The Application Study Of The Analysis And Calculation Method Of The Small Watershed Storm Flood In Hilly Region

In the global, annual mountain torrents resulted in great disaster. China is a mountainous country, in recent years mountain torrents disasters has become a flood disaster in China resulted in casualties of the main disaster species. Shandong Province is the Chinese mountain torrents disaster prone areas, in recent years occurred disasters caused by the loss of statistical threat of flood disasters in hilly area in Shandong Province and caused the loss becomes greater. In hilly area, the majority of the population living area is no flash flood warning, and the current flood early warning and forecasting also exist many difficulties. Therefore, the establishment of the effective flash mountain torrents warning method in more serious mountain torrents disaster areas is the urgent need of the mountain torrents disaster prevention and management. Among them, analysis of the storm flood of small watershed of hilly area calculation is the basis of mountain torrents disaster early warning and forecasting. This paper is a combination of Shandong Province, mountain torrents disaster prevention project, analysis and calculation of storm flood of small watershed in hilly area of, in order for mountain torrents disaster prevention and early warning.In Ju county, Rizhao City, Shandong Province, the big stone river watershed as an example, field measurements river section, section of stage discharge relation is calculated, river and flood characteristics were analyzed, the field survey on basin mountain torrents disaster in history, visits to traces of historical flood and the measurement.Using the rainfall data measured by design storm calculation and analysis, using the current commonly used three kind of traditional flood calculation method (rational method, instantaneous unit hydrograph method, regional empirical formula method) and try to design flood calculation and analysis on the using watershed hydrological model (HEC-HMS model), each four methods are used to calculate the frequency of peak flow. Then the four methods to calculate the peak flow carries on the contrast analysis, especially based on the field survey to the flood marks and corresponding rainfall data verify flood calculation method of identifying the most appropriate in hilly region of small watershed flood calculation method, and preliminary analysis of the influence of rainfall on peak flow calculation results.Finally draws the conclusion:in the traditional method, reasoning formula method for calculation in small watershed in the hilly area of rainstorm and flood, and instantaneous unit hydrograph method and empirical formula method does not apply in small watershed in the hilly area; watershed HEC-HMS hydrology model is applicable to calculate the storm flood of small watershed in the hilly regions. But taking into account the demands of the terrain data is relatively high and compared with the traditional method, the modeling process is relatively complex, so it is only recommended under the conditions of using watershed hydrological model of small watershed in hilly area of storm flood analysis and calculation, in the general case, rational method can meet the requirement; antecedent rainfall values of right and wrong is peak flow calculation accuracy and mountain torrents disaster early warning and forecast the key factors, and due to the antecedent rainfall is dynamically change with time, so the best way is to the real time monitoring, in order to carry out dynamic early-warning of mountain torrents disasters.