1. RAP 1._____ layer of atmosphere that weather occurs in (atm layers) 2._____ most abundant gas in the atmosphere (atmosphere) 3._____changes from water vapor to a liquid (water cycle) 4._____ where most water is evaporated from (water cycle 2) 5._____ rise in the global temperature due to an increase in carbon dioxide (water cycle 2)

2. Water Cycle 1. What is runoff? 2. What is percolation? 3. What is an aquifer? 4. What is a water shed?

3. Answer to Key Questions 1. Runoff is precipitation that reaches Earth’s surface and flows over the land and eventually reaches lakes, rivers, and oceans. Runoff dissolves and collects minerals

4. 4.2 How water moves in the water cycle 2. Percolation is the process of liquid moving through a substance that has many tiny holes or “pores”. Groundwater can move through soil because the soil is porous.

5. 3. Aquifer-groundwater that is collected in underground areas of sediment and rocks When groundwater is removed from an aquifer for human consumption, it can take 300 to 1,000 years or more to replenish the supply.

6. 4.2 How water moves in the water cycle Groundwater that is not pumped from an aquifer flows to oceans. Aquifers are important water sources. The Ogallala Aquifer is in danger of becoming depleted because the water is being used faster than it can be replenished.

7. 4.2 Watersheds 4. Watershed -an area of land that catches all precipitation and surface runoff. The water that comes to many homes in the United States originates in a watershed that can be local or from another region.