# Nutrient Delivery Ratio - Validation data type

**URL:** <https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-validation-data-type/2475>\
**Category:** Software Support\
**Tags:** ndr\
**Created:** [February 2, 2022, 1:46pm UTC](https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-validation-data-type/2475 "2022-02-02T13:46:45Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![samkshyaa](https://avatars.discourse-cdn.com/v4/letter/s/6a8cbe/32.png) [@samkshyaa](https://community.naturalcapitalalliance.org/u/samkshyaa)\
**Post date:** [February 2, 2022, 1:46pm UTC](https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-validation-data-type/2475/1 "2022-02-02T13:46:46Z")

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Hi. For the Nutrient Delivery Ratio, I will need water quality data to calibrate/ validate the model. In which format should the data be and what period of data is suggested for optimal results?  
Thanks.

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**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:** [February 2, 2022, 3:57pm UTC](https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-validation-data-type/2475/2 "2022-02-02T15:57:14Z")

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Hi @samkshyaa -

[The User Guide has a small section](https://storage.googleapis.com/releases.naturalcapitalproject.org/invest-userguide/latest/ndr.html#comparison-to-observed-data) that talks about calibrating the model - have you seen it? It includes a [link to this paper (Redhead et al 2018)](http://nora.nerc.ac.uk/id/eprint/519381/) that talks about how this was done for a study in England.

~ Stacie