« Retourner aux résultats de recherche
par De Geest, Anne Marieke 
Promoteur Giacomo, Santini;Catani, Filippo
Publication Non publié, 2021-08-31
Promoteur Giacomo, Santini;Catani, Filippo
Publication Non publié, 2021-08-31
Mémoire
| Résumé : | Metal demand is increasing due to increasing energy use and transition to global clean energy. However, mining of the Grasberg copper and gold deposits in the tropical environment of Papua, Indonesia, could have detrimental effects on local ecosystems. While effects of deforestation and mine tailings deposition are somewhat known, the detrimental effects of overburden stockpile failure have not yet been explored. This is becoming increasingly important as climate warming causes an increase in prolonged and heavy precipitation events, which can lead to failure of waste piles. These failures could release potentially harmful sediments into the Ajkwa river system. This thesis provides an approach to modelling overburden stockpile failure without field measurements, relying on remote sensing, available literature, and expert knowledge. Using SAGA, a sensitivity analysis was performed for the Gravitational Process Path (GPP) model. Process path, run-out distance, deposition and velocity of stockpile failure were simulated using different friction coefficient values. Friction is expected to decrease over time due to weathering and consequent increase of fines within a stockpile and is subject to short-term variability determined by the amount of rainfall. Subsequently, an appropriate friction coefficient range was established for the overburden stockpiles at Grasberg (0.4 < μ < 0.6). No direct impacts of stockpile failure scenarios on the local environment were established, however, there were signs of acid rock drainage. The proposed method is best suited for modelling of remote or large areas. This thesis establishes a baseline for comparative analysis with more complex models in similar environments. |
