【作者】 胡蓓蓓；

【导师】 许世远； 陈振楼；

【作者基本信息】 华东师范大学 ， 自然地理学， 2009， 博士

【摘要】 自然灾害风险是当代国际社会、学术界普遍关注的热点问题。沿海城市是世界上人口、经济和社会发展的重要区域和集聚中心,也是自然灾害易发和频发区域。天津市滨海新区是继深圳经济特区、浦东新区之后,又一带动区域发展的新的经济增长极。然而,特殊的自然地理条件和沿海人为活动的影响,使滨海新区成为我国沿海受自然灾害影响较大的地区之一。开展天津市滨海新区主要自然灾害风险评估研究将为该区制定综合自然灾害风险管理范式、应急控制预案和可持续发展模式提供理论基础和科学依据。在国家自然科学基金项目(40730526、40571006和70703010)的资助下,本文在运用经验模态分解(EMD)和Mann-Kendall等方法分析天津市滨海新区主要自然灾害变化特征及其形成机理的基础上,基于概率分析和情景模拟,运用编译的基于GIS的计算机程序和水文数学模型对天津市滨海新区地面沉降、暴雨内涝、风暴潮等自然灾害进行了风险评估,依此提出了天津市滨海新区自然灾害风险管理的对策和建议。本文取得的主要结论如下:(1)天津市滨海新区主要自然灾害各自特征如下:累计地面沉降较大、地面沉降趋势减缓;海平面持续上升、月平均海平面汛期较高;降水总体趋于减少、年内分配不均、暴雨频次增多且强度增大;年最高潮位持续较高、各月出现频率不均、风暴潮出现频次不断增加、风暴潮灾害严重。(2)基于自然灾害系统理论构建了既反映累计地面沉降情况又考虑地面沉降主要致灾因子及其变化发展趋势的地面沉降相对风险评价指标体系,天津市滨海新区地面沉降相对风险评估结果表明:该区地面沉降高风险区和较高风险区主要位于汉沽区城区,塘沽区胡家园街、杭州道街、向阳街和新港街,津南区葛沽镇,以及大港区的中塘镇和小王庄镇。(3)鉴于地面沉降演化的地质系统渐变性特征,从主要致灾因子考虑建立地面沉降数值模型。设计三种地下水开采方案,编译计算机程序预测地下水位动态变化过程中的地面沉降值,并计算不同方案下的地面沉降损失。至2020年,三种方案下天津市滨海新区最大累计沉降量分别达650mm、520mm和150mm;全区平均累计沉降量分别达268mm、177mm和95mm;地面沉降损失分别达122.21×10~8元、80.71×10~8元和43.32×10~8元。(4)自行开发了基于GIS的洪水淹没区计算模块,利用模块中无源淹没程序计算和模拟了不同重现期暴雨内涝的淹没范围和淹没深度,根据不同淹没水深损失率计算出淹没损失。现状条件下,发生千年一遇、二百年一遇和五十年一遇暴雨时,天津市滨海地区分别有22.85%、20.06%和16.42%的土地不同程度受淹,淹没损失分别达28.16×10~8元、23.89×10~8元和18.46×10~8元。(5)根据地面沉降和海平面上升预测结果设计了最不利、适中和最理想化三种情景,分别评估了2020年三种情景下不同重现期暴雨内涝风险。至2020年,发生千年一遇、二百年一遇和五十年一遇暴雨时,在最不利的情景一下:天津市滨海新区分别将有32.73%、29.34%和26.01%的土地不同程度受淹,受淹人口分别为225～338万、203～305万和176～264万,淹没损失分别达220.89×10~8元、181.39×10~8元和139.12×10~8元;在最理想的情景三下:该区分别将有29.06%、25.83%和22.58%的土地不同程度受淹,受淹人口分别为200～300万、179～268万、150～224万,淹没损失分别达174.48×10~8元、135.29×10~8元和111.53×10~8元。(6)根据历史上典型风暴潮淹没情景,在现有防潮堤的情况下,运用圣维南和薄壁堰自由出流等公式推求不同频率风暴潮进潮量,利用开发的有源淹没程序计算不同频率风暴潮淹没范围。天津市滨海新区出现频率为5%、1%和0.5%的年最高潮位分别达4.54m、4.92m和5.08m(大沽零点基面);现状条件下,三种频率风暴潮可能淹没的土地面积分别达5.25km~2、58.38 km~2和118.50km~2;淹没损失分别达1.79×10~8元、3.93×10~8元和5.06×10~8元。(7)根据天津市滨海新区主要自然灾害风险评估结果,确定天津市滨海新区自然灾害风险管理的对策:加强地面沉降防治管理、加强防洪减灾体系建设、加强泻湖——防潮堤等海挡工程体系建设以及加强“三廊三带三区”生态用地的布局和建设等。更多还原

【Abstract】 Natural disaster is the hotspot question in international society and academe. Coastal cities are important areas and strategic focus of people convergency,national economy and society development.However,natural disasters happen easily and frequently in these areas.Tianjin Binhai New Area(TBNA) lies in the center of the Bohai Rim Region.Following the Shenzhen Special Economic Zone and Pudong New Area,TBNA becomes a new polarization of economic development which drives regional growth.Affected by physical-geographical conditions and human activities, TBNA is one of the areas where the loss from natural disasters is very fierce and fatal in the coastal areas in China.This dissertation will provide bases of theory and scientific tools for natural disaster risk management model,emergency plan and sustainable development model. This dissertation was financially supported by the National Natural Science Foundation of China(No.40730526,No.40571006 and No.70703010).Based on the analysis of change characteristics of major natural disaster by Empirical Mode Decomposition(EMD) and Mann-Kendall test and its formation mechanism,this dissertation assessed the risk of land subsidence,torrential rain and storm surges in TBNA respectively by probability analysis,scenarios simulation,GIS and hydrological mathematical model.Based on the assessment result,specific strategies were put forward for natural disaster risk management.Several main conclusions are shown as follows:(1)The main characteristics of major natural disaster in TBNA are as follows:the accumulative subsidence is large but the trend of land subsidence is slow;sea level rises persistently,and is higher in flood season;the precipitation tends to decrease in general,annual distribution of precipitation is uneven,and frequency and intensity of the torrential rain have an obvious increasing tendency;the annual high tidal level continues high,the monthly distribution of the annual high tidal level is uneven,the frequency of storm surge increases continually,and the disaster is very fierce.(2)Based on the system approach and the natural disaster risk index theory,an indicator framework for assessing the land subsidence risk was designed,in which there were 3 first level indicators(the hazard,the vulnerability,and the capability of disaster prevention and reduction) and 9 second level indicators.The very high risk and high risk areas were mainly in the part of the Hangu downtown,Hu Jiayuan Sub-district,Hang Zhoudao Sub-district,Xiangyang Sub-district,Xingang Sub-district,Gegu Town,Zhongtang Town,and Xiao Wangzhuang Town.(3)Different from sudden disasters,land subsidence is a slow-onset geohazard and accumulated over years.In terms of the main causing factor,the numerical model of land subsidence was established.With three groundwater extraction scenarios,the computer program was compiled to predict the land subsidence in the process of dynamic changes of groundwater level.Maintaining the same condition of groundwater exploitation in 2007(Scenario 1),from 2007 to 2020,the maximum accumulative subsidence in TBNA will be 650ram and the average accumulative subsidence will be 268mm.With 2%decreases in groundwater exploitation year by year(Scenario 2),the maximum accumulative subsidence will be 520mm and the average accumulative subsidence will be 177mm.With the water from South-to-North Water Transfer Project replacing groundwater exploitation completely (Scenario 3),the maximum accumulative subsidence will be 150mm and the average accumulative subsidence will be 95mm.To 2020,the loss induced by land subsidence under Scenario 1,Scenario 2 and Scenario 3 will be 122.21×10~8yuan,80.71×10~8yuan, and 43.32×10~8yuan respectively.(4)Based on GIS,the calculation model of flood submerged area was established. The submerged area and depth were calculated by the module of“non-source flood”. On the basis of the loss rate of different submerged depth,the submerged loss was gained.In accordance with the GDP of Tianjin Binhai area in 2007 and present situation for land use,the submerged area is 22.85%,20.06%and 16.42%;and the loss of submerged is 28.16×10~8yuan,23.89×10~8yuan and 18.46×10~8yuan respectively induced by torrential rain with return period of 1000,200,and 50 years.(5)To 2020,three scenarios were design.Scenario 1:268mm average subsidence and 55mm sea-level rise;Scenario 2:177mm average subsidence and 40mm sea-level rise;Scenario 3:95mm average subsidence and 24mm sea-level rise.In accordance with population scale,GDP,and land allocation in 2020 by master plan,under Scenario 1,the submerged area is 32.73%,29.34%and 26.01%;inundated population accounts for 225～338×10~4,203～305×10~4 and 176～264×10~4;and the loss of submerged is 220.89×10~8yuan,181.39×10~8yuan and 139.12×10~8yuan respectively induced by torrential rain with return period of 1000,200,and 50 years.Under Scenario 2,the submerged area is 30.70%,27.47%and 24.23%;inundated population accounts for 212～318×10~4,193～289×10~4 and 165～248×10~4;and the loss of submerged is 199.68×10~8yuan,150.31×10~8yuan and 126.03×10~8yuan respectively induced by torrential rain with return period of 1000,200,and 50 years.Under Scenario 3,the submerged area is 29.06%,25.83%and 22.58%;inundated population accounts for 200～300×10~4,179～268×10~4 and 150～224×10~4;and the loss of submerged is 174.48×10~8yuan,135.29×10~8yuan and 111.53×10~8yuan respectively induced by torrential rain with return period of 1000,200,and 50 years.(6)According to representative storm surge in history and the existing tidal barrier, tidal influx volume of storm surge in different frequency was calculated by hydrological mathematical model,and the submerged area of storm surge in different frequency was calculated by the module of“source flood”.The Gumbel method was used to calculate the annual high tidal level in different frequency.The annual high tidal level is 4.54m,4.92m and 5.08m in the frequency of 5%,1%and 0.5%.The submerged area account for 5.25km~2,58.38km~2 and 118.50km~2;and the loss of the submerged is 1.79×10~8yuan,3.93×10~8yuan and 5.06×10~8yuan respectively induced by storm surge in the frequency of 5%,1%and 0.5%.(7)In accordance with result in risk assessment of major natural disaster,this dissertation proposed the implementation strategies for the natural disaster risk management and suggestions on implementation of the natural disaster risk management in TBNA.更多还原