Creating Isopach Map

adamoilandgasadamoilandgas Global Mapper UserPosts: 2
edited March 2014 in Elevation Data
Hi,

I realize this is a very novice question, but it's fundamental to helping me get started with using global mapper. I read the post: http://www.globalmapperforum.com/forums/elevation-data/10083-creating-isopach-maps.html which gave me some ideas but not enough to put the pieces together. Would you be willing to walk me through the process?

Were I am starting:

I have several data points, each with two elevation depths retrieved from well logs, one value representing the depth of one layer of strata and the other representing another layer of strata.

How can I use use global mapper to connect each of these data points, then convert these data points into a fluid isopach map, with the rounded curves that are typical of contour maps?

Also, is there a way to create contour maps fore each layer of strata by using the elevation value from each data point?

Again thank you for your patience with my novice question. I really appreciate your time and help.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    What you can do if you have 2 separate elevation attributes is open the OPtions dialog for the layer and select which attribute to get the elevation values from, then grid the data with the Analysis menu command to create an elevation grid from vector layers. You can then create contours from that grid using the Analysis menu command to Generate Contours.

    Then go back to the Options dialog and select the other attribute as the 'elevation' attribute and grid the data again, then create contours from that, giving you 2 different sets of contours based on the different elevations.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Global Mapper
  • adamoilandgasadamoilandgas Global Mapper User Posts: 2
    edited March 2014
    Thank You Mike,

    I was able to generate a contour map for each layer based upon your instructions. Thank you. Based upon what was generated, I have a few more questions that could really use your expert guidance.

    First, is there a way to create more smooth elevation lines? On the left is what I would like to achieve (conceptually), and on the right is what I was able to create based upon your instructions in global mapper. Is there a way to create an output similar to the example on the left, or would it require more data points?

    botsalt.jpg countour.png

    My second set of questions is in regards to isopachs. I was able to generate an isopach using the Elevation Grid from Vector Data menu, but the output has no color variation because the variance in elevation is insignificant. Again on the left is what I was hoping to achieve, and on the right was what I was able to generate. Can I achieve something similar to what's on the left? Also I couldn't create contours as the range wasn't large enough. How can I do this?

    images.jpg2014-03-22 15_04_21-Global Mapper v15.1 (b030214) [64-bit] - REGISTERED.png

    Sorry for the novice questions. Your last instructions gave me a really great launching point, and if you could help me solve the above problems I would be extremely grateful.

    Thank you for your time and guidance.
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2014
    How dense were your data points? Usually a dense set of data points will generate pretty smooth contours, but it looks like maybe you only had a few so the TIN-based grid resulted in rather angular contours. There is an option when contours to smooth the contours, but it can only do so much.

    For the coloring, if you go to the Vertical Options tab of the Configuration dialog make sure that you don't have water display enabled as that could make everything blue. Also check the option there to 'Color Elevations Based on Visible Elevation Values' and select the Atlas Shader. This should make the color variation be maintained regardless of range, so if you zoom in on an area with a tiny range the full color range for that shader will be applied to just the on-screen range.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Guru
    geohelp@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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