关键词: 西藏, 日照时数, 气温, 降水, 风速, 相对湿度

Abstract: On basis of the monthly data for the period 1961-2010 collected from 38 observational stations over the Tibet Plateau，by means of the climate tendency rate，accumulative anomaly and GIS spatial interpolation methods，the temporal-spatial variations of climatic variables over the Tibet in the recent 50 years were systematically studied，and the differences of climate change in different sub-regions were shown. The results indicated that: in the last 50 years，Tibet showed an increase of sunshine （with the linear tendency rate of 3.04 h/10 a），temperature（0.58 ℃/10 a），precipitation（12.5 mm/10 a），decrease of wind speed（0.13 m·s^-1·10 a^-1），and slightly rising trend of the average relative humidity（0.1%/10 a）. Distribution and change of the climate facters in different regions divided by geomorphologic situation are remarkable. Sunshine is longest in the northern Tibet Plateau，with a trend of decrease，while shortest in high mountains and deep valleys regions of east Tibet，but increased obviously. Annual mean temperature is highest in Lake Basin Valley Region of south Tibet，with slowly rising rate，and lowest in northern Tibet Plateau，warming fastest. The most average annual precipitation is in northern Tibet Plateau，while least in east Tibet，and precipitation increases obviously in Lake Basin Valley Region of south Tibet. Average wind speed is maximum in northern Tibet Plateau，minimum in high mountains and deep valleys regions of east Tibet，and all regions showed increased first and then decreased trend. Relative humidity is high in Himalaya Mountains region and in high mountains and deep valleys regions of east Tibet，low in northern Tibet Plateau and in Lake Basin Valley Region of south Tibet，and increase in all regions.

Key words: Tibet Plateau, sunshine duration, temperature, precipitation, wind speed, relative humidity