1998年昌江流域暴雨洪水分析

1998年昌江发生了建国以来最大洪水，文章从天气环流背景、降雨特征等方面分析这次洪水形成的特点和发展过程。     

Improvement of rainwater infiltration and storage capacity by an enhanced seepage well: From laboratory investigation to HYDRUS-2D numerical analysis

Seepage well is an emerging Low Impact Development (LID) technology that can effectively control the storm runoff. However, its rainwater infiltration rate and storage capacity still require further enhancement. By setting a horizontal infiltration structure at the bottom of conventional rainwater seepage well (CSW), an enhanced seepage well (ESW) was proposed in this study, and its infiltration performances compared with the permeable pavement (PP) and the CSW were systemically investigated using static infiltration experiment and HYDRUS-2D simulation. The results showed that the infiltration efficiency of ESW was significantly higher than that of PP and CSW, and the process of water infiltrated through soil mainly controlled the macroscopic infiltration rate. The Nash-Sutcliff Efficient (NSE) index was used to evaluate the accuracy and reliability of the HYDRUS-2D model, and the results of NSE values greater than 0.75 (varied between 0.75 and 0.91) confirmed the applicability of HYDRUS-2D to describe correctly the hydraulic behavior of the ESW system. Simulation infiltration tests showed that the ESW performed a higher average infiltration rate and fewer total runoff volume than the CSW, indicating the effectively enhancement of the infiltration and water retention capacity of ESW, especially under heavy rainfall intensities. Additionally, the ESW system exhibited an excellent runoff-control and rainwater retention capacity in an actual rainfall scenario.     

Modeling sediment resuspension and transport induced by storm wind in Apalachicola Bay, USA

Sediment is an important environmental factor for aquatic ecosystem and oyster productivities of Apalachicola Bay located in Florida, USA. Based on the data analysis in this study, surface wind speed is highly correlated to the turbidity of water column, which results from sediment resuspension and transport in the Apalachicola Bay. In this paper, an application of a 3D sediment transport model to predict the wind-induced sediment transport in Apalachicola Bay is described. The sediment model is coupled with a 3D hydrodynamic module in the Environmental Fluid Dynamics Code (EFDC) model that provides information on estuarine circulation and salinity transport under normal temperature conditions. The hydrodynamic model was calibrated with field observations of water levels and salinity. The sediment transport model solves the transport equation with sources and sinks terms to describe sediment deposition and resuspension. The coupled hydrodynamic and sediment transport models were used to investigate wind-induced total suspended sediments (TSS) resuspension and transport in the bay. For the period June 1–July 30, 2005 two storm events with strong winds gave model results of TSS concentrations that compared well with the field observations. Model simulations reasonably reproduce the sudden increase of sediment concentrations during the storm events. Maximum sediment concentrations in the bay during the two storm events were 10 times or more than those in the pre-storm conditions. Spatial sediment transport from model simulations indicate active sediment resuspension and transport near areas of highly productive oyster beds. The model predictions of TSS and salinity can be used as inputs to an oyster dynamic model (Wang, H., Huang, W., Harwell, M., Edmiston, L., Johnson, E., Hsieh, P., Milla, K., Christensen, J., Stewart, J., Liu, X., 2008. Modeling eastern oyster population dynamics in response to changing environment in Apalachicola Bay, Florida. Journal of Ecological Modeling 211, 77–89) to support the ecological study of oyster growth and mortality in the aquatic ecosystem of Apalachicola Bay.     

Transient Rainfall-Runoff Loadings to a Partial Exfiltration System: Implications for Urban Water Quantity and Quality

Modification of rainfall-runoff processes by urban infrastructure and anthropogenic activities impacts receiving waters and the surrounding terrestrial environment. Infiltration–exfiltration systems such as a partial exfiltration reactor (PER) when loaded by transient sheet flow have the potential to attenuate the impact of both the quantity and quality of urban runoff. These in situ systems are subject to highly variable water quality and quantity while functioning under variably saturated flow conditions. To improve the understanding of field-scale PER performance as a rainfall-runoff unit operation and process, a two-dimensional (2D) numerical model was used to simulate the effluent hydrograph and water content profiles under transient hydraulic loadings. Richard’s equation was applied in the 2D model using parameters estimated from laboratory experiments and hydrographs measured for an in situ PER. The temporal dynamics of the water content illustrated the ability of the PER to lower peak flow, redistribute volume, and attenuate temporal aspects of the inflow hydrograph. Results demonstrated the role of the PER to attenuate runoff water quantity, while also providing water quality improvements, as illustrated for suspended solids and dissolved Cu. Simulation of historical events for different surrounding soils illustrated the critical role of surrounding soil conditions on PER performance. While the PER demonstrated water quantity attenuation benefits for design storms (1, 2, 5?year return periods), results also illustrate how a given PER design for clayey soils conditions can be limiting for intense events. Evaporation was a dominant mechanism for the drying process in the PER upper layer; with a residual moisture content in the porous pavement layer achieved in less than 2?days in summer for Cincinnati, Ohio.     

基于Storm的流数据KNN分类算法的研究与实现

KNN算法是一种简单、有效且易于实现的分类算法,可用于类域较大的分类。近年来对KNN算法的研究偏向于静态大数据集,不过,在越来越多的情况下要用KNN算法在线实时处理流数据。考虑到流式数据流量大,连续且快速,不易存储和恢复等特性,以及流处理系统Storm对流数据处理具有实时性、可靠性的特点,提出了基于Storm的流数据KNN分类算法,该算法首先对整个样本集进行划分,形成多个片集,然后计算出待分类向量在各片集上的[K]近邻,最后再将所有片集[K]近邻归约得出整体[K]近邻,实现待分类向量的分类。实验结果表明,基于Storm的流数据KNN分类算法能够满足大数据背景下对流数据分类的高吞吐量、可扩展性、实时性和准确性的要求。     

基于Kafka和Storm的车辆套牌实时分析存储系统

城市机动车数量、出行量的增加,使得车辆套牌现象屡禁不止.交管部门为了解决套牌监测的难题,采用传统的识别方式（如基于人工识别、基于牌照识别、基于射频识别等）.然而面对海量的日志记录,这些方式普遍存在效率低、实时性差的问题.为此引入大数据技术,提出一个基于Kafka和Storm的车辆套牌实时分析存储系统.Kafka可以作为中间件进行缓存,提高数据采集和数据分析的同步性,还能避免数据丢失;Storm框架可以实现日志信息的实时计算,然后将套牌车辆信息存入指定文档中.整个系统具有实时、分布式存储、稳定、可扩展等特性.     

滨海城市应急避难场所配置评价与优化研究 ——以风暴潮灾害影响下厦门市为例究

文章以典型滨海城市厦门市为例,进行 风暴潮灾害情景下的灾害影响分析及应急避难 场所分布、可达性、服务性进行评价,为滨海城 市在风暴潮灾害情景下的城市韧性建设提供一 定的参考。结果表明在1.08 m及4.92 m海洋增水 情况下厦门市将分别有331和632个重要城市基 础设施处于灾害风险中。根据应急避难场所可 达性及服务评价,现有的82处大型应急避难场 所和234处其他紧急避难场所不能有效覆盖和 服务灾害风险区域,对此提出了一些应急避难场 所优化和增设的建议。     

Evaluating accidents in the offshore drilling of petroleum: Regional picture and reducing impact

This study examined several accidents over the last 56 years in the offshore drilling of petroleum. The aim is to examine the situation in relation to jack-ups, drill ships, semi-submersible and platforms and have a better awareness and understanding which may reduce the number of accidents. The materials examined were available published reports and data on exploration and production activities. From 219 accidents recorded the highest was due to blowouts with 46.1%, followed by storms and hurricanes with 15.1% and structural failures with 11.4%. High fatalities occurred at the Funiwa 5 platform in Nigeria with 230, the Piper Alpha platform in the North Sea with 167 and the Keilland semi-submersible in Norway. Other high fatalities were recorded at the Ocean Ranger fire and sinking, Java Sea sinking, Bohai 2 and Bohai 3 fire and sinking. Worker training and discipline must be maintained at a high level. The facilities must be kept sea-worthy and reliable through regular maintenance.     

Design of Infiltrating Basin by Soil Storage and Conveyance Capacities

Abstract

Design of storm water storage basins must take both surface infiltrating flow and subsurface seepage flow into consideration. Standing water can result from the condition that the subsurface seepage capacity is less than the surface infiltrating capacity or the basin storage volume exceeds the soil pore volume underneath the basin. To avoid a prolonged draining operation, an infiltrating basin must be designed under the constraints of the soil pore storage capacity before saturation and the soil conveyance capacity after saturation. In this study, the potential flow model is developed to estimate the soil pore storage volume underneath the basin and to predict the conveyance capacity through the saturated soil medium between the basin and the local groundwater table. The potential flow model for infiltrating water flow provides a quantifiable basis to define the soil constraints and to compare various alternatives at the basin site.