Overview of Runoff

Aerial view of flooding in a remote village of Sierra Leone, Africa

An accurate estimate of runoff from rain and snowmelt is one of the most important elements of the flood forecast process.

In this section we will define runoff and introduce some important terms used when discussing the rainfall-runoff process. We will discuss the runoff from both rain and snowmelt and how it relates to the overall hydrologic forecasting process.

In this section you will learn to:

  • Define rainfall runoff
  • Identify the general movement of water both on the surface and in the ground
  • Recognize the different terms associated with groundwater and runoff
  • Understand the relationship between precipitation/snowmelt rate and infiltration