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.

issues about ecological water use are summarized from its concep t, background, estimation method and research ad2 vances. On the basis of the summary, some questions in research at p resent and the possible breakthrough in mechanism investigation of ecologicalwater use are put forward. At last, it is pointed out that under the background of climate warming and shortage ofwater re2 source, the spatial and temporal variation of ecologicalwater use corresponding to supp ly and demand balance ofwater resource will be2 come hot scientific issue.

The operation synthetical system for hailmonitoring, warning and hail supp ression command in Northwest China consists of four sub - systems, including the hail disaster database, the hailmonitoring system, the hailwarning system and the hail supp ression commanding system. Based on the p resent research results, the system has used the new data from Dopp lerweather radar, satellite remote sensing, lightningmonitoring and so on to build a powerful, convenient and open command p latform for hailmonitoring, warning and supp ressing by the p rimary means of the computer network and software technology. The system is valuable in the operation app lication. And this paper has highlighted the function and the design of the system.

:Minqin oasis lies to the northeast of Hexi corridor and lower reaches of Shiyang river,the environment there had degenerated
obviously in recent 40 years.The hungriness of soil, death of vegetation and other facts about Minqin oasis were analysed,the cause of
formation from the change of climate and human activity had been analysed too,Several suggestions of environment protection were
put forward at last.