Property:Extended model description
From CSDMS
This is a property of type Text.
T
This process component is part of a spatially-distributed hydrologic model called TopoFlow, but it can now be used as a stand-alone model. +
This process component is part of a spatially-distributed hydrologic model called TopoFlow, but it can now be used as a stand-alone model. +
This process component is part of a spatially-distributed hydrologic model called TopoFlow, but it can now be used as a stand-alone model. +
B
This program calculates backwater curves over a sand-bed stream with a specified spatially constant bed slope S. The calculation uses the hydraulic resistance formulation of Wright and Parker (2004) (but without the flow stratification correction). +
D
This program calculates the 1D bed evolution of a sand-bed river after installation of a dredge slot. The calculation begins with the assumption of a prevailing mobile-bed normal flow equilibrium before installation of the dredge slot. The flow depth H, volume bedload transport rate per unit width qb and volume suspended transport rate per unit width qs at normal flow are computed based on input values of discharge Qww, channel width B, bed material sizes D50 and D90, sediment submerged specific gravity Rr and bed slope S.
The sediment is assumed to be sufficiently uniform so that D50 and D90 are unchanging in space and time. The input parameter Inter specifies the fraction of any year for which flood flow prevails. At other times of the year the river is assumed to be morphologically dormant.
The reach is assumed to have length L. The dredge slot is excavated at time t = 0, and then allowed to fill in time with no subsequent excavation. The depth of initial excavation below the bottom of the bed prevailing at normal equilibrium is an input variable with the name Hslot. The dredge slot extends from an upstream point equal to ru*L to a downstream point rd*Hslot, where ru and rd are user-input values.
The porosity lamp of the sediment deposit is a user-input parameter.
The bedload transport relation used in the calculation is that of Ashida and Michiue (1972). The formulation for entrainment of sediment into suspension is that of Wright and Parker (2004). The formulation for flow resistance is that of Wright and Parker (2004). The flow stratification correction of Wright-Parker is not implemented here for simplicity. A quasi-equilibrium formulation is used to computed the transport rate of suspended sediment from the entrainment rate.
A backwater calculation is used to compute the flow. The water surface elevation at the downstream end of the reach is held constant at the value associated with normal flow equilibrium.
Iteration is required to compute: a) the flow depth prevailing at normal flow; b) the friction slope and depth prevailing at normal flow, b) the friction slope and depth associated with skin friction associated with skin friction from any given value of depth, and b) the minimum Shields number below which form drag is taken to vanish.
A
This program computes 1D bed variation in rivers due to differential sediment transport. The sediment is assumed to be uniform with size D. All sediment transport is assumed to occur in a specified fraction of time during which the river is in flood, specified by an intermittency. A Manning-Strickler relation is used for bed resistance. A generic Meyer-Peter Muller relation is used for sediment transport. The flow is computed using a backwater formulation for gradually varied flow. +
This program computes 1D bed variation in rivers due to differential sediment transport in which it is possible to allow the bed to undergo a sudden vertical fault of a specified amount, at a specified place and time. Faulting is realized by moving all notes downstream of the specified point downward by the amount of the faulting.
The sediment is assumed to be uniform with size D. All sediment transport is assumed to occur in a specified fraction of time during which the river is in flood, specified by an intermittency. A Manning-Strickler formulation is used for bed resistance. A generic relation of the general form of that due to Meyer-Peter and Muller is used for sediment transport. The flow is computed using the normal flow approximation. +
B
This program computes fluvial aggradation/degradation with a bedrock-alluvial transition. The bedrock-alluvial transition is located at a point sba(t) which is free to change in time. A bedrock basement channel with slope Sb is exposed from x = 0 to sba(t); it is covered with alluvium from x = sba(t) to x = sd, where sd is fixed. Initially sba = 0. The bedrock basement channel is assumed to undergo no incision on the time scales at which the alluvial reach responds to change. In computing bed level change on the alluvial reach, the normal (steady, uniform) flow approximation is used. Base level is maintained at x = sd, where bed elevation h = 0. The Engelund-Hansen relation is used to compute sediment transport rate, so the analysis is appropriate for sand-bed streams. Resistance is specified in terms of a constant Chezy coefficient Cz. +
A
This program computes gravel bedload and size distribution from specified values for the bed surface size distribution, the sediment specific gravity, and the effective bed shear velocity (based on skin friction only). +
This program computes the time evolution of the long profile of a river of constant width carrying a mixture of gravel sizes, the downstream end of which has a prescribed elevation. In particular, the program computes the time evolution of the spatial profiles of bed elevation, total gravel bedload transport rate and grain size distribution of the surface (active) layer of the bed. The river has constant width. The upstream point, at which sediment is fed, is fixed in the horizontal to be at x = 0. The vertical elevation of the upstream point may change freely as the bed aggrades or degrades. The reach has constant length L, so that the downstream point is fixed in the horizontal at x = L. This downstream point has a user-specified initial elevation hdI.
Gravel bedload transport of mixtures is computed with a user-specified selection of the Parker (1990), or Wilcock-Crowe (2003) surface-based formulations for gravel transport. Sand and finer material must first be excluded from the grain size distributions, which then must be renormalized for gravel content only, in the case of the Parker (1990) relation. In the case of the Wilcock-Crowe (2003) relation, the sand is retained in the computation. +
This program computes the time evolution of the long profile of a river of constant width carrying a mixture of gravel sizes, the downstream end of which has a prescribed elevation. +
S
This program implements the calculation for steady-state aggradation of a sand-bed river in response to sea level rise at a constant rate, as outlined in Chapter 25 of the e-book. +
R
This program is a companion to the program SteadyStateAg, which computes the steady-state aggradation of a river with a specified base level rise at the downstream end. This program computes the time evolution toward steady-state aggradation.
The calculation assumes a specified, constant Chezy resistance coefficient Cz and floodplain width Bf. The sediment is assumed to be uniform with size D. All sediment transport is assumed to occur in a specified fraction of time during which the river is in flood, specified by an intermittency. If grain size D < 2 mm the Engelund-Hansen (1967) formulation for total bed material transport of sand is used. If grain size D >= 2 mm the Parker (1979) bedload transport formulation for gravel is used. The flow is computed using the normal flow approximation. The reach has downchannel length L, and base level is allowed to rise at a specified rate at the downstream end. +
This program provides two modules for studying the approach to mobile-bed normal equilibrium in recirculating and sediment-feed flumes containing uniform sediment.
The module "Recirc" implements a calculation for the case of a flume that recirculates water and sediment. The module "Feed" implements a calculation for the case of flume which receives water and sediment feed. +
T
This pseudo-2D (cross-section, 1 independent variable x) numerical model permits calculating 1D lithospheric flexure with different rheologies, in combination with faulting, loading, and erosion/deposition. The programs are developed in C for Linux platforms, graphic output is produced using GMT scripts, and standard PCs match the CPU and memory requirements. The software is available for free under a GPL license. +
W
This subroutine computes the deep water significant wave height and period at each point under a hurricane +
S
This tool can be used to map out areas of hillslopes where the emergence of bedrock drives an increase in surface roughness. The tool requires an input DEM in float format and will output the rasters, also in float format, for three eigenvectors that together describe the distribution of normal vectors within a user-defined neighbourhood for each pixel. +
C
This tool is used for examining bedrock channels. The tool is based on the assumption that the stream power incision model (SPIM) adequately describes channel incision. Channels profiles are converted to chi-elevation space, where chi is a transformed longitudinal coordinate that takes drainage area into account. The tool uses a variety of statistical tests to extract the most likely series of segments with distinct steepness in chi-elevation space. It also performs statistical tests to determine the best fit m/n ratio, where m is an area (A) exponent and n is a slope (S) exponent in the SPIM with E = K A^m S^n, where E is an erosion rate and K is an 'erodibility'. +
T
This tool is used to creates a "profile-smoothed" DEM from an input DEM. +
H
This tool produces a flow path for each hilltop pixel on a landscape, generating hillslope length and relief data at a hillslope scale. These data can be used to discriminate between linear and nonlinear sediment flux laws at a landscape scale.
The model requires an input DEM in float format and produces a series raster and plain text output files which can be visualized and analysed using code provided at: https://github.com/sgrieve/LH_Paper_Plotting
For detailed information about how to use this tool please refer to the documentation (http://www.geos.ed.ac.uk/~smudd/LSDTT_docs/html/basin_metrics.html). +
