Further details of the changes to survey method, sample design, estimation approaches and the effects of applied caps will be made available in the GBDVS Background Quality Report 2023.
Mae rhagor o fanylion am y newidiadau i ddull yr arolwg, dylunio'r sampl, dulliau amcangyfrif ac effeithiau’r capiau a ddefnyddir ar gael yn Adroddiad Ansawdd Cefndir 2023 GBDVS.