| A | B |
|---|
| permeable | allows water to flow through |
| impermeable | does not allow water to flow through |
| humus | decayed organic material in soil |
| horizons | soil layers |
| bedrock | the source of soil particles |
| weathering | process of breaking rock into small particles |
| clay | soil with small, flat particles |
| groundwater | water that falls to earth and soaks into the ground |
| unsaturated | not filled with water |
| saturated | filled with water |
| aquifer | underground layer of rock that sotres water |
| zone of aeration | unsaturated soil or rock |
| zone of saturation | saturated soil or rock |
| water table | top of zone of saturation |
| runoff | water that runs downhill along the earth's surface |
| delta | soil deposited by a river as it slows down and meets the ocean |
| floodplain | land on each side of a river that receives nutrient rick soil during floods |
| natural | resources obtained from the Earth |
| renewable | resources that can be reused or replaced |
| nonrenewable | resources that are used faster than they can be replaced in nature |
