What role does vegetation play in river discharge?

Vegetation plays a significant role in river discharge by decreasing runoff. When vegetation, such as trees and plants, is present in a watershed, it acts to intercept rainfall and promote infiltration into the soil. The roots of plants create channels in the soil, allowing water to penetrate more deeply rather than flowing directly over the surface. As a result, more water is absorbed and stored in the soil, which can then be taken up by plants or slowly released into the river system over time.

Additionally, vegetation helps to slow down the movement of water across the land, reducing the speed and volume of surface runoff. This buffering effect means that during heavy rainfall, the risk of flooding is minimized, as there is a natural mechanism for managing excess water.

The other choices indicate different roles that vegetation could play, but they do not correctly reflect the established relationship between vegetation and runoff in hydrology. Vegetation naturally contributes to a healthier watershed by maintaining balanced hydrological cycles and stabilizing soil, which ultimately leads to reduced runoff.