# Biophysical Table Kc value definition with scarce data **URL:** \ **Category:** Science, Research & Data\ **Tags:** annual-water-yield, kc-parameter\ **Created:** [May 23, 2025, 6:44pm UTC](https://community.naturalcapitalalliance.org/t/biophysical-table-kc-value-definition-with-scarce-data/6000 "2025-05-23T18:44:26Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![lucasabudm](https://avatars.discourse-cdn.com/v4/letter/l/e47774/32.png) [@lucasabudm](https://community.naturalcapitalalliance.org/u/lucasabudm)\ **Post date:** [May 23, 2025, 6:44pm UTC](https://community.naturalcapitalalliance.org/t/biophysical-table-kc-value-definition-with-scarce-data/6000/1 "2025-05-23T18:44:26Z")
Recently I gathered all data necessary for processing the Annual Water-Yield Model. The last thing I need to do is fill a column for Kc coefficient, I only have the LULC raster with some different classes but I can’t go further to define some climate and agriculture parameters that would be helpful to insert the respective Kc to each Land cover classes. What is the best way to estimate a Kc value for each LULC code? ---
**Author:** ![swolny](https://yyz1.discourse-cdn.com/flex031/user_avatar/community.naturalcapitalalliance.org/swolny/32/181_2.png) [@swolny](https://community.naturalcapitalalliance.org/u/swolny)\ **Post date:** [May 27, 2025, 1:48pm UTC](https://community.naturalcapitalalliance.org/t/biophysical-table-kc-value-definition-with-scarce-data/6000/2 "2025-05-27T13:48:51Z")
Hello @lucasabudm - Have you checked out the [Data Sources section](https://storage.googleapis.com/releases.naturalcapitalproject.org/invest-userguide/latest/en/annual_water_yield.html#appendix-1-data-sources) of the Annual Water Yield chapter of the User Guide? It provides a link to an FAO document that lists many Kc values (mostly agriculture, but a few others too), and there are a couple of other suggestions for ways to estimate Kc. ~ Stacie