Which test is used to evaluate how easily a soil drains water?

The permeability test is used to evaluate how easily a soil can drain water, making it essential for understanding drainage characteristics. This test measures the rate at which water moves through the soil's pores, which is critical in applications such as site development, agriculture, and environmental engineering.

Soils with high permeability allow water to flow through them quickly, which can affect vegetation, water retention, and structural stability. In contrast, soils with low permeability can create drainage issues, potentially leading to problems like waterlogging or increased pressure on foundations.

While the California Bearing Ratio test assesses the strength of subgrade soils, and the field density test measures the compaction of soils, both focus on different properties rather than water drainage. Sieve analysis determines the particle size distribution in a soil sample, which can influence drainage indirectly but does not directly measure how water moves through the soil.