Model help:HydroTrend: Difference between revisions

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| Base flow is typically the minimum amount of discharge that still reaches the river outlet, generated by deep ground aquifers.  
| Defines the constant annual baseflow which occurs in the basin. This is analogous to a deep groundwater pool. Baseflow should be bigger than 0 and smaller than the total precipitation discharge.
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| The shallow groundwater (sub-surface storm flow) exponent is used in draining the groundwater pool to the river.
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| Saturated hydraulic conductivity
| K<sub>sat</sub>
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| Saturated hydraulic conductivity describes water movement through saturated media. See [[Model:HydroTrend#Saturated_hydraulic_conductivity|table]] for saturated hydraulic conductivity values in relation to texture.
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Revision as of 08:18, 2 November 2010

The CSDMS Help System

HydroTrend

Climate driven hydrological transport model

Model introduction

HydroTrend is an ANSI-standard C numerical model that creates synthetic river discharge and sediment load time series as a function of climate trends and basin morphology and has been used to study the sediment flux to a basin for basin filling models. As a drainage basin simulator, the model provides time series of daily discharge hydraulics at a river mouth, including the sediment load properties. HydroTrend was designed to provide input to lake or shelf circulation and sedimentation models (Steckler et al., 1996; Syvitski and Alcott, 1995b), and study the impact of land-sea fluxes given climatic change scenarios (Moore, 1992; Syvitski and Andrews, 1994). HydroTrend simulates the major processes that occur in a river basin, including:

  • Glacierized areas with advances and retreats depending on the climate scenario,
  • Snow accumulation in the winter and melt in the subsequent spring/summer,
  • Rainfall over the remaining portions of the basin with canopy evaporation,
  • Groundwater recharging and discharging,
  • The impact of reservoirs.

Model parameters

Parameter Description Unit
Input directory Determine if you want to use the "GUI" interface to provide input parameter values or use a text file with the input parameters by providing the location of the file on the server. [-]
Site prefix Part of the input and output file name e.g. the name of the geographic location, or project [-]
Case prefix Part of the input and output file name that provides you the opportunity to do different scenario simulations for e.g. the same location, or project [-]
Parameter Description Unit
Run duration [years]
Parameter Description Unit
Starting mean annual temperature Mean annual temperature at the river mouth at the start of the simulation. (Notice: this is not a spatial average basin width parameter!) [°C]
Change in mean annual temperature The trend or change per year in the annual temperature [°C/year]
Standard deviation of mean annual temperature The standard deviation about the trend line that the annual temperatures will have. [°C]
Parameter Description Unit
Starting mean annual precipitation Annual total spatial river basin average precipitation rates for the beginning of the simulation [m/year]
change in mean annual precipitation The trend or change in the total annual precipitation [m/year/year]
Standard deviation of mean annual precipitation The standard deviation about the trend line that the annual precipitation will have. [m/year]
Parameter Description Unit
Lithology factor Sediment production varies with lithology, hard versus weak lithology: (0.5 - 3):
  • L=0.5 for basins comprised principally of hard, acid plutonic and/or high-grade metamorphic rocks.
  • L=0.75 for basins comprised of mixed, mostly hard lithology, sometimes including shield material.
  • L=1.0 for basins comprised of volcanic, mostly basaltic rocks, or carbonate outcrops, or mixture of hard and soft lithologies.
  • L=1.5 for basins characterized by a predominance of softer lithologies, but having a significant area of harder lithologies.
  • L=2 for fluvial systems draining a high proportion of sedimentary rocks, unconsolidated sedimentary cover, or alluvial deposits.
  • L=3 for basins having an abundance of exceptionally weak material, such as crushed rock, or loess deposits, or shifting sand dunes.
[-]
Anthropogenic facor Anthropogenic factor (0.3 - 8.0), disturbance to landscape:
  • Eh = 0.3: for basins with a high density population (PD > 200 km2) and GNP/capita > $15K/y
  • Eh = 1.0: for basins with low human footprint (PD smaller than 50 km2)
  • Eh = 2.0 - 8.0: for basins with the high density population (PD > 200 km2) and GNP/capita is lower than $1K/y
[-]
Lapse rate The change in temperature per change in elevation. Parameter used to determine the snow - rain transition zone [°C/km]
Starting ELA Glacier equilibrium line altitude is the long-term balance point along a glacier. The ELA is where the amount of accumulated snow and ablated water are equal. [m]
Change in ELA Is the linear change per year of the equilibrium line altitude due to a shift in the climate [m/year]
Dry precipitation (nival and ice) evaporation fraction The percentage of the dry precipitation (nival&ice) which will be evaporated. [-]
River length The length of the main stem of the river to determine the lag time before water reaches the river outlet. [km]
Mean volume of reservoir If the reservoir capacity is more than 0.5km3, Trap Efficiency (TEbasin) will be calculated based by: (TEbasin = 1.0 - (0.05 / exp(Rvol/RQbar)0.5, where Rvol = Reservoir volume and RQbar = the mean inflow discharge)[1].
If the reservoir capacity is less than 0.5km3, (TEbasin = ( 1.0 - (1.0 / (1 + 0.0021 *D * ((Rvol * 1e9) / Rarea)))) where Rvol = Reservoir volume and Rarea (km2) = drainage area above the Reservoir) and D, set to 0.1, represents the reservoir characteristics [2]
[km3]
Drainage area of reservoir The Upstream area of the river basin that drains into the reservoir. [km2]
Parameter Description Unit
k River mouth velocity coefficient [m/s]
m River mouth velocity exponent [-]
a River mouth width coefficient [m]
b River mouth width exponent [-]
Average river mouth velocity The average stream velocity, used in the model to determine the flow routing [m/s]
Constant annual baseflow Defines the constant annual baseflow which occurs in the basin. This is analogous to a deep groundwater pool. Baseflow should be bigger than 0 and smaller than the total precipitation discharge. [m3/s]
Trapping efficiency Deltaic area typically trap sediment e.g. due to the low slope angle of the area. The fraction of deltaic trapping (0 - 1) can be provided here. [-]
Delta gradient Delta gradient determines the slope of the riverbed that determines the amount of bedload reaching the river mouth. [m/m]
Parameter Description Unit
Maximum groundwater storage Maximum capacity spacial averaged shallow ground water pole of the drainage basin [m3]
Minimum groundwater storage Minimum capacity spacial averaged shallow ground water pole of the drainage basin [m3]
Initial groundwater storage Spatial averaged shallow ground water pole of the drainage basin at the start of the simulation. [m3]
Groundwater coefficient [m3]
Groundwater exponent The shallow groundwater (sub-surface storm flow) exponent is used in draining the groundwater pool to the river. [-]
Ksat Saturated hydraulic conductivity describes water movement through saturated media. See table for saturated hydraulic conductivity values in relation to texture. [mm/day]
Parameter Description Unit
Output directory [-]
Interval between output files [-]
Mean Velocity file [-]
Mean Width file [-]
Mean Depth file [-]
Mean Water Discharge file [-]
Mean Sediment Discharge file [-]
Mean Bedload Flux file [-]

Uses ports

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Provides ports

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Main equations

Q = Qr + Qn + Qice - QEv ± Qg = Water discharge at the river mouth [m3/s] (1)
Qs = ω B Q0.31 A0.5 R T for T ≥ 2 °C = Long-term suspended sediment load at the river mouth [kg/s] (2a) or
Qs = 2ω B Q0.31 A0.5 R for T < 2 °C = Long-term suspended sediment load at the river mouth [kg/s] (2b)
B = L (1 - TE) Eh = importance of geology and human factors (3)
(Qs[i] / Qs) = ψ[i] (Q[i] / Q)Ca = Daily suspended sediment load at the river mouth [kg/s] (4)
Qb[i] = (ρs / ρs - ρ) * (ρ g Q[i]β S eb) / (g tan λ) when u ≥ ucr = Daily bedload at the river mouth [kg/s] (5)


Nomenclature

Symbol Description Unit
Q Long-term water discharge [m3/s]
Qr Water discharge generated by rainfall [m3/s]
Qn Water discharge generated by nival melt [m3/s]
Qice Water discharge generated by glacier melt [m3/s]
QEv Water discharge loss by evapo-transpiration processes [m3/s]
Qg Water discharge loss or generated by ground water [m3/s]
Qs Long-term suspended sediment load (30yrs or longer) [kg/s]
ω Constant, (0.02) [-]
A Drainage basin area [km2]
R Drainage basin relief [km]
T Drainage basin temporal and spatial mean temperature [°C]
L Lithology factor [-]
TE Trapping efficiency of reservoirs / lakes [-]
Eh Anthropogenic factor [-]
Qs[i] Daily suspended sediment load [kg/s]
Ψ[i] Daily random variable with a log-normal distribution [-]
Q[i] Daily water discharge [m3/s]
Ca Annual rating term coefficient with a normal distrbution [-]
Qb[i] Daily bedload [kg/s]
ρs Sand density [kg/m3]
ρ Fluid density [kg/m3]
g Acceleration due to gravity [m/s2]
β Bedload rating term [-]
S Slope of the riverbed [m/m]
eb Bedload efficiency [-]
λ Limiting angle of response of sediment grains lying on the river bed [-]
u Stream velocity [m/s]
ucr Critical stream velocity [m/s]

Notes

Any notes, comments, you want to share with the user

Numerical scheme


Examples

An example run with input parameters, BLD files, as well as a figure / movie of the output

Follow the next steps to include images / movies of simulations:

See also: Help:Images or Help:Movies

Developer(s)

Albert Kettner

Key HydroTrend Papers

  • Kettner, A.J., and Syvitski, J.P.M., 2008. HydroTrend version 3.0: a Climate-Driven Hydrological Transport Model that Simulates Discharge and Sediment Load leaving a River System. Computers & Geosciences, 34(10), 1170-1183, doi:10.1016/j.cageo.2008.02.008.
  • Syvitski, J.P.M., Morehead, M.D. and Nicholson, M., 1998. HYDROTREND: A Climate-driven Hydrologic-Transport Model for Predicting Discharge and Sediment Loads to Lakes or Oceans. Computers & Geosciences, 24(1), 51-68, doi:10.1016/S0098-3004(97)00083-6.
  • Syvitski, J.P.M., and J.M. Alcott, 1995. RIVER3: Simulation of River Discharge and Sediment Transport. Computers and Geosciences, 21(1), 89-101, doi:10.1016/0098-3004(94)00062-Y.

References

  1. Vörösmarty, C.J., Meybeck, M., Fekete, B., and Sharma, K. (1997) The potential of neo-Castorization on sediment transport by the global network of rivers. Human Impact on Erosion and Sedimentation, IAHS, 245, 261-273.
  2. Verstraeten G., and Poesen, J. (2000) Estimating trap efficiency of small reservoirs and ponds: methods and implications for the assessment of sediment yield. Progress in Physical Geography, 24, 219-251.

Links

Model:HydroTrend