Aquaveo & Water Resources Engineering News

Tips for Flow Budget in GMS

By aquaveo on November 13, 2019

In any groundwater model, knowing how much of the groundwater is available for use determines the fate of any project planned for the area. It is often a crucial part of a model to determine an accurate water budget or flow budget. MODFLOW can calculate its own flow budget and can also make use of the ZONEBUDGET program to calculate the water budget for subregions of a model. Knowing how to use both the MODFLOW flow budget and the ZONEBUDGET program greatly enhances the value of models built in GMS.

PZONEBUDGET example

With that in mind, here are some tips for making use of a flow budget and ZONEBUDGET in GMS:

  • If ZONEBUDGET is used to calculate a budget for the entire modeled area, the values for each budget term should match the MODFLOW budget except in situations where there are multiple stresses of the same kind in the same cell (e.g. a pumping well and a recharging well in the same cell).
  • You can confirm your approach by calculating the cumulative volumes for the entire model and seeing if they match the MODFLOW outputs.
  • Computer precision could be a cause of small discrepancies between the budgets produced by ZONEBUDGET and MODFLOW. ZONEBUDGET accumulates budget totals using double precision, and MODFLOW uses single precision. Because of the use of double precision, ZONEBUDGET's output should generally be more accurate than MODFLOW's; however, differences in output are not likely to be significant except for some very large models.
  • You can find the correct cumulative volume of water entering a given zone using the flow rate. This is done by multiplying the rate by the length of the corresponding time step.
  • Rates reported are for the same duration of the matching time step. Time steps stair step, so there the value is the same for the entire time step.

For an overview of ZONEBUDGET in GMS, see our tutorial and try it out in GMS today!

Blog tags: 
GMS

Working with Large DEMs

By aquaveo on November 6, 2019

Do you have a project that requires using a large DEM? Digital Elevation Model files are a great source for terrain data in WMS. A lot of projects require using DEMs which makes it important to use the data available.

Using a large DEM file can present some complications in WMS. A large file may cause the program to slow down or have difficulty processing. So it is important to make certain to use a DEM that contains mostly relevant data and doesn’t contain an excess of nonessential information.

But how do you know if the DEM data you are pulling is enough? Is more watershed data always better?

Example of DEM in WMS with contours turned on.

Pulling in more data doesn’t insure better results. Though WMS is able to handle a massive amount of data (which is not a guarantee) the hardware in your computer may not be able to handle it. In general, a DEM twice the size of your watershed is probably sufficient for most models. More than twice your watershed size tends to just bog down the model causing you to face unnecessary wait times.

What should you do if your watershed data is not loading?

If your data is taking a long time to load try adjusting the resolution. After using the Get Data from Map tool, and making your selection in the Data Service Options dialog, you will be able to select your desired resolution in the Zoom dialog. Selecting a lower resolution zoom level should make the DEM easier to work with in WMS.

You could also try breaking up the DEM into multiple DEMs. That way your computer is not overwhelmed by trying to download one huge file all at once. Then while you’re working on your model you can turn on just the DEM(s) you need.

Third party software can be used to break up the DEM or reduce the resolution.

DEMs remain an excellent source for data for projects in WMS. Download WMS today!

Blog tags: 
WMS

Using the Prune Arc Tool

By aquaveo on October 30, 2019
The Prune Arc tool is relatively new to SMS, and we're excited to show you just how useful it can be.

The Prune Arc tool is similar to the smooth arc function in SMS. This Smooth Arc tool is useful when eliminating noise from a rough arc, and can make your variations more mathematically stable. This can be extremely handy in working with a model—especially in situations like coastal modelling, which are prone to busy edges. Unfortunately, smoothing an arc can also change the shape of the arc to the point where it no longer matches the actual coastline.

You may come across a situation where your imported arcs have a lot of unnecessary roughness or concave areas that you want to eliminate without redistributing your vertices along the rest of the arc.

If this is the case, the Prune Arcs function is just the tool for the job. This tool trims—or prunes—rough edges and outlying spikes without rounding or reshaping the rest of the arc. Specifically, it allows you to focus on smoothing one side of the arc. This is helpful in coastal modeling where there may be a small river mouth, a harbor, cove or other concave sections that you do not want to include in your model.

Prune arc example

Access the Prune Arc tool by doing the following:

  1. Use the Select Feature Arcs tool to choose the arc or arcs you wish to prune.
  2. Right-click on the selected arcs then, in the menu, select the Prune Arc(s) command.

This will bring up the Prune Arcs dialog box, from which you can choose your pruning settings.

There are two types of pruning that can be done: Constant and Spatially Varying.

  • Constant will prune everything within a specific measurement set by you. This measurement is in meters by default. The larger the number, the more dramatic the pruning will be.
  • Spatially Varying uses the numbers in a particular dataset to establish the parameters of the pruning. This dataset is chosen in the Prune Arcs dialog box.

Importantly, you must choose which side of the arc to prune. The sides of the arc are determined by the arc direction. So if the arc is moving south to north, the left side of the arc will be on the left side of your screen. If the arc is moving west to east, the left side with be towards the top of your screen. Make certain you are pruning the correct side of the arc.

Try out using the Prune Arc tool in SMS 13.0 today!

Blog tags: 
SMS

Tips for Using Multiple Conceptual Models

By aquaveo on October 23, 2019

Have you ever built a model in GMS that uses multiple conceptual models? Doing this offers a few advantages. However, there are potential pitfalls as well when doing this. We will discuss some of the advantages in using multiple conceptual models and what to watch out for.

A conceptual model may contain one or more map coverages. Each coverage should contain feature objects defining key structures of the groundwater model, such as wells, rivers, or recharge. Everything in the conceptual model can then be mapped over to a grid or MODFLOW model.

Example of multiple conceptual models in the Project Explorer

Beyond using folders under a single conceptual model, one of the main advantages with using multiple conceptual models is for organization. When wanting to make variations on a model, it is helpful to have one base conceptual model and then multiple variant conceptual models. The entire base conceptual model may be duplicated to provide a starting point for other variations, or individual coverages may be duplicated and dragged to other conceptual models. Duplicating the base conceptual model can be particularly helpful if you already have transport species defined for MODFLOW-related models.

For example, you can use one conceptual model for a base steady-state model, then create another conceptual model for a transient predictive model. With this you can map the base conceptual model to MODFLOW and run that model. After you have the base results, you can duplicate the solution datasets to preserve them, adjust Global Options—such as Stress Periods—if needed, and then map the predictive model to the grid to run your second MODFLOW model.

When using multiple conceptual models, there are few items to look out for. These include:

  • When changing the conceptual model, changes are not automatically made to the MODFLOW model or other models being used. The conceptual model must be mapped over to the groundwater model in order for the defined features to be included in the model run.
  • When mapping over the conceptual model, it will overwrite any existing data in the same packages contained in the conceptual model. If you want to update the model with the new conceptual model, this is the correct workflow. However, if the original conceptual model used packages that are no longer used in the new conceptual model, then there could be an error in the model run. Always review your model after mapping to confirm the features mapped as you intended.
  • When using MODFLOW-USG, and you have multiple UGrids, make certain the conceptual model is mapping to the correct UGrid or model. It will map to the active UGrid.

Working with multiple conceptual models can expand your options for your model. Try out the conceptual model and other features of GMS today!

Blog tags: 
GMS

Converting a 2D Scatter to a Raster

By aquaveo on October 16, 2019

Have you ever needed to convert a 2D scatter set to a raster? A new feature of SMS 13.0 allows converting a 2D scatter set to a raster from the right-click menu in the Project Explorer.

Being able to convert from a 2D scatter set to a raster is particularly useful when collaborating with a colleague, or switching between programs. There are many types of raster files that can be shared between different applications.

To convert a 2D Scatter right-click on the 2D Scatter Set under Scatter Data folder in the Project Explorer and go to Convert | Scatter → Raster.

In the Interpolate to Raster dialog you have three options for Interpolation:

  • Linear
  • Inverse Distance Weighted
  • Natural Neighbor

Each option for interpolation is slightly different from the other focusing more on lower z values, higher z values, or the x and y values. Feel free to compare all three with your 2D scatter set.

Once you have selected the interpolation type you can choose to truncate some of the data by clicking on the Options button to launch the Interpolate dialog. Using the truncating option removes data from your raster. Some scenarios many only be visible in Plan view.

When you have selected your interpolation method, and truncation value if you so desire, then selecting OK will direct you to saving your raster file. You have two file type options:

  • Geo TIFF Tiles (*.tif)
  • Arch Info ASCII Grid Files (*.asc)

If you select the ASCII file type you may be asked to select a global projection, whereas the TIFF option does not. By default the raster will be imported into your current project.

When converting a scatter set to a raster the program may need to make some adjustments to outlying points. With each of the interpolation options, SMS adjusts the data for slightly different raster results.

You can see that the converted raster closely reflects the original dataset. The scale on the left of the Graphic Window will show you how closely the two are alike.

2D raster to scatter example

Now that you know how easy it is to convert a 2D scatter set to a raster try it in SMS today!

Blog tags: 
SMS

Aquaveo User Conference 2019

By aquaveo on October 9, 2019

The 2019 Aquaveo User Conference is going on now. It started yesterday, October 8th, and will wrap up today, October 9th. We are enjoying meeting with users from around the world. In attendance are users from the United States, Germany, Portugal, South Africa, and other places around the globe.

At the conference, we announced some of the new features and upcoming changes to our products that we are excited about:

  • Making XMS functionality available for use outside of the traditional interface.
  • More web-based applications for portability and ease of access.
  • Simplifying and unifying tools so it is easier to find and use the functionalities available.
  • Project management tools to track the history of a model.
  • 3D bridge modeling in SMS.
2019 Aquaveo User Conference

Talking to those in attendance, we learned they enjoyed:

  • Learning more about software features and functionality.
  • Learning how to improve their model development process.
  • Discovering benefits of Aquaveo’s software over other software.
  • Talking to developers and learning tips for model development.
  • Being able to show off their models and receive feedback on them.
Eva Loch presenting at the 2019 Aquaveo User Conference

We’d like the thank the following for participating during our user conference:

If you couldn’t make it to the Aquaveo User Conference this year, watch our website and Facebook page for future conferences.

Blog tags: 
GMS
SMS
WMS
AHGW
CityWater

Classifying Material Zones

By aquaveo on October 2, 2019

Do you ever struggle to assign materials to a grid from solids? In GMS, the Solids to MODFLOW command is a useful tool for this, but it’s not successful in all cases. This command can sometimes make alterations to the stratigraphy. The command also does not work with models that make use of a mesh.

The good news is, there is another way! The Classify Material Zones command allows you to assign material zones from solids to a grid using just a few steps. The general workflow for doing this is as follows:

  1. First, you'll want to create a grid or mesh that is the same shape and has as many layers as your solids.
  2. Next, right-click on your grid and choose the Classify Material Zones command.
  3. In the Classify Material Zones dialog, ensure that your solids are selected and choose your desired classify algorithm.
  4. Finally, click OK and your grid materials will be matched to the solids.

When setting the classify algorithm, there are two options: "Centroid" and "Predominant material". The "Centroid" option assigns each cell the material located at its centroid. Using the "Predominant material" option assigns each cell the material that is present in the highest volume.

Below is a comparison between the two classify algorithms on a sample grid, "Centroid" on the left and "Predominant material" on the right. Select the algorithm that best represents your modeling area.

Example of the Classify Zones algorithms

The end result of using the Classify Materials Zones tool is that a new material set, based on the materials in your solids, will be added to your grid or mesh.

Try using the Classify Material Zones tool in GMS today!

Blog tags: 
GMS

Tips for Finding Information on the XMS Wiki

By aquaveo on September 25, 2019

The Aquaveo XMS Wiki contains over 8000 pages of information and images about SMS, GMS, WMS, and other Aquaveo products (collectively called "XMS"). While we try to make the information as easy to find as possible, sometimes the sheer volume of available information can make a particular search term harder to locate. Here, we discuss a few ways to find the information you need using the XMS Wiki.

Help Button

Most dialogs in SMS, GMS, and WMS contain a Help button at the bottom of the dialog window. Clicking this button will generally take you directly to a page on the XMS Wiki about that dialog. This is the quickest way to find information about a dialog.

Navigation Links

When you visit any page on the XMS Wiki, an "XMS Projects" menu is found at the top left of the page. Click on any of the products listed there to be taken to the main page for that product. Once there, click on any of the links in the Wiki Sections section on the lower right to be taken to a table of contents listing all of the pages discussing the features of that product.

Example of the XMS Wiki

At the bottom of the main page for the product, there is also a navigation template listing main topics for that product. This allows you to quickly navigate to any of those main topics.

Search Field
Example of the XMS Wiki Projects menu

Directly below the "XMS Projects" menu is a search field. If you start typing in that field, the XMS Wiki will attempt to locate a page containing what you type. To find a page about a particular product, preface the search term with that product's abbreviation, followed by a colon and the search term. For example, if you are searching for information about the bridge scour features in SMS, type "SMS:Bridge Scour" and a list of articles will appear below the search box. Simply select the desired article to be taken directly to it.

You can also enter only the search term and select the "containing…searchterm", where "searchterm" is the term you entered in the search box. This will bring up a list of pages containing the term you entered. This can be useful when you don't know what the page might be named, but you know a term that might be used on that page.

Categories

At the bottom of every page on the XMS Wiki is a list of one or more categories. This provides another way to locate information on a given topic. Simply click on the category to find a list of pages, images, and additional categories related to that topic.

Google

One option that is often overlooked is to use the power of the Google search engine. To search for pages or information on the XMS Wiki, enter "searchterm site:xmswiki.com", replacing "searchterm" with the word or words you are seeking. This tells Google to provide results only from the XMS Wiki. Click this link for an example.

Page Prefixes

Most pages on the XMS Wiki are prefaced by a product abbreviation. When reviewing search results, make sure the page you are on has the appropriate abbreviation at the beginning of the page title (e.g., "SMS:Display Options", "GMS:Display Options", "WMS:Display Options"), as similar pages may be found for various products.

Page Notices

Sometimes when searching for information or a feature, you may find pages that document obsolete or future features. These pages will have notices at the top indicating this status. There are other types of notices that may appear at the tops of pages, as well, so always be sure to read any notices that appear.

Try out these search methods today by visiting the XMS Wiki today!

Blog tags: 
GMS
SMS
WMS

Snapping Mesh Nodes to Arcs

By aquaveo on September 18, 2019

After generating a mesh, you might notice that not all of the nodes line up along key features. There are a few ways to resolve this, but SMS 13.0 introduces a new method: the Snap Mesh to Arcs command.

In order to use the Snap Mesh to Arcs command, you must have the following:

  • 2D Mesh
  • Map coverage

Once you have the needed components, snap the nodes to an arc by doing the following:

  1. On the map coverage, draw an arc or arcs where you want to move the mesh nodes.
  2. Select the desired arcs.
  3. Make certain the correct map coverage and mesh are active in the Project Explorer.
  4. Right-click on the map coverage in the Project Explorer and select Snap Mesh to Arcs.
  5. Specify a tolerance value in the Snap Mesh to Arcs dialog.
Example of snapping mesh nodes to arcs

The command aligns the nodes in the mesh to the selected arcs in the map coverage. If no arcs are selected, this command will move nodes for all arcs in the coverage, so be certain to either select the correct arcs or make certain there are no extra arcs on the coverage.

When using the tool, it will only work with the active mesh and the active map coverage. Be certain that the correct mesh and map coverage are active in the Project Explorer.

It should be noted that not all nodes will be snapped to the selected arc. Any node that could cause instability, if moved, in the mesh will not be moved. Furthermore, nodes outside of the tolerance value will not be moved. When the nodes have been moved they cannot be moved back, therefore it might be a good idea to first use the tool on a duplicate of the target mesh then, if the results are good, rerun the tool on the target mesh.

The Snap Mesh to Arcs tool can be a useful addition to your mesh editing tools. Try it out in SMS today!

Blog tags: 
SMS

Using Display Options with Multiple UGrids

By aquaveo on September 11, 2019

Have you experienced setting display options for an unstructured grid only to see those settings not take? In GMS, each unstructured grid (UGrid) uses its own set of display options. A common reason for display settings not appearing is selecting the wrong UGrid when you have multiple UGrids.

Changing the UGrid display settings will only affect one UGrid at a time. So it is important to make certain the correct UGrid display options are being changed.

There are three ways to reach the Display Options dialog for UGrids:

  • Display Options macro
  • Display Options command in the Display menu
  • Display Options command in the UGrid Data right-click menu in the Project Explorer
Display Options list showing multiple UGrids

Once in the Display Options dialog, check to see which UGrid is active. This is done by looking a the list on the left side of the dialog. The list on the left will indicate which By default, the display option will be set for the active UGrid. So one method to make certain you are setting display options for the correct UGrid, it to make certain that UGrid is the active UGrid in the Project Explorer before entering the Display Options dialog.

Multiple UGrids in the Project Explorer

The Display Options dialog can be used to change display settings for a UGrid that is not active. This is done by selecting the desired UGrid from the list on the left in the dialog. It should be noted that selecting a UGrid in th Display Options dialog does not cause the UGrid to become the active UGrid in GMS. So when you exit the Display Options dialog, you may need to change which UGrid is active in the Project Explorer to see the display setting changes.

It should be noted that which UGrid is active also matters when accessing the Dataset Contours Options dialog.

Hopefully, this helps clarify how to set display options in projects that have multiple UGrids. Make use of Ugrids disaply options in you project using GMS today!

Blog tags: 
GMS

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