(一)排水标准扣排水方案选定的意义排水标准和方案的比較选定是排水规划設計中最主要的工作,它决定着整个工程的規模及措施,所采取的标准及方案,不但在技術上应是可能的,在經济上也必須是合理的。排水标准过高(排水能力太大),受益虽有增加,但大大提高了河道、涵閘等工程的造价。排水标准过低(排水能力大小),花钱虽少,但河道涵閘过小,就不能解决应解决的內涝災害。即使在同一排水标 (A) Drainage standard deduction drainage significance of the program Drainage standards and programs for comparison and selection of drainage planning and design is the most important work, which determines the size of the entire project and measures taken by the standards and programs, not only in technology It should be possible and economically justifiable. Drainage standards are too high (drainage capacity is too large), although the benefits have increased, but greatly increased the cost of rivers, culverts and other projects. Drainage standards are too low (the size of drainage capacity), although the money is small, but the river culvert is too small, it can not solve the waterlogging to be solved. Even in the same drainage standard