Environmental impact assessment of salt harvesting from the salt lakes

摘要

Urmia Saline Lake, USL which is registered as an international park by the United Nations, has suffered hypersalinity and serious dryness in recent years. Increasing the dryness trend has been led to a great tendency, especially by private sectors to harvest salt from different parts of the bed sediments. During this study the four- step process was used for environmental impact assessment of such a large scale salt harvesting activities with specialized Folchi matrix and enriched by data on heavy metal concentrations in the limited number of sediment samples. Impact analysis using matrix showed that the most significant impacts were on environmental components, namely “land use”, “gradient and topography of the lake bed” and “hydrology and lake water quality” with score values of 73.22, 73.21 and 72.45, respectively. The mean concentrations of As, Cd, Cr, Hg, Pb, Ni and Zn in salt and sediment samples were 15.2±8.8, 0.05±0.047, 15±8.2, 0.54±0.3, 11.9±6.28, 15.4±9.56 and 22.3±13.66 mg/kg, respectively. The higher concentration of arsenic and lead in comparison with earth crust averages, warns that dispersion of salt particles from storage piles may affect local people’s health. This study provides readers and authorities with environmental impacts of salt harvesting from unique saline Lake of Iran, presents effective management options such as stopping any unlicensed and unrestrained salt harvesting activities on the USL bed, avoiding deep excavations, minimizing accumulation of piles to prevent the diffusion of salt particles etc. and also specialized the Folchi matrix for application in similar projects.