关键词: 大气降水; 水质; 时空变化; 离子特性; 污染类型; 吉安市;

Abstract: Based on 48 water samples collected from 12 atmospheric precipitation monitoring stations of Ji'an hydrologic Bureau in 2019,we analyzed the temporal and spatial variation of chemical characteristics from precipitation pH value, conductivity, ion concentration and its time variation trend, precipitation pollution type, etc.The results showed that:(1) The type of precipitation in Ji'an City was neutral or alkaline, the main pollution sources of precipitation were vehicle emission or nitric acid pollution.(2) SO42- and NO-3 were the main anions in precipitation, accounting for 80.1% of the total anion concentration; Ca2+ and NH+4 were the main cations, accounting for 90.9% of the total cation concentration.(3) There was no obvious seasonal variation of anion and cation concentration in precipitation, but the contents of Cl-,NO-3,Mg2+ and Na+ in the precipitation were less in the first, second and third quarter, and increased significantly in the fourth quarter; the contents of Ca2+ increased significantly in the third and fourth quarter; the contents of NH+4 content in the first and fourth quarter was significantly higher than that in the second and third quarter; and the contents of SO42- decreased significantly in the third quarter.

Key words: atmospheric precipitation; water quality; temporal and spatial variation; ionic features; pollution type; Ji'an City;