一、经济分析各国在规划、设计和修建水利工程之前,大都进行详细的经济合理性分析。这种分析已成为“工程经济学”的组成部分。经济合理性是以效益、成本的比值而确定的。效益指工程建成后每年所得直接效益;成本指总投资加上利息按偿还年限分摊的固定成本,再加上年运行管 I. Economic Analysis Most countries conduct detailed economic rationality analysis before planning, designing and constructing water conservancy projects. This analysis has become an integral part of Engineering Economics. Economic rationality is determined by the ratio of benefits to costs. Benefit refers to the direct benefit from the project after it is completed. The cost refers to the fixed cost of the total investment plus interest amortized over the repayment period, plus the annual operating cost