HE Ping^1,4, LI Jin-xiao², Liu Guang-min¹, Li Hong-bo³ 

（1.The Department of Geography And Tourism Management, Chuxiong Normal University, Yunnan Province, Chuxiong 675000, China;
2．College Of Environmental Science And Engineering, Nanjing Information Engineering University, Nanjing 210044, China；
3. Lincang Meteorological Bureau of Yunnan，Lincang 677000,China;
4.The Department of Atmospheric and Ocean Science, Beijing University, Beijing 100084, China) 

Abstract: Based on the meteorological data of Lincang City and its suburbs during 19612010, this paper analyzed its regulations of interdecadal variation, annual variation, monthly variation and daily variation. The results showed that the annual variation of relative humidity has been declining, the most seasonal variation of relative humidity appears in summer, and the least appears in spring, and the most daily variation of relative humidity appears at 8 o’clock, and the least appears at 14 o’clock. Lingcang dry island intensity has begun to increase since 1971. At about 8 o’clock, the intensity of dry island effect is weak, and the most dry island effect appears at 20 o’clock. On the other hand, the least intensity of dry island effect appears in June, and the highest intensity of dry island effect appears in October. Through grey relationship analysis of the man-induced factors and natural factors which influence the intensity of dry island effect, we have drawn such a conclusion that the best part which influences the intensity of dry island effect in natural factors is the low cloud cover, and the best part which influences the intensity of dry island effect in man-induced factors is the urban population. Moreover, man-induced factors are more influential than natural factors.

Key words: Yunnan Plateau; Lincang City; relative humidity; dry island effect.

EARTH AND ENVIRONMENT Vol. 42, No.3, Tot No.299, 2014, Page 383-388