Géoinformatique et géostatistique : un aperçu

Interpretation of the Sources of Radioactive Elements and Relationship between them by Using Multivariate Analyses in Anzali Wetland Area

F Darabi Golestan, A Hezarkhani and MR Zare

Interpretation of the Sources of Radioactive Elements and Relationship between them by Using Multivariate Analyses in Anzali Wetland Area

The Anzali Wetland complex (37°23΄ to 37°37΄ E _ 49°19΄ to 49°35΄ N), is situated on the southwest shore of the Caspian Sea adjacent to Bandar-e-Anzali town on the northern boundary in Gilan province, northern Iran. The average radionuclide values for the 33 sampled points (26 deposit samples and 7 soil samples) were 24.66 Bq Kg-1 for Ra-226, 31.94 Bq Kg-1 for Th-232, 459.98 Bq Kg-1 for K-40, 3.72 Bq Kg-1 for U-235, and 11.66 Bq Kg-1 for Cs-137. Environmental problems (tourist zone sea-beach), agriculture waste (fertilizers, pesticides, herbicides especially from rice-fields), polluted rivers(10 biggest rivers) and industrial wastewater (30 main polluted factories) cause an anomaly in area. Correspondence analysis, principal component analysis (PCA) and cluster analysis applied to the data matrix to evaluate analytical results. According to this methods, three category of elements is recognized: (1) Th-232, Ra-226 and K-40; (2) Cs-137; (3) U-235. About 10 tributary rivers flow into Anzali Wetland Complex and cause a total precipitation near to 1500 -2000 mm / year. This fact implies that there exists a high rate of changes in this area, and many factors and characters must contribute or influenced in Interpretation and analyses. With comparison of average activity in Iran, average values of 226Ra and 232Th in sediment samples, respectively are lower and higher than the average observed in Iran. By comparing average activity of elements in the Anzali wetland area is lower than the average data in the world that published by UNSCEAR in 2000, but amount of K range and average is higher than the world.