Arc StormSurge: Integrating Hurricane Storm Surge Modeling and GIS

Arc StormSurge is a data model that integrates geographic information systems and the hurricane wave and surge model SWAN+ADCIRC, which is the coupling of the Simulating WAves Nearshore (SWAN) wave model and the Advanced Circulation (ADCIRC) hydrodynamic model. The Arc StormSurge data model is a geodatabase, which is a relational database that can contain georeferenced information. It includes feature classes in feature datasets and tables, all related among them through relationship classes, and raster catalogs and grids. In addition to the data model schema, Arc StormSurge includes a number of pre‐ and post‐processing tools that help integrate spatial data and numerical modeling. As an illustration, Arc StormSurge was used to support the modeling of Hurricane Bret, which made landfall in the Corpus Christi area in Texas in 1999. By using Arc StormSurge, it was possible to take advantage of already available geo‐referenced information (e.g., base maps, land cover datasets, and monitoring station locations) for the model setup, and for identifying spatial patterns in the model results by presenting them in map format.     

Introduction to the special issue of Ecological Modelling: “Advances in Modeling Estuarine and Coastal Ecosystems: Approaches, Validation, and Applications”

The development and application of ecosystem models in estuarine and coastal systems has grown exponentially over the past four decades. Models have become ensconced as major tools for both heuristic study of ecosystem structure and function as well as for informing management decisions, particularly with respect to cultural eutrophication. In recent years an ever-expanding toolbox of modeling approaches is being offered to complement traditional methods. This expansion of modeling in estuarine and coastal science was exemplified by four sessions devoted to modeling at the 2007 biennial conference of the Estuarine Research Federation in Providence, RI. We felt the time was right to propose a special session of Ecological Modelling to synthesize talks from these sessions to present the state of the art in coastal and estuarine modeling. The collection of papers contained in this special issue presents a diversity of traditional and novel modeling approaches, methods for assessing model validity and predictability, and the utility of models in management applications. We believe that together these papers provide an excellent overview of current approaches to modeling estuarine hydrodynamics, water quality, and ecosystem/food web dynamics, applications of complex and relatively simple modeling approaches, applications in both deep and shallow coastal systems, goals relevant for both heuristic and management applications, and perspectives based on traditional mechanistic model development as well as more recent alternative approaches.     

内循环生物流化床反应器的理论分析

从反应器理论、生物膜动力学及水力学的角度对内循环式三相生物流化床反应器的流态、生物膜降解有机物及启动挂膜特性进行分析,认为在内循环三相流化床中Ｄ／ｕｄ＝ｃｏｎｓｔ,对于一般城市污水处理系统求出了效率因子,建立了内循环速度与反应器尺寸的关系,同时提出了可能进一步提高反应器处理效率的优化途径。     

重庆主城区污水排放截流处理方案的比较

重庆市主城排水系统的污水处理方案从以自然汇水区为主的排水和处理方案转为集中截流处理。本文利用MIKE模型，对重庆市主城排水系统项目的各方案进行了比较，结合模型的解析结果，提出应结合三峡成库时间，采用分阶段逐步提高的最优方案。     

三峡水库蓄水运行初期(2003—2012年)水环境演变特征的“四大效应”

自2003年三峡水库首次蓄水至2012年工程竣工验收启动,针对三峡水库蓄水运行初期的水环境演变研究较多,但整体性、综合性科学认识仍然缺乏.基于水环境多要素跟踪观测研究,综合采用现场观测、室内试验、数理统计、模型模拟、同位素及保守离子示踪等技术手段,系统剖析了特大型、高变幅水位水库运行背景下水动力变异及其所伴生的水环境演变特征,从水动力、水质、水生态、污染物输移角度,提出了三峡水库水环境演变过程中的“四大效应”,主要包括干支流水动力特性的“分化”效应、上游-干流-支流水质演变“同步”效应、水动力变化对藻类水华暴发的“胁迫”效应、水动力变化对同等负荷条件下污染源危害的“迭加”效应等.考虑到大型水库生态系统的演替和稳定是一个长期过程,建议继续强化长江上游梯级水电开发影响下的三峡水库水环境演变跟踪调查研究,适时开展三峡工程对库区水环境影响的后评估.      

A RATING-CURVE METHOD FOR HYDRODYNAMIC SIMULATIONS IN CONTAMINANT TRANSPORT MODELING1

ABSTRACT: Accurate prediction of hydrodynamics is of great importance to modeling contaminant transport and water quality in a river. Flow conditions are needed in estimating potential exposure contamination levels and the recovery time for a no-action alternative in contaminated sediments remediation. Considering highly meandering characteristics of the Buffalo River, New York, a three-dimensional hydrodynamic model was selected to route upstream flows through the 8-km river section with limited existing information based on the model's fully predictive capability and process-oriented feature. The model was employed to simulate changes in water depth and flow velocity with space and time in response to variation in flow rate and/or water surface elevation at boundaries for given bottom morphometry and initial conditions. Flow conditions of the river reach where historical flow data are not available were computed. A rating-curve approach was developed to meet continuous and event contaminant modeling needs. Rating curves (depth-discharge and velocity-discharge relationships) were constructed at selected stations from the 3-D hydrodynamic simulations of individual flow events. The curves were obtained as steady solutions to an unsteady problem. The rating-curve approach serves to link flow information provided by the hydrodynamic model to a contaminant transport model. With the approach, the linking problem resulting from incompatible model dimensions and grid sizes can be solved. The curves will be used to simulate sediment movement and to predict contaminant fate and transport in the river.     

MODELING TIDAL HYDRODYNAMICS OF SAN DIEGO BAY,CALIFORNIA1

ABSTRACT: In 1983, current data were collected by the National Oceanic and Atmospheric Administration using mechanical current meters. During 1992 through 1996, acoustic Doppler current profilers as well as mechanical current meters and tide gauges were used. These measurements not only document tides and tidal currents in San Diego Bay, but also provide independent data sets for model calibration and verification. A high resolution (100-m grid), depth-averaged, numerical hydrodynamic model has been implemented for San Diego Bay to describe essential tidal hydrodynamic processes in the bay. The model is calibrated using the 1983 data set and verified using the more recent 1992–1996 data. Discrepancies between model predictions and field data in both model calibration and verification are on the order of the magnitude of uncertainties in the field data. The calibrated and verified numerical model has been used to quantify residence time and dilution and flushing of contaminant effluent into San Diego Bay. Furthermore, the numerical model has become an important research tool in ongoing hydrodynamic and water quality studies and in guiding future field data collection programs.     

A SCALED HYDRAULIC MODEL OF THE PEACH BOTTOM ATOMIC POWER STATION DISCHARGE1

ABSTRACT: A scaled hydraulic model was used as a schematic representation of the Peach Bottom Atomic Power Station (PBAPS) discharge into Conowingo Pond during critically low river flows. The model approximated flow and temperature patterns and the degree of recirculation are assessed. Under normal operation the effluent is carried downstream and dissipated within about two miles. However, during dry weather years, river inflows can decrease substantially, resulting in unknown recirculation of effluent and flow patterns in Conowingo Pond. This study was conducted to investigate and predict flow patterns in Conowingo Pond under critically dry weather conditions. A threshold river flow is also identified that indicates a measure of the river's ability to maintain downstream advection of the effluent. The study suggests a number of unexpected current patterns, potential recirculation of the effluent, and changes in the dilution of the effluent.     

蜂窝陶瓷固定化细胞气升式内循环生物反应器的水力学特性

在鼓泡塔式 (BubbleColumns ,BC)和气升式循环 (AirliftLoop ,AL)生物反应器基础上 ,于内循环管中加装蜂窝陶瓷载体 ,开发出蜂窝陶瓷固定化细胞的气升式内循环生物反应器 (Internal Airlift Loop Bioreactor with Cells Immobilized onto Ceramic Honeycomb Support,IALBR-CICHS) .采用示踪技术通过测定反应器的水力停留时间分布来考察上述 3种反应器的有效工作体积和反应器内走旁路流体的比例 .实验和理论分析表明 ,IALBR-CICHS可大大提高反应器的有效工作体积 ,减少流体走旁路的比例 .     

湖泊流体动力学模型及实验

从二维浅水非恒定流的控制方程出发,建立了一个二维湖泊流体动力学模型.并根据天津于桥水库的实际情况,对该水库引水期和非引水期的湖水流场的不同情况进行了模拟试验.结果表明,在引水期水库的流场达到稳定状态时,水库流场有一个自东向西的水流主要通道.还对水库出口处有初始水体流速的情况进行了模拟.模拟的结果与于桥水库的实际污染物浓度分布基本一致.