宁夏固原站大气干湿沉降变化初探

Analysis on Variation in Atmospheric Dry and Wet Deposition in the Guyuan Station of Ningxia

利用宁夏固原站2002年以来降水pH值和大气干沉降通量观测数据,分析了固原市区降水pH值和干沉降通量的时间、频率的分布特征及相关关系。结果表明,固原的降水呈弱碱性,存在的明显的月、季变化,冬春pH值高,达到7.40以上,夏秋逐渐降低,在7.00附近变化,呈现出单峰单谷值的变化趋势,且近年来呈上升趋势。大气干沉降通量在5月份存在极大值,12月份达到极小值。3-7月均为正距平,8-次年2月为负距平,呈明显的单峰谷型分布,自2004年以来,呈缓慢减少趋势。大气干沉降通量、降水月pH值与降水量三者之间存在一定的相关关系。

Based on precipitation pH value and dry precipitation data of the Guyuan station since 2002 in Guyuan station of Ningxia,the temporal distribution and frequency characteristics and correlations of the precipitation pH value and dry precipitation in the Guyuan station were analyzed.The results showed that the precipitation of the Guyuan station was alkaline.There were apparent existences of monthly and seasonal variation which reached more than 7.40 in winter and spring,and gradually reduced in the vicinity of 7.00 in summer and fall.The seasonal variation showed a single peak-valley pattern while the annual precipitation pH value showed upward trend in recently years.Dry precipitation reached from maximum in May to minimum in December.From March to July it showed positive anomaly,from August to February it showed negative anomaly,which was a ovbious single peak and valley type distribution.There was a slow decreasing trend since 2004.Dry precipitation,precipitation and precipitation pH value had a certain correlation.