Paper Title
Effect Of Drought On Waterquality Variations With Using AQ.QA Software In Karoon River- Iran

Abstract
One of kinds of the natural disasters is drought. Our country, Iran, about every five years experiences a 2-3 year period of drought. The study area is a basin of Karoon River with average annual rainfall 515.5 mm. In this research, the data of a ten year period interval obtained from hydrometric stations at the Gotvand dam, Ahwaz and Bahmanshir River in Abadan was used. Next the data was analyzed by Aq.Qa software package. The results showed that at the downstream of Ahwaz and Bahmanshir station, the water was found as C4S4 Class in some months that are unsuitable for agriculture and drinking uses. The Piper chart indicated that the water quality is not steady along the course and the dominant cations in most of the years are Na+ K>Ca>Mg and the dominant anions in the Gotvand station are Cl> HCO3 >SO4 and at Ahwaz and Bahmanshir stations are Cl>SO4>HCO3. The dominant type at the all stations is choloro- sodic Na-Cl. Key words: Drought, Water Quality, River and Aq.Qa Software