新疆城市酸雨分布特征及变化趋势分析

Analysis of Distribution and Variation Trend of Acid Rain in the Cities of Xinjiang

通过对新疆乌鲁木齐、伊宁、哈密与和田4个城市1991-2008年降水pH值、K值(电导率)及相关的天气气候资料处理,分析了新疆城市酸雨分布特征和变化趋势。结果表明:北疆城市酸雨观测次数远远多于南疆城市,新疆城市降雨pH平均值有逐年平缓降低的趋势,乌鲁木齐和伊宁变化起伏大,哈密与和田变化小,K平均值年变化较为复杂,并且变化剧烈。北疆城市平均pH值明显低于南疆城市,大部分在6.0附近波动,总体呈下降趋势,南疆城市降水pH平均值变化幅度小于北疆城市,降水pH平均值大部分在7.00附近波动;北疆城市平均K值远低于南疆城市,起伏变化平缓且有逐年降低趋势,南疆城市变化剧烈。影响降雨pH平均值和K平均值大小的因素有很多,对于南北疆城市的这种变化,降水量多少可能是其主要的因素,南疆沙尘多也可能是其影响因素之一。

By investigating pH value, K value （conductance） and correlative climate data in Urumqi, Yining, Kumul and Hotan Cities from 1991 to 2008, and analyzing the character of distribution and variation trend of acid rain in Xijiang. Results show： there are more observation times of acid rain in Northern Xinjiang cities than Southern Xinjiang Cities, and there is a slow decreasing trend of yearly average pH value. The changes of Urumqi and Yining cities are dramatic, but Kumul and Hotan cities are not so much. The average changes of K value are more complex and dramatic. The average pH value in Northern Xinjiang cities is significantly lower than Southern Xinjiang cities, and mostly is fluctuating in the vicinity of 6.0. The change range of average pH value is narrower in Northern Xinjiang cities than Northern Xinjiang cities and mostly is fluctuating in the vicinity of 7. 0. At the same time, the average K value in Northern Xinjiang cities is far below than Xinjiang cities. There is a downward trend of the average K value in Northern Xinjiang cities but the change is dramatic. The effect factors of the average pH value and K value are so many, and precipitation may be the main factor, and the same time much dust may be one of factors in Southern Xinjiang cities.