Term
| • How do you know when a river has reached flood stage? |
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Definition
| Water levels in a channel exceed bank. (The stage at which the river will overflow its banks) |
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Term
| • What land use and channel zone changes may increase flooding and/or flood damage? |
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Definition
| Agriculture, straightening, bank failure, removal of roughness. Urbanization, loss of riparian zone… |
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Term
| • What are three different types of drought? |
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Definition
Agriculture Drought: Soil moisture insufficient for plant needs.
Hydrological Drought: Extended period of low flows.
Meteorological Drought: Extended period of low precipitation. |
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Term
| • Explain how each of the following land uses affect watershed function: agriculture, grazing, timber harvest, urban, mining |
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Definition
Agriculture: Increases erosion, decrease infiltration, change albedo, ET, change drainage, modifies nutrients, NPS from fertilizers and pesticides, affects water supply, population, food supply.
Grazing: Increased infiltration, soil compaction.
Timber Harvest: Increased erosion and overland flow (if clearcut), ther is more water flow/yield from the lack of transpiration from trees.
Urban: Increased runoff, loss of roughness.
Mining: Metals getting into water area. |
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Term
| • If a channel is straightened and loses its riparian zone, how does this affect flood susceptibility? |
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Definition
| Means loss of roughness/riparian zone can perhaps increase flood zone because there is nothing around to soak up the water? |
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Term
| • What are some of the main objectives of watershed management? |
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Definition
Maintain High Water Quality
Sustaining Water Quantity
Limit Erosion
Sustaining Habitat, Biodiversity |
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Term
| • What methods can be used to limit overland flow and maximize infiltration in an urban area? In areas with other types of land use? |
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Definition
Decrease impermeable surface area, promoted infiltration and decreased overland flow, increased roughness and complexity of drainage channels.
Areas with other Types of Land Use: GIS evaluation of watersheds forest health, slope steepness, soil erodibility, controlled burns, forest thinning, more vegetation for high erosion. |
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Term
| • What may be the benefit of constructing a sediment basin in an area with high overland flow and erosion? |
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Definition
| Benefit of Construction a Sediment Basin in an area with High Overland Flow and Erosion: Acts as a temporary pond built to capture eroded or disturbed soil that is washed off during rain storms and protect the water quality. |
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Term
| • What are some of the main objectives of channel zone management? |
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Definition
| Maintain water quality, aquatic habitat, minimize susceptibility to flood damage. |
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Term
| • What may be the benefits of vegetated buffers surrounding channels? |
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Definition
| Lowers water temperatures, source of woody debris, improve habitat, reduce sediment, organic material, nutrients, pesticides and other pollutants migrating to the stream. Also reduces erosion. |
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Term
| • Give examples of best management practices. |
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Definition
Agriculture: Planting along contours, filter strips, nutrient management.
Forestry: Streamside and road management, fire management, revegetation.
Urban: Detention ponds, vegetated swales, infiltration basins, permeable pavement. |
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Term
| • Why must watershed and channel zone management be integrated? |
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Definition
| To sustain watershed function. Promote infiltration/decrease overland flow, protect from erosion, allow space for channel migration, riparian zone buffer. |
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