Hanhzhou City Drainage Model Coupling Application Research

For a long time, the urban rainwater pipe and the regional channel were managed separately by municipal department and water conservancy department in our country. In fact, inconsistencies are very easy to be found between these two departments, in drainage standard, design methods and other aspects. These inconsistencies cause difficulties in urban drainage system designing, which should be considered in a more integrated way.For the existing drainage system, the hydrodynamic coupling model of city municipal drainage and drainage area can be used to diagnose the clear reasons of waterlogging; and suggest the solution subsequently. For the drainage systems in planning, the model can be used to determine overall pipeline, river drainage system layout and its scale, which strengthen the basis of future operation and management. Moreover, combining with meteorological, hydrological forecast, the conduit coupling hydrodynamic model can be used as an early warning system, which will be very helpful for decision making in flood situations.This paper chooses Hangzhou as its example. Surveys and analysis have been made in the aspects of geography, hydrology, meteorology, social economy, city construction and planning, the status of waterlogging disaster, causes of regional rivers, flood (tidal) characteristics of water, city drainage facilities, regional flood control and drainage facilities. Based on the previous research results, the paper establishes the river network large scale unsteady flow model and small scale conduit coupling model, the hydrological analysis, hydraulic calculation, control measures effect analysis, optimization of city drainage engineering pattern, system of perfect drainage city. This paper provides a reference for the future designing of similar city drainage system.