Evaluation Of Groundwater Quality In Guilan Province For Agricultural And Industrial Uses

Groundwater resource is one of the major sources of freshwater supply in the world. In recent years the extraction of groundwater in the North of Iran is increased to supply increasing demands for agricultural and industrial consumptions, because of surface water resource limitation. The aim of this research was to evaluate the quality of groundwater for various uses i.e. agricultural and industrial consumptions in four main regions i.e. Lahijan, Astaneh, Talesh and Fumanat. In this paper, three indicators i.e. Langelier, Ryznar and Puckorius indices and furthermore Wilcox classification method, were used to assess groundwater quality in this region. According to Langelier index, there was not an especial trend in groundwater quality during study period, some years there was a tendency to settle and in some years did not tend to corrode, where 85.61, 55.4 and 39.54 percent of the wells in the area in 2002, 2004 and 2009, respectively, had a tendency to settle. Ryznar and Puckorius indices suggest that the water is corrosive (both indices values>6). In 2002, 2004 and 2009 according to Ryznar index, 84.17, 97.12 and 98.45 percent of the wells in the area had a tendency to corrode. According to the Wilcox classification method, almost all of the samples classified in 'good' class, and have no restriction to use in agriculture.