CHARACTERISTICS OF THE CLIMATIC VARIATATION IN ZOIGÊ IN THE PAST 45 YEARS AND ITS EFFECTS ON THE ECO-ENVIRONMENT IN THE AREA

Grassland degradation and desertification have become one of the prominent environmental problems in the Zoigê area.This paper analyzes the characteristics of the climatic variation from 1957 to 2001 and its influence on the eco-environment in the Zoigê area.The annual average temperatures in the area showed a marked tendency of increase,with an increase rate of about 0.23℃ per 10 years,and the seasonal temperatures also showed a tendency of increase,which is especially the case in autumn(from September to November) and winter(from December to February) when the temperatures rose more significantly.The annual precipitation showed a slight decrease tendency,with a decrease rate of 1.75mm per years.In autumn and spring(from March to May),the precipitation showed a tendency to decrease year by year,and more marked decrease was recorded in autumn.However,in summer(from June to August) and winter the precipitation shows a tendency to increase year by year.Affected by warming and drying,the frozen ground and vegetation in Zoigê changed.The eco-environmental problems such as grassland degradation and desertification have had great effects on the social,economic and eco-environmental development in the area.