On Change in Mean Maximum Temperature,Minimum Temperature and Diurnal Range in Jianzha in the Upper Reach of Yellow River

Based on the temperature data in Jianzha during 1961- 2007,the trends of annual mean air temperature,annual mean maximum and minimum temperature and diurnal temperature were analyzed. The results showed that annual mean temperature increased obviously for Jianzha in the last 48 years,especially in winter,it kept space with Qinghai Province. The climatological warming trend was 0. 24 ℃ /10a,the autumn take second place. The increasing range of mean maximum temperatures is more dominant than that of mean minimum temperatures, this feature was much more distinct in autumn and summer. Annual mean diurnal temperature has increased,especially in autumn. The increasing trend is the main reason which causes the increasing of maximum temperature,a typical feature of the increasing trend of annual mean diurnal temperature is that the increasing range of mean maximum temperature is above the minimum temperature.