Value is missing

Software Support
1

Excuse me, why can’t I calculate the value of ls.

2

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3

The LS raster will have nodata where any of the inputs to the LS equation have nodata:

  • average aspect (intermediate_outputs/weighted_avg_aspect.tif)
  • slope (intermediate_outputs/slope.tif)
  • flow accumulation (intermediate_outputs/flow_accumulation.tif)

Do these intermediate outputs have nodata in the same places? Does your DEM have nodata in those places?

4

There are the four data you mentioned above.Can you help me analyze this?

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5

As shown, there is no problem with the slope data and DEM data.So I guess it’s a problem with the value setting?Threshold Flow Accumulation（setting 1000） ？or Maximum L Value（setting 300）？

6

@Chrisfans based on these graphics, it appears that the weighted_avg_aspect.tif output may be the source of these nodata holes in the LS output. The weighted_avg_aspect.tif raster is derived from the flow direction (flow_direction.tif), which is derived from the pit-filled DEM (pit_filled_dem.tif), which is derived from the aligned DEM (aligned_dem.tif), which is derived from your DEM.

Do you see these same nodata holes in any of those rasters? Are they present in the DEM you are passing in to InVEST?

Neither the flow accumulation nor the maximum L value should be affecting these nodata holes.

7

Dear Sir.,there are the does the data you mentioned.And i have Another question,Whether the DEM must be the same in data edge with the Watersheds?

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8

Based on these images (and it’s difficult to say for certain because of the aliasing in the flow direction image), it looks like there might be an issue with the way the flow direction raster is being created. Would you please upload your DEM and your logfile here or else email them to me at jdouglass@stanford.edu so I can take a close look?

Thanks,
James

9

@Chrisfans I’m very sorry about how long it’s taken me to get back to you on this!

I received some emails with your data from 163.com, but I’m unable to access the files. Would you please try sharing them with an alternate file sharing service such as Microsoft OneDrive, Google Drive or Dropbox?

Thank you,
James

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