平原联围感潮河网暴雨洪涝灾害风险分析:以珠江三角洲中顺大围为例  

Flood risk analysis of local heavy storms in the embanked tidal river plain:a case study behind the zhongshan-shunde joint levee in the lower pearl river delta

作　　者：徐张帆 王先伟[1,2,3] XU Zhangfan;WANG Xianwei(School of Geography and Planning,Sun Yat-Sen University,Guangzhou 510275,Guangdong,China;Guangdong Provincial Engineering Research Center for Public Security and Disasters,Guangzhou 510275,Guangdong,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519080,Guangdong,China)

机构地区：[1]中山大学地理科学与规划学院,广东广州510275 [2]广东省公共安全与灾害工程技术研究中心,广东广州510275 [3]南方海洋科学与工程广东省实验室(珠海),广东珠海519080

出　　处：《水利水电技术（中英文）》2021年第8期51-65,共15页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(41871085)。

摘　　要：珠江三角洲联围内部河网排涝受到局地暴雨、流域洪水、海洋潮汐和风暴潮等多种因素影响,面临复杂严峻的洪涝灾害威胁。以中顺大围为例,利用高精度的河涌断面测绘数据和陆地地形数据(DEM)融合生成水上水下一体化的高程模型(DEBM);并基于DEBM构建水位-库容曲线和水量平衡模型,建立综合暴雨径流、泵排量和外江潮位的联围水闸排水量计算方法,分析中顺大围在不同外江潮位顶托影响下的局地暴雨排涝防洪能力与洪灾风险。结果表明:与DEM相比,DEBM能更准确地表征联围内部的蓄洪容量,如在0.5 m水位时,河涌蓄洪容量从100万m^(3)(DEM)增加到4300万m^(3)(DEBM),可为泵闸调度和防洪能力分析提供更精确的基础数据。联围内部的排涝主要依靠水闸重力外排,但其排涝能力易受外江顶托影响;泵站排涝稳定可控,是辅助排涝的重要手段,更是外江遭遇极端洪潮水位顶托时的关键防洪减灾设施,但受制于泵站位置与水泵功率。在内江起始水位为1 m、面临百年一遇24 h降雨时,考虑外江不同潮位时水闸的重力自排以及泵站抽排,联围内部河涌水位最高将达到1.84 m,淹没面积达到中顺大围内部面积的33%,淹没区人口达49万;在面临外江极端洪潮水位顶托、水闸无重力自排时,联围内部河涌水位将达到2.16 m,淹没面积占44%,影响72万人口。研究成果对中顺大围以及其它平原感潮河网联围的防洪减灾应对与社会经济发展规划具有一定的参考价值和指导意义。The stormwater drainage behind the embanked channels in the lower Pearl River Delta is affected by the watershed flood,ocean tide and storm surges,causing complicated and severe flood threats.Taking the Zhongshan-Shunde Joint Levee as an example,we infuse the high-precision riverbed survey data into the land terrain(DEM)to construct a Digital Elevation-Bathymetry Model(DEBM),which is applied to compute the water level and storage capacity curve of embanked channels and to establish a water balance model to calculate the drainage rate of the sluices integrating storm runoff,pump and tide levels of the outer rivers.The results show that DEBM is more accurate than DEM to represent the flood storage capacity behind the levees.For example,when the water level is 0.5 meters,the flood storage capacity increases from 1.0×10^(6) m^(3)(DEM)to 43.0×10^(6) m^(3)(DEBM),which can provide more accurate data for the planning and operation of sluice and pump facilities and flood risk management.The sluice discharge plays a crucial role in stormwater drainage behind the embanked channels,but being severely impacted by the water levels in the outer main rivers,while the pumps also play an important role especially during the outer flood discharge and high tides,but being constrained by the location and pump capacity.When the initial water level of the inner channels is at 1m and it encounters with a 1:100a and 24-hour heavy storm,considering the sluice discharge and the full capacity of pumps,the maximum water level in the inner channels will reach 1.84 m,and inundate 33% area with a population of 490,000.Under the same storm and initial inner water level but in extreme situations of flood discharge and high tides,when sluices can not drain out due to higher water levels in the outer main rivers,the maximum water level of the inner channels will reach 2.16 m,submerge 44% area and affect 720,000 people.These results are significant in the operating,supervising and construction planning for flood control facilities in the study are

关 键 词：联围 感潮河网 水量平衡模型 水闸重力排水 洪灾风险 降水 洪水 

分 类 号：TV212.53[水利工程—水文学及水资源]