Research On The Early-warning System Of Mountain Torrent Disaster Dynamic Precipitation Base On The HMS Model

China is the mountain torrent disasters, the direct economic losses caused by mountain torrent disaster is very serious every year. In order to avoid casualties and property losses brought about by the mountain flood disasters,China launched the project of " China Mountain torrent disaster Prevention Planning".Shandong province determined 56 counties(city, area) in 2013. 49000 km2 mountain torrent disaster prevention and control area is involved. Wendeng Weihai Shandong province as the research objectand of this research and divided small watershed as 10~50km2,researched the mountain torrent disaster warning. The main research content is as follows:(1) This paper collected rainfall and runoff data from 4 Hydrological Station in the study area. Used heavy rain measured method and contour diagram method to calculate the design storm rainfall amount, choose the heavy rain measured method at last by comparing the advantage and disadvantage of these two methods. In the analysis of net rainfall, initial and constant loss was selected when comparing with rainfall runoff-experiential correlation method. As for the confluence analysis, rational formula method, the unit hydrograph method and HMS model method were used. The traditional method was mainly used to calculate the storm flood in small watershed.(2) HMS hydrological model was established based on the computation module embedded in hydrological model including runoff(SCS model curve method), flow confluence(SCS unit hydrograph method), base flow(exponential decay method), and Channel flood routing model(muskingum Method). The rainfall-runoff relationship in small river basin was simulated and calibrated using the observed data. The early warning rainfall within the flow confluence time was counted by trial method using HMS hydrological model.(3) Building a critical-warning indicator based on HMS watershed hydrological model, and using the scenario of Runoff model and Direct Runoff model to simulated and forecasted floods. By evaluating the accuracy of floods reference to the national code, a dynamic early-warning indicator which applied to the wendeng district of Weihai City was selected.Finally, the disaster prevention of rainfall warning in wendeng district of Weihai City were obtained. Constituting the water level which prepare to transfer or immediate transfer with rainfall warning rises and falls 10%, and make a chart for critical rainfall with town as its basic unit.