Analysis of Spatial-temporal and Ion Characteristics Change of Precipitation in the Southwest of China, from Policy Perspective

According to the data from Luzhou environmental monitoring center from 2015 to 2018, the tendency of spatial-temporal and ion characteristics in precipitation have been analyzed in order to demonstrate the precipitation pollution status. Traditionally, the environment may become worse as the development of the economy, especially in the developing countries. However, the results show that the quality of precipitation has been improved during these four years. The annual average pH value of precipitation in Luzhou City increased, and the frequency and conductivity of acid rain declined, which indicates that the quality of precipitation improved annually. This may due to a strictly political strategy enacting. The decrease of the equivalent concentration ratio of SO42- and NO3- demonstrated the transformation of pollution type, evolving from a typical sulfuric acid to a mixed type of sulfuric and nitric acid, indicating the economic transformation. The correlation coefficient between SO42- and NO3- was high. This may be because SO2 and NO2 emitted from industrial enterprises entered the atmosphere together in the same way. The strong correlation between F- and SO42-, NO3- may relate the pollution sources such as cement and glass enterprises. It is necessarily to strengthen the management of relative enterprises.