Climate Changes And Influence Of Urbanization On It In ShanXi Province's Arer During The Last 45 Years

The observation stations in Shan Xi Province are divided into the country stations, urban stations and basic-reference stations according to the population and the location of those stations. Based on the meteorological elements of the national basic- reference stations and ordinary stations in this area from 1960 to 2004, such as the maximum and the minimum temperature, the precipitation, the number of heavy rain days and the mean wind speed, etc, the analyses are made in two time series which are from 1960 to 2004 (latter 45 years) and from 1980 to 2004 (latter 25 years) in this thesis. With the comparison of each elements of the city stations and those of the nearby county stations separately, and with the assumption that the variety of the surface climate observation records of country stations along with time series is the natural variation trend of climate, the influence of urbanization to the surface climate observation records are tentatively got from the comparison. The temperature, the precipitation and the wind speed are analyzed especialiy.The following conclusions are drawn:With the influence of urbanization, the obvious decrease trend is found for the diurnal temperature range of mean temperature of the city stations compared with the country stations, especially in summer and winter.In summer with flush precipitation, the urbanization makes the precipitation increase relatively. But in other seasons, the urbanization makes the precipitation decrease. Especially in the droughty area and in spring and winter with less precipitation, the trend that the urbanization makes the precipitation decrease is more evident.For all types of observation stations in Shan Xi Province in latter 45 years, the numbers of heavy rain days decrease obviously with time, and the range of decrease of the basic- reference stations are less than the decrease of those country stations and city stations. In latter 25 years for all types of observation stations in Shan Xi province, the numbers of heavy rain days weakly decrease. But for the big city Tai Yuan, the numbers of heavy rain days in latter 45 year and in latter 25year all increase. With the influence of urbanization, the numbers of heavy days increase after 1980s of those city stations, especially the big city station and the station near the major coalfields.After the analyses of the variation of the annual, the season and the month mean wind speed, it seems that the urbanization makes the mean wind speed decrease.