长沙市防洪建设中若干重要问题探讨

Study on several important problems about urban flood-control construction of Changsha city

探讨了全国重点防洪城市长沙市防洪建设中的若干重要问题 :防洪标准、设计洪水位、防洪大堤高度等的确定 ;建设方针与程序、整体防洪能力建设、防洪建设与基础设施建设和景观建设协调发展等。长沙设计洪水位的确定应综合考虑以下几个方面 :湘江长沙段洪水与其支流和东洞庭湖洪水不存在高标准洪水同期遭遇问题 ,更不存在同频率洪水遭遇问题 ;湘江洪水流量与水位关系不是长沙洪水设计的主要依据 ;而南洞庭湖洪水位顶托和河道槽蓄量减少是影响长沙洪水位高低的动、静态因素。目前 ,长沙城市堤防设防高度偏高 ,减少了大堤的稳定性 ,造成了无效投资 ,影响了城市景观。防洪工程建设应分期实施、先除险后加固、注重整体防洪能力的提高 ,并处理好与城市基础设施建设和景观建设的关系。

Seveal problems about urban flood control construction of Changsha city, akey important flood control city in China, are studied These issues include the establishment of flood control standard, flood level designing and height determination of floodwalls; construction policy and program; entire flood control power construction; harmonious development among flood control installations construction, infrastructure construction and urban landscape construction,etc The designed flood recurrence interval (flood control standard) in Changsha city is 100a The establishment of flood level designing should take the following aspects into consideration: high standard floods in Xiangjiang River flowing through Changsha city and its branches as well as Dongting Lake have never met with each other nor the occurrence of the same frequency flood; relation is not the major evidence of flood design;and the amplitude of setup of flood of the South Dongting Lake is a unsteady influencing factor and the reduction of channel storage is a steady influencing factor of flood level in Changsha city Flood control levee altitude is higher than the real demand of Changsha city,which reduces the levee steadiness, and causes ineffective investment and influence on the urban landscape The flood control projects must be constructed step by step,firstly excluding the dangerous factors and then reinforcing levee and therefore improving the entire flood control power, also be harmonized relations with the construction of urban infrastructure and the construction of urban landscape