Nutrient Retention and Valuation Process:


Shawn: Most up to date data is available on the velocity website along with the corresponding outputs.

Shawn: The outputs for valuation have been posted to the velocity cite as they are too large for the wiki.They are in the file


I ran the model here is the service layer output.w_retain is the Ecosystem service in biophysical terms.


Shawn: Here are the files that I am currently working with.


Shawn: One oversight that Dr. Hess noticed is that the Biophysical Table values are not representative of the Land Covers that we would like to examine. The zipped folder below includes a different .dbf file. I will proceed to test different parameters and see what the results yield.




For anyone interested, I have attached the data that allows the model to run on the Upper Neuse. This is the base data that I have altered to assess the water yield model. You will find all six rasters that we are using and two biophysical tables (one in a file geodatabase and one without any other associations.) Up to this point, I have been running the free standing dbf file. Please send feedback!

FAO Background on etk coeff. for crops:
FAO Data on etk coefficients for specific crops:

You need LAI values to determine etk values for other areas...deciduous forest is estimated here:

Still looking for other values for etk...

SSURGO Database template for Access. Seemed to work well.


Here is the most concise Water Purification Model files I can muster. WE SHOULD ALL BE USING THE SAME MODEL!!! Unfortunately, I was not able to get Soil layers working. So it still needs good soil layers. The problem with Shawn's model is that there is no data with the Soil layers. So Shawn will need to include the appropriate dbase with the layers. I attempted to do this. It was relatively east to create an Access database using the template SSURGO provides and add the data. But, the Soil Data Viewer plugin recommended by User Manual that works with ArcMap only runs on Windows XP! Perhaps the class will have resources to help out.


Here is the paper recommended by the User Guide on ROOTING DEPTH: Canadell, et al. (1996) Maximum rooting depth of vegetation types at the global scale. Oecologia 108

10/16/10 2:00 a.m.
Hey gang,
Here is good climate data. Precip is solid. ETo is OK. I computed it using the Hargreaves formula. I think I found a mistake with the formula, which I will share with the class. I am going to try and compare it to the FAO when I can get some further help.

That's awesome Shawn. Here is an article with a list of nutrient export coefficients. I'm still waiting on a response from April James about values for either the Triangle or North Carolina.

Here is another article.

Here's an interesting article on BMPs used to reduce nitrogen export in the Nuese River Basin

By Shawn
I was able to get the model working using these files

Neal's attempt. Has Precip and ET raster as "one value". Also clipped and merged soils layer.

Lessons learned (10/07/2010)
Creating county raster clips (based on DEM)
Tool: Extract by Mask
Input Raster:
Input Raster or Feature mask data: *county*
Output: *county name*

Create vector from Raster
IN Spatial Analyst Toolbar>Convert>Raster to Vector

To create county-wide values: use field calculator to input data > I used GRID ID

Create Raster from vector
IN Spatial Analyst Toolbar>Convert>Vector to Raster
USE GRID_ID as raster base
Product: A raster for entire county with one value.

Data for Temp for Granville County
Added: 10/07/2010
By: Shawn
Comment: The county changed measurement location in 1994

Article:Nitrogen sources to watersheds and estuaries: role of land cover mosaics and losses within watersheds
Added: 10/07/2010
By: Shawn

Data for Temp and Precipitation: Needed for Evapotranspiration and Precipitation rasters
Added: 10/05/2010
By: Shawn

Here is the precipitation data for the counties. The average temperatures are included.

I am not sure if we need this information, but here is a link to one of the projects I completed in undergraduate on sustainable water quality. There is data on the different nitrogen/phosphorous values by county from 2000 to 2005. I don't have the data for 1992 but it can be requested. It does take a long time to organize