Earth Science (EARTH-1141) - Streams/Groundwater Vocab

Chapter 9: Running water and groundwater

hydrologic cycle

the unending circulation of Earth’s water supply. The cycle is powered by energy from the sun and is characterized by continuous exchanges of water among the oceans, the atmosphere, and the continents

evaporation

the process of converting a liquid to a gas; how water enters the atmosphere from the ocean

infiltration

movement of surface water into rock or soil through cracks and pore spaces

runoff

water that flows over the land rather than infiltrating into the ground; the rate of rainfall exceeds the ground’s ability to absorb it

transpiration

the release of water vapor to the atmosphere by plants

evapotranspiration

the combined effect of **evaporation** and **transpiration**

drainage basin

the land area that contributes water to a stream; aka watershed

divide

imaginary line that separates the drainage of two streams; often found along a ridge

headward erosion

the extension upslope of the head f a valley due to erosion

dendritic pattern

stream system that resembles the pattern of a branching tree; relatively uniform underlying material means that the pattern is determined by slope direction of land

radial pattern

stream system running in all directions away from a central elevated structure such as a volcano

rectangular pattern

drainage pattern characterized by numerous right-angle bends that develops on jointed or fractured bedrock

trellis pattern

system of streams in which nearly parallel tributaries occupy valley scut in folded strata

laminar flow

the movement of water particles in straight-line paths that are parallel to the channel. The water particles move downstream, without mixing

turbulent flow

movement of water in an erratic fashion, often characterized by swirling, whirpool-like eddies. Most streamflow is of this type

gradient

the slope of a stream; generally measured in feet per mile

discharge

the quantity of water in a stream that passes a given point in a period of time

longitudinal profile

cross section of a stream channel along its descending course from the head to the mouth

pothole

circular depression in a bedrock stream channel created by the abrasive “drill-like” action of particles swirling in fast-moving eddies

dissolved load

the portion of a stream’s load that is carried in solution

suspended load

the fine sediment carried within the body of flowing water

bed load

sediment that is carried y a stream along the bottom of its channel

settling velocity

the speed at which a particle falls through a still fluid. the size, shape, and specific gravity of particles influence settling velocity

saltation

transportation of sediment through a series of leaps or bounces

capacity

the total amount of sediment a stream is able to transport

competence

measure of the largest particle a stream can transport; a factor that is dependent on velocity

sorting

the process by which solid particles of various sizes are separated by moving water or wind

alluvium

unconsolidated sediment deposited by a stream