Hydrograph

StandHyd

OTTHYMO object	VOSWMM object
StandHyd	Subcatchment

The parameters of VOSWMM subcatchment are assigned as:

• NHYD = StandHyd NHYD
• Name = StandHyd Name
• Storm Index = StandHyd Storm Index
• Area = StandHyd Area
• Width = Area/area_average(LGP, LGI), where area_average(LGP, LGI) is the area weighted average of LGP and LGI based on the area of pervious and impervious area of StandHyd
• Slope (%) = area_average(SLPP, SLPI), where area_average(SLPP, SLPI) is the area weighted average of SLPP and SLPI based on the area of pervious and impervious area of StandHyd
• %Imperv = StandHyd TIMP
• N-imperv = StandHyd MNI
• N-perv = StandHyd MNP
• Dstore-imperv = StandHyd DPSI
• Dstore-perv:
  • If importing a single-event OTTHYMO project:
    • If the Loss Model of the StandHyd pervious area is SCS or Proportional: Dstore-perv = StandHyd IA
    • If the Loss Model of the StandHyd pervious area is Horton: Dstore-perv = StandHyd DPSP
  • If importing a continuous OTTHYMO project: Dstore-perv = StandHyd IA
• %Zero-imperv = 0
• Subarea Routing
  • If importing a single-event OTTHYMO project: Subarea Routing = Imperv
  • If importing a continuous OTTHYMO project: Subarea Routing = Pervious
• Percent Routed
  • If importing a single-event OTTHYMO project: Percent Routed = (TIMP-XIMP) / TIMP x 100, where TIMP and XIMP are parameters of StandHyd
  • If importing a continuous OTTHYMO project: Percent Routed = (TIMP-XIMP) x Fraction_SubareaRouting / TIMP x 100, where TIMP and XIMP are parameters of StandHyd and Fraction_SubareaRouting is Fraction Runoff Indirectly Imp. in the OTTHYMO Simulation Engine.
• Infiltration parameters:
  • If importing a single-event OTTHYMO project
    • If StandHyd Loss model is SCS:
      • Infiltration model = Curve Number
      • Curve Number = StandHyd CN
    • If StandHyd Loss model is Horton:
      • Infiltration model = Horton
      • Curve Number = StandHyd CN
      • Max. Infil Rate = StandHyd Fo
      • Min. Infil Rate = StandHyd Fc
      • Decay Constant = StandHyd DCAY
    • If StandHyd Loss model is Proportional: use Horton method and keep default parameters as in VOSWMM.
  • If importing a continuous OTTHYMO project
    • Infiltration model = Curve Number
    • Conductivity = StandHyd Saturated K
    • Curve Number = StandHyd CN
• Other parameters keep as default as in VOSWMM. Please note the Snow Pack and Land Uses may be updated under certain conditions. Please refer to the section of Importing of Scenario and Pollutant Concentrations and Land Uses for details.
  

NasHyd

OTTHYMO object	VOSWMM object
NasHyd	Subcatchment

The parameters of VOSWMM subcatchment are assigned as:

• NHYD = NasHyd NHYD
• Name = NasHyd Name
• Storm Index = NasHyd Storm Index
• Area = NasHyd Area
• %Imperv = 0
• Dstore-perv = NasHyd IA
• Infiltration parameters:
  • If importing a single-event OTTHYMO project
    • Infiltration model = Curve Number
    • Curve Number = NasHyd CN
  • If importing a continuous OTTHYMO project
    • Infiltration model = Curve Number
    • Conductivity = NasHyd Saturated K
    • Curve Number = NasHyd CN
• Other parameters keep as default as in VOSWMM. Please note the Snow Pack and Land Uses may be updated under certain conditions. Please refer to the section of Importing of Scenario and Pollutant Concentrations and Land Uses for details.
  

ScsHyd

OTTHYMO object	VOSWMM object
ScsHyd	Subcatchment

The parameters of VOSWMM subcatchment are assigned as:

• NHYD = ScsHyd NHYD
• Name = ScsHyd Name
• Storm Index = ScsHyd Storm Index
• Area = ScsHyd Area
• %Imperv = 0
• Infiltration parameters:
  • If importing a single-event OTTHYMO project
    • Infiltration model = Curve Number
    • Curve Number = ScsHyd CN
  • If importing a continuous OTTHYMO project
    • Infiltration model = Curve Number
    • Conductivity = ScsHyd Saturated K
    • Curve Number = ScsHyd CN
• Other parameters keep as default as in VOSWMM. Please note the Snow Pack and Land Uses may be updated under certain conditions. Please refer to the section of Importing of Scenario and Pollutant Concentrations and Land Uses for details.
  

WilHyd

OTTHYMO object	VOSWMM object
WilHyd	Subcatchment

The parameters of VOSWMM subcatchment are assigned as:

• NHYD = WilHyd NHYD
• Name = WilHyd Name
• Storm Index = WilHyd Storm Index
• Area = WilHyd Area
• %Imperv = 0
• Dstore-perv = WilHyd IA
• Infiltration parameters:
  • If importing a single-event OTTHYMO project
    • Infiltration model = Curve Number
    • Curve Number = WilHyd CN
  • If importing a continuous OTTHYMO project
    • Infiltration model = Curve Number
    • Conductivity = WilHyd Saturated K
    • Curve Number = WilHyd CN
• Other parameters keep as default as in VOSWMM. Please note the Snow Pack and Land Uses may be updated under certain conditions. Please refer to the section of Importing of Scenario and Pollutant Concentrations and Land Uses for details.