Data-Derived Global Land Values

Your Land's Value

Calculator Method

This tool will allow you to get a very rough estimate of your land's carbon sequestration value based on the vegetation value of the nearest MODIS selected site.

First find your latitude and longitude here. Then click on the button below.

co2 sequestration calculator

 

If your field site is not within a few kilometers of the nearest MODIS selected subset site, use custom MODIS data to make a more accurate determination of your land's carbon sequestration value. Use the following instructions to generate land values:

Get Lat/Lon Information

Use the itouchmap to find the latitude and longitude you are interested in.

Get Data from NASA

GCI charts use three data sources, GPP, NPP, and NDVI for selected MODIS sites. However, since NPP is not globally available, GCI has developed a simple protocol to determine NPP values from GPP. NDVI can be downloaded to double check GPP values.

  1. Go to the MODIS Data Server to obtain spatially customized data.
  2. Enter latitude and longitude.
  3. Select MOD17A2 Gross Primary Production (GPP).
  4. If you wish to include NDVI data, select MOD13Q1 Vegetation Indices (NDVI, EVI).
  5. Choose the size of your cutout by selecting a number of km2 to display. The finest grain available here is 1 km X 1 km, however, there is a way to drill down once you have the data.
  6. Select all dates (this is the default).
  7. Enter an email address to receive data. Earth observation data from MODIS is a global service provided by the U.S. government. There is no cost, and there is no spam.
  8. Click Continue.
  9. Click Create Subset.
  10. Data for the selected subset will be sent to you by e-mail. It rarely takes longer than 15 minutes to receive, though the site states that it can take up to 72 hours to deliver your data.

Prepare Data

Import to Excel

For all datasets, data arrives in a .csv file. Open the .csv file. Select all (Ctrl A), copy (Ctrl C) and paste (Ctrl V) into an Excel file.

Sort Data

The procedure to use Excel to organize NDVI data is as follows. Similar algorithms are used for all datasets. Comments italicized. We need to sort the data to show only NDVI values. In order to do this, we need to assign the bands a numeric designation.

  1. Insert a new column, which will be called Column A, before the dataset.
  2. Give each data type a number. In NDVI/EVI datasets, there are 12 data bands. We are only interested in the NDVI band, whose column now is G. Expand column G to see the full names of the bands. The first occurrence of NDVI data usually occurs at A6. If we start numbering there, NDVI data will be accessible. Correspondingly, we can begin our numbering at A2 (descending)
    Beginning at A2, enter the following series of numbers: 9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4 etc.
  3. Continue this numbering series 1 through 12 for all data. Each non-empty line should be associated with a number you have entered in Column A. Check to make sure that NDVI data is always associated with the number 1.
  4. Select all.
  5. Select Data|Sort|Sort by (Column A)|Sort On (values)|Order Smallest to Largest.
  6. Select OK.
  7. Remove error flag values.

Parse, Sort and Clean GPP Data

Go to http://globalcarbonindex.org and choose a site near the location you seek to chart. Click on Get Chart image to see the information page for that site. Find the Conversion Ratio. Multiply each year's ∑GPP data by the conversion ratio to obtain NPP values.

A general description for this procedures is as follows: Adapt NDVI procedures for GPP data as necessary with the following additional steps. Remove QC Fail data. Search for 32761, 32762, 32763, 32764, 32765, and 32766 for NPP/GPP data. These are error codes, and can be mistaken for actual data values. Remove them from your spreadsheet. If you are also assessing NDVI or EVI data, remove -3000 values, which are also error flag values.

Sum GPP Data and Convert to NPP

GPP data can only be related to NPP data if summed for the year, or annualized. To sum GPP data, insert a row at the end of each year and use AutoSum to generate ∑GPP for each year. Go to http://globalcarbonindex.org and choose a site near the location you seek to chart. Click on Get Chart image to see the information page for that site. Find the Conversion Ratio. Multiply each year's ∑GPP data by the conversion ratio.

Convert for Price

Scale and convert data according to calculations page.

Format Data for Annotated Time Series Charting

The Annotated Time Series chart format used by Google to present stock chart data is used to visualize parsed and annualized data. The customary format for displaying these data is to show the most current date first. Display NDVI and NPP data in descending order.