Fresh Science

Building environmentally friendly mountains in the outback: design of Post-Mining Landscapes For Erosion Control – Gary Sheridan

Coal-mining has disturbed over 50,000 ha of land that requires more than $1 Billion to rehabilitate. Scott’s software is being used to design mountains that won’t wash away.

A new computer program capable of estimating soil erosion rates is set to help solve a billion dollar environmental and economic headache for the mining industry.

The program, designed by The University of Queensland’s (UQ) Centre for Mined Land Rehabilitation and the School of Land and Food, will assist mine site rehabilitation officers with the design of post-mining landscapes.

UQ Researcher, Gary Sheridan, said the program was developed as a result of laboratory research which allowed more efficient and effective analysis of factors affecting soil erosion.

Speaking at ScienceNOW! in Melboure, he said the laboratory research incorporated the unique reconstruction of the mining landscape ‘in miniature’ and use of rainfall simulators to reproduce tropical rainstorms.

“The program is an easy to use tool allowing mine site environmental officers to get rehabilitation right the first time, therefore saving the mining industry money, while providing environmental benefits from reducing the impacts of mining and maximizing the chances of rehabilitation success.”

Mr Sheridan said coal mining in Queensland had disturbed more than 50,000 ha which required more than $1 billion to rehabilitate.

“Everyday, earth moving equipment with buckets the size of a house are used to remove rock and soil from above the coal seam and dump it into steep waste piles up to 60 m in height.”

“These waste piles are very unstable, and the local high intensity tropical storms can result in severe erosion.”

“Erosion causes failure of rehabilitation, and sediment can pollute local streams, affecting plant and animal life.”

He said the control of soil erosion was a major prerequisite for the replacement of a stable ecosystem on this land and soil erosion could be controlled by lowering the steep piles into rolling hills and then revegetating.

“Most of the rehabilitation costs are associated with the earthworks to lower the steep piles, however the optimal slope is not known and varies from one mine to the next.”

“Small changes in the final slope can have a major impact on the success and cost of rehabilitation however determining the optimum slope in the field is difficult.”

He said more efficient methods of research such as that undertaken by The University of Queensland were needed to solve the erosion problems from rehabilitated mine sites.