اثرات زيست محيطي معدن كاري در منطقه اولنگ استان گلستان (جنوب راميان)

The Environmental Impacts of Mining in Olang Area, Golestan Province (South Ramian)

Olang Coal Mines in the Ghareh Chai watershed are located 100-130 km far from Gorgan and 20 km to the south of Ramian. In this research, the environmental impacts of these mines in this region includ ing impacts on soil and water resources, slope instability and river bed erosion have been investigated. To evaluate the effects of mine drainage and surface pollutants, 34 water samples were collected in two different seasons, spring and summer. The samples were collected from mine drains and upstream and downstream of the junction points of such drains with streams, and subjected to analysis for chemical constituents. The results have shown that mine drainage has increased salinity and organic content of natural streams, but it has not significantly affected the concentration of heavy metals and other constituents. The most polluted samples are those located close to the dumps. This suggests that improper disposal of mine dumps, which are extensive in the area, is the main cause of soil and water pollution. Therefore, proper sealing of such dumps and optimum management of mine drainage is needed to minimize the negative impacts of coal mining. To evaluate the slope instability and land sliding associated with mining activities, first of all, the position of all land slides were located and mapped. The causes of each landslide were then identified. The analysis shows that land sliding is more common in the mining areas, and human activity together with natural causes such as geology, climate and hydrology play important roles in the occurrence of landslides. Keywords: Environmental effects, Mining, Olang, Golestan Province For