The research of below-cloud scavengingof rainwater in Guilin City

Sequential samples of single precipitation event were collected by the use of specially de-signed semi-automatic sequential precipitation collector in the spring of 1988 in Guilin City. ThePH value and soluble chemical species such as SO42-, NO3-, NH4+, Ca2+, Mg2+, Na+, K+, F- and Cl- were analyzed. An apparent decrease in the concentration of all ions except H+ and NO3- wasobserved at the initial portion of the events. The relative acidity increased as the event progress.The concentration of H+ was the result of comprehensive actions of all ions. The average scavengingratio of events was calculated and it is found that SO42- was the major contributor for acid rain inGuilin and Ca2+ was the important neutralizer.