# CMAQv5.3.1: Errors with Online WB Dust calculations and BELD4

**URL:** <https://forum.cmascenter.org/t/cmaqv5-3-1-errors-with-online-wb-dust-calculations-and-beld4/1364>\
**Category:** CMAQ\
**Created:** [March 12, 2020, 7:00pm UTC](https://forum.cmascenter.org/t/cmaqv5-3-1-errors-with-online-wb-dust-calculations-and-beld4/1364 "2020-03-12T19:00:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![abi0010](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@abi0010](https://forum.cmascenter.org/u/abi0010)\
**Post date:** [March 12, 2020, 7:00pm UTC](https://forum.cmascenter.org/t/cmaqv5-3-1-errors-with-online-wb-dust-calculations-and-beld4/1364/1 "2020-03-12T19:00:35Z")

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Hello…I had trouble with the WB Dust online calculation when using BELD4. There were a number of NCLD references that read as missing. I switched back to BELD3 which ran well. Was wondering if this is an issue anyone else has come across. I could be doing something wrong (most likely).

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**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [March 12, 2020, 11:01pm UTC](https://forum.cmascenter.org/t/cmaqv5-3-1-errors-with-online-wb-dust-calculations-and-beld4/1364/2 "2020-03-12T23:01:08Z")

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Please see [our response](https://forum.cmascenter.org/t/dust-lu-2-file-forest-variable-not-correct/1305/21) in a [related thread on windblown dust](https://forum.cmascenter.org/t/dust-lu-2-file-forest-variable-not-correct/1305).

Unfortunately, at the moment the BELD4 file generated by the spatial allocator does not contain all the land use categories expected by the CMAQ dust module when CTM\_WBDUST\_BELD is set to BELD4. We are investigating this issue and plan to update the code and/or model documentation in the future.

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**Author:** ![abi0010](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@abi0010](https://forum.cmascenter.org/u/abi0010)\
**Post date:** [March 13, 2020, 12:42am UTC](https://forum.cmascenter.org/t/cmaqv5-3-1-errors-with-online-wb-dust-calculations-and-beld4/1364/3 "2020-03-13T00:42:37Z")

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Thank you much! Best.