DP Sosi
DP Sosi
DP Sosi
Disclaimer
This presentation was prepared using draft rules which may vary slightly from those to be published in the final 2011 Coaches Manual. The rules as they appear in the 2011 NSO Coaches and Student Manuals will serve as the official rules for this event.
CHANNEL TYPES
c. Channel types: braided, meandering, straight
SEDIMENT
d. Sediment: weathering, erosion, forms and sizes, transportation, deposition
STREAM FLOW
f. Perennial and intermittent stream flow, stream gauging and monitoring, stream flow calculations, discharge, load, floods, recurrence intervals, and for C-Division only Chezy and Manning equations
GROUNDWATER
g. Groundwater: zone of aeration, zone of saturation, water table, porosity, permeability, aquifers, confining beds, hydraulic gradient, water table contour lines, flow lines, capillarity, recharge and discharge
GROUNDWATER: Porosity
Porosity is the percentage of the volume of the rock that is open space (pore space). This determines the amount of water that a rock can contain.
GROUNDWATER: Porosity
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Well-rounded, coarsegrained sediments usually have higher porosity than finegrained sediments, because the grains do not fit together well.
GROUNDWATER: Porosity
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Poorly sorted sediments usually have lower porosity because the fine-grained fragments tend to fill in the open space.
GROUNDWATER: Porosity
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Since cements tend to fill in the pore space, highly cemented sedimentary rocks have lower porosity.
GROUNDWATER: Porosity
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In igneous and metamorphic rocks porosity is usually low because the minerals tend to be intergrown, leaving little free space. Highly fractured igneous and metamorphic rocks, however, may have high porosity.
GROUNDWATER: Permeability
Permeability is a measure of the degree to which the pore spaces are interconnected, and the size of the interconnections. Low porosity usually results in low permeability, but high porosity does not necessarily imply high permeability.
GROUNDWATER: Permeability
It is possible to have a highly porous rock with little or no interconnections between pores. A good example of a rock with high porosity and low permeability is a vesicular volcanic rock, where the bubbles that once contained gas give the rock a high porosity, but since these holes are not connected to one another the rock has low permeability.
GROUNDWATER: Permeability
A thin layer of water will always be attracted to mineral grains due to the unsatisfied ionic charge on the surface. This is called the force of molecular attraction.
GROUNDWATER: Permeability
If the size of interconnections is not as large as the zone of molecular attraction, the water can't move. Thus, coarse-grained rocks are usually more permeable than finegrained rocks, and sands are more permeable than clays.
Groundwater: Aquifers
An aquifer is a large body of permeable material where groundwater is present in the saturated zone. Good aquifers are those with high permeability such as poorly cemented sands, gravels, and sandstones or highly fractured rock.
GROUNDWATER: Capillarity
Plants pull water upward from the water table into open spaces through capillary action. Capillarity refers to the rate at which this water is pulled upward. Soils containing large open spaces have high permeability and low capillarity.
KARST FEATURES
h. Karst features: sinkholes, solution valleys, springs, disappearing streams, caves developed as a consequence of subsurface solution. Karst topography: a distinctive landform assemblage developed as a consequence of the dissolving action of water on carbonate bedrock (usually limestone, dolomite, or marble).
Sinkholes are commonly funnel-shaped and broadly open upward. Sinkholes may be a few feet to more than 100 feet in depth, though usually ranging from 10 to 30 feet. Sinkhole diameter sizes range from a few square yards to several acres in area.
Karst springs occur where the groundwater flow discharges from a conduit or cave. Karst springs or "cave springs" can have large openings and discharge very large volumes of water. Sinkholes and sinking streams that drain to a large karst spring can be many miles away from the spring.
LAKE FEATURES
j. Lake features: inflow and outflow, physical and chemical properties, stratification, shorelines, waves
WETLANDS
k. Wetlands: bogs and marshes, interactions between surface and groundwater
The river flow out of a drainage basin depends upon three main factors: 1. The amount of precipitation 2. The losses by evaporation or evapotranspiration 3. The gains or losses from the storage areas: surface storage, soil moisture and groundwater stores.
POLLUTION
n. Pollution: types, sources and transport
Workshop Activity # 1
The next five slides show five different kinds of drainage patterns. The drainage patterns illustrated, in mixed order, are: annular, radial, dendritic, trellis and deranged. Write these names onto a piece of scratch paper for use in identifying the five drainage patterns that follow.
1. TRELLIS
A pattern of channels resembling a vine growing on a trellis. Develops where tilted layers of resistant and nonresistant rock form parallel ridges and valleys.
2. RADIAL
Channels radiate outward like spokes of a wheel from a high point.
3. DENDRITIC
Irregular pattern of channels that branch like a tree. Develops on flat lying or homogenous rock.
4. DERANGED
Channels flow randomly with no relation to underlying rock types or structures.
5. ANNULAR
Long channels form a pattern of concentric circles connected by sort radial channels. Develops on eroded domes or folds with resistant and nonresistant rock types.
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies this stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies the stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies the stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies the stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Choose the term to the right that identifies the stream feature.
A. Alluvial fan B. Braided stream C. Channel Bar D. Cut Bank E. Delta F. Meander
Chapter 11: Stream Processes, Landscapes, Mass Wastage, and Flood Hazards Chapter 12: Groundwater Processes, Resources, and Risks