【摘要】 运用R/S(Rescaled Range Analysis)方法,对1951—2000年过去50年西安市的气温、降水、相对湿度和日照百分率等气候因子的冬(12、1、2月)、夏(6、7、8月)和年平均值进行了分析计算,各因子的Hurst指数H均大于0.5,说明了4个因子存在明显的Hurst现象,反映出西安市过去50年来气候变化存在趋势性成分。过去50年气候资料统计表明,西安市气温呈现升高趋势,而降水、相对湿度和日照百分率则呈下降趋势,城市化效应已经对西安局地气候产生显著的影响。更多还原

【Abstract】 R/S(Rescaled Range Analysis) is an effective method in fractal geometry and has been extensively used in many fields.This paper analyzes the temperature,precipitation,relative humidity and sunshine percentage in winter(from December to February) and summer(from June to August) and their annual averages in the Xi’an region since recent 50 years from 1951 to 2000.The results are as follows:(1) The Hurst indexes of temperature in winter and summer and its annual average are 0.70,0.82 and 0.67,those of precipitation in winter and summer and its annual average are 0.76,0.87 and 0.61,those of relative humidity in winter and summer and its annual average are 0.68,0.78 and 0.66,and those of sunshine percentage in winter and summer and its annual average are 0.89,0.96 and 0.94,respectively.These reveal that all the Hurst indexes are higher than 0.50,and the four climatic factors have the significant Hurst phenomena.Thus,it can be proven that such climate change in Xi’an will be continued;(2) The differences of the Hurst indexes of these climatic factors in winter and summer and their annual averages are significant.The Hurst indexes of these climatic factors in summer are higher than those in winter.It can be concluded that the seasonal intensity of climatic change caused by urbanization in Xi’an will be continued,and the climate change caused by urbanization in summer will be more significant than that in winter in the future.The statistical results of climatic data observed since recent 50 years in Xi’an show that the temperature in winter and summer and its annual average will be continuously increased.From the 1980s,the average annual temperature in Xi’an has been significantly increased.However,there have been decreasing trends in precipitation,relative humidity,and percentage of sunshine duration in Xi’an since recent 50 years.更多还原