Assessment of Standard Syntaxis of Basin and Sub-basin Flood and Urban Drainage in Taihu Basin

Based on the existing flood control projects under the current flood control and drainage standards of the Taihu Basin, sub-basin, and urban, a 50a return period design storm that is the most unfavorable condition for flood control in the basin is selected as the rainfall data and input into the hydrological and hydrodynamic model for simulation. The safety capacity (K) and safety coefficient (Ki) are used to evaluate the standard syntaxis of basin and sub-basin flood and urban drainage in Taihu Basin The results show that the basin, sub-baisn flood control standards and urban drainage standards are deficient of standard syntaxis. The current flood control standards of basin can basically prevent the 50a return period flooding of basin, but the sub-baisn flood control standards and urban drainage standards are shortage. The contradiction of standard syntaxis of basin and sub-basin flood and urban drainage in the northern of the study area is more prominent than that in the southern. The urban drainage activities by polder areas have affected the flood discharge capacity of the channels of basin and sun-basin along the river, and further increased the pressure of the flood control regulation and storage of the Lake Tai. It is urgent to accelerate the construction of the key projects to improve the flood control standards in the northern of Taihu Basin.