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Enquiry about the simulation of urban coastal flood

Hi, communities guys! I generated the 3D model and DSM of the study area in Context Capture! May I know how to conduct simulation by using OpenFlows? For example, what numerical model should be used? What modules in simulation should be selected? Are there any step by step guidelines or video can be provided for the urban flooding simulation case? Or are there any user manuals?

Here is the orthophoto of my study area, I want to find out the inundation areas which are affected by storm surges during the typhoon cyclones.

  • Hello Cherry,

    I think this query may be in relation to your earlier forum post on generating DSM data from ContextCapture which was answered by my colleague Douglas. Is this regarding the same project?

    Assuming its the same query and continuing from the point where you would have your terrain built in OpenFlows FLOOD; the next step would be to prepare your model for flood simulation. I am sharing some links to our learning resources such as video playlists, learning guides and sample datasets for your perusal. These can guide you into following your modeling and simulation requirements,

    OpenFlows FLOOD YouTube Playlist

    OpenFlows FLOOD Fundamental Training

    Learning Resource Guide for users of OpenFlows FLOOD

    The learning resource guide has the Generic and Quick Start Guides for setting up your flood simulation study.

    Also, we have a new release of OpenFlows FLOOD CONNECT Edition (v 10.03.00.01) with a host of new features, tools and improvements. See the link below to know what's new in this version;

    What's New in OpenFlows FLOOD (10.03.00.01)

    Hope this helps.


    Regards,

    Yashodhan Joshi

  • Hi Cherry Chue,

    OpenFlows FLOOD can perform flood analysis for a different range of applications, from:

    1) explicitly simulating the storm surge generation (with a regional scale coastal hydrodynamic model coupled with a regional scale meteorological model, providing winds and atmospheric pressure to the hydrodynamic model);

    2) implicitly simulating the storm surge sea level elevations as a boundary condition for a high resolution model of the flooded coastal area;

    I remind you that OpenFlows FLOOD's main objective is to quantify the temporal and spatial variability of water elevations and flow in the a certain area. It computes how much and when, each area of your region of interest is affected, taking into account that water is flowing, find obstacles, deviating from buildings, infiltrating and flowing in/out of storm water drainage systems. 

    If you have information how on what is the storm surge water elevations (e.g. obtained from tide gauge observations or from other models), then you should follow option 2. If it's option 1, let me know so I can guide you with a bit more information. 

    Assuming you have the storm surge sea level data, and as this is a very limited area (i.e. relatively small area), you can set up a "MOHID Land" simulation and use a variable sea level elevation as boundary condition. 

    Unfortunately, in the current release of FLOOD (10.03) the time-variable water level boundary condition is not readily available in the module RunOff input options. You need to follow these steps:

    1) Go to the "droplet icon" on the top left corner and click Settings. Then un-select the option "Use property grid to edit model configuration files". This will allow you to edit the model configuration files manually and add options that are not available via the user interface. 

    2) Setup your model simulation (see post above with available documentation on how to do it). 

    3) Create a time series file with the sea level data. You can follow the instructions described here for rainfall. Simple follow the same steps but using the sea level data. Save the file as ".\General Data\Boundary Conditions\StormSurge.dat"

    4) Depending on how you've created your Grid Data digital terrain model, you must verify the elevation data at the open boundary of your model domain. FLOOD will consider that the open boundary will be the points below a certain elevation (defined by a keyword called MAX_DTM_FOR_BOUNDARY). Using the Edit Grid Data tool, you can for example set the values of the model domain open boundary to -5 and set the MAX_DTM_FOR_BOUNDARY : -4. This means that all grid points with elevation lower than -4 and near the model domain edges, will be considered open boundary, and the sea level data from the storm surge will be imposed there. 

    5) In the module RunOff define the following options:  

    IMPOSE_BOUNDARY_VALUE : 1 

    ALLOW_BOUNDARY_INFLOW : 1

    MAX_DTM_FOR_BOUNDARY : -4

    <begin_boundary>
    FILE_IN_TIME                         : TIMESERIE
    DEFAULTVALUE                      : 0.0
    FILENAME                                : ..\General Data\Boundary Conditions\StormSurge.dat
    DATA_COLUMN                        : 2
    <end_boundary>

    5) run the simulation, visualize the results with the water level rising through the open boundary and flooding the coastal area.

    Please let me know if you require any additional information. 

    Kind regards,

    Luis

  • Thanks for your quick response, Luis! I have solved the problem of the geographical coordinates issues. I would like to conduct an analysis by using the scenario 2 that you have mentioned above. 

    I still have several questions! Firstly, I can't find this option  "Use property grid to edit model configuration files" under the setting.

    Also, I tried to create a time simulation file, would you mind to help me check the format, does it sound rational to you?

    NAME : Station Name
    COORD_X : 0
    COORD_Y : 0
    SERIE_INITIAL_DATA : 2010 1 1 0 0 0
    TIME_UNITS : MINUTES

    minutes water_level
    <BeginTimeSerie>
    15.0 -2.0
    45.0 0.0
    85.0 1.5
    145.0 2.5
    185.0 3.0
    225.0 3.5
    245.0 3.734
    <EndTimeSerie>

    One more question, where can i set up the boundary parameters in the openflow platform. I can't find the setting in edit grid data!

    Thanks for your help! your advice and feedback are constructive, Luis!

    Looking forward to your reply!^^

  • Hi Cherry Chue,

    If you can't find the option  "Use property grid to edit model configuration files" it's possibly because you're not using the latest release of OpenFlows FLOOD. I strongly recommend you upgrade to 10.03 version. You can do so using your Connection Client. 

    Regarding the water level time series file, please take into account that the time series period must contain the simulation period. This means that the initial date for the simulation must be 2010 Jan 1st at 00:15 a.m. and finishes 245 minutes after the series initial date (2020 January 1st at 00:00)

    The Edit Grid Data tool is a generic way of changing values in a Grid Data file (e.g. DTM file). Please see this video where this tool is used to edit the DTM Grid Data values using a buildings shapefile. In your case you can use the "Value Filter" or "Select by Mouse" options to select the open boundary grid cells. Please let me know if you need any additional information about this. 

    Kind regards,
    Luis

     

  • Hi Luis! Thanks for you detailed and useful feedback and guidelines. I installed the latest version and I can find the option "Use property grid to edit model configuration files"! But I am still confused in the setting of SERIE_INITIAL_DATA : If the whole simulation period will last for 245 minutes, does it mean i should input " SERIE_INITIAL_DATA : 2010 1 1 4 5 "if it starts in 2010 January 1st at 00:00 and finishes at 2010 January 1st 4:05. If it is wrong, what is the correct input of the " SERIE_INITIAL_DATA"?

    Regarding to your instruction of Edit Grid Data, I have created a Manning DSM and conducted "Defining Grid Data for Surface’s Roughness coefficient " by using the vegetation and building software. What do you mean by selecting open boundary grid cells? Does it mean i need to digitize the coastlines and input in OpenFlows as a shapefile and set its user value = -4? what is the difference between MAX_DTM_FOR_BOUNDARY and model domain open boundary?

    According to the simulation, dos it mean i can solely follow the settings stated in the Quickstart Urban Flood Simulation? What should i select for the modules in simulation?

     

    I am so sorry as I am quite difficult to catch up since this is my first time to do such analysis by this software! Luis, Thanks for addressing my problems steps by steps! Looking forward to your reply. If there are short videos about the storm surge flooding will be appreciated too.