Spatio-temporal Distribution Characteristics Of Climate Change In The Tianshan Mountainous, China

Based on the daily data of 24 meteorological stations in the Tianshan Mountains, the author engaged in a spatial-temporal analysis of temperature and precipitation at first. Secondly, the daily potential evaporation of these meteorological stations was respectively calculated using related data, and then make statistics to monthly, seasonally and yearly potential evaporation, after that calculated the earth's surface humid index and make statistics to seasonally and yearly earth's surface humid index by monthly precipitation and potential evaporation. Finally, make spatial-temporal analysis of wind speed data. This paper comprehensively analyzed the spatial and temporal distribution characteristics of climatic change of Tianshan Mountains through related data, and revealed some climatic change characteristics of Tianshan Mountains in 50 years.We draw the conclusion:(1) On an average in Tianshan Mountains the climatic tendency rate of annual mean temperature and annual precipitation are 0.3℃/10a and 10.5mm/10a, which indicate the temperature and precipitation are obviously ascending especially the temperature in autumn and winter; The annual temperatures in most parts of the area (Excl Kuqa) show a warming tendency, the same as precipitation (Excl Qijiaojing), Precipitation enhancement is obviously in Urumqi and the next are Yining and Akqi; The temperature and precipitation in different seasons show different spatial discrepancies; The annual temperature before 1980s is relatively lower, warming rapidly in 1990s. The annual precipitation rise steadily since 1960s especially in 2000s; The annual temperature abrupt change happened in 1982, 1984 and 1986. It is corresponded to winter temperature abrupt change. The annual precipitation abrupt change happened in 1991, which is corresponded to summer.(2) The changing rate of annual potential evaporation varied at -2.48 mm/a, since the 1960s the annual potential evaporation has presented an undulated decreasing trend, and the decreasing trend was more evident since 1986. It began to increase since 2000; The potential evaporation increased in autumn, however, decreased in other seasons especially in spring; Regional variations exist in the interannual change in space, and the potential evaporation in Qijiaojing presents an increasing trend all year round; The potential evaporation is increasing before 1980s but decreasing after that;Spatial differentiations exist in different years; There were high multiple correlation coefficient between the climatic factors and potential evaporation. Different climatic factors have different influencing degree to potential evaporation. The potential evaporation decreased remarkably because sunshine duration and wind speed are decreasing, while temperature was the key factor influencing potential evaporation in autumn.(3) The change rate of annual humid index was 0.04 /10a, which indicated that the humid condition of study area has been improved; The annual humid index has presented an undulated increasing trend, especially in spring and summer. The earth's surface is relative drier before 1975 but moister after that; Most part of Tianshan Mountians in the annual, spring and summer are becoming wetter; The annual change of dry-wet conditions shows that the study area is discrepant in space, the southern area of Tianshan Mountain, Hami basin and most part of Tianshan Mountians are becoming wetter;There is no obvious period change in annual humid index. The spring departure sequence vibration is the clearest about 22 years, about 25 years in summer, about 15 and 7 years in autumn and about 12 years in winter.(4) The change rate of annual wind speed was -0.13(m/s)/10a, which indicated that the wind speed has presented a decreasing trend and more obvious than that of china; The wind speed is bigger before 1980s but smaller after that; The wind speed abrupt change test is notable and unanimous between annual and summer and autumn. The abrupt change happened in 1980, while the abrupt change of spring happened in 1982, and that of winter happened in 1979; The annual wind speed departure sequence vibration is the clearest about 11 years. There may exists longer period because of a shorter sequence. The negative correlation exists between wind speed and temperature. The temperature influences the wind speed in some degree especially the mean minimum temperature influence. It needs to further research why the wind speed in Qijiaojing presented an obvious trend. We guess it may have respect to its location and topography.