An Evaluation of Temporal and Spatial Variation of Arsenic Anomalies in Water Resources of Sahand Dam Using Statistical Methods

In order to identify and control of heavy metal pollutions such as arsenic، the areas with high anomaly، distribution and trend of the changing of pollution in the study area should be determined. Due to the importance of Sahand dam in providing of water for drinking، industrial and agricultural and the reports of the unfavorable effects of drinking water containing high levels of arsenic on people''s health، the study of water quality is essential in this area. In the present study، to assess the temporal variation of arsenic anomalies hydrochemical data of quality monitoring provided by East Azerbaijan Regional Water Authority during 2002-2012 was used. Also، hydrochemical data related to 50 collected samples during September 2012، by the geology department of Tabriz University was used to determine the origin of high concentration of arsenic، the region of high potential of groundwater pollutions and depict the map of the spatial distribution of arsenic anomalies in the region. Among statistical methods، cokriging method was selected for interpolation of arsenic concentration in the study area. The process of geostatistical modeling، drawing the variogram، and selecting optimal model done using geostatistical software (GS+) and depicting the arsenic distribution map was prepared with Arc GIS software.