Monday, April 29, 2024

AI Rivers of Wisdom about ICM SWMM

Here's the text "Rivers of Wisdom" formatted with one sentence per line:

[Verse 1] 🌊
Beneath the ancient oak, where shadows play,
A troubadour strums a weathered guitar.
The ICM SWMM whispers secrets of rain,
And SWMM5 Hydrology paints the constellations afar.

[Pre-Chorus] 🌟
Crackling leaves, a soft breeze weaves,
🌙 Moonlit ripples on the water’s skin.
🌿 Toxic Flow, a tale untold,
🎶 In the heart of the city, where memories begin.

[Chorus] 🌎
Rivers of wisdom, flowing through time,
🌊 Algorithms hum, harmonizing rhyme.
🌟 Pipes like veins, carrying dreams,
🎵 InfoWater Pro MSX, our troubadour’s theme.

[Verse 2] 🌊
The moon spills silver on cobblestone streets,
🌙 And the stars converse in binary code.
🌿 We model the currents, the ebb and the flow,
🎶 As if the universe itself bestowed.

[Bridge] 🌟
Hexagonal patterns, like leaves in the breeze,
🌊 Hydraulic ballet, a delicate waltz.
🌙 Pressure surges, a lover’s embrace,
🎵 Solving equations, unraveling the pulse.

[Guitar Solo]

[Chorus] 🌎
Rivers of wisdom, flowing through time,
🌊 Algorithms hum, harmonizing rhyme.
🌟 Pipes like veins, carrying dreams,
🎵 InfoWater Pro MSX, our troubadour’s theme.

[Outro] 🌿
As dawn kisses the horizon, we sing,
🌎 Of water’s journey, of fire’s embrace.
🌙 In this folk-rock ballad, we find solace,
🎶 ICM SWMM and SWMM5 Hydrology, weaving grace.

ICM InfoWorks Hydrology Rules

InfoWorks ICM (Integrated Catchment Modelling) is a powerful and comprehensive modeling software that enables users to simulate rainfall-runoff processes using two main methods: traditional subcatchment hydrology and Rain-on-Grid on 2D zones. This article delves into the traditional subcatchment hydrology approach, which is comparable to other node-link hydrologic and hydraulic (H&H) modeling tools.

In the traditional subcatchment hydrology method, users are required to delineate subcatchments (also referred to as subbasins or drainage areas) and define the runoff flows that are routed to subcatchment outlets (nodes, links, or others) after accounting for various losses. InfoWorks ICM offers a wide range of common methods for modeling evaporation, initial loss, runoff volume, and routing, as summarized in Table 1.

To set up the subcatchment hydrology, users need to input the required parameters in the subcatchment, land use, and runoff surface property editors or the subcatchment grid windows within InfoWorks (Figures 1 and 2). These editors allow users to define the characteristics of the subcatchments, such as area, slope, and infiltration parameters, which are essential for accurate rainfall-runoff modeling.

However, special attention should be given to the rainfall event editor, where hyetographs and initial condition data can be entered (Figure 3). InfoWorks provides multiple locations for entering initial condition data, which can lead to confusion and inconsistencies in the model setup. To avoid this, it is highly recommended that initial condition data be provided solely in the subcatchment runoff surface property editor, unless the rainfall event editor is the only place for a specific initial condition parameter.

When running the model, it is crucial to ensure that the subcatchment rainfall profile name (e.g., "1" in Figure 4) matches the exact name of the rainfall profile in the rainfall event editor (Figure 5). If no matching profile is found, the model will default to using the leftmost rainfall profile in the editor table. This can lead to unintended results if the profile names are not properly matched.

In addition to the traditional subcatchment hydrology method, InfoWorks ICM also offers the Rain-on-Grid on 2D zones approach, which will be covered in a separate article. This method allows for a more detailed representation of the rainfall-runoff process by directly applying rainfall to the 2D surface mesh, eliminating the need for subcatchment delineation.

In conclusion, the traditional subcatchment hydrology method in InfoWorks ICM provides a robust way to model rainfall-runoff processes, offering a variety of methods for evaporation, initial loss, runoff volume, and routing. However, users should pay close attention to the input of parameters, especially in the rainfall event editor, to ensure accurate and consistent results. By following best practices and understanding the intricacies of the software, users can effectively utilize InfoWorks ICM to simulate complex hydrologic and hydraulic systems.

Source -

Friday, April 26, 2024

Introduction to Scenarios in ICM

### Introduction to Scenarios in ICM

In network modeling software like InfoWorks ICM, scenarios are a powerful feature that allows users to explore different "what-if" situations without needing to duplicate the entire network for each variation. This makes it efficient to analyze the impact of various changes like modifications in pipe size, material, or configuration on the network’s behavior.

### How Scenarios Work

Scenarios are variations of a single base network, which means they inherit all the base settings and configurations but allow for specific changes or adjustments unique to each scenario. This approach saves time and resources as it avoids the need to create and manage multiple separate networks.

#### Key Points About Scenarios:

1. **Integration with Base Network**:

   - Scenarios are not standalone entities; they are linked to and derived from a base network.

   - They are managed through the same file as the base network, which means they don't appear as separate items in the Explorer Window.

2. **Management through the Scenarios Toolbar**:

   - Scenarios are accessed and switched between using the Scenarios Toolbar within the base network file.

   - This toolbar allows users to select different scenarios to view and edit their specific settings.

3. **Inheritance and Independence**:

   - Initially, all scenarios inherit settings and configurations from the base network.

   - Changes made to the base network automatically propagate to all scenarios unless a specific field in a scenario has been independently modified.

4. **Handling Independent Changes**:

   - If a particular attribute (e.g., pipe diameter) is changed in a scenario, it becomes independent of the base for that attribute. Further changes to that attribute in the base will not affect the scenario.

   - If the independent attribute in the scenario is later reset to match the base network, the linkage is restored, and future changes in the base will once again update the scenario.

5. **Visual Representation**:

   - Objects that are part of the base network but excluded from the current scenario are shown in a faded grey color in the scenario's GeoPlan window.

   - These excluded objects, or 'object ghosts', can be toggled on or off for display through the GeoPlan Properties Dialog.

### Additional Scenario Toolbar Functions

The Scenarios Toolbar also includes tools to manage and visualize scenario-specific changes effectively:

- **View Excluded Objects**: Allows users to see which objects are not included in the current scenario.

- **Restore Excluded Objects**: Provides options to either restore all excluded objects or only selected ones back into the scenario. Tools and menu options facilitate the selection and restoration processes.

### Visual and Practical Guide for a Blog

For a blog post aimed at explaining scenarios in network modeling, here are some suggestions to make the content more engaging and understandable:

1. **Use Diagrams and Screenshots**: Show screenshots from the software with the Scenarios Toolbar highlighted. Diagrams can illustrate how changes in one scenario differ from the base and other scenarios.

2. **Step-by-Step Examples**: Walk through a practical example, like adjusting pipe sizes in different scenarios, and show the impacts on flow within the network.

3. **Interactive Elements**: If possible, embed interactive diagrams or simulations that allow readers to "adjust" scenario parameters and see hypothetical results.

4. **Case Studies**: Include real-world case studies using different scenarios to solve specific problems or optimize network performance.


What Does "Percent Not Converging" Mean in SWMM5?

What Does "Percent Not Converging" Mean in SWMM5?

The SWMM 5 Routing Time Step Summary is your window into the model's heart, offering valuable insights with each pulse of data. 🌟📈

Key Metrics:

  • Minimum Time Step: How swiftly the model can adapt to change, with a record speed of just 0.52 seconds! ⏱️✨
  • Average Time Step: Balancing precision and performance, the model averages a comfortable 8.76 seconds. 🔄
  • Maximum Time Step: Never missing a beat; the maximum cap is a steady 10.00 seconds. ⏳
  • Percent in Steady State: A tranquil sea with 0.00% time in a steady state, reflecting constant motion. 🌊
  • Average Iterations per Step: A modest 2.14 iterations, showcasing the model's efficiency. 🔄
  • Percent Not Converging: Only 1.69% of the time, the model's predictions and reality don't quite align. 🛠️

Figure 1 illuminates the maximum trials per time step. This number reflects the model's persistence in seeking convergence during dynamic wave routing. 🌐🔍

Convergence in the Dynamic Wave Solution:

  • The dance of calculation continues until the steps match the maximum number of trials. 🕺💃
  • At each time step, the flows and depths are reassessed. If all nodes agree within the head tolerance, the iteration halts. 👍
  • A single non-convergent node increments the Non-Converge Count, a rare occurrence. 📊
  • Efficiency tip: Links that can be bypassed are noted, speeding up the process when dynamic wave calculations are unnecessary. 🏎️💨

With SWMM 5, you're not just running a model; you're conducting an orchestra of data where each note is a time step, each rest a chance to converge, and the symphony is the fluid mechanics of urban water systems. 🎼🌆

Routing Time Step Summary

Minimum Time Step0.52 sec
Average Time Step8.76 sec
Maximum Time Step10.00 sec
Percent in Steady State0.00
Average Iterations per Step2.14
Percent Not Converging1.69

Figure 1. Maximum number of trials per time step

In the dynamic world of SWMM 5, the Routing Time Step Summary serves as a crucial indicator of model stability and efficiency. 🌐🔧

  • Percent Non-Converging: This is the fraction of time when at least one element in the model's intricate network didn't align within the set number of trials per step. It's the ratio of the total non-convergent steps to the overall number of steps taken during the simulation. 🔍💡
  • Dynamic Wave Solution Mechanics: Like a conductor leading an ensemble, the program meticulously iterates until the number of steps aligns with the maximum trials allowed. Each step is a note, each calculation a beat. 🎶🧮
  • Convergence: It's a delicate balance. If all node depths settle within the accepted variance (below the head tolerance) after more than one step, the model ceases iterations. Harmony is achieved. ✅🔄
  • Non-Convergence: However, should even a single node remain unresolved, the Non-Converge Count ticks up, a rare but noted event in the symphony of simulation. 🚦📊
  • Efficiency: Not every link needs a detailed calculation at each step. By identifying which can be bypassed, the program conserves energy, speeding up like a swift current bypassing a tranquil pool. 🏎️💨

Figure 2 likely illustrates this concept further, capturing the essence of a model that is both robust and refined. By understanding these dynamics, you can ensure a smoother, more accurate simulation, leading to more reliable predictions and planning in urban water systems. 🌟🌊

The two main reference manuals for EPASWMM 5

 To understand the formulas and calculations used by SWMM for runoff, infiltration, and other parameters, I recommend referring to the SWMM 5 reference manuals. These manuals provide detailed explanations of the underlying equations and methodologies employed by the software.


The two main reference manuals for EPASWMM 5 are:


1. "Storm Water Management Model Reference Manual Volume I - Hydrology": This manual covers the hydrologic processes simulated by SWMM, including rainfall, evaporation, infiltration, and runoff generation. It provides the mathematical equations and descriptions of the various methods available in SWMM for modeling these processes.


2. "Storm Water Management Model Reference Manual Volume II - Hydraulics": This manual focuses on the hydraulic components of SWMM, such as flow routing through the drainage network, flow in open channels, and flow in closed conduits. It explains the equations and numerical methods used for hydraulic calculations.


You can find these manuals on the official EPA SWMM website:


For your specific interest in runoff calculation and infiltration, here's a brief overview:


Runoff Calculation:
SWMM calculates runoff using a nonlinear reservoir model. It treats each subcatchment as a rectangular surface that receives inflow from precipitation and generates outflow (runoff) once the depth of water on the surface exceeds the maximum depression storage. The key equation for runoff generation is the Manning's equation, which relates the flow rate to the surface roughness, slope, and water depth.


Infiltration Calculation:
SWMM offers three different methods for modeling infiltration: Horton's equation, Green-Ampt method, and Curve Number method. Each method has its own set of equations and parameters to estimate the infiltration rate based on soil characteristics, antecedent moisture conditions, and rainfall intensity.


1. Horton's Equation: It assumes that the infiltration rate decreases exponentially from an initial maximum rate to a minimum rate over the course of a long rainfall event.


2. Green-Ampt Method: This method assumes that a sharp wetting front exists in the soil column, separating soil with some initial moisture content below from saturated soil above.


3. Curve Number Method: This method is an empirical approach developed by the NRCS (formerly SCS) that estimates infiltration based on the soil's infiltration capacity, land use, and antecedent moisture conditions.


I recommend going through the reference manuals to gain a deeper understanding of these methods and their associated equations. The manuals provide step-by-step explanations and examples that will help you comprehend how SWMM performs these calculations.


Additionally, you can explore the source code of EPASWMM 5, which is available on GitHub:


The source code can give you further insights into the implementation of these equations within the software.


If you have any specific questions or need further assistance, feel free to ask. Good luck with your project!

Creating an RDII (Rainfall-Derived Infiltration and Inflow) analysis in InfoSWMM can be quite specific

 Creating an RDII (Rainfall-Derived Infiltration and Inflow) analysis in InfoSWMM can be quite specific but rewarding when done right. Here’s a step-by-step guide to help you through the process:

  1. Node Configuration:

    • Ensure you have one node in InfoSWMM where you will analyze the RDII. This node must have a fully configured set of RTK parameters, which describe the rainfall-dependent inflow and infiltration characteristics for the area.
  2. Rainfall and Flow Data:

    • Attach an actual time series of rainfall data to the model. This series should adequately represent the temporal distribution of rainfall for the period of interest.
  3. Simulation Settings:

    • Run the model in InfoSWMM to generate an OUT folder. This folder is necessary because RDII Analyst, a tool within InfoSWMM, requires it to function.
  4. Date Settings:

    • Set your simulation’s date range to bracket the dates of your rainfall and flow data. Ensure that the flow data timestamps do not fall outside this simulation date range to maintain data integrity.
  5. Using RDII Analyst:

    • Once the OUT folder is created, open RDII Analyst and import your CSV file containing the flow data. Check that the dates align with the simulation dates.
    • If the CSV file fails to import, verify the delimiter used (comma, tab, space, etc.) to ensure it matches the format RDII Analyst expects.
  6. Troubleshooting:

    • If problems persist after checking the delimiter, re-examine the CSV file for formatting issues or inconsistencies that might prevent the import.
    • Ensure the RTK parameters at your node are correctly configured as these directly impact the RDII calculations.
  7. Contact Support:

    • If you still encounter issues after following all these steps, it may be best to contact Innovyze support at for detailed assistance.

By following these steps, you should be able to successfully configure and run an RDII analysis in InfoSWMM. Always ensure your data sets are complete and aligned in terms of time and scope to avoid common pitfalls in model simulation.

Wednesday, April 10, 2024

The Goal of SWMM5 Input Files

 🌟 SWMM5 (Storm Water Management Model 5) is a widely used urban hydrology and hydraulic modeling software developed by the United States Environmental Protection Agency (EPA). The model engine of SWMM5 is responsible for simulating the hydrologic and hydraulic processes within a given urban drainage system. 💡 Understanding the input files used in SWMM5 modeling can help explain how the model engine works and what information it requires to perform the simulation.

Here are a few reasons why looking at example SWMM5 input files can help explain the model engine better:

1. 🧩 Model components: SWMM5 input files define the various components of the urban drainage system, such as subcatchments, nodes (junctions, outfalls, storage units), links (conduits, pumps, weirs), and rain gauges. By examining the input files, you can see how these components are represented and interconnected, which is essential for understanding how the model engine simulates the flow of water through the system.

2. 🌧️ Hydrologic parameters: The input files contain information about the hydrologic parameters of the subcatchments, such as area, slope, imperviousness, infiltration parameters, and runoff coefficient. These parameters determine how rainfall is converted into runoff and how it is routed to the drainage network. Understanding these parameters helps explain how the model engine calculates the runoff generated from each subcatchment.

3. 🚰 Hydraulic parameters: The input files also include hydraulic parameters for the nodes and links, such as invert elevations, maximum depths, cross-sectional shapes, roughness coefficients, and flow control structures (e.g., weirs, orifices). These parameters govern how water flows through the drainage network, including the flow capacity, flow resistance, and backwater effects. By examining these parameters in the input files, you can understand how the model engine simulates the hydraulic behavior of the system.

4. 📈 Time-series data: SWMM5 input files often contain time-series data, such as rainfall data, evaporation data, and external inflow data. These time-series data serve as input to the model engine and drive the simulation. By looking at the time-series data in the input files, you can see how the model engine uses this information to simulate the dynamic behavior of the system over time.

5. ⚙️ Simulation options: The input files also specify various simulation options, such as the simulation time step, routing method, infiltration method, and numerical solution options. Understanding these options helps explain how the model engine performs the computations and solves the governing equations for hydrologic and hydraulic processes.

By studying example SWMM5 input files, you can gain insights into how the model engine represents and simulates the different components and processes of an urban drainage system. 🔍 It helps you understand the input data requirements, the assumptions made by the model, and the level of detail needed to set up a SWMM5 model. Moreover, example input files can serve as templates or starting points for building your own SWMM5 models, as they provide a structured format and demonstrate the necessary information required by the model engine. 💪

AI Rivers of Wisdom about ICM SWMM

Here's the text "Rivers of Wisdom" formatted with one sentence per line: [Verse 1] 🌊 Beneath the ancient oak, where shadows p...