🌧️ Runoff Volume Models
🌐 Runoff volume models in InfoWorks help determine the amount of rainfall 🌦️ that transitions into the drainage system 🚿, considering initial losses 💧.
🔧 Set the Runoff Volume Model within the Runoff Volume Type field of the Runoff Surface. This surface then links to one or more Land Use objects 🌱 which connect to one or more subcatchments.
🤝 Surfaces of varying types might be combined in one model. Remember to set the correct initial conditions in the Rainfall Event for each surface type used.
📘 Runoff Model Overview
| 📌 # | 📖 Model | 🚦 Type | 💡 Comments | 📊 Runoff Surface Data Fields Used | 👥 Appropriate For |
|---|---|---|---|---|---|
| 1️⃣ | Constant Infiltration (ConstInf) | Individual | Set constant infiltration from surface to groundwater. | Fixed Runoff Coefficient, Infiltration Loss Coefficient | General usage |
| 2️⃣ | DefConLoss | Individual | Based on HEC-HMS model. | Maximum Deficit, Infiltration Loss Coefficient | Advanced hydrological modeling |
| 3️⃣ | f1-Rsa | Individual | Calculates effective rainfall using Quasi Linear Reservoir Method. | Minimum runoff, Maximum runoff, Saturated rainfall | Standard in Japan 🇯🇵 |
| 4️⃣ | Fixed percentage runoff | Individual | You define the percentage of rainfall that becomes runoff. | Fixed Runoff Coefficient | When runoff percentage is known |
| 5️⃣ | Green-Ampt | Individual | Used only on pervious surfaces. | Green Ampt Conductivity, Green Ampt Suction, etc. | US with SWMM model 🇺🇸 |
| 6️⃣ | Horner | Individual | Determines net rainfall on urban subcatchments. | Horner Alpha, Horner Beta, Horner Recovery | Urban areas 🏙️ |
| 7️⃣ | Horton | Individual | Used only on pervious surfaces. | Decay factor, Initial infiltration, etc. | Rural and pervious surfaces 🌳 |
| 8️⃣ | HortonSWMM | Individual | Specialized for pervious surfaces. | Decay factor, Initial infiltration, etc. | Desbordes or SWMM models |
| 9️⃣ | New UK (Variable) PR | Total catchment | UK model for changing catchment conditions. | New UK Depth, API30 | UK pervious catchments 🇬🇧 |
| 🔟 | PDM | Total catchment | Requires PDM option enabled. | - | Specialized usage |
| 1️⃣1️⃣ | ReFH | Individual | Based on procedures by CEH. | ReFH Cini (rainfall event initial condition), ReFH BF0 | Most UK subcatchments 🇬🇧 |
| 1️⃣2️⃣ | SRM | Total catchment | Requires PDM option enabled. | - | Specialized usage |
| 1️⃣3️⃣ | UKWIR | Total catchment | Uses UKWIR equation by HR Wallingford. | Effective impermeability, IF, etc. | UK catchments 🇬🇧 |
| 1️⃣4️⃣ | USA Soil Conservation Service (SCS) method | Individual | A rural catchment model. | SCS Depth, SCS Index (rainfall event initial condition) | Rural catchments 🌾 |
| 1️⃣5️⃣ | Wallingford Procedure (Fixed) PR | Total catchment | Default model for the UK. | Fixed Runoff Coefficient, Wal. Proc Distribution | UK urban catchments 🇬🇧 |
| 1️⃣6️⃣ | CN | Individual | Rural catchment model similar to SCS. | Curve number, SCS Index (rainfall event initial condition) | Rural catchments 🌾 |
| 1️⃣7️⃣ | DWA (Grenzwertmethode) | Individual | German initial loss and runoff model. | Decay factor, Initial infiltration, etc. | Catchments in Germany 🇩🇪 |
| 1️⃣8️⃣ | CNSWMM | Individual | Developed by US EPA. | Curve number, SCS Index (rainfall event initial condition) | Rural and pervious surfaces 🌳 |
