Study On The Influence Of City's Development On Flood Prevention And Water-log Draining Of The Segment Of Haihe River At Tianjin

As a big city, the problem of flood prevention and water-log draining of Tianjin has considerable representation because of its important position. Concerning of the urbanization process of Tianjin, this dissertation analyses the influence of city's development on flood prevention and water-log draining of the segment of Haihe River at Tianjin.The dissertation analyses the influence of urbanization on hydrology situations, the property of flood and water-logging, the mechanism of disaster generation. Considering the difference of runoff characteristics on different underlying surface in the area of plain tidal river network, the confluence segment of Haihe River at Tianjin has been divided two parts and respectively named suburban area and pipe network draining of town, and suitable method is adopted respectively in each surface to construct the urban rainfall-runoff model which simulates the process of runoff generation and confluence of town and the process of pipe's confluence and the runoff generation and confluence model of suburb'surface. Saintvenant Equations discreted by 4-point Preissmann implicit scheme, is used to calculate river flood water level. At last, because of the integration of the urban rainfall-runoff model, the model of runoff generation and confluence of suburb's surface,the river network hydrodynamics, the hydraulics model of Haihe River'confluence area has been constructed fully.At last, the dissertation has simulated the designing water-level of river network under different conditions of coming water and adjustment using the model constructed and the main achievements of it have provided guidance for the programming of flood prevention and water-log draining of Tianjin, also, the methods suggested here are applicable to other similar hydrological problems of cities in plain tidal river network area.