奉化江、甬江治理对姚江防洪能力的影响及对策

浙江省境内的姚江与奉化江汇合后形成甬江，属浙江省八大水系之一．随着奉化江、甬江两岸堤防的建成，两江洪水归槽致使洪水位抬高，对姚江东排能力产生一定的影响．据此，经水文分析、明渠非恒定流水力学计算，利用一维非恒定流模型，定量分析了奉化江、甬江两岸建堤后对姚江东排能力的影响，通过多方案比选确定最优方案．考虑平原北侧钱塘江水位低、排洪距离短的优势，疏通平原骨干河道向北排洪能力、扩建北排闸门，增大北排钱塘江能力的措施，变被动地受姚江大闸闸下水位影响为主动地扩大北排能力，为姚江防洪能力的提高明确对策．

Flood Protection Impact of Yong and Fenghua River Regulation on Yao River

Yong River is one of the 8 water systems in Zhejiang province, starting from the meeting point of Yao River and Fenghua River. Currently, floodwater of Yao River is drained eastwardly to Yong River. The impact of dike construction of Fenghua River and Yong River is analyzed in this paper on the eastward floodwater drainage of Yao River based on 1D non- steady numerical model. The main countermeasure supposed to reduce the impact is to enlarge the northward drainage ca- pacity to Qiantang River, thus, the floodwater drainage situation of Yao River could change from passively influenced by the downstream water stage of Yaojiang gate to actively drained to northward.