Perpustakaan Digital ITB

Mine voids are one of the resulting land changes from mining activities, especially coal mining using the open pit method. Mine voids could be filled with rain water and groundwater, which in turn become pit lakes. Pit lakes are classified as miscellaneous reclamation options - “Reklamasi Bentuk Lain" and can be utilized as water reservoirs, flood controls, ecosystem buffering, aguaculture, agriculture and/or power generation. Nevertheless, without proper management, mine voids yield the potential to harm human beings and the environment. Therefore, the existence af mine voids needs to be identified spatially and temporally to monitor and prepare a management Plan as soon as possible. The existence of objects on the earth 's surface, including mine voids, can be remotely acguired using remote sensing technigues, including using satellites. Sentinel 2 satellite imaginary data can be used for land change and monitoring, thus mine voids can be identified spatially and temporally using these data. In this study, mine voids mapping was carried out initially to extract water bodies based on land cover classification using various spectral indices, ie., NDVI, NDWI, and mNDWI and then the accuracy for each classification was assessed by calculating the Kappa value. The NDWI-based classification shows higher Kappa values than NDVI and mNDWI, thus giving a more accurate classification. Further Jiltering processes of water bodies using Mine Permit Area (WIUP) polygons are done to identify mine voids which are located within WIUP. In 2018, there are 192 potential mine voids within WIUP and 34 potential mine voids outside WIUP, while in the year 2020 there are 219 potential mine voids within WIUP and 31 potential mine voids outside WIUP. Voids mapping in this study could roughly classifv mine voids but other water bodies within WIUP (setiling ponds, sumps) could not be further distinguished. In addition, the geometrical parameters of mine voids are poorly calculated by this method. Additional methods need to be applied to increase ihe accuracy of determining, classifying and calculating mine voids and their geometrical parameters.