Urban Flood Risk Mitigation [Soil Hydrologic Groups]

Science, Research & Data
1

I used the InVEST Urban Flood Risk Mitigation model to analyze a watershed in Italy, but the issue is that the required Soil Hydrologic Groups data is only available at a 250 m resolution. This leads to inaccurate results. How can I fix this? many thanks in advance

2

Hello @Cristina -

Soil data is often a limiting factor for our models. While it’s great that the global datasets (FutureWater’s HiHydroSoil and HYSOGs250m) exist, they do have coarse resolution, which is especially limiting if we’re working in a relatively small area.

The only other thing I can recommend is to see if national or local soil data is available that you can use instead. If you can find a more local soil database, it might already have soil group data. Or there might be a soil map with appropriate data to derive soil group values, that you can use to create your own soil hydrologic group map. The User Guide includes one way of deriving your own SHG layer using saturated hydraulic conductivity, and the HYSOG documentation shows another way, using sand and clay information:

  • 1 - Group A: low runoff potential (>90% sand and <10% clay)
  • 2 - Group B: moderately low runoff potential (50-90% sand and 10-20% clay)
  • 3 - Group C: moderately high runoff potential (<50% sand and 20-40% clay)
  • 4 - Group D: high runoff potential (<50% sand and >40% clay)

Sorry this isn’t easier!

~ Stacie