To support the development and evaluation of the GREENHOUSE spatial and temporal upscaling framework, within-field (metres) measurements are carried out to determine the diurnal and seasonal trends in CO2, CH4 and N2O emissions over dominant UK land-covers. For each of the GREENHOUSE measurement campaigns, a comprehensive knowledge of the spatial variability in site characteristics (e.g. soil moisture and solar radiation) that may affect trace gas exchanges is key to deciding the best possible locations for deploying monitoring instruments. These instruments chiefly include the York Skyline automated chamber system and eddy covariance flux towers.
To help decide the instrument installation locations used throughout the GREENHOUSE Dairy farming field campaign at the SRUC Dairy Research Centre, located in Dumfries, a land survey was conducted to capture the spatial variability in topography and soil moisture. Using a GPS referenced total station, spot heights were sampled at approximately 10 metres intervals across the entire field. The soil moisture was also recorded at each of the spot height points with the exception of those in the west and south-west extents of the field where the variability in topography was relatively small.
Map plotting the data processed from the GREENHOUSE Dairy farming field site showing the spatial variability in a) height and b) soil moisture (m3/m3). Note: soil moisture measurements were not collected in west and south-west extents.
Post-processing of the survey data included applying differential GPS corrections to the survey point locations, followed by spatially interpolating the height data to a regular grid (1 metre). The soil moisture values were also interpolated, within the extents of the sampled area, to match the spatial resolution of the height data. A 3-dimensional visualisation model, including locations of existing eddy covariance towers, was generated to further aid in the interpretation of the spatial variability in topography and soil moisture at the Dairy farming site.
Animation of the 3-dimensional topography of the Dairy Farming site, showing the location of electricity pylons (on the edge of the site) and of the two flux tower (near the center).