Monitoring change is important for many reasons, and for those working in planning, development and environmental management it can be crucial in ensuring that the characteristics of an area are maintained or enhanced. Earlier this year Environment Systems was commissioned to undertake up-to-date analyses of the natural, built and historic environments, and to identify the different types of change that have taken place since 2007. The study focused on the Dorset area, specifically in the Dorset AONB and an extended area including parts of Hampshire, Wiltshire and Somerset.
Initially our work focused on the natural environment. Detailed Phase 1 habitat data existed for part of the study area, but there were large gaps in coverage which we had to fill to create a seamless map. We achieved this using remote sensing image analysis of Sentinel-1/2 data and image segmentation using a classification rule-base to identify the basic land cover types. These includednarable, improved grassland, semi-improved grassland, heath, scrub, urban, water, wetland and woodland. In addition, we created habitat connectivity layers for the four key networks: heathland, grassland, woodland and wetland, via landscape permeability analysis.
The built environment presented a different set of challenges because the project required us to not only provide spatial data for the total urban extent in 2007 and 2017 with a range of comparisons but also for a number of features of interest including quarries, pylons, wind turbines, solar farms, caravan and camping sites, and car parks.
Additionally, we provided statistics and spatial data summarising areas that make up the historic environment. These included scheduled monuments, listed buildings, conservation areas, parks and gardens and designed landscapes. This was achieved using data from Historic England and Natural England.
Understanding how habitats have changed over time is important in an AONB especially from a planning perspective. We carried habitat change detection analysis by comparing the current habitat map against older data, and where no previous habitat data existed, through statistical analysis of satellite image data to identify changes in the reflectance characteristics over time.
Much of the data will be shared via DorsetExplorer, Dorset County Council’s publicly accessible mapping portal.