GPHY 102 Lecture Notes - Lecture 16: Water Cycle, Vadose Zone, Walkover

• School: Queen's University
• Department: Geography
• Course: GPHY 102
• Professor: Dr.Trezino

Document Summary

The study of the earth"s water system and its cycling (movement through the hydrological cycle). Fresh water on land and beneath the earth"s surface accounts for about 3 percent of the hydrosphere"s total water (most locked into ice sheets and mountain glaciers). Groundwater accounts for a little more than 0. 5 percent (many times larger than the amount of fresh water in lakes, streams, and rivers, which account for only 0. 03 percent of the entire water resources of the earth). Most soils are capable of absorbing the water from light or moderate rainfalls by infiltration (water enters the small natural passageways between irregularly shaped soil particles, as well as the larger openings in the soil surface). The precipitation that infiltrates the soil is temporarily held in the soil layer as soil water, occupying the soil water belt. This water can return to the surface and then to the atmosphere through direct evaporation from the soil and through transpiration (evapotranspiration).