ILCL Parameters for Soils in UK

[Ajinkya 0]

Hi,

 

I am doing a direct rainfall model and i would like to use ILCL method of infiltration in my model. The model is very sensitive to the Green-Ampt method. Can anybody suggest the parameters for using this method for different types of soils in UK or suggest me an appropriate source where I can find this?

Thanks in advance

Ajinkya

[Stephanie Dufour 0]

Hi Ajinkya,

Table 4.7 in the SuDS Manual (C697) produced by CIRIA provides a range of infiltration rates based on soil type.

The sensitivity of the results when using the Green-Ampt method likely lie in the correlation of UK Soils types to the USDA soil types hardwired in TUFLOW. It can be very subjective trying to relate information obtained from National datasets to the USDA soil types which is perhaps why you have noticed a variation in model results. Note that we are currently working with a University to derive data for UK specific soils.

Should you proceed with using the ILCL method as opposed to the Green-Ampt, keep in mind that this is a more simplistic method of estimating infiltration and the soil will only become saturated based on a defined depth to groundwater (the default is infinitely deep). It is recommended to write the Map Output Types IR (infiltration rate), CI (cumulative infiltration) and dGW (depth to groundwater) to help you determine the amount that is infiltrated in the model. 

 

 

[RA2279 0]

Hi,

What is the best source of information on typical infiltration data for different UK Soil Types to use within TUFLOW? The thread above (from 2015) suggested that the SuDS Manual was a good source; is this still considered to be the best available or has better data been recently published (note reference to 'currently working with a University to derive data for UK specific soils)?

Like others on here, I am noticing that models in rural catchments are sensitive to the choice of GREEN AMPT soil type and that modelled flow results appear to be unrealistically large when using the GREEN AMPT method (for example when compared to flow estimated using a more 'traditional' rainfall-runoff methodology such as ReFH2 or FEH Statistical).

Any guidance or updates appreciated,

Ruth

 

[groganm 0]

Hi,

I'd like to second Ruth's request. Is anyone aware of any updated or alternate sources for UK specific infiltration parameters for any of the methods available in TUFLOW?

Thanks

Michael