Study on Functions and Countermeasures of Disaster Prevention and Reduction of Urban Green Land

From the advanced experiences at home and abroad,according to the requirements of emergency evacuation at earthquake disaster,then strategies and methods to disaster prevention and reduction functions of urban green land construction were put forward.

Evaluation of Infiltration Capacity and Water Retention Potential of Amended Soil Using Bamboo Charcoal and Humus for Urban Flood Prevention

In Japan, floods occur frequently in urban areas because non-infiltrating areas are seeing increased urbanization. To prevent floods, urban basins must improve the infiltration capacity and water retention of the whole basin. There are several basic technologies for river basin management, such as infiltration trenches or rainwater storage. However, a method of soil amendment that prevents flood disasters has not been established. This study aims to evaluate the infiltration capacity of soil amendments using bamboo charcoal and humus. A constant-head infiltration test and rainfall simulation were conducted to evaluate the properties of the soil amendments. The constant-head infiltration test＇s results showed that soils mixed with 30% humus had the greatest potential for influencing initial and final infiltration rates, and the more the mixing rates of bamboo charcoal and humus were increased, the higher the water retention capacity. The results of the rainfall simulation showed that soils mixed with 30% humus had the highest final infiltration rates and lowest multiplication spillage. To reduce the runoff volume using soil amendment technology, it is important to delay overland flow, and the hydraulic properties of the soils mixed with bamboo charcoal and humus were as effective as those of granite soils.

Reflection on China's Disaster Prevention and Mitigation Construction after Rainstorm and Snowstorm

On July 10,2004,Beijing was hit by the rainstorm that has not been seen for many years,which caused water accumulation in many places of the urban area,power supply interruption in many places,and traffic paralysis for nearly 5 h. On July 12,2004,the rainstorm in Shanghai lasted less than 1 h,but it caused 7 deaths,more than 20 injuries,extensive power outages and traffic paralysis. At the end of 2005,the continuous snowfall in Weihai City of Shandong Province for half a month caused direct economic losses of over 200 million yuan,and the continuous heavy snowfall had a serious impact on people’s lives. From July 17 to 23,2021,Henan Province suffered a rare extremely heavy rainstorm in history,with a direct economic loss of 120.6 billion yuan. Faced with such urban meteorological disasters and other types of urban disasters,combined with the current situation of disaster prevention and reduction in China,what will managers,decision-makers,and experts and scholars think about from them.

Possibilities of urban flood reduction through distributed-scale rainwater harvesting

Urban flooding in Chittagong City usually occurs during the monsoon season and a rainwater harvesting(RWH)system can be used as a remedial measure.This study examines the feasibility of rain barrel RWH system at a distributed scale within an urbanized area located in the northwestern part of Chittagong City that experiences flash flooding on a regular basis.For flood modeling,the storm water management model(SWMM)was employed with rain barrel low-impact development(LID)as a flood reduction measure.The Hydrologic Engineering Center's River Analysis System(HEC-RAS)inundation model was coupled with SWMM to observe the detailed and spatial extent of flood reduction.Compared to SWMM simulated floods,the simulated inundation depth using remote sensing data and the HEC-RAS showed a reasonable match,i.e.,the correlation coefficients were found to be 0.70 and 0.98,respectively.Finally,using LID,i.e.,RWH,a reduction of 28.66%could be achieved for reducing flood extent.Moreover,the study showed that 10%e60%imperviousness of the subcatchment area can yield a monthly RWH potential of 0.04e0.45 m3 from a square meter of rooftop area.The model can be used for necessary decision making for flood reduction and to establish a distributed RWH system in the study area.

Urban Flood Disaster Risk Assessment and Planning Response: A Case Study of Handan, Hebei Province

Flood disaster is a serious threat to urban security,and flood control and drainage planning is an important measure to ensure urban security.This paper takes planning guidance to empirical research as the main axis.On the basis of meteorological data and spatial data,through the analysis on the risk of disaster-causing factors of flood disasters,the sensitivity of disaster-pregnant environment,the vulnerability of disaster-bearing bodies and the ability of disaster prevention and mitigation,12 indicators are selected to construct a comprehensive evaluation index system for flood disaster risk.Handan City is taken as an example to study the spatial distribution characteristics of flood disaster risk.Based on AHP,weights are assigned to the evaluation indicators of flood disasters in the system,and the risk visualization is carried out in GIS.According to comprehensive risk assessment results,it could put forward corresponding disaster prevention planning strategy for defending flood disaster in Handan City.

Comprehensive System for Urban Flood Prevention in China and Counter-measures to Reduce Calamities

By reviewing the general state of urban flood calamities of the past 40 years and more, this article tries to explore the causes of urban flood, especitlly the man-made factors. It puts forward the ideas of setting up a comprehensive system for urban flood prevention. This comprehensive system consists of six sub-systems such as: 1) command system; 2) system of flood control and drainage works; 3) system of keeping away of flood and coping with flood; 4) system of flood forecast; 5) flood -fighting and rescue system; 6) flood-preventing legislative and insurance system. This article also puts forward the counter-measures to avert floods and reduce the calamities.I.The General State of Urban Flood Calamities for the Last Few Years in

Planning of Urban Public Disaster-prevention Green Spaces: A Case Study of Living Water Park in Chengdu City

Based on disaster-prevention functions of urban public green spaces, necessity and significance of emergency shelters in a city were analyzed. Taking Living Water Park in Chengdu for example, planning of urban public disaster-prevention green spaces was analyzed to further explore planning of urban disaster-prevention green space system and refugee spaces, and provide instructions for the planning and construction of urban disaster-prevention green spaces in China.

Quantitative analysis of impact of green stormwater infrastructures on combined sewer overflow control and urban flooding control

Stimulated by the recent USEPA＇s green stormwater infrastructure （GSI） guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows （CSOs）, also known as low impact development （LID） approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model （SWMM） model was adopted in this study to simulate the behaviors of GSI systems in a well- developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst pertbrmance tor high intensity and long durataon events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term controlstrategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event,

Development laws of geological hazards along urban highway in Southwest China and countermeasures for prevention and control

China is a mountainous country with highly developed road geologic hazards, which pose a great threat to theconstruction and operation of highways, bridges, and tunnels and to the safety of people and property. This paperdiscussed the types, basic features, formation, and prevention conditions of road geologic hazards in China basedon field research and study data collected thus far. The study considered an urban area of a city in southwestChina as the center and a geological field investigation was performed over a total of 282 km on three importantlifeline projects. The results show: Types of geologic hazards along the highways are mainly avalanches, debrisflows, and landslides, respectively. Among them, the landslips are mainly distributed along the roads, with slip,dumping, and wrong break types as the main ones;the debris flows are widely distributed, mainly concentrated inthe river valleys;and the unstable slopes are relatively few in number. Geological disasters are characterized bylarge-scale and concentrated triggering in time and space, and a single disaster can easily trigger other disasters,thus forming a chain of disasters. Neotectonic movement, seismic activity, topography, climatic conditions,stratigraphic lithology, and human activities are important factors leading to geologic hazards in the study area.This study is of great practical significance for reducing the occurrence of roadbed diseases and prolonging theservice life of highways.

基于MIKE URBAN的城市内涝模型应用

针对日益突出的城市内涝问题,为了减少内涝灾害的发生、达到防洪排涝的目的,以成都市某小区为例,基于对小区排水管网的概化处理,雨量分配利用芝加哥雨型,应用MIKE URBAN软件模拟小区排水管网在不同降雨强度下承压运行情况及管点溢流情况,并通过设置小型调蓄池和扩增管径两种途径改善城市内涝状况。结果表明:改造后管网设计重现期由2年一遇提高到10年一遇,管段承压状况得到明显改善。在遭遇10年一遇降雨时,管道峰值流量明显降低,典型管道削峰率达62. 5%,管网过水能力大幅度增加。在今后排水系统改造中,应当使城市管网与雨水调蓄池等海绵措施相结合,实现削减峰值雨量,从源头上防止内涝的发生。该模型具有建模简单、运算精确的特点,对城市防洪排涝相关研究有较好的借鉴意义。

Characteristics of Rainstorm and Flood Disaster in Shaoyang City and Flood Protection Countermeasures

Based on ground meteorological observation data at 10 representative stations of Shaoyang City during 1951-2017 and rainfall data at over 220 automatic weather stations during 2005-2017,statistical analysis on rainstorm and flood disaster in Shaoyang was conducted. Occurrence characteristics and rule of rainstorm and flood disaster were found,and disaster situation was evaluated and analyzed. The results showed that（ 1）there was almost local rainstorm and flood in Shaoyang City every year,with strong seasonal characteristic.（ 2） The loss caused by rainstorm and flood disaster was the most serious in various meteorological disasters.（ 3） Rainstorm and flood disaster generally had the sudden and devastating characteristics. Via the analysis and research on rainstorm and flood disaster,defense measure and countermeasure of rainstorm and flood were proposed,which could provide scientific decision basis for party and government leading flood relief,and had important guidance significance for preventing and mitigating disasters by government agencies.

基于组合赋权-云模型的城市洪涝灾害韧性评价方法

基于城市系统应对洪涝灾害事件的响应过程,从基础抵御、防灾预警、应急响应和适应恢复4个方面构建了包含4个一级指标和20个二级指标的城市洪涝灾害韧性评价指标体系,在此基础上通过可拓层次分析法和熵权法对指标分别进行主观和客观赋权,结合博弈论理论进行组合赋权,提出了基于组合赋权-云模型的城市洪涝灾害韧性评价方法。南京市6个行政区的验证结果表明:该方法可有效评价城市洪涝灾害韧性水平,6个行政区中建邺区、江宁区为高韧性地区,鼓楼区、秦淮区为较高韧性地区,雨花台区为中等韧性地区,溧水区为较低韧性地区。

基于知识图谱的城市洪涝灾害链推演及时空特性解析

城市洪涝灾害具有链式传播特性,解析城市洪涝灾害链的传递规律和时空演变特征对于阻断灾害链具有重要意义。本研究以郑州“7·20”特大暴雨洪涝灾害中地铁5号线被淹和京广快速路隧道被淹2个事件为案例,构建知识图谱揭示灾害链传递规律。通过复盘灾害链的演变过程,从中识别灾害链中的诱发点、引爆点、扩散点以及放大点,并着重分析致灾机理以及灾害链的时空特性,以灾害曲线形式直观展示不同灾害链的影响程度。郑州“7·20”洪涝灾害典型案例解析表明,两事件存在多个灾害链阻断时机,在救灾过程中应综合考虑灾前、灾中因素的影响,果断采取断链措施,并且要充分发挥应急措施的时效性,及时阻断引爆点和扩散点,降低洪涝灾害损失。该方法能够应用于链式灾害的复盘,指导分析具体事件的致灾机理和救灾切入点。

城市生态防减灾中人工智能技术应用的进展与逻辑框架

在全球气候变化影响下,传统工程防灾难以解决自然灾害风险的不确定性问题。生态防减灾(Eco-DRR)作为国际韧性城市的前沿理论,对我国韧性城市发展有重要参考价值,人工智能(AI)技术可以很好地解决城市生态防减灾的不确定性问题,然而当前Eco-DRR理论研究与AI技术的实践应用存在断层。该文使用PRISMA2020框架调查城市Eco-DRR中AI技术应用的实践案例,通过质性研究总结城市Eco-DRR中AI技术的应用场景,从生态系统灾害调节服务评估、自然灾害风险评估、Eco-DRR方案决策以及Eco-DRR实施监测与后评估4个阶段剖析城市Eco-DRR中AI技术应用的典型案例。最后基于案例研究提出城市Eco-DRR领域AI技术应用的逻辑框架,总结其在应用过程中工具选择和数据准备的实践经验,探讨城市防灾中Eco-DRR的智能实现途径,为我国城市综合防灾和韧性城市建设提供借鉴。

利比亚德尔纳2023年极端洪水模拟复盘分析

全球气候变化背景下,极端强降雨和洪涝等水文事件的极值屡屡刷新历史记录,造成重大损失。2023年9月10—11日,在地中海飓风“丹尼尔”的影响下,利比亚东北部地区发生罕见特大暴雨,引发德尔纳市上游两座水库接连溃决,造成巨大人员伤亡。本文对德尔纳市极端洪水事件进行了梳理,并以德尔纳市洪灾及受影响区域为研究对象,建立了二维水动力模型,对溃坝洪水进行了模拟和复盘分析。通过哥白尼应急管理服务(Copernicus Emergency Management Service,CEMS)提供的受灾数据对模型结果进行对比验证(CEMS持续监测欧洲和全球即将发生或实时发生的灾难事件)。结果显示,影响德尔纳市的溃坝洪水持续了2 h左右,对城市的破坏主要集中在前30 min。本次复盘分析了德尔纳市溃坝洪水演进与风险分布特征,可为我国城市地区大坝溃决风险防控、早期预警和应急管理提供参考借鉴,同时也可为世界其他地区的大坝溃决风险防控、早期预警和应急管理提供参考借鉴。

考虑人群活动的城市场所洪涝灾害风险动态评估——以深圳市为例

为了揭示人群动态活动对城市洪涝灾害风险的影响,本文引入场所视角,建立了考虑人群活动的城市场所洪涝灾害风险评估模型,以深圳市福田区4个典型社区为例分析了工作日和休息日的白天、晚上4个时段下不同类型场所的洪涝灾害风险变化。结果表明:①除危险性以外,频繁的人群活动亦会增加场所的洪涝灾害风险,与人群活动相关的指标权重达0.31;②不同类型场所的洪涝灾害风险差异显著,且随着人群活动动态变化,生活场所平均风险最高,在4个时段波动较小;居住型混合场所洪涝平均风险次之,但晚上时段比白天高25%左右;商业场所、公共服务场所和办公型混合场所平均风险也较高,在工作日白天高于其他时段;绿色休闲场所在4个时段风险都最低;③居住型社区和综合型社区的洪涝风险存在显著差异,居住型社区为持续性高风险社区,其高风险场所占比在4个时段均超过40%,尤其在晚上达60%,而综合型社区风险呈现出工作日白天高于其他时段的特征,其高风险场所比例最高达54%。

基于生活圈的城乡一体化防灾空间构建方法研究

为推进城市与乡村防灾减灾救灾能力同步提升,以生活圈理论为指导构建城乡一体的防灾空间布局,推动城乡防灾设施配置一体化发展。首先,该文按照中灾正常、大灾可控、巨灾可救的目标,明确应对不同水准灾害影响的防灾生活圈层级对应关系;其次,从“常态中心性”和“灾害危险性”两个维度出发建立各村镇单元的防灾重要性评价指标体系,由此确定城乡各级防灾中心节点。在此基础上,利用防灾中心地、服务半径法和泰森多边形等方法构建“基础—拓展—综合”三级防灾生活圈,以此为依托并结合不同圈域城乡防灾目标要求,按照分类分级和平灾结合原则对各级生活圈进行防灾设施一体化配置,并以某县为例进行实证分析,为我国城乡防灾减灾一体化建设提供参考。

基于随机森林优化算法的城市群洪涝灾害韧性时空演变研究

为了提升城市应对灾害的能力,对城市洪涝灾害韧性进行研究。基于“驱动力-状态-响应(DSR)”模型建立城市洪涝灾害韧性评估指标体系,采用随机森林优化算法(RF)构建城市洪涝灾害韧性评估模型,通过均方根误差(RMSE)和决定系数(R2)评价模型性能。以关中平原城市群为例,分析西安、宝鸡、咸阳、商洛、铜川、渭南、临汾、运城、平凉、天水、庆阳等11座城市2011~2020年的城市洪涝灾害韧性时空演变规律。结果表明:驱动力和状态对城市洪涝灾害韧性水平影响较大,响应对城市洪涝灾害韧性水平影响较小;在时间序列上,关中平原城市群各城市洪涝灾害韧性水平发展存在较大差异,但整体处于平稳上升的状态,其中铜川的城市洪涝灾害韧性水平提升最为明显;在空间格局上,城市群洪涝灾害韧性水平呈现出由核心城市向外围递减的空间结构特征,各城市的洪涝灾害韧性等级的空间分布存在不均衡的现象。研究结果可为关中平原城市群韧性城市建设提供指导。

城市轨道交通工程防淹能力评估方法研究

近年来我国城市轨道交通工程水淹事件频发,人民生命财产安全受到威胁。交通运输部在2022年7月修订的《城市轨道交通初期运营前安全评估管理办法》中增加了“工程项目防洪专项论证报告等材料”作为轨道交通新线投入初期运营前的前提条件之一,因此开展城市轨道交通工程防淹能力研究十分必要和紧迫。本文从外部风险、基础防汛能力、防汛预警能力、应急救援能力等方面研究了影响城市轨道交通工程防淹能力的关键因素,利用专家打分法、层次分析法构建了评估指标体系及其权重系数,并根据我国现行法律法规标准规范提出了各指标评分细则,建立了城市轨道交通运营线路防淹能力评估方法,以期为我国汛期城市轨道交通运营安全提供技术支撑。