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Fahad

Problem SMS regarding DEM, memory and units

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HI all experts,

1. I am kinda new to SMS. My problem is, in the tutorial TUFLOW 2D simulation the data for the boundary conditions (Flow VS time) and (Head VS time) are in cms and meter unit. But when I put the data into SMS bc part it says at top that the units are in cfs and foot. So, I need to convert the original data provided in SMS tutorial in feet and then put in to BC part in SMS?

2. Also, I exported a dem of my study area from arcgis in to sms and converted to 2d scatter. But the values are almost 3 times less than that of in Arcgis. In Arcgis the vertical unit is in State plane US feet projection (for new jersey). I checked the projection in SMS. Its still the same. Also I put the planar and vertical unit in SMS to US feet. Then why I am having this 3 times less value in SMS.

3. Another problem is my dem is very high resolution (10 ft). When I do the 2d scatter conversion my whole SMS crashed and my pc got hanged totally. I can't even move my mouse. I checked one time. And saw that all of my 8gb of ram is used. Now, I am only working with a very very small are by upscaling the DEM. This works actually. But ultimately I need to analyzed the whole area for my research. So, should I need a high performance computer to do this.

Please help me. 

Thanks in advance.

--Fahad 

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Fahad,

1. You don't have to convert. The units for flow vs time or Head vs Time are consistent with whatever units the display projection is using. You can check the units of the display projection by selecting "Display | Projection..."

2. Sounds like a projection units issue. In SMS you can specify the "Display Projection" and each individual object also has an "Object Projection". Right click on the scatter set in the Project Explorer and choose "Projection..." to see what it is set at. Make sure the units for it are "Feet" as you have them specified in ArcGIS.

3. Unless you need your DEM to be a scatter set, to perform edits, you can leave it as a Raster and use that for the Grid Elevations. The raster can be specified for use in the "Grid Frame Properties" under elevation options as shown in the attached image. If you do need it in scatter format, here are some options: 1) use SMS to create a resampled raster at a newly specified larger resolution than 10 ft and then convert to scatter (note: this will degrade the elevation data making it more coarse, yet it will allow you to thin the number of points that will be created) and 2) Turn off the display of "Points" and "Triangles" in the scatter set options of the Display Options before converting the DEM to a scatter set. This will ease the burden on your computer graphics. Unfortunately it will probably not do much with the RAM issue as the conversion does require a good amount of RAM for larger scatter sets.

Let us know what works.

-Calberts

gridframeprop.png

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