Analyses on Spatial-Temporal Differentiations of Air Temperature in Gansu Province during 1979-2008

Based on the ArcGIS Analyst platform,the ten-day mean air temperature in Gansu Province during 1979-2008 is analyzed by the CoKriging method with spatial interpolation,and 1 km×1 km surface data of ten-day mean air temperature are obtained.The results show that the averages of mean error,root mean square error,mean standard deviation,standardized mean error and root mean square standard deviation are-0.00046,1.998,1.809,0.0035 and 1.087 ℃,respectively.According to the characteristic of spatial-temporal differentiations of ten-day,monthly and annual mean air temperatures,it is found that there is lesser differentiation in the Southeast,and larger in other region in space.The trend of ten-day mean air temperature has been steadily dropping in the periods of the 23th-24th,the 24th-26th,the 25th-27th,the 33th-35th and the 34th-36th,in contrast,it has a steadily decreasing trend in the periods of the 4th-6th,the 5th-7th,the 6th-8th,the 7th-9th and the 8th-10th.Moreover,the monthly mean air temperature appears slight descendent trend in July and slight ascendent trends in March,May and October.The annual mean air temperature in Gansu Province in 1979-2008 is 8.05 ℃.The minimun temperature of 3-year running mean in 1983-1985 is 7.13 ℃ and the maximum temperature,8.82 ℃,which has obviously ascendent trend.