ارزيابي ريسك زيست محيطي معدن كاري در تالاب ها(مطالعه موردي تالاب ميقان استان مركزي)

Environmental Risk Assessment of mining in Meyghan wetland

تالاب ميقان در فاصله15 كيلومتري شمال شرقي شهر اراك واقع شده است. اين بررسي در سال هاي 1390-1389 و در طي 4 مورد بازديد منطقه اي و پيمايش زميني از منطقه در فواصل زماني مختلف از نقاط مختلف تالاب صورت پذيرفت و با استفاده از نرم افزار ArcGis نقشه هاي پايه مورد نياز از منطقه مورد مطالعه تهيه شد، سپس با استفاده از تصاوير ماهواره ايبراي سال هاي 2002 و 2008 و عكس هاي هوايي سال 1334 كه از سطح منطقه برداشت شده و استفادهاز نرم افزارErdasيك مقايسه و برآوردي از ميزان تغييرات حاصله در حوزه تالاب ميقان صورت پذيرفت. آناليزهاي مربوط به وضعيت كمي و كيفي آلاينده هاي كارخانه املاح كه در مجاورت تالاب است، مورد بررسي قرار گرفت و همچنين وضعيت كمي و كيفي فاضلاب شهري اراك كه از بخش جنوب شرقي به تالاب وارد مي گردد نيز مورد بررسي قرار داده شد، در نهايت ريسك هاي مرتبط با فعاليت هاي معدن كاري، شناسايي و با استفاده از روش ماتريس آناليز ارزيابي خطر بر اساس دو پارامتر شدت و احتمال سطح ريسك شان مشخص گرديد، همچنين با استفاده از روش 3D-Melborne بر اساس سه پارامتر تماس، احتمال و پيامد سطح ريسك عوامل خطر زاي ناشي از فعاليت معدن كاري بر روي جوامع انساني تحت تاثير مشخص و در نهايت پيشنهاداتي براي كاهش و تقليل اثرات عوامل خطرزاي ناشي از فعاليت معدن كاري در منطقه ارايه گرديد

Mighan Wetland is located in 15km North-east of Arak, geographic coordinate 49 42 00 to 50 20 00 east longitude and 24 07 00 to 34 41 30 north latitude. 4 times the region was observed during the research. Basic maps of the regions were studied using ArcGis software. Afterward a comparison and estimation of changes in the wetland were done by using images taken by Liss-III sensor satellite (Indian satellite Resourcesat-1) for 2002 and 2008 and aerial image by Army geography dept. in 1334 by Erdas software. Data gathered regarding qualitative and quantitative conditions of pollutants produced by mining industries in vicinity and beside Sulphate sodium mines were examined; moreover, same examinations were conducted involvingdischarged wastewater from Arak City into the wetland from southeast. Results were used to identify risk factors threatening the wetland; the factors may be classified into two main groups: related to mining operation and not related to mining operations. By identifying risks roots in mining operations, risk assessment analysis matrix was done based on intensity and risk probability level. Risk assessment analysis matrix is an effective tool for estimating acceptable risk level through establishing a bi-character sensing system to asses risk’s safe level. Moreover, 3D-Melborn method was used to estimate risks of contacting with hazardous factors resulted from mining activities on public based on three parameters of contact, probability and consequences and a set of countermeasures were introduced. Finally, altering processes in the regions through time were used as the basis to predict risks resulted from mining activities. The study has recommendations in order to reduce the hazards resulted from such activities