Messages

16

Map Making Support / Looking for US land cover data

« on: June 11, 2008, 07:46:42 PM »

I’m looking for United States land cover data (wooded, etc.) in vector format.

National Map Seamless Server
http://seamless.usgs.gov/website/seamless/viewer.htm

National Map Seamless Server has National Atlas land cover data listed but when I’ve tried to download it the only format available appears to be GeoTiff.

I either get “Extracting data…Please wait for the data to be returned”…forever; or I get an error message after clicking the download button.

National Atlas
http://www.nationalatlas.gov/atlasftp.html

National Atlas has the land cover data available by state as a Geotiff with the value of each pixel representing a land cover type.  I’ve been able to download from there, but have not found a way to turn the Geotiff into a vector format file that can be used for Garmin map making.

So I’m looking for either a source of the data already in vector format or a way to convert the Geotiff.

Perry

17

Map Making Support / Forest Service data

« on: June 11, 2008, 07:30:55 PM »

Forest Service data

The FSGeodata Clearinghouse is a pretty good source for Forest Service data.  Individual National Forests may also have GIS data available from their web sites.

JAN 2016 EDIT: New FS clearinghouse link: http://data.fs.usda.gov/geodata/

http://svinetfc4.fs.fed.us/clearinghouse/index.html

Select Vector Data Gateway

Here is the procedure I use:
From tabs at top of screen select Zoom to Location > select Forest (NF) > select the NF of interest > press Submit.  It will load an over view map of that NF.
The indented instructions are probably not needed, can likely go directly to download tab.
   Click on the Layers/Legend tab on the right > click the Layers tab.
   Click on the right arrow next to the Base Map Data to see layers available.
   Clicking on a layer listing will turn it on or off.
   Click refresh.
   May need to zoom in to see some data layers.
Click the Download tab at the top > click Extract Layers.
Click the Extract Location tab.  Select the Download radio button.
Click I have read the disclaimer…important detail.
Click on the right arrow next to the Base Map Data to see layers available.  Turn on desired layers by clicking on them.
Click the left Select Item drop box to select a NF, then select the forest from the right drop box.
Click Submit.
It will display: Extracting Layers and Display a File Download dialog to download the zipped file. 
The Extracting layers can take a few minutes.

When the file is unzipped this will create a .shp, .shx, and .dbf for each layer

Perry

18

Map Making Support / Water Data tutorial

« on: June 08, 2008, 03:15:00 PM »

I read through the Water Data tutorial.

If you happen to get duplicate subbasins in your NHD shapefiles how is that handled?

Thanks for the very helpful site.

Perry