Water and Ground
Hydrologic Cycle
The hydrologic cycle is also known as the water cycle. Most students learn about the water cycle in elementary school and the information regarding changes little by the time high school rolls around. Without the water cycle, life dies out since everything requires water to survive.
The hydrologic cycle is also known as the water cycle. Most students learn about the water cycle in elementary school and the information regarding changes little by the time high school rolls around. Without the water cycle, life dies out since everything requires water to survive.
Evaporation - An energy transfer that changes liquid to gas; heat is absorbed
Transpiration - Also called evapotranspiration; evaporation of water released by plants; accounts for about 10% of water vapor entering atmosphere Condensation - An energy transfer that changes gas to liquid; heat is lost Precipitation - Occurs when a substance falls out of solution; in this case, it's water, snow, sleet, or hail falling from clouds Infiltration - Occurs when water "soaks" into the ground; enters the groundwater supply Runoff - Surface water that moves horizontally; rivers, streams, water flowing off of pavement, etc. Surface water - Water found on the surface of Earth Groundwater - Water found underground |
Zone of Aeration
This is the permeable upper layer in which water percolates down toward the water table. The pore spaces are filled with air. Permeable - Water is able to move through it Percolate - Trickle Porosity - The amount of open space (pore) between sediment particles |
Water Table
The water table is the top of the Zone of Saturation and the bottom of the Zone of Aeration. The water table is variable depending on how much rain and groundwater an area has. |
Zone of Saturation
This the lower layer in which the pore spaces are filled with water (saturated). The bottom of this zone is typically an impermeable confining layer that keeps the water from flowing too far underground. Impermeable - Water cannot move through it Confining layer - An impermeable layer that prevents water from moving vertically |
Karst Topography
Karst topography is a landscape characterized by sinkholes and caves formed by rocks dissolving underground. The most common rock that forms karst in our state is limestone. Other karst forming rocks are gypsum, rock salt, and dolostone. In our state, the karst topography is found in the Valley and Ridge province. Streams that flow into a sinkhole is called a disappearing stream. Sinkholes are formed by the underlying rock dissolving away; then, the ceiling collapses because the top can't support the overlying weight. Humans can cause sinkholes when underground pipes burst and wash away the surrounding sediment.
Karst topography is a landscape characterized by sinkholes and caves formed by rocks dissolving underground. The most common rock that forms karst in our state is limestone. Other karst forming rocks are gypsum, rock salt, and dolostone. In our state, the karst topography is found in the Valley and Ridge province. Streams that flow into a sinkhole is called a disappearing stream. Sinkholes are formed by the underlying rock dissolving away; then, the ceiling collapses because the top can't support the overlying weight. Humans can cause sinkholes when underground pipes burst and wash away the surrounding sediment.
One of the major problems with karst topography is that it is virtually impossible to know where the water is flowing underneath the ground. Water dissolves many passages in karst regions and, thus, the water flowing into it could go anywhere. Some passages allow streams to cross watersheds and/or carry pollution from one area to a major water source.
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Weathering, Erosion, and Deposition
Weathering and erosion are essentially the same thing except that erosion includes transportation away from the site of weathering. Weathering can be accomplished in two ways: physical/mechanical and chemical. Physical weathering (aka mechanical weathering) occurs when a rock is broken down but chemically stays the same. In other words, as a rock is broken apart physically, the pieces coming off of the rock remain the same material as the rock itself. Only the overall size and shape of the rock is altered when weathered physically. Chemical weathering also changes the size and shape of a rock, but does so through chemical means such that the material being removed is chemically altered. For example, when limestone weathers chemically, the rock dissolves in the presence of acid and the calcium carbonate changes to carbon dioxide and a calcium salt. The weathered material is not the same as the original material.
Erosion accomplishes much the same as weathering, but offers transport as well. When rock is eroded, it breaks down and is moved to another location by the eroding agent. Agents of erosion/weathering are wind, water, ice, gravity, plants, animals, and even people.
Deposition occurs wherever the eroding agent loses the energy to carry the material. High energy media (strong winds or fast water) can carry larger particles or push larger particles some distance from the point of origin. As the eroding agent loses energy, the ability to carry particles diminishes. As the wind or water slows down, it deposits the largest particles it is carrying at that point. High energy environments deposit or push around rocks. Medium energy environments deposit sand. Low energy environments deposit mud. When a river encounters a bay, gulf, or the ocean, the energy level drops completely and all particles are deposited.
Weathering and erosion are essentially the same thing except that erosion includes transportation away from the site of weathering. Weathering can be accomplished in two ways: physical/mechanical and chemical. Physical weathering (aka mechanical weathering) occurs when a rock is broken down but chemically stays the same. In other words, as a rock is broken apart physically, the pieces coming off of the rock remain the same material as the rock itself. Only the overall size and shape of the rock is altered when weathered physically. Chemical weathering also changes the size and shape of a rock, but does so through chemical means such that the material being removed is chemically altered. For example, when limestone weathers chemically, the rock dissolves in the presence of acid and the calcium carbonate changes to carbon dioxide and a calcium salt. The weathered material is not the same as the original material.
Erosion accomplishes much the same as weathering, but offers transport as well. When rock is eroded, it breaks down and is moved to another location by the eroding agent. Agents of erosion/weathering are wind, water, ice, gravity, plants, animals, and even people.
Deposition occurs wherever the eroding agent loses the energy to carry the material. High energy media (strong winds or fast water) can carry larger particles or push larger particles some distance from the point of origin. As the eroding agent loses energy, the ability to carry particles diminishes. As the wind or water slows down, it deposits the largest particles it is carrying at that point. High energy environments deposit or push around rocks. Medium energy environments deposit sand. Low energy environments deposit mud. When a river encounters a bay, gulf, or the ocean, the energy level drops completely and all particles are deposited.