Hydrology and groundwater notes testmasters

Hydrology and groundwater notes testmasters: Hydrology – Science that is concerned with the occurrence, movement and
distribution of water within the Earth (land and ocean) and atmosphere.
• Hydrologic cycle – Continuous process by which water is purified by evaporation and transported from the Earth’s surface including oceans to the atmosphere and back to the land and oceans as precipitation.

• Watershed, drainage basin – Topographically defined area drained by a river or system of interconnected rivers such that the entire outflow from the area is discharged through a single outlet.

Hydrology and groundwater notes testmasters: Precipitation – Includes rain, snow and other forms of water falling from the atmosphere in liquid or solid phase into the land and oceans.

• Evaporation – Physical process by which water is vaporized into the atmosphere from free water surface and land areas.

• Transpiration – Water from the soil is absorbed by plant roots and eventually discharged into the atmosphere through little pores in the leaves called stomata.

It is a side effect of the plant needing to open its stomata in order to obtain carbon dioxide from the air for photosynthesis.

Transpiration cools plants and allows flow of nutrients from the plants roots to its stems and leaves.

• Evapotranspiration – Combined processes by which water is transferred to the atmosphere from open water surfaces and vegetation.

• Potential Evapotranspiration – Measure of how much the atmosphere controls evapotranspiration independent of the surface hydrologic conditions. Quantity of water evaporated from an idealized extensive free water surface per unit area, per unit time under existing atmospheric conditions.