An Effective Way to Determine Maximum Capacity of Pump Stations for Urbanized Polders

Rapid urbanization increases much more inundations by changing the initial surface of agricultural polders, in which capacity of pump stations isn´t enough for more runoff than before. No effective way is suitable to get the right capacity in urbanized polders due to their particularities. In this paper, a calculation formula, derived from water banlance with consideration of inner rivers´ storage (water surface ratio) and neglect of other influence factors, is used to generate maximum capacity of pump stations with different water surface ratios in the polder. As to the nonlinear relationship in the formula, a special method is used in the case study. Relationship between the capacity and water surface ratio is founded. According to cost comparision, an optimal group of capacity and water surface ratio is provided for decision makers.