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cga-wm / advgis-echo

This is the echo version of Advanced GIS (Fall 2021)
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Solve Special Works 3 - Watershed Delineation #4

Open dt-woods opened 3 years ago

dt-woods commented 3 years ago

Questions, comments, methods, ideas, or approaches.

Christine8691 commented 3 years ago

In looking at Special Works 3 - Watershed Delineation- The lat long location of the irrigation pump on Salvador Creek is located in a developed area on top of a residential house along the main road. I was just wondering if I am not looking at the lat long correctly? I assume it is decimal degrees and lat is 38.3326 and long is -122.3017. Or is this just a very rough estimation? Seems today with GIS and GPS, the lat long could be more accurate or am I doing something wrong? image

dt-woods commented 3 years ago

If you zoom out a little, do you see a stream?

RE: location accuracy. I wouldn't trust a client to provide high accuracy coordinates unless they specifically say so.

Christine8691 commented 3 years ago

Has anyone located the 10 m elevation data for Napa, CA? I found 30m.

GraceMolino commented 3 years ago

I am trying to use Extract by Attribute tool for a raster I created to solve the Advanced Level problems. The raster is an integer file format however, the raster cell values still have decimals. The query for the tool is saying there is an error with the expression "Value">76638 which I know is within the range of values for the raster. Is this because of the decimals? Does anyone have any ideas to work around this? Another tool or way to get rid of the decimals?

dt-woods commented 3 years ago

Do you have a screenshot of this error?

GraceMolino commented 3 years ago

ExpressionError This is when I try to verify the query.

dt-woods commented 3 years ago

Try removing quotes from around "Value"

GraceMolino commented 3 years ago

same error message when I do that.

dt-woods commented 3 years ago

I'm not sure "Select By Attribute" is the right tool. Try using the conditional (Con) tool. You can create a new raster with only the pixels of interest (e.g., where VALUE > 76638) and it should create a VAT with associated pixel counts.

GraceMolino commented 3 years ago

I still got the error message when I tried to verify but when I ran Con, it completed successfully and worked! Thanks!

dt-woods commented 3 years ago

Glitch in the validation? Glad to hear the process worked anyways.