Over the past 50 years, temperature in the Northwest China p resented a significant rising trend, while p recip itation change was different in different p lace. Warming and drying trend is evident in the whole Northwest China, but the local appearswarming and wetting phenomenon. With the global warming, glaciers retreat and snow line rises, permafrost melts, wetlands degradation, lakes shrink, river flows decrease, water resource becomes scarcer, and eco - environmental degradation. According to IPCC forecast results, the climate warming trend in this region in the future will be more p ronounced. The countermeasures to p rotect the ecological environment, imp rove the comp rehensive climate change monitoring system, launch specific research on the key regional climate changep rocesses, and other suggestionswere put forward.
The spatial distribution ofwater resource shortage in China is summed up from the p ractical condition and sustaining devel2 opment angles. The actuality and trend ofwater resource are reviewed, the characteristic ofwater cycle and water resource utilization in arid region ofNorthwest China are analyzed. And research advances on water cycle and effective utilization ofwater resource in arid re2 gion are summarized, the scientific countermeasures about effective utilization of water resource in arid region are p reliminarily dis2 cussed. Finally, some important scientific issues aboutwater cycle and effective utilization ofwater resource in arid region ofNorthwest China are put forward.
The change of the 0℃level height in summer over the northeast side of the Qilian Mountain was analyzed, and the relationshipbetween the 0 `C; level height and surface temperature, precipitation, water vapor content in atmosphere and stream flow of inland rivers were discussed. Results show ; (1) The 0℃level height was obviously higher than normal in the late 1950s and the 1960s, and lower in the 1980s. It presented downward irend from the late 1960s to 1970x, and upward trend in the 1980s and 1990x, and it downward again in the first 4 years of the 21 s2 century; ( 2 ) From May to September, the positive correlation was found between the 0℃level height and surface temperature, water vapor content in atmosphere, and it was negatively correlated with precipitation, and there was low correlation
In this paper，some facts of creeping environment problems in Hexi region of Gansu province were given，it was pointed out that environment deterioration and climate abnormity aroused by humanactivities could impact on the persistent development of society and economy，people should think much of this problem.
The reasons of sandstorm occurring frequently in spring in Hexi corridor were analyzed .we found special geographical locadon .particular topography and physiognomy and arid climatic background are the main reasons. The number of sandstorm occurring in Hexi corridor has decreased since 1955 in general ,most in 1970 s'.least in 1990 s'.The results show that the occurring of sandstorm in Hexi corridor connects with winter monsoon of East Asia .and has吨h correlation with SST of Middle East Pacific in prophase autumn and winter. When the SST was higher .the winter monsoon of East Asia would be weaker .the number of sand storm occurring in Hexi corridor would be less than usual. On the contrary .it would be more.
In this paper，the level and the main methods were given about the drought climatic prediction in China at present，it was pointed out that the method of numerical model's prediction would be more important developmental direction of climateprediction in the future，because the method not only has explicit physical basic，but also has excellences of o句ectivity and quantification. Develop- ment of high resolution regional climate model provide many new ideas and methods for simulation andprediction of regional climate from 1990'sof last century. High resolution regional climate model fitting to Northwest China urgently require to develop for the studies of drought climatic changing regulation and prediction at this times.
