Feature selection methods for characterizing and classifying adaptive Sustainable Flood Retention Basins

The European Union’s Flood Directive 2007/60/EC requires member states to produce flood risk maps for all river basins and coastal areas at risk of flooding by 2013. As a result, flood risk assessments have become an urgent challenge requiring a range of rapid and effective tools and approaches. The Sustainable Flood Retention Basin (SFRB) concept has evolved to provide a rapid assessment technique for impoundments, which have a pre-defined or potential role in flood defense and diffuse pollution control. A previous version of the SFRB survey method developed by the co-author Scholz in 2006 recommends gathering of over 40 variables to characterize an SFRB. Collecting all these variables is relatively time-consuming and more importantly, these variables are often correlated with each other. Therefore, the objective is to explore the correlation among these variables and find the most important variables to represent an SFRB. Three feature selection techniques (Information Gain, Mutual Information and Relief) were applied on the SFRB data set to identify the importance of the variables in terms of classification accuracy. Four benchmark classifiers (Support Vector Machine, K-Nearest Neighbours, C4.5 Decision Tree and Naïve Bayes) were subsequently used to verify the effectiveness of the classification with the selected variables and automatically identify the optimal number of variables. Experimental results indicate that our proposed approach provides a simple, rapid and effective framework for variable selection and SFRB classification. Only nine important variables are sufficient to accurately classify SFRB. Finally, six typical cases were studied to verify the performance of the identified nine variables on different SFRB types. The findings provide a rapid scientific tool for SFRB assessment in practice. Moreover, the generic value of this tool allows also for its wide application in other areas.     

中国古城防洪的成功范例——成都

本文论述成都古城在城市防洪和城市水利上的有效措施,包括城市选址、凿金堂峡、建都江堰以及建设城市水系等,也分析了成都城水患的原因和管理的重要性。认为成都古城是中国古城防洪的成功范例。     

Validating a rapid assessment framework for screening surface water flood risk

This research evaluates performance of a rapid assessment framework for screening surface water flood risk in urban catchments. Recent advances in modelling have developed fast and computationally efficient cellular automata frameworks which demonstrate promising utility for increasing available evidence to support surface water management, however, questions remain regarding trade‐offs between accuracy and speed for practical application. This study evaluates performance of a rapid assessment framework by comparing results with outputs from an industry standard hydrodynamic model using a case study of St Neots in Cambridgeshire, UK. Results from the case study show that the rapid assessment framework is able to identify and prioritise areas of flood risk and outputs flood depths which correlate above 97% with the industry standard approach. In theory, this finding supports a simplified representation of catchments using cellular automata, and in practice presents an opportunity to apply the framework to develop evidence to support detailed modelling.     

下莱茵流域河道半自然化、生态防洪与雨水管理案例

“给河流更多空间”是当前欧洲和北美河道生态修复．洪水风险管理的共同目标与策略。莱茵河流域管理重点已由水质改善转向水质、水量、生态综合管理。通过实地调查和案例研究,着重介绍了下莱茵河道半自然化与洪泛地建设、JBA雨洪管理技术与城市设计实例,例证了：(1)高度城市化地区主河道半自然化与生态防洪的可行性；(2)雨水管理在城市综合防洪中的必要性：(3)水环境友好型城市设计对重塑城市滨水区活力的重要作用。     

深圳市东湖公园湖泊污染治理

城市公园内的湖泊水体往往补充水源不足，自净能力脆弱，当受到水污染时易出现湖水变黑发臭而破坏公园美景，使其失去使用价值。介绍了深圳市东湖公园人工湖的污染治理方案。实践证明，结合水利防洪、环境保护、园林绿化等措施进行综合治理，通过采取截污、清淤、补水、修复湖泊堤岸及拦水橡胶坝等措施，可使湖泊水质得到彻底改善。合理的设计使人工湖不仅具有滞洪防洪功能，还可对公园地下水起到调节和补充作用。该项目为城市公园湖泊污染综合治理进行了一次探索和实践。     

厦门海沧新城内湖湖水调蓄分析

本文从海沧新城防洪规划,新城城市设计,内湖景观规划出发,通过对内湖排水计算,提出湖水调蓄方法,并强调内湖涵闸管理对内湖景观功能与防洪功能实现的重要性。     

太原汾河景区水功能的开发与利用

就太原汾河景区建设中水功能的开发与利用进行了总结归纳，分析探讨了河流在防洪、水利、环境三项功能的关系与作用，以实现水资源的合理有效开发。     

Using rainfall radar data to improve interpolated maps of dose rate in the Netherlands

The radiation monitoring network in the Netherlands is designed to detect and track increased radiation levels, dose rate more specifically, in 10-minute intervals. The network consists of 153 monitoring stations. Washout of radon progeny by rainfall is the most important cause of natural variations in dose rate. The increase in dose rate at a given time is a function of the amount of progeny decaying, which in turn is a balance between deposition of progeny by rainfall and radioactive decay. The increase in progeny is closely related to average rainfall intensity over the last 2.5 h. We included decay of progeny by using weighted averaged rainfall intensity, where the weight decreases back in time. The decrease in weight is related to the half-life of radon progeny. In this paper we show for a rainstorm on the 20th of July 2007 that weighted averaged rainfall intensity estimated from rainfall radar images, collected every 5 min, performs much better as a predictor of increases in dose rate than using the non-averaged rainfall intensity. In addition, we show through cross-validation that including weighted averaged rainfall intensity in an interpolated map using universal kriging (UK) does not necessarily lead to a more accurate map. This might be attributed to the high density of monitoring stations in comparison to the spatial extent of a typical rain event. Reducing the network density improved the accuracy of the map when universal kriging was used instead of ordinary kriging (no trend). Consequently, in a less dense network the positive influence of including a trend is likely to increase. Furthermore, we suspect that UK better reproduces the sharp boundaries present in rainfall maps, but that the lack of short-distance monitoring station pairs prevents cross-validation from revealing this effect.     

基于遥感与无线定位技术的防洪减灾信息系统的设计与实现

防洪减灾信息系统是一项重要的综合性非工程防洪减灾措施,但现有系统存在灾情报警信息传输不及时等问题。为此,采用遥感影像数据及无线定位技术进行了系统设计,实现了防洪数据的查询与管理、接警无线定位、空间分析等关键技术。并通过实例说明了该系统能够实现防洪信息的高效、统一的管理,提高综合防汛减灾的能力。     

国家射箭基地山地旅游项目雨洪控制与利用设计探讨

山地生态旅游项目的雨洪问题已经成为一个融合市政、水利、景观、环境、生态等多方面内容的建设、治理、管理的复杂性问题,在项目启动初期就应该作为规划设计的重要部分予以重视。本文从山地项目雨水系统设计层面,结合生态理念及园林景观设计,探讨山地项目雨洪控制与利用的途径,实现对雨水资源的有效管理。     

水口水库拦洪蓄满度影响因素分析与对策探讨

本文通过采用排列图法对水口水库年均汛末拦洪蓄满度低的影响因素进行分析,得出洪水预报误差大和库水位回蓄时机偏迟的两大影响因素,进而制定人工修正洪水预报模块和增加控制判别条件对策,提高水口水库的拦洪蓄满度,实现洪水资源的科学利用。     

The effects of water management on annual maximum floods of Lake Como and River Adda at Lecco (Italy)

This paper presents the results of an analysis aimed to assess the impact exerted on the flood regime of Lake Como and its emissary by different kinds of waterworks in the Adda basin (Italy). This includes construction of reservoirs in the Alps, increase in flow capacity of the exutory and regulation of Lake Como. The assessment of the management effect on peak floods is of particular interest as flood damages could be particularly heavy in densely populated areas along the lake banks and in the river flood plain downstream of the lake. The analysis is carried out by comparing the annual maxima of Lake Como levels and the river Adda discharges at Lecco, at the lake exutory, in different real and hypothetical situations. Both the construction of alpine reservoirs and the improvement of flow capacity of the exutory decrease lake levels and flood discharges, while lake regulation (for irrigation and power production) increases them. The overall effect is a generalised reduction of the flood levels and a slight increase in the discharges with return periods lower than 10 years. The discharges with higher return periods, instead, remain unchanged. The difference between peak and mean daily discharges negligible in all cases disappears altogether for return periods higher than 10 years.     

NbS在城市雨洪韧性规划中的应用研究

城市雨洪灾害的产生与气候变化、土地利用、防洪排涝基础设施空间布局等密切相关。大量研究证实,单一依靠市政改造雨水管网的传统做法工程成本高、改造难度大,实际效果不理想。而基于自然的解决方案(Nature-based Solutions,Nb S)倡导对生态系统的最小干预,将灰蓝绿基础设施有机结合,为城市雨洪韧性规划提供了一种新思路。采用“理论研究+应用案例”相结合的方法,首先分析了将Nb S理念应用到城市雨洪韧性规划中的切入点,提出Nb S视角下城市雨洪韧性规划的一些思考;其次,应用MIKE FLOOD模型,对场地雨洪风险进行评估;最后,结合应用案例特点,以堤防岸线、水系网络、水位管理为抓手,阐述了Nb S理念在城市雨洪韧性规划中的具体方案。结果表明,Nb S视角下的城市雨洪韧性规划方案具有可行性,以期共同推动Nb S实施行动。     

从得水到治水——浅析风水水法在古代城市营建中的运用

水是生命之源 ,又属五害之首。本文从传统水文化下的得水观念入手 ,分析了风水水法的特点和在古代城市中的巧妙运用 ,总结出城市得水与防洪这一对矛盾体在风水指导下完美结合的历史经验。     

防汛墙的变形规律及其失效模式评判

本文采用有限元方法分析典型防汛墙结构变形规律,在采用比奥团结理论为基础的关口－太田本构关系的基础上,模拟土体的弹塑性性态及土体与墙体的共同作用,包括考虑因河床冲刷和河道疏浚引起的单元减少以及水位升降引起的荷载变化,及采用模糊数学的综合评判原理对防汛墙的失效模式进行了评判,分析得出导致墙体破坏的主要因素,成果可供防汛墙结构的安全性的监控和维护参考。     

基于WebGIS的城市防洪信息系统建立与开发

在综合考虑水利行业和堤防工程的现状以及WebGIS实现技术的基础上,设计开发了基于浏览器服务器体系的城市防洪暨堤防信息管理系统,实现了空间数据、属性数据、多媒体数据的网络共享和初步协同工作,解决了防汛应急、雨情、水情、工情、灾情等信息管理问题,并在安庆城市防洪暨堤防信息管理中取得了较好的应用效果。     

与洪水和谐相处——科学发展观指导下的城市防洪规划

结合新一轮济南市城市总体规划——城市防洪规划的编制,探讨了基于科学发展观编制城市防洪规划的热点问题:一是合理利用土地,即城市建设不与洪水争地;二是确定城市防洪标准时必须合理与适度,不应一味地追求所谓的高标准,而城市除涝标准应大幅度提高;三是强调雨洪资源化利用,将雨洪灾害转变为资源;四是变堵为疏,重视滞蓄洪区的规划,给洪水以出路;五是河道治理采用生态型河道,体现由以往的改造自然转变为回归自然、顺应自然的治理理念;六是广泛利用防洪非工程措施。     

非平原城市排洪规划技术路线研究

对非平原城市的防洪排涝规划进行了新的诠释和定义,通过对排洪规划重现期的选择、城区洪峰流量的推求方法、排洪规划方案的确定、城市内河水面线的计算以及排洪规划与城市竖向规划之间的配合等方面的研究,提出了非平原城市排洪规划的初步技术框架.     

The management of urban surface water drainage in England and Wales

Partly in response to the UK flooding events of 2007, a number of reports have recently been produced addressing the legislative, administrative, institutional and structural practices that are required to improve urban surface water management and hence reduce future flooding incidents and associated pollution impacts. This paper addresses the principal barriers to progress that have been identified and how these are likely to be overcome. Improved and integrated organisational structures, process and procedures are required and relationships between flood risk management and water quality need to be addressed at regional, area and local levels as well as legislative clarification on surface water discharges. Nontechnical aspects will need to be supported by new modelling approaches for flood risk prediction at both local and catchment scale with effective communication systems and tools being developed and implemented for full and effective stakeholder participation.     

Coregionalization analysis of heavy metals in the surface soil of Inner Mongolia

Due to potential problems associated with their deficiencies or toxicities, heavy metals in soils are of great environmental concern. To evaluate heavy metal contents and their relationships in the surface soil of Inner Mongolia, soil samples were collected from 344 sites and contents of copper, lead, zinc, cadmium, nickel, chromium, mercury, cobalt, vanadium and manganese were determined. In this article, coregionalization of these ten heavy metals is investigated using factorial kriging. Vegetation type, parent material type and soil pH, with respective characteristic ranges of 200, 400 and over 1000 km, are identified as the primary factors that control the spatial distribution of soil heavy metals. At the scale of 200 km, heavy metal relationships mainly reflect the result of biocycling. Their relationships at the intermediate scale (400 km) are thought to be derived from the atomic substitution of metals in the parent materials. Effects of soil pH on the adsorption of heavy metals by soil organic materials could explain their relationships at the large spatial scale (over 1000 km).