Water Water Everywhere AIM What is the hydrologic
- Slides: 24
Water, Water Everywhere AIM: What is the hydrologic cycle?
Water Cycle (hydrologic cycle)
1. Water enters the atmosphere by… Evapotranspiration – all evaporation from earth and plants. a. Evaporation – Water changes from a liquid to a gas. -Most water evaporates from the oceans. -Wind and high temps speed up evaporation. b. Transpiration – water in plants evaporates
2. Water leaves the atmosphere by… a. Condensation – Water changes from a gas to liquid to form clouds. b. Precipitation – any form of water that falls from clouds (rain, snow, sleet, hail)
3. Where does the water go? a. Runoff –water that flows over the ground, -eventually leads back to a larger body of water b. Accumulation – when water collects into large bodies, or falls directly into it (reservoirs)
c. Infiltration – when water seeps (sinks) into the ground to be stored as groundwater d. aquifer – an underground layer of rock or soil that contains water e. Water table – point between saturated and unsaturated soil below the surface -Lakes, rivers and oceans are where the water table comes to the surface
4. Factors that affect infiltration a. Porosity: empty spaces between sediments in soil. b. Permeability: The ability of water to pass through sediments in the ground. c. Saturation: the amount of water in the ground Permeability animation
5. Factors that affect Porosity a. Shape of Sediment § Round- High Porosity § Flat-Low Porosity b. Sorting of Sediment § Well Sorted (Uniform Size)- High Porosity § Unsorted (Mixed Sizes)- Low Porosity c. Packing of Sediment § Loosely packed- High Porosity § Tightly packed- Low Porosity
Shape of Sediment
When comparing Porosity of varying samples: if volume of sediments sorting of sediments and packing of sediments are the same… Porosity is the same!
6. What affects Permeability? a. porosity determines permeability § Shape § Sorting § packing b. Impermeable: water doesn’t pass through (clay)
7. Rate of Infiltration Permeability animation a. Gravel and Sand: Quick Infiltration Because there are larger spaces between the pieces of gravel and grains of sand where water can go through easily. b. Silt and Clay: Slow Infiltration Silt and clay are smaller but have more surface area, more places for water to move between them.
Hurray for Porosity! http: //www. brainpop. com/science/earthsystem/groundwater/
8. Factors that affect runoff: a. Impermeable soil increases runoff b. Gradient (Slope) – steeper will cause more runoff c. Saturated soil– wetter ground will decrease permeability and cause more run off d. Groundcover – vegetation decreases runoff, concrete increases runoff.
9. Capillary Action: -when water moves upward in soil/sand. -The smaller the particles, the more surface area the faster the capillary action (cohesion) -makes water available for plant roots transpiration into atm
Fill it in…
Which processes of the water cycle return water vapor directly to the atmosphere? (1) evaporation and transpiration (2) infiltration and capillarity (3) freezing and precipitation (4) water retention and runoff
Which soil characteristic allows greater amounts of water retention? (1) large-size particles (2) small-size particles (3) high-density particles (4) low-density particles
A paved blacktop parking lot was built on what was once a soil-covered field. This area will now experience increased runoff when rain occurs because the paved parking lot has (1) less capillarity (2) less permeability (3) greater infiltration (4) greater porosity