The structure design, data flow frame, characteristic and founction of themeteorologywarning and commanding service system forLanzhou railway flood preventionwas inrtroduced in this paper. By using network technology, the system provided a highly effective, high quality and prompt service platform for the Lanzhou Railroad Bureau. The system provides the real-timemeteorological data, 72 hours fine prediction, three times line prediction in a day, mid-rangeweather forecast and the flood disaster information as well as jurisdictionalboundary chartalong the route. Moreover, based on statistics ofall flood disaster information provided byLanzhou Railroad Bureau andmeteorological data during the period of2002-2007, the temporal and spatial distribution of flood dasster along the railway route has been obtained, and the flood disaster features under the different type andmagnitude ofprecipitationwas also obtained and five gradeswarning ranks have been established, the railway line flood disasterwarning signal is issued for 15 routes, respectively.

Based on the meteorological data of dustweather, the dailymean temperature and p recip itation inMinqin in sp ring from 1976 to 2005, the temporal and spatial characteristics of dustweather and relations between dustweather and weather conditions, water resources as well as human activitieswere analyzed. The results show thatmost of the dustweather occurred from noon to evening and lasted for 1 to 2 hours, and it p resented decreasing trend. Dust weather has negative correlation with p recip itation in Minqin area in sp ring. Itwas also revealed that the special geographical location, the significant reduction of Shiyang River runoff and population growth and so on resulted in more dustweather in sp ring.

Based on the application of Lanzhou Doppler radar products, the theory pattern of vertically integrated liquid water content (VIL) which is one of radar physical quantity products was introduced in this article. Several issues was brought forward from some aspects of the influence of radar detecting range and height, reflectivity intensity on the calculation of VIL, as well as VIL changed with season variation, so as to supply some references to distinguish severe convective weather based on VIL.

The content，structure，functions，characteristics and key implementing technologies of the Guiding Weather Forecast System in Northwest China are introduced in detail，which is a three levels network architecture based on Active Server Pages（ASP）technology and the Browser / Server（B/ S）. It proves in the practical application that this system is a perfect meteorological information management system for its integrating and sharing information among each department of meteorological bureaus expediently.