Drainage Basin Flashcards
What is a drainage basin?
The drainage basin is the catchment area from which water in a river system is sourced.
What is the watershed?
The watershed is the boundary between one drainage basin and another. It forms an imaginary line that typically follows a ridge of high land, such that rain falling on opposite sides of the ridge will flow into different drainage basins.
A drainage basin is a system, is it an isolated, closed or open system?
A drainage basin is an open system, as there are inputs and outputs that transfer mass and energy into and out of the system.
What is groundwater storage?
Rock layers below the surface are saturated, storing water in cracks and pores.
What us interception storage?
Precipitation held above the ground on the surfaces of plants and trees.
What is stemflow?
Water running down stems and branches of plants and trees to reach the ground.
What is infiltration?
The downward movement of water into the soil.
What is percolation?
The downward movement of water through rock due to gravity, which occurs below the soil layer.
What is run-off?
Run-off is water that flows out of the drainage basin in the river, over the surface.
What is precipitation?
Water that falls from the atmosphere to the Earths surface.
- Rain
- Snow
- Sleet
- Hail
What is evapotranspiration?
Moisture being removed from vegetation by the combined process of evaporation and transpiration.
What type of graph is used to study the water balance?
A water budget graph.
What is soil moisture utilisation?
When precipitation reduces and soil moisture stores begin to be used.
What is soil moisture surplus?
When soil moisture and groundwater is replenished. The excess may lead to saturation and increased surface run-off.
What is soil moisture deficit?
When there is a shortage of soil moisture stores and deeper groundwater reserves and surface reservoirs need to be used.
