What are 3 limiting factors in a river?

Answer 1

The three limiting factors to the flow of a river are:

1. the level of input precipitation as rainfall or snowfall
2. the level of evaporation of that rainfall or sublimation of high altitude snowfall at low pressure
3. the absorption of water by vegetation in the soils

These factors together create:

• three zones of high runoff, one at the equator and the other two in the cool high latitudes where low rooting densities and evaporation allow large rivers even with low precipitation
• one zone of moderately low runoff in the arid northern hemisphere subtropics where generally annual-dominated vegetation allows for some runoff on the rare occasions rain falls
• one zone of extremely low or no runoff in the ancient arid lands of Australia and Southern Africa where extremely old soils and low precipitation mean that runoff only occurs under unusually heavy rainfall

The key difference between the two latter groups is that:

• In the first region, soils are young are have high levels of nutrients due to the absence of leaching. This favours annual plants that grow only after rain, as low rooting densities are adequate for nutirent absorption
• In contrast, on the extremely old soils of Australia and Southern Africa - consisting of kaolinitic clays formed under much wetter climates in the Mesozoic - low rooting densities are inadequate to gain any nutrition
• • Plants on Australian and Southern African soils must have very dense proteoid root systems to absorb minimal quantities of phosphorus.
  • As a result, they use much more water than plants in other arid and semiarid regions, and runoff ratios can be as much as 90 percent lower for a mean annual rainfall of 300 millimetres.

Answer 2:

Three limiting factors

1 Catchment area, This not only includes size but the region ie the Sahara Desert compared with the Andes Mountain range

2 Height above sea level

3 Soils . The river may travel over rock ,through rock, through sand or dense soils making the river speed up- slow down