What is one of the main reasons for measuring the cone of depression in groundwater?

Measuring the cone of depression in groundwater is crucial for understanding the effects of pumping on local water levels. When water is extracted from a well, the surrounding groundwater level declines, creating a depression in the water table known as the cone of depression. This measurement helps assess how much the water levels are being drawn down due to extraction and can provide insight into the sustainability of water resources in that area. Monitoring the cone of depression also allows water resource managers to evaluate the potential impact on nearby wells, surface water bodies, and overall groundwater availability. This is essential for managing and protecting water resources effectively.

The other options focus on aspects that do not directly relate to the impact of groundwater extraction on water levels. Identifying sediment layers, estimating the age of water, or determining mineral composition involve geological assessments or water quality evaluations, which, while important, do not address the immediate effects of pumping activities.