The Hydrological Computation And Research On Flood Control And Governance Of Torrential Flood Ditch

The flood caused by rainfalls which happens in the mountainous regions anddisaster induced by the torrential floods which happens in both sides of mountaintorrents ditch such as debris flow,landslide and so on is called torrential flood ditchdisaster. Torrential flood ditch disaster will cause damage to the national economyand people’s lives and properties. Small watershed area in hilly regions possess smalldrainage area, river channel with poor storage capacity and steep slope. And torrentialflood ditch disaster usually occurs in this kind of drainage basin. It comes suddenlyand strongly, and will make a huge impact on people’s life and property security.Engineering measures combined with non-engineering measures should be taken totreat the torrential flood ditch where the disaster is serious. Analyzed and calculateddesign flood of drainage basin reasonably is the basic data that we need to grasp atfirst hand in torrential flood ditch governance. Hence, researching for thehydrological computation on the torrential flood ditch watershed is of greatsignificance. In this paper, the main contents and conclusions are as follows:1.Consulting and digesting the research status and achievements abouthydrological computation domestic and overseas roundly and systematacially. Thehydrological calculation method mainly conclude the reasoning formula method,instantaneous unit hydrograph method,etc．2. Watershed hydrological simulation analysis based on DEM and GIS will obtainbasin characteristics data to make a contrastive analysis with the data in CAD, thendiscussed whether the result of watershed information that extract from the GIShydrological analysis based on the DEM map is reasonable or not,it works out that thedrainage area and slope is reasonable.3. After analysis and comparison, adopt the method in storm manual ascalculation method in researching mountainous basin flood in this paper.4.According to the practical situation of the drainage basin, analyzed theconstitution of the downstream control cross-section’s designed flood. Considering the situation of engineering biased safety, meanwhile, proceed from the availability ofdata and the convenience of calculation，we adopt the computing method thatsuperpose the peak of interval flood peak and the peak of the flood released fromreservoir．5. Utilizing HEC-RAS model to calculate water surface profile,and research andcontrast the drop of the water surface profile before and after treatment,then analyzethe reasons and put forward suggestions to govern torrential flood ditch.