Difference between revisions of "Module RunoffProperties"

Revision as of 18:17, 1 June 2011

Overview

This is the module in Mohid Land that handles runoff properties, meaning that controls transport (dependent on fluxes computed in runoff). In this module property transformation is not computed since this is usually a fast process and there is not time for microbiological activity or chemical equilibrium. This is also the module that handles erosion/deposition to compute sediment and particulate properties sources and sinks (from sediment bed to runoff water and vice-versa).

Main Processes

Property Transport

Time discretization of property transport in Module RunoffProperties can be explicit or implicit. If user chooses to use implicit formulation, fluxes between runoff cells are implicit computed and also Drainage Network interaction where sinks in runoff occur. Runoff interaction acting as source to runoff and sinks from vegetation (particulate organic material easily eroded from manure) are always computed explicitly.

Spatial discretization (horizontally and vertically) of property transport in Module RunoffProperties can be chosen from several options as in ModuleWaterProperties for each property (e.g. Upwind order 1 to 3, CentralDifferences, LeapFrog..) In order to boost the computation, RunoffProperties has the option of choosing all the same discretization for all the properties (discussed below).

Insert equations for property transport

 $Insert formula here$

Insert equation for diffusivity

 $Insert formula here$

Erosion/Deposition

Erosion and deposition are function of the shear stress at the soil surface, meaning that higher velocities will tend to erode material and lower velocities will tend to deposit. Sediment bed is simulated as a "fluff layer" representing the easy eroded material in soil.

Insert equation for erosion

 $Insert formula here$

Insert equation for deposition

 $Insert formula here$

Partition

Partition between particulated and dissolved species is done using a user ratio.

Other Features

Outputs

Output is done in terms of timeseries and HDF following the MOHID standards.

References

Data File

Keywords

Units in runoff properties
  Transported properties (soluble)             : g/m3 (or mg/l)  
  Adsorbed properties (non soluble)            : ug/kgsoil   
  Bottom layer Properties (bottom transition)  : kg/m2    

ADVDIFF_EXPLICIT              : 0/1               [1]        !REMARK: Horizontal diffusion is always explicit
                                                              (1 - horiz adv is explicit; 0 - horiz adv is implicit 
NEW_FORMULATION               : 0/1                [0]        !if 1 then spatial methods will be the same for all properties
     ADVDIFF_METHOD_H         : integer      [UpwindOrder1]   !Spatial methods for horizontal advection
                                                              !UpwindOrder1 = 1, UpwindOrder2 = 2, UpwindOrder3 = 3, P2_TVD = 4,
                                                               CentralDif = 5, LeapFrog = 6    !
<beginproperty>
  PARTICULATE                 : 0/1               [0]         !Property physical state: 0 - Dissolved ; 1 - Particulate
    EROSION                   : 0/1               [0]         !Compute erosion (source/sink term) - only read if PARTICULATE : 1
    DEPOSITION                : 0/1               [0]         !Compute deposition (source/sink) - only read if PARTICULATE : 1
      WS_TYPE                 : integer           [1]         !1 -constant;2 -concentration function - only read if DEPOSITION : 1
        WS_VALUE              : real                          !Fall velocity value - only read if WS_TYPE : 1
  ADVECTION_DIFFUSION         : 0/1               [0]         !Property advection - diffusion
      ADVDIFF_METHOD_H        : integer      [UpwindOrder1]   !Spatial methods for horizontal advection
                                                              !UpwindOrder1 = 1, UpwindOrder2 = 2, UpwindOrder3 = 3, P2_TVD = 4,
                                                               CentralDif = 5, LeapFrog = 6    
      ADVDIFF_TVD_LIMIT_H     : integer        [Superbee]     !Horizontal advection non-linear stability conditions
                                                               MinMod = 1, VanLeer = 2, Muscl = 3, Superbee = 4, PDM = 5
      ADVDIFF_VOLUME_RELATION_MAX : real          5.          !The relation between adjacent volumes above which 
                                                              !the advection is upwind
  SOIL_CHEMISTRY              : 0/1               [0]         !Use PREEQC model to change property (source/sink model)
  SOIL_QUALITY                : 0/1               [0]         !Use SedimentQuality model to change property (source/sink model)
  PARTITION                   : 0/1               [0]         !Compute partition between dissolved-particulate phases
      PARTITION_COUPLE        : char               +          !Name of the property (oposite phase) to compute partition
      PARTITION_FRACTION      : real               -          !Percentage of mass of a property in a determined phase 
      PARTITION_RATE          : real            [1 s-1]       !Kinetic rate of partition to reach equilibrium
      USE_SED_REF_CONC        : 0/1               [0]         !Use cohesive sediment concentration as a reference
          SED_REF_CONC        : real              [1]         !Reference cohesive sediment concentration to partition
<endproperty>

Sample

OUTPUT_TIME               : 0 3600
TIME_SERIE_LOCATION       : ..\General Data\TimeSeries\TimeSeriesLocation2D_2.dat
!
!Advection diffusion options
ADVDIFF_EXPLICIT          : 0
!(1 - adv explicit; 0 - adv implicit; diff always explicit)
 

NEW_FORMULATION           : 1   !1 - do not use moduleadvectiondiffusion (removed advection computation); 0 - old formulation
ADVDIFF_METHOD_H          : 1   !UpwindOrder1 = 1. UpwindOrder2 = 2. UpwindOrder3 = 3. P2_TVD = 4.
!CentralDif = 5. LeapFrog = 6

!Dispersion
<begin_dispersion_trans>
NAME                      : dispersion trans
INITIALIZATION_METHOD     : CONSTANT
DEFAULTVALUE              : 0.0
REMAIN_CONSTANT           : 1
<end_dispersion_trans>
 

!!!!!!!!!!BEGIN SHEAR EROSION/DEPOSITION PARAMETERS!!!!!!!!!!!

HMIN_CHEZY                : 0.0001  !0.0005   !m

<begin_critical_shear_erosion>
NAME                      : critical shear for erosion
INITIALIZATION_METHOD     : CONSTANT
DEFAULTVALUE              : 0.2  !Pa = N/m2
REMAIN_CONSTANT           : 1
<end_critical_shear_erosion>

<begin_critical_shear_deposition>
NAME                      : critical shear for deposition
INITIALIZATION_METHOD     : CONSTANT
DEFAULTVALUE              : 0.1  !Pa = N/m2
REMAIN_CONSTANT           : 1
<end_critical_shear_deposition>

<begin_erosion_coefficient>
NAME                      : erosion coefficient for shear
INITIALIZATION_METHOD     : CONSTANT
DEFAULTVALUE              : 5.0E-6  !5.0E-4     !kg m-2 s-1
REMAIN_CONSTANT           : 1
<end_erosion_coefficient>

!!!!!!!!!!END SHEAR EROSION/DEPOSITION PARAMETERS!!!!!!!!!!! 


!!!!!!!!!!BEGIN SPLASH EROSION PARAMETERS!!!!!!!!!!! 

SPLASH_HCRITIC_COMPUTE     : 1
SPLASH_HCRITIC             : 0.1   !m water column height where exponent decay is about 40% of maximum value
SPLASH_EROSIVERAIN_METHOD  : 2     ! 1-constant erosive rain ; 2-use real rain for erosive rain
 SPLASH_EROSIVERAIN_VALUE : 30.   ! mm/h for erosive rain (read if SPLASH_EROSIVERAIN_METHOD : 1)
 
<begin_soil_detach>
NAME                      : erosion coefficient for rain splash
INITIALIZATION_METHOD     : CONSTANT
DEFAULTVALUE              : 0.1         !g/J
REMAIN_CONSTANT           : 1
<end_soil_detach> 

!!!!!!!!!!END SPLASH EROSION PARAMETERS!!!!!!!!!!!

!
!Property declaration
<beginproperty>
NAME                      : nitrate
UNITS                     : mgN/l
ADVECTION_DIFFUSION       : 1
DESCRIPTION               : nitrate
DEFAULTVALUE              : 1.0
ADVDIFF_MOLECULAR_DIFF_COEF :  0.0
TIME_SERIE                : 1
OUTPUT_HDF                : 1
<endproperty>

Properties needed to run erosion/depositio: cohesive sediment and each other particulate have to be marked as particulate and erosion deposition parameters defined.

<beginproperty>
 NAME                    : cohesive sediment
 UNITS                   : mg/l
 DESCRIPTION             : Calcium in soil solution
 PARTICULATE             : 1
 ADVECTION_DIFFUSION     : 1
 EROSION                 : 1
 DEPOSITION              : 1
   WS_TYPE               : 1              !1 - constant; 2 - Concentration function
     WS_VALUE            : 1E-10 !1E-4    !m/s (read if WS_TYPE : 1)
 SPLASH_EROSION          : 0
 DEFAULTVALUE            : 2.8e-3         !mg/l
 BOTTOM_CONC             : 1.0            !kg/m2
 ADVDIFF_MOLECULAR_DIFF_COEF  : 0.0       ! 1.15741E-8
 TIME_SERIE              : 1
 OUTPUT_HDF              : 1
<endproperty>

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