National Land Cover data set 2011
Land cover datasets are not published annually, the most recent land cover dataset is from 2011. titled NLCD 2011 Land Cover (1.1 Gb) available at the following URL. http://www.mrlc.gov/nlcd11_data.php
Also available is a layer displaying land cover change from 2001- 2011. We may want to consider utilizing this layer in the future.
The data is too big to serve from our Geoserver (which is a server provides the map image). Here are options:
- Reclassification
- Reclassification of the data can reduce the size the data. However, it is still 700MB. We tested the reclassified dataset via Geoserver. There is some performance issue
- Resize
- Resizing means change of resolution of the data. It is not preferable when the end user wants the detail view of the data; but it can improve the performance
- Using Land cover data service
- http://gisdata.usgs.gov/service_access_list.php?serviceid=Dataset_46&dataset=NLCD%202011%20Land%20Cover
- Apparently, USGS already had mapping service for the land cover 2011. We could use this service
- But we can't reclassify the data on the fly
- Note, :
- URL for legend http://isse.cr.usgs.gov/arcgis/services/LandCover/USGS_EROS_LandCover_NLCD/MapServer/WMSServer?request=GetLegendGraphic&service=WMS&format=image/png&version=1.0.0&layer=31
- URL for capability (list of layers: our layer is 31): http://isse.cr.usgs.gov/arcgis/services/LandCover/USGS_EROS_LandCover_NLCD/MapServer/WMSServer?request=GetCapabilities&service=WMS
Pesticide annual use 2008-2012
9 Comments
Michael Brennan
Jong Lee
Jong Lee
Michael Brennan In the shp, there are no discharge information.
Michael Brennan
Jong Lee Discharge information is under the heading Summary_Av
Jong Lee
Michael Brennan I am trying to aggregate the point source info (Summary_Av) to huc 8 polygon. Do I need to "sum" these values within each huc 8 polygon or "average" ??
Jong Lee
This is a screenshot of aggregated point sources by HUC 8. (colored by sum of point source values). I will copy the data at our box share.(filename is agg.7z)
Michael Brennan
Jong Lee Yes sum of source values is more appropriate. By displaying the sum of point source values we effectively present the total nitrogen picture - Point source + nonpoint source = nitrate/ nitrogen load. Displaying the total sum of point sources also lays the foundation for phase II to display the change in total point sources over the time period.
Thanks
Jong Lee
Another example of viz with rivers; You can see some hot spots (huc 8 regions) around rivers
Michael Brennan
Jong,
I think the state borders are necessary to provide context. Having the great Lakes depicted helps, but audiences aren't going to have a sense of location things are. I'm assuming the Great river shapefile doesn't line up with the state lines shape file. Do you want me to try and find two shape files that do line up? I think having all three shape files would be the best course of action, with the states as the bottom layer, point sources as second and great rivers as the top layer.The great rivers shape file in your second image varies in color from dark blue to light blue ( in areas where the point source shapefile is over layed). It might be better to make the Great Rivers File the top layer so the Blue line is a consistent color.
Also the color scheme appears to be more drastic in the initial image, is there an option to stick with the initial color scheme?
John Sloan
Michael,
I'm suggesting the following alternative to the label for this data layer. I think it's important to state that this is a HUC8 watershed. I like the ability to see which HUC8s have the highest point sources. In the future, we want to be able to click on the HUC8 watershed and see a list of the actual point sources along with the accompanying data.
"Total annual nitrogen from point sources by HUC8 watershed (avg. 2007-2014)"