：降雨-径流过程中悬浮泥沙的流失主要集中在径流前期，其峰值出现在雨强最大时；集镇径流污染的影响主要表现在径流前期，是径流前期铵态氮偏高的主因；降雨-径流过程中，颗粒态氮与可溶态氮比（PN/DN）、颗粒态磷与可溶态磷比（PP/DP）的峰值均出现在雨强较大时：其中PN/DN多小于1，而PP/DP范围为1.1~30.2，说明氮素流失主要通过可溶态的方式，而磷的迁移以颗粒态磷为主。因此在紫色丘陵区建议利用湿地植物与沉砂池等综合措施控制土壤侵蚀和非点源污染以保护当地生态环境安全。     

Laboratory study of impacts of concrete fragment sizes on wetland water chemistry

This study investigated the effects of urban concrete materials, of different particle sizes, immersed in water through a laboratory-based experiment. Water was sourced from a high conservation-value wetland (Blue Mountains upland swamp). Prior to the experiment, wetland water was dilute (32.5 μS/cm), acidic (pH 5.3) and had detectable major ion concentrations of only sodium and chloride. Water was exposed to three treatments of different concrete fragment sizes (whole, crushed and fine). All treatments increased conductivity and pH and also resulted in modified ionic composition where calcium, potassium, hydroxide, carbonate and sulphate were recorded at much high levels. The extent and speed of water chemistry changes was linked to the particle size of the concrete. The results of this study support the hypothesis that concrete can be an environmentally hazardous material influencing water quality in urban catchments.     

Groundwater salinisation on atoll islands after storm‐surge flooding: modelling the influence of central topographic depressions

Fresh groundwater lenses (FGLs) are of utmost importance for human survival on small and isolated atolls. This article examines saline damage to atoll FGLs from wave washover caused by storm surge and studies the particular influence of central topographic depressions (CTDs). We model storm surge over atoll islets of contrasting widths (400 and 800 m), both with and without CTDs of various sizes. Three key findings emerge. First, under equilibrium undisturbed conditions, the CTD slightly reduces the size of the FGL compared to atoll islets without this feature. Second, during marine flooding, prior saturated conditions at the base of a CTD impede seawater infiltration into the substrate, thereby limiting saline damage in that location. Third and most crucial, however, the amount of salt accumulated within the CTD is significant, ranging from 2 to 10 times higher than the net subsurface infiltration during the period of the storm inundation.     

柳江流域“2010.6”暴雨洪水特性分析

受高空槽和切变线影响2,010年6月16-20日,柳江流域出现了范围广、历时长、强度大的强降雨过程,强降雨导致柳江、融江、洛清江、贝江、石榴河均发生了超警洪水,石榴河四排站出现1967年建站以来第2位大洪水,重现期约为15年一遇。通过对本次暴雨洪水特性进行分析,掌握柳江流域洪水特性,提高洪水预报精度,为防洪减灾提供参考。     

Comparative seismic design optimization of spatial steel dome structures through three recent metaheuristic algorithms

Steel dome structures, with their striking structural forms, take a place among the impressive and aesthetic load bearing systems featuring large internal spaces without internal columns. In this paper, the seismic design optimization of spatial steel dome structures is achieved through three recent metaheuristic algorithms that are water strider (WS), grey wolf (GW), and brain storm optimization (BSO). The structural elements of the domes are treated as design variables collected in member groups. The structural stress and stability limitations are enforced by ASD-AISC provisions. Also, the displacement restrictions are considered in design procedure. The metaheuristic algorithms are encoded in MATLAB interacting with SAP2000 for gathering structural reactions through open application programming interface (OAPI). The optimum spatial steel dome designs achieved by proposed WS, GW, and BSO algorithms are compared with respect to solution accuracy, convergence rates, and reliability, utilizing three real-size design examples for considering both the previously reported optimum design results obtained by classical metaheuristic algorithms and a gradient descent-based hyperband optimization (HBO) algorithm.     

洪涝灾害人口损失研究进展

洪涝灾害经常造成大量的人员死亡,不仅给人们心理上造成巨大创伤,还给生产生活带来严重的破坏,成为对社会影响最为严重的自然灾害之一。随着民生水利的提出,洪涝灾害中人口死亡研究受到各级水行政主管部门的关注。现详细介绍了洪涝灾害中影响人员损失的主要影响因子(即水深、流速、水位上涨速率、水温、疏散撤离和救援等)方面的国内外研究进展,以及溃坝洪水、沿海风暴潮、海啸和江河洪水等4种主要洪涝灾害类型中人口损失的估算方法。最后结合我国灾害人口损失研究的现状,对人口损失研究的发展趋势进行了展望。     

基于降雨观测资料的山洪预警标准研究

山洪灾害是山区小流域发生频次最高危害最大的自然灾害，利用降雨观测资料及时进行山洪预警是山洪灾害避险的有效手段。本文从河道安全泄洪流量出发，提出了最小临界雨量和临界雨力的新概念和计算方法，并在此基础上构建了暴雨临界曲线，以降雨观测资料在暴雨临界曲线图上所处的位置作为山洪预警的判断标准，通过某小流域三场洪水暴雨资料的验证，证明其方法是合理的。用暴雨临界曲线作为山洪预警的判别方法易于农村干部群众掌握，适宜于山区小流域各地防范山洪灾害中使用推广。     

浅谈市政雨水管渠流量设计推理公式的理论假设及其应用

阐述雨水管渠流量设计中推理公式的推导过程及其在实际工程中的应用技巧,在此基础上,总结得出面积叠加法、流量叠加法以及流量叠加法应用在独立面积中求雨水流量的相关方法,并指出该公式的应用范围。     

绕阳河下游辽河油田遭受内涝的原因及对策

利用工程技术治理内涝,必须进行细致的现场勘查,探明内涝根源,再经过科学论证,才能保证工程项目的可行性及合理性,而周密和符合实际的设计是保证工程功能性的必要条件,但是,合理利用水资源,减少水土流失才是根治内涝的根本条件.