What is 'stripping ratio' in surface mining?

The stripping ratio is a crucial concept in surface mining as it represents the relationship between the volume of overburden that must be removed to access a certain amount of coal. This ratio is calculated by dividing the amount of overburden removed by the amount of coal extracted. A lower stripping ratio indicates that less overburden is being removed for each unit of coal mined, making the operation more economically efficient.

Understanding the stripping ratio is essential for planning and operating mining operations, as it impacts both the cost and environmental impact of mining activities. Options that discuss coal extraction per worker, land area affected, or the depth of coal seams do not directly relate to the economic and operational efficiency conveyed by the stripping ratio and thus do not capture this critical aspect of surface mining adequately.