River Series 2 Flashcards
A Limited, convenient, and usually clearly defined and unambiguous topographic unit, available in a nested hierarchy of scales on the basis of stream ordering
Basin Geomorphic Unit
Response system open to a cascade of inputs and outputs
A Physical Process
T or F. If a drainage basin and channel morphology are related to the geologic, climatic and hydrologic character of the basin, then it is necessary to describe the features quantitatively in order to investigate these relationships.
T
________ of the Basins maybe most appreciated when studying storm hydrographs where in an elongated catchment.
Shape
Valuable indicator of the relationship between climate, vegetation, and resistance of rock and soil to erosion.
Density of the Stream networks
Drainage density formula
(∑𝐿)/𝐴 Where:
L= Stream Length
A= Drainage Basin Area
Quantitative measurement and generalization of land surface geometry. The complexity of drainage basins are derived from their being composed of _____, ______, ______, ______, ______, and ______.
divides, hillslopes, valley heads, terraces, floodplains and channels.
The texture of the patterns of a basin has a control on the __________
hydrology of the drainage basin
The Morphometric features of an erosional basin have been classified into _____, _____, _____, and ________.
linear, area, relief and gradient attributes.
____________ states that the number of streams of different orders in a drainage basin tends closely to approximate an inverse geometric series in which the first term is the number of streams of order one.
law of stream number
____________ states that the average lengths of the streams of each of the different orders in a basin closely approximate a direct geometric series in which the first term is the average length of streams of the first order.
law of stream length
___________ states that slopes of streams of different orders are related to the stream order by an inverse geometric series
law of stream slopes
____________ states that the main drainage basin areas of streams of different orders tends to closely approximate a direct geometric series in which the first term is the mean area of the first order basins.
law of drainage basin area
____________ states that the drainage areas of streams of each order and the total stream length contained within and supported by these areas is direct logarithmic function.
law of contributing areas
____________ a direct logarithmic function of the area of the drainage basin of the stream above the point at which discharge was measured.
discharge of a stream
An index of the potential energy available in the drainage basin. The higher the ______ the higher the erosional forces acting on the basin.
Relief
Determines the erodibility of the surface materials, and to some extent the permeability
Lithologic variations
Gives secondary permeability for fluid flow, and a primary control for the orientation and drainage pattern of a system.
Geologic structures
Enumerate morphometric controls.
- Relief
- Lithologic variations
- Geologic structures
- Climate and vegetation
Enumerate erdogenic method.
Initiation
Elongation
Elaboration
Maximum extension
Integration
Development of stream pattern on a pristine surface.
Initiation
The growth of the channel into the available area and blocking out of the network
Elongation
Filling out the network with lower order tributaries
Elaboration
When drainage density is the greatest and the network fills the open spaces
Maximum extensions
Loss of identity of the small order streams with progressive reduction of drainage density through time.
Integration
Most commonly formed on horizontally bedded and uniform sediments or on uniformly resistant crystalline rocks.
Dendritic
Usually develops on moderate to steep slopes, but also where regional structure, such as outcropping resistant rock bands, are elongated and parallel. All forms of transition can occur this type and dendritic and trellis pattern.
Parallel
Patterns most commonly on dipping or folded sedimentary or weakly metamorphosed sedimentary rocks; also areas of joints and faults which intersect with right angles and old sand dunes with parallel alignment
Trellis
Usually have a more or less perpendicular turns mainly caused by crisscrossing fractures.
Rectangular
Occurs around domes or cones, and particularly common on volcanic areas.
Radial
Patterns also develop around domes, where there exists alternating resistant and weak beds, so that the major channels cut through the strike and the low order streams follow the dip of the rocks.
Annular
Can occur in a variety of conditions where local hummocks and depressions inhibit a continuous channel network. Irregular glacial deposits or erosional hollows due to solution of underlying lithology, irregular thawing permafrost. Coastal dunes, delta plains, and wind eroded hollows
Multibasinal
Incised into rocks with complicated structural patterns. Associated with crystalline metamorphic rocks with a history of intense folding, jointing, intrusions, alterations, and faulting.
Contorted
