The Water Cycle By: Saiesh Kalva Vivian Tran Huan Nguyen What is the Water Cycle? 70% of the Earth is covered by water. Water even exists as a gas known as water vapor. Now all this water must move around, and this is where the water cycle comes in. The water cycle, also known as the hydrologic cycle, is the constant movement of water between the land, atmosphere, and bodies of water. Overview of the Water Cycle The water cycle is made up of several steps, similar to all processes. 4 steps of the Water Cycle: Evaporation/Transpiration Condensation Precipitation Redistribution Evaporation Evaporation- The transfer of water from Earths surface to the troposphere. The main factors of evaporation include wind speed, temperature, humidity, and radiation. Water Vapor Water vapor is the gaseous form of water. This water vapor condenses to form clouds, which we will get to in a later time. Transpiration The evaporation of water through stomata, in the leaves of plants. Evaporation and transpiration combined is known as evapotranspiration. Condensation Condensation is where water vapor in the air condenses and saturates the air. These water droplets clump together and form what we call clouds. When does Condensation stop? Condensation occurs until air is saturated Water condenses around particles Particles become too heavy and fall Beginning of precipitation Precipitation After the water condenses, according to our cycle, the water must come back to Earth. It does so through precipitation. Precipitation is the movement of water from the atmosphere back to Earths surface. Types of Precipitation Rain Hail Sleet Snow Rain Most common form of precipitation Can occur almost anywhere Rain drops can fall as fast as 22 mph Frozen Rain Sleet Precipitation that has frozen or refrozen before it has hit the surface Smaller than hail Known as ice pellets Below freezing in atmosphere Snow Softest form of precipitation Occurs at certain times in certain places Atmosphere cooler than when with sleet Hail Irregular lumps of ice Generally the most destructive Most rare type of precipitation Similar to crushed ice Redistribution of Precipitation Evaporation Vegetation Infiltration-runoff Infiltration- groundwater Ice and its role Glaciers Soil moisture turns into permafrost Change from 1/3(33%) of Earth to about 1/8(12%) of Earth How have people affected the Water Cycle? Building dams and reservoirs Cutting down trees, and creating buildings Emission of carbon dioxide How does the Water Cycle affect people? Provides precipitation for humans Effects decisions on plans How does the Water Cycle affect Geography? Changes climate Erosion Creates bodies of water