钱塘江海塘防洪御潮经济效益评估研究

Research on economic benefit evaluation of Qiantang dyke for defending storm tide and flood

钱塘江海塘经过1950～1957年、1997～2003年二个阶段的系统建设,大大提高了防洪潮标准,发挥了显著的减灾效益。本文在对风暴潮溢流、溃堤数值模型以及两岸资产价值推求方法研究的基础上,采用实际发生年法和频率曲线法,分别对钱塘江海塘一期、二期工程防洪御潮的经济效益进行了评估。一期工程以1950年为基准年,共投入资金1.82亿元,防洪效益为20.64亿元,效益费用比为11.34;二期工程以1997年为基准年,共投入资金25.56亿元,防洪效益为109.64亿元,效益费用比为4.29。评估结果表明钱塘江海塘工程的防洪潮经济效益是十分显著的。

The flood control standard of Qiantang dyke was greatly enhanced through construction of project phase 1 during 1950～1957 and project phase 2 during 1970～2003.This paper evaluates the economic benefit of these two project phases in defending storm tides and floods,by adopting the real-year method and the frequency-curve method,based on a simulation of storm tide by numerical model and an analysis of property.Results show that the benefit-cost ratio is 11.34 of project phase 1 with the benefit of 2064 millions and the cost of 182 millions RMB,and that the ratio 4.92 with benefit 10.964 millions and cost 2.556 billions of project phase 2.Hence,Qiantang dyke greatly reduces the economic losses caused by storm tides and floods.