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Green-Ampt Infiltration Parameters: Difference between revisions

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sensitive to the changes in the hydraulic conductivity with the mid and high values providing a lot of infiltration and no runoff at the downstream gauge. As expected, the higher the hydraulic conductivity, then the more infiltration that occurs and the less runoff that is seen at the gauge.<br>
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''Image 6''<br>
'''[[File:Fig6 hydroconduct.png|600px|Figure 106: Sensitivity of simulated flow at 3 gauge locations in the Plynlimon Gwy catchment to the initialSaturated soilHydraulic moistureConductivity parameter in the Green-Ampt infiltration model when using a clay soil type.''']]<br>▼
 
'''Figure 6: Sensitivity of simulated flow at 3 gauge locations in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model when using a clay soil type.'''<br>
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[[File:Fig7 hydroconduct.png|600px|Figure 7: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.]]<br>
 
'''Figure 7: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the Saturated Hydraulic Conductivity parameter in the Green-Ampt infiltration model.'''<br>
 
== Porosity ==
The porosity value represents the volume of dry voids per volume of soil and provides the maximum moisture deficit that is available, the difference between the moisture content at saturation and at the start of the simulation.<br>
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[[File:Fig7 porosity sens.png|600px|Figure 7: Sensitivity of simulated flow at 3 gauge locations in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]]<br>
 
'''Figure 78: Sensitivity of simulated flow at 3 gauge locations in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.'''<br>
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[[File:Fig8 porosity sens.png|600px|Figure 8: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.]]<br>
 
'''Figure 89: Sensitivity of cumulative infiltration in the Plynlimon Gwy catchment to the porosity parameter in the Green-Ampt infiltration model.'''<br>
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== Initial Soil Moisture Deficit ==
The initial soil moisture deficit determines how much infiltration capacity is available during the simulation. The moisture deficit is the difference between the saturated moisture content and the initial moisture content and is expressed as a fraction. 4 scenarios were simulated which set the initial soil moisture deficit at 0% (default), 25%, 50% and 75%. As expected, the wetter the soil at the beginning of the simulation, the less infiltration that occurs and therefore the increased runoff as shown by increased flows at the 3 flow gauges. The sensitivity of the simulated outputs to the initial soil moisture deficit appears to be more significant at the beginning of the event and becomes less sensitive as the first peak is experienced. This is due to the wetting of the soils which leads to saturation and the convergence in the potential infiltration rate.<br>
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''Image 9/10''<br>
▲'''Figure 10: Sensitivity of simulated flow at 3 gauge locations in the Plynlimon Gwy catchment to the initial soil moisture in the Green-Ampt infiltration model.'''<br>
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== In built USDA soil type ==
The model was also run with the default in-build USDA soil types. Figure 11 shows the outputs. As expected the higher the soil type, then typically the more the infiltration and the lower the produced runoff. Soils 8-11, which represent sandy soils to not show any runoff in this example as the rainfall is all infiltrated.<br>
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''Image 10/11''<br>
'''Figure Caption NEEDED'''
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