Welsh Government has commissioned an Earth observation (EO) classification map to support the identification of the invasive Japanese Knotweed Fallopia japonica (JKW) within Snowdonia National Park. The project will be leveraging citizens and COBWEB technologies to validate this JKW EO map, leading to greater accuracy, and therefore a more targeted response when combating the spread of invasive species.

JKW is a plant originating from the far east of Asia and was introduced to the UK as an ornamental plant. Due to its vigorous growth from even small parts of rhizomes (stems/roots) it has spread widely, both by natural, e.g. the transport of rhizomes through rivers, and by anthropogenic means, e.g. the transport of soil containing rhizomes between construction sites.

The control of JKW remains an important issue for local authorities, as the dense stands negatively impact local biodiversity by outcompeting native plants and, particularly around rivers, increasing the risk of soil erosion by preventing the growth of grass species.

Environment Systems (who is producing the EO map) is conducting an object-based image analysis of aerial photographs to spatially assess the likelihood of JKW being present in sites throughout Snowdonia National Park. Citizens will then visit these areas and, using the COBWEB app, will conduct a visual assessment to verify if JKW is present. The data collected, including geo-located photographs, will then be validated using the developing COBWEB Quality Assurance technologies.

It is hoped the science of remote sensing will complement the traditionally costly and slow data collection on the ground by targeting specific areas. This will simultaneously ensure that other areas, such as delicate habitats, are not disturbed.  Furthermore, this approach can be used in other land cover maps, where the data collected on the ground can be used to validate the remote sensing approach. Recording what the citizen sees enables calibration of the remotely sensed data and aids in the interpretation and analysis of what is being sensed. Ultimately, citizens will improve the ways in which JKW is identified from the Earth Observation datasets (aerial photography etc.).