1.7 The Hydrologic (Water) Cycle

Which elements are the most important to the productivity of photosynthetic organisms?

carbon, hydrogen, and oxygen

Define biogeochemical cycles

the movements of matter within and between ecosystems

Explain “pools” and “flows” of matter

• pools: components that contain the matter (air, water, and organisms)

• flows: process that move matter between pools

Define hydrologic cycle

movement of water through the biospere

What is the importance of water?

fuels everything

Define transpiration

release of water from leaves during photosynthesis

What are the 3 distinct routes water takes when it falls on land?

1. may return to the atmosphere by evaporation after being taken up by plant roots

2. water can be absored by the soil and percolate down into groundwater

3. water can move as runoff across the land surface into streams and rivers reaching the ocean

Define evapotranspiration

the combined amount of evaporation and transpiration

Define runoff

water that moves across the land surface and into streams and rivers

 Define infiltration

from precipitation that percolated through the soil

List the human activities that affect the hydrologic cycle and the result of each

• harvesting trees from a forest can reduce evapotranspiration by reducing plant biomass

• humans can divert water from one area to another to provide water for drinking

describe the water cycle

1. The sun releases solar radiation heating up the ocean. Then evaporation ( water to vapor) begins

2. then, transpiration begins where the leaves of the water falls off due to photosynthesis

3. with all this evaporation, condensation occurs and the water droplets condense and turn into clouds

4. then once the water droplets get heavy precipitation happens and it either goes through surface runoff or into the soil

5. infiltration happens and this is when the water goes into the soil

6. down the mountain percolation happens, which is when the water goes through the soil and the porous rocks

7. the aquifer is an underground water storage

8. it then goes back into the ocean