Question

The two primary forces that drive a river system are ______ and ______.

Multiple select question.
a) gravity
b) tributaries
c) sediment size
d) channel depth
e) precipitation
f) sediment load

Answer 1

The two primary forces that drive a river system are a. gravity, which moves the water downhill, and e. precipitation, which adds water to the system.

Step-by-step explanation:

The two primary forces that drive a river system are a. gravity and e. precipitation. Gravity is the force that pulls river water downhill toward the ocean, which is essential for the movement and flow of a river system.

Precipitation, which includes rain and melted snow, directly contributes to the volume of water in a river through surface runoff and groundwater seepage, thereby influencing river discharge — the volume of water moving through a river channel over time. Tributaries, sediment size, channel depth, and sediment load, although important components of a river system, are not the primary driving forces like gravity and precipitation.