# \#ndr **URL:** https://community.naturalcapitalalliance.org/tag/ndr/7.md [Latest](https://community.naturalcapitalalliance.org/latest.md) · [Categories](https://community.naturalcapitalalliance.org/categories.md) · [Tags](https://community.naturalcapitalalliance.org/tags.md) --- ## [Biophysical table parameters](https://community.naturalcapitalalliance.org/t/biophysical-table-parameters/6526)
**Author:** [@johanndrr96](https://community.naturalcapitalalliance.org/u/johanndrr96)\ **Replies:** 1\ **Last updated:** [October 22, 2026, 3:22pm UTC](https://community.naturalcapitalalliance.org/t/biophysical-table-parameters/6526 "2026-10-22T15:22:11Z")
Hi all, I started using the Nutrient Delivery Ratio model and when I try to access the nutrient parameter database by natcap, it says the link is broken. Is there a new link for that database or where can I find the val… --- ## [Question about post-processing NDR nutrient retention indicators to focus on natural and semi-natural land covers](https://community.naturalcapitalalliance.org/t/question-about-post-processing-ndr-nutrient-retention-indicators-to-focus-on-natural-and-semi-natural-land-covers/6518)
**Author:** [@Fernbg77](https://community.naturalcapitalalliance.org/u/Fernbg77)\ **Replies:** 0\ **Last updated:** [October 14, 2026, 3:55pm UTC](https://community.naturalcapitalalliance.org/t/question-about-post-processing-ndr-nutrient-retention-indicators-to-focus-on-natural-and-semi-natural-land-covers/6518 "2026-10-14T15:55:59Z")
Hello everyone, I am using the Nutrient Delivery Ratio (NDR) model in InVEST to assess the spatial contribution of nitrogen (N) and phosphorus (P) regulation in the Complejo Cenagoso del Bajo Sinú watershed, in Córdoba,… --- ## [NDR total export doesnt correspond with sum of subsurface and surface xport](https://community.naturalcapitalalliance.org/t/ndr-total-export-doesnt-correspond-with-sum-of-subsurface-and-surface-xport/6503)
**Author:** [@vulpen](https://community.naturalcapitalalliance.org/u/vulpen)\ **Replies:** 1\ **Last updated:** [September 9, 2026, 9:13pm UTC](https://community.naturalcapitalalliance.org/t/ndr-total-export-doesnt-correspond-with-sum-of-subsurface-and-surface-xport/6503 "2026-09-09T21:13:49Z")
What is the issue or question you have? My issue is that when I run the model of NDR, the output seems wrong and therefore I don’t understand how to analyse my results. The results show different values for total export … --- ## [NDR measured runoff and Application rate in Biophysical Table](https://community.naturalcapitalalliance.org/t/ndr-measured-runoff-and-application-rate-in-biophysical-table/6493)
**Author:** [@Kantharajan](https://community.naturalcapitalalliance.org/u/Kantharajan)\ **Replies:** 1\ **Last updated:** [August 28, 2026, 4:19pm UTC](https://community.naturalcapitalalliance.org/t/ndr-measured-runoff-and-application-rate-in-biophysical-table/6493 "2026-08-28T16:19:45Z")
Hello InVEST Community… I just want to understand the Load Data types used in the InVEST User Document (Given below) "These two types of loading values are denoted application-rate and measured-runoff, respectively, in… --- ## [Could not convert string to float: ''](https://community.naturalcapitalalliance.org/t/could-not-convert-string-to-float/6411)
**Author:** [@Dimple](https://community.naturalcapitalalliance.org/u/Dimple)\ **Replies:** 7\ **Last updated:** [May 18, 2026, 1:29pm UTC](https://community.naturalcapitalalliance.org/t/could-not-convert-string-to-float/6411 "2026-05-18T13:29:24Z")
When I use this module to calculate water purificationIt has never been successful.Always show could not convert string to float:＂I revised the biophysics table again and checked that it was out of control.And I download… --- ## [Unable to show full area](https://community.naturalcapitalalliance.org/t/unable-to-show-full-area/6413)
**Author:** [@Dimple](https://community.naturalcapitalalliance.org/u/Dimple)\ **Replies:** 1\ **Last updated:** [May 18, 2026, 1:08pm UTC](https://community.naturalcapitalalliance.org/t/unable-to-show-full-area/6413 "2026-05-18T13:08:54Z")
When the nutrient delivery ratio module is used for calculating the water quality purificationWhen the nutrient transport ratio module is used to calculate the water quality purification, the output result is inconsisten… --- ## [Sensitivity Analysis Code for NDR No Data Issues](https://community.naturalcapitalalliance.org/t/sensitivity-analysis-code-for-ndr-no-data-issues/6369)
**Author:** [@cobleer1](https://community.naturalcapitalalliance.org/u/cobleer1)\ **Replies:** 4\ **Last updated:** [April 1, 2026, 9:47pm UTC](https://community.naturalcapitalalliance.org/t/sensitivity-analysis-code-for-ndr-no-data-issues/6369 "2026-04-01T21:47:48Z")
I have taken the code for running sensitivity analysis on NDR for an older version of InVEST and attempted to update it to the current version for use on Phosphorus with my data. I am having this issue where the results … --- ## [Is it possible to calibrate or feed NDR and SDR models using SWAT model outputs?](https://community.naturalcapitalalliance.org/t/is-it-possible-to-calibrate-or-feed-ndr-and-sdr-models-using-swat-model-outputs/6332)
**Author:** [@Fernbg77](https://community.naturalcapitalalliance.org/u/Fernbg77)\ **Replies:** 2\ **Last updated:** [February 19, 2026, 6:07pm UTC](https://community.naturalcapitalalliance.org/t/is-it-possible-to-calibrate-or-feed-ndr-and-sdr-models-using-swat-model-outputs/6332 "2026-02-19T18:07:45Z")
Hello everyone, I recently came across the Colombian study “Assessing the Effectiveness of the Use of the InVEST Annual Water Yield Model for the Rivers of Colombia: A Case Study of the Meta River Basin” (https://doi.or… --- ## [What are the SDR/NDR model output units?](https://community.naturalcapitalalliance.org/t/what-are-the-sdr-ndr-model-output-units/6330)
**Author:** [@tharindu\_bawantha](https://community.naturalcapitalalliance.org/u/tharindu_bawantha)\ **Replies:** 3\ **Last updated:** [January 26, 2026, 1:45pm UTC](https://community.naturalcapitalalliance.org/t/what-are-the-sdr-ndr-model-output-units/6330 "2026-01-26T13:45:52Z")
Hello everyone, I’m currently working with the SDR and NDR models using a 30m × 30m SRTM DEM. I have a question about interpreting and converting the output units. According to the InVEST User Guide, the model outputs a… --- ## [Subject: Validity of using historical climate data (WorldClim 1970-2000) with a 2025 LULC map](https://community.naturalcapitalalliance.org/t/subject-validity-of-using-historical-climate-data-worldclim-1970-2000-with-a-2025-lulc-map/6327)
**Author:** [@Fernbg77](https://community.naturalcapitalalliance.org/u/Fernbg77)\ **Replies:** 2\ **Last updated:** [January 23, 2026, 12:36am UTC](https://community.naturalcapitalalliance.org/t/subject-validity-of-using-historical-climate-data-worldclim-1970-2000-with-a-2025-lulc-map/6327 "2026-01-23T00:36:13Z")
Hello everyone, I would like to raise a question regarding temporal consistency in the application of the InVEST Annual Water Yield (AWY), Sediment Delivery Ratio (SDR), and Nutrient Delivery Ratio (NDR) models. I am c… --- ## [Using NDR outputs to map nutrient trapping](https://community.naturalcapitalalliance.org/t/using-ndr-outputs-to-map-nutrient-trapping/6239)
**Author:** [@gabi89](https://community.naturalcapitalalliance.org/u/gabi89)\ **Replies:** 6\ **Last updated:** [January 9, 2026, 6:04pm UTC](https://community.naturalcapitalalliance.org/t/using-ndr-outputs-to-map-nutrient-trapping/6239 "2026-01-09T18:04:15Z")
Hi! I’ve been reviewing the InVEST Sediment Retention model, particularly the Sediment Downslope Trapping component (which outputs the “Avoided Export” layer), and I’d like to try a similar type of analysis using a nutri… --- ## [NDR Retention Raster & units of load rasters](https://community.naturalcapitalalliance.org/t/ndr-retention-raster-units-of-load-rasters/6241)
**Author:** [@Taherunnesa](https://community.naturalcapitalalliance.org/u/Taherunnesa)\ **Replies:** 11\ **Last updated:** [January 7, 2026, 6:34pm UTC](https://community.naturalcapitalalliance.org/t/ndr-retention-raster-units-of-load-rasters/6241 "2026-01-07T18:34:43Z")
@swolny How do I calculate nutrient retention in InVEST? The modified load raster is expressed in kg/year, while the export raster is in kg/ha/ year. --- ## [NDR Retention Raster](https://community.naturalcapitalalliance.org/t/ndr-retention-raster/6313)
**Author:** [@Fernbg77](https://community.naturalcapitalalliance.org/u/Fernbg77)\ **Replies:** 2\ **Last updated:** [January 7, 2026, 5:09pm UTC](https://community.naturalcapitalalliance.org/t/ndr-retention-raster/6313 "2026-01-07T17:09:21Z")
I am currently working with the InVEST Nutrient Delivery Ratio (NDR) model in a predominantly flat watershed, and I have a conceptual question regarding the interpretation of pixel-level nitrogen retention. When estimati… --- ## [How does NDR handle nodata values near boundaries of input data?](https://community.naturalcapitalalliance.org/t/how-does-ndr-handle-nodata-values-near-boundaries-of-input-data/6175)
**Author:** [@siyuliu](https://community.naturalcapitalalliance.org/u/siyuliu)\ **Replies:** 3\ **Last updated:** [October 6, 2025, 11:40pm UTC](https://community.naturalcapitalalliance.org/t/how-does-ndr-handle-nodata-values-near-boundaries-of-input-data/6175 "2025-10-06T23:40:27Z")
Can the model operate normally if there are nodata values (on national boundaries) in the land use data within the study area? Due to the high spatial resolution and large research area, I am asking this question to avoi… --- ## [Subsurface data in NDR](https://community.naturalcapitalalliance.org/t/subsurface-data-in-ndr/6201)
**Author:** [@h.kazmi](https://community.naturalcapitalalliance.org/u/h.kazmi)\ **Replies:** 2\ **Last updated:** [September 25, 2025, 2:34pm UTC](https://community.naturalcapitalalliance.org/t/subsurface-data-in-ndr/6201 "2025-09-25T14:34:33Z")
Hello everyone. I want to run the NDR model, but I don’t know what numbers I should set for these two alternatives. 1- Subsurface Critical Length and 2- Subsurface Maximum Retention Efficiency. For both nitrogen and… --- ## [Tutorial videos](https://community.naturalcapitalalliance.org/t/tutorial-videos/6203)
**Author:** [@h.kazmi](https://community.naturalcapitalalliance.org/u/h.kazmi)\ **Replies:** 2\ **Last updated:** [September 22, 2025, 5:51pm UTC](https://community.naturalcapitalalliance.org/t/tutorial-videos/6203 "2025-09-22T17:51:05Z")
Hello everyone. Are there any tutorial videos for each of the InVEST models? I searched on Google but couldn’t find anything. --- ## [Calibrating and Validating the InVEST NDR Model in Data-Scarce Regions](https://community.naturalcapitalalliance.org/t/calibrating-and-validating-the-invest-ndr-model-in-data-scarce-regions/6191)
**Author:** [@Mariam](https://community.naturalcapitalalliance.org/u/Mariam)\ **Replies:** 0\ **Last updated:** [September 8, 2025, 6:25pm UTC](https://community.naturalcapitalalliance.org/t/calibrating-and-validating-the-invest-ndr-model-in-data-scarce-regions/6191 "2025-09-08T18:25:27Z")
Dear NatCap Community, I am excited to share that our new paper has just been published: Using machine learning for long-term calibration and validation of water quality ecosystem service models in data-scarce regions. … --- ## [Average Runoff Proxy (number, optional) parameter](https://community.naturalcapitalalliance.org/t/average-runoff-proxy-number-optional-parameter/6156)
**Author:** [@Eshetu](https://community.naturalcapitalalliance.org/u/Eshetu)\ **Replies:** 2\ **Last updated:** [August 22, 2025, 7:17am UTC](https://community.naturalcapitalalliance.org/t/average-runoff-proxy-number-optional-parameter/6156 "2025-08-22T07:17:16Z")
Dear scholars, I ran the InVEST model leaving the Average Runoff Proxy (number, optional) parameter empty. However, to maintain a consistent reference for the runoff proxy index, specifying a fixed average value could e… --- ## [NDR runs, and the result is NAN](https://community.naturalcapitalalliance.org/t/ndr-runs-and-the-result-is-nan/6143)
**Author:** [@bai](https://community.naturalcapitalalliance.org/u/bai)\ **Replies:** 7\ **Last updated:** [August 21, 2025, 1:49pm UTC](https://community.naturalcapitalalliance.org/t/ndr-runs-and-the-result-is-nan/6143 "2025-08-21T13:49:07Z")
What is the issue or question you have? NDR runs, and the result is NAN. What do you expect to happen? I checked the intermediate\_outputs and found that flow\_direction\_ndr is good, but flow\_accumulation\_ndr is completel… --- ## [Nutrient Delivery Ratio: load\_type\_x](https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-load-type-x/6083)
**Author:** [@ceileigh](https://community.naturalcapitalalliance.org/u/ceileigh)\ **Replies:** 7\ **Last updated:** [August 18, 2025, 1:16pm UTC](https://community.naturalcapitalalliance.org/t/nutrient-delivery-ratio-load-type-x/6083 "2025-08-18T13:16:23Z")
The software indicates that load\_type\_x (load\_type\_p, in my case) must have a numerical input in the biophysical table, however, the user guide suggests that the options should be inputted as either ‘application-rate’ or… --- ## [Why there is nodata area in the result of NDR?](https://community.naturalcapitalalliance.org/t/why-there-is-nodata-area-in-the-result-of-ndr/6132)
**Author:** [@Momo1](https://community.naturalcapitalalliance.org/u/Momo1)\ **Replies:** 1\ **Last updated:** [August 8, 2025, 1:18pm UTC](https://community.naturalcapitalalliance.org/t/why-there-is-nodata-area-in-the-result-of-ndr/6132 "2025-08-08T13:18:07Z")
I made a buffer in elevation data, but there was still nodata area in the result of NDR. Why does this happens? How to solve it? Can I assign zero to the nodata area? --- ## [NDR model result with empty pixels](https://community.naturalcapitalalliance.org/t/ndr-model-result-with-empty-pixels/6112)
**Author:** [@Eshetu](https://community.naturalcapitalalliance.org/u/Eshetu)\ **Replies:** 4\ **Last updated:** [July 25, 2025, 5:36pm UTC](https://community.naturalcapitalalliance.org/t/ndr-model-result-with-empty-pixels/6112 "2025-07-25T17:36:47Z")
My NDR (Nutrient Delivery Ratio) model output shows no pixels within my study watershed (all masked out). I used the filled Copernicus DEM (GLO-30) and delineated the watershed using the InVEST Delineation Tool. For la… --- ## [NDR: Which loading type is appropriate?](https://community.naturalcapitalalliance.org/t/ndr-which-loading-type-is-appropriate/6114)
**Author:** [@Eshetu](https://community.naturalcapitalalliance.org/u/Eshetu)\ **Replies:** 1\ **Last updated:** [July 25, 2025, 12:47pm UTC](https://community.naturalcapitalalliance.org/t/ndr-which-loading-type-is-appropriate/6114 "2025-07-25T12:47:23Z")
thank you dear swolny. I have question related to load type. I prepared biophysical table from literature (all values from recent studies). I have no field data. so, which load type is appropriate for me ? application … --- ## [Clarification on Using Field Soil Nutrient Data and NoData Outputs in NDR](https://community.naturalcapitalalliance.org/t/clarification-on-using-field-soil-nutrient-data-and-nodata-outputs-in-ndr/6062)
**Author:** [@Aatreyee](https://community.naturalcapitalalliance.org/u/Aatreyee)\ **Replies:** 9\ **Last updated:** [July 2, 2025, 4:44pm UTC](https://community.naturalcapitalalliance.org/t/clarification-on-using-field-soil-nutrient-data-and-nodata-outputs-in-ndr/6062 "2025-07-02T16:44:13Z")
Dear Community, I am currently working with the Nutrient Delivery Ratio (NDR) model and have the following queries: I have access to field-level soil data that includes nitrogen and phosphorus concentrations at both … --- ## [NDR output units and conversion from kg/pixel to kg/ha](https://community.naturalcapitalalliance.org/t/ndr-output-units-and-conversion-from-kg-pixel-to-kg-ha/6051)
**Author:** [@yuxing](https://community.naturalcapitalalliance.org/u/yuxing)\ **Replies:** 5\ **Last updated:** [June 26, 2025, 2:08pm UTC](https://community.naturalcapitalalliance.org/t/ndr-output-units-and-conversion-from-kg-pixel-to-kg-ha/6051 "2025-06-26T14:08:47Z")
Hello! I’m currently using the InVEST Nutrient Delivery Ratio (NDR) model with input DEM and land use data at a 30m × 30m resolution. The rainfall (used as the runoff proxy) is at a coarser resolution of 1000m × 1000m. … --- ## [Urban stormwater quality vs Nutrient Delivery Ratio](https://community.naturalcapitalalliance.org/t/urban-stormwater-quality-vs-nutrient-delivery-ratio/6042)
**Author:** [@ReissM](https://community.naturalcapitalalliance.org/u/ReissM)\ **Replies:** 1\ **Last updated:** [June 13, 2025, 11:40am UTC](https://community.naturalcapitalalliance.org/t/urban-stormwater-quality-vs-nutrient-delivery-ratio/6042 "2025-06-13T11:40:48Z")
Hi, I’m trying to understand the conceptual differences between the Nutrient Delivery Ratio (NDR) model and the urban stormwater model when it comes to water quality. Both seem to quantify some form of avoided runoff o… --- ## [A framework to validate InVEST NDR using open-access monitoring data in the US](https://community.naturalcapitalalliance.org/t/a-framework-to-validate-invest-ndr-using-open-access-monitoring-data-in-the-us/5377)
**Author:** [@Mariam](https://community.naturalcapitalalliance.org/u/Mariam)\ **Replies:** 5\ **Last updated:** [April 22, 2025, 3:27pm UTC](https://community.naturalcapitalalliance.org/t/a-framework-to-validate-invest-ndr-using-open-access-monitoring-data-in-the-us/5377 "2025-04-22T15:27:09Z")
Hi everyone, I am using InVEST NDR for my graduate research, recently with the support of a team of coauthors, we published a framework to validate InVEST NDR using open-access monitoring station data from the Water Qua… --- ## [Why is P or N export larger than P or N load in result?](https://community.naturalcapitalalliance.org/t/why-is-p-or-n-export-larger-than-p-or-n-load-in-result/5938)
**Author:** [@Momo1](https://community.naturalcapitalalliance.org/u/Momo1)\ **Replies:** 1\ **Last updated:** [April 16, 2025, 9:28pm UTC](https://community.naturalcapitalalliance.org/t/why-is-p-or-n-export-larger-than-p-or-n-load-in-result/5938 "2025-04-16T21:28:08Z")
In the results of NDR, the average value of N or P export is smaller than that of modified\_load N or P. I think it’s reasonable. But the maximum value of N or P export is larger than that of the modified\_load N or P. As … --- ## [The watershed\_results\_ndr.gpkg calculated by NDR is only partially displayed when opened, suggesting that part of the image is drawn incorrectly.](https://community.naturalcapitalalliance.org/t/the-watershed-results-ndr-gpkg-calculated-by-ndr-is-only-partially-displayed-when-opened-suggesting-that-part-of-the-image-is-drawn-incorrectly/5885)
**Author:** [@bellona](https://community.naturalcapitalalliance.org/u/bellona)\ **Replies:** 3\ **Last updated:** [March 26, 2025, 2:28pm UTC](https://community.naturalcapitalalliance.org/t/the-watershed-results-ndr-gpkg-calculated-by-ndr-is-only-partially-displayed-when-opened-suggesting-that-part-of-the-image-is-drawn-incorrectly/5885 "2025-03-26T14:28:11Z")
The watershed\_results\_ndr.gpkg calculated by NDR is only partially displayed when opened, suggesting that part of the image is drawn incorrectly. --- ## [Nodata areas in NDR/SDR-scaling factors](https://community.naturalcapitalalliance.org/t/nodata-areas-in-ndr-sdr-scaling-factors/5870)
**Author:** [@dgw\_awf](https://community.naturalcapitalalliance.org/u/dgw_awf)\ **Replies:** 4\ **Last updated:** [March 20, 2025, 12:03am UTC](https://community.naturalcapitalalliance.org/t/nodata-areas-in-ndr-sdr-scaling-factors/5870 "2025-03-20T00:03:12Z")
Hi NatCappers, I am exploring the impacts of a wetland and riparian buffer restoration scenario against a business-as-usual scenario using the SDR and NDR models. The nodata area created when running the models results … [Next page](https://community.naturalcapitalalliance.org/tag/ndr/7.md?match_all_tags=true&page=1&tags%5B%5D=ndr)