Water Cycle and the Distribution of Water

Transpiration: The process of transferring water from the roots up to the leaves of the plant to facilitate nutrient transfer. The water is evaporated at the leaves.

Baby water cycle concept

The elementary water cycle:

Better…

EVEN BETTER, but still lacks time and amount information EVEN BETTER, but still lacks time and amount information!, like 90% of clouds are from ocean evaporation!

What happens to rain fall? Of 100 drops of rain 2 Goes into “ground water” 2 make it into our faucets 66 drops go back into the sky Within a week 30 of them go into creeks and rivers

But… how do those 66 drops make it back? IN TEXAS.. 2 Goes into “ground water” 2 make it into our faucets 66 drops go back into the sky Within a week 30 of them go into creeks and rivers

But… how do those 66 drops make it back? IN TEXAS.. 2 Goes into “ground water” 2 make it into our faucets 33 drops evaporate directly 33 drops make it via TRANSPIRATION 30 of them go into creeks and rivers

Atmosphere Source: US Geological Survey www.usgs.gov

Million dollar question. Are these % of where water is static? Could they change? If you listen to news, you would know that most scientists that study it know the ocean level has risen 1-2ft in the past 50 years, and will rise several more feet in the next 50 years. What does this do to our percentages? In the “Ice age” … how might these amounts be different?

Lets talk TIME for a second How long does it STAY in each place. This is called “residence time” Some places you can guess have LONG residence times Oceans, lakes, glaciers, groundwater Some places you can then guess have SHORT residence times Clouds, rivers, soils, animals and plants.

Lets talk SPECIFIC times Reservoir Average residence time of a water molecule Antarctica 20,000 years Oceans 3,200 years Glaciers 20 to 100 years Snow 2 to 6 months Soil moisture 1 months Groundwater 100 – 10,000 years Lakes 10 to 100 years Rivers 1 to 6 months Atmosphere 9 days A single cloud 40 minutes

Lets talk Water USES City use Drinking water Sanitation Lawn water Car washing Farm use Crops, etc. Industry use making energy. Cooling plants Used in the manufacturing process

Where do we get the water we use? Three main sources: Rivers Ground water Lakes (man made reservoirs) Sources rarely used: Rain catchers/harvesters (mainly at homes) Oceans – it has to be desalinated (taking salt out is expensive) Sources never used for human needs: Glaciers, soil water, plant and animals

Assignment tomorrow Story of a water molecule. 1-2 pages, tell the story of 1 water molecule’s unique experience A group that gets seperated and comes back together. Will need to include at least 15 changes, and convince me you have an in depth understanding of the complexity of the water cycle Changes, places, timing, etc.