This dataset consists of headwater erosion process data for sites across Wales between 2021 and 2023, collected as part of the Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP) National Field Survey. Data include the classification and extent of erosion features. Headwater stream survey data was collected from 101 x 1km squares across Wales, collected as part of the Environment and Rural Affairs Monitoring and Modelling Programme (ERAMMP) National Field Survey. Erosion features were identified in 99 surveyed headwater streams. ERAMMP follows an earlier monitoring programme, the Glastir Monitoring and Evaluation Programme (GMEP), which was set up by the Welsh Government in 2013 to monitor the effects of the Glastir agri-environment scheme on the environment and ran from 2013 to 2016. The field survey element for both GMEP and ERAMMP was based on a stratified random sampling design of 300 x 1km square sites across Wales (225 of which were resurveyed for ERAMMP in 2021-23, though not all squares contained headwater streams). It was managed by the UK Centre for Ecology & Hydrology. Full details about this dataset can be found at https://doi.org/10.5285/6973d1b1-4814-4ff5-8daa-4d825ca3c4b9
