1、1 1.1 The early warning system of flood disasters significance As we all know, China is extremely frequent flood disasters hit countries, annual flood season flash floods triggered by rainfall, mudslides, landslides have caused heavy casualties and property losses, not only seriously threaten the li
2、ves of the masses, but the majority of seriously restricting the mountain hill areas of economic and social development and the people become rich, of building a moderately prosperous society goals. According to statistics from 1950 to 1990, Chinas flood death toll from a total of 22.5 million, of w
3、hich the number of deaths hilly 15.2 million, 67.4% of total deaths, average annual deaths 3707 people. Every year from 1992 to 1998 the number of deaths due to flash floods disaster is about 1900 3700 people, accounting for about flood deaths 62% 69%； flood disasters from 1999 to 2002 the number of
4、 deaths dropped to 1,100 1,400 people, but accounting for Flood death toll had risen to 65% to 75%； 2003,2004, respectively, of flood disasters caused by 767 and 815 deaths, accounting for the number of floods killed 49% and 76%. Thus, the number of deaths caused by flood disasters account for the p
5、roportion of the national flood death toll was increasing year by year trend, the harm caused by flood disasters increasing, more and more weight loss, flood control work has become urgent to solve the outstanding problems in . Flood disasters over a broad area, with significant multiple, sudden and
6、 strong disorder destructive, defense is very difficult. And Chinas heavy rain area, flash floods disaster-prone areas and populated areas overlap, more so the losses caused by flash floods layers increased. Statistics show that more than 2100 county-level administrative region of China, there are m
7、ore than 1,500 distribution in Mountainous Areas by the flash floods, mudslides, landslides threaten a population of 7,400 people. September 4, 2004, Premier Wen Jiabao instructed: torrential disasters, causing huge losses, disaster prevention and disaster reduction has become a 2 prominent issue. M
8、ust make the fight against flood disasters in an important position to conscientiously sum up experiences and lessons of flash floods characteristics and patterns of occurrence, adopt comprehensive prevention and control measures to minimize losses caused by disasters. In 2004, led by the Ministry o
9、f Water Resources, in conjunction with Ministry of Land Resources, China Meteorological Administration and other relevant departments, has established a national leading group of mountain flood control planning to begin preparation of the national mountain flood prevention plan. October 2006, Nation
10、al Disaster Prevention Planning, flash report through the review to study and explore the characteristics of flood disasters occur and laws, scientific and reasonable planning countermeasures and prevention programs, and gradually establish and improve the disaster prevention and mitigation system f
11、or increasingly critical of the flood disasters in China to determine the control status of norms. According to the plan target by 2010, China will focus on prevention and control area in the flood disasters initially built for the surveillance, communications, forecasting, early warning and other n
12、on-engineering measures based, non-engineering measures and the combination of engineering measures, the mitigation system. 1.2 Research Methods mountain flood warning system 1.2.1 The main features of flood disasters 1, sudden strong Torrential rain caused by the disasters, the storm intensity, cou
13、pled with the specific geological, geomorphological and other surface conditions, leading to flash floods ferocious. Metamorphic massif in Henan Province, severely weathered limestone and granite mountains composed of mostly easy to erosion, is conducive to landslides, avalanches and debris flow for
14、mation； hilly steep slopes and deep valleys, elevation ups and downs, fast runoff . Because many rivers in Henan Province, a large gradient, therefore, the rapid convergence, flood fierce rally, easy to produce flash floods disasters. Flash floods from rainfall to the formation of generally a few ho
15、urs or even less than an hour, more difficult to accurately forecast and control. 3 2, ferocious, destructive strength Since the end of steep mountain river, short process, flow speed, the impact of strong, destructive big, mining, transport and harm life and property are very serious. Its outstandi
16、ng performance is a strong destructive causing serious casualties and infrastructure damage, recovery is very difficult, or even destructive. July 2003 Huai River in early heavy rains in the southern mountains, bamboo round rural North County mall war village, burst in the July 10 debris flow, flow
17、rate 12.3 m / s, a destroyed house, a family of three all died. 3, the seasonal high frequency Precipitation is induced by flash floods, landslides, mudslides main reason for higher rainfall year in geological disasters have significantly higher frequency. 4 September flood season, especially in the
18、 main flood season 6 to 8 months, is a mountain flood-prone period. In the same basin, may occur even in the same year several flood disasters. According to statistics of Hunan Province, Hunan province flash flood disasters occurred in about 95% of flood disasters throughout the year, of which 6 to
19、8 months annual flood disasters account for about 80% of flood disasters. 4, regional apparent strong-prone Flash floods occurred mainly in the mountainous, hilly and mound, especially in the center of the storm area, storm impact when the easy formation of surface runoff, leading to flash floods, s
20、cour disaster. 1.2.2 The causes of flood disasters The flood disaster in the main stream and weather, topography and human factors and so on. Sudden flooding rain is the main factor of flood disasters caused by heavy rain causes of the formation is the main reason for the flood disaster, coupled wit
21、h human factors, the impact of topography, but also contributed to the formation of flood disasters. 1, the precipitation is caused by the most direct cause of flood disasters Uneven distribution of rainfall during the year, the annual variation and other characteristics, due to different conditions produce rain, flood with
