  One of the biggest environmental problems of our time is the increase in
illegal landfills in forests, rivers, on river banks and other secluded places.
In addition, waste in rivers causes damage not only locally, but also
downstream, both in the water and washed ashore. Large islands of waste can
also form at hydroelectric power stations and dams, and if they continue to
flow, they can cause further damage to the natural environment along the river.
Recent studies have also proved that rivers are the main source of plastic
pollution in marine environments. Monitoring potential sources of danger is
therefore highly important for effective waste collection for related
organizations. In our research we analyze two possible forms of waste
detection: identification of hot-spots (i.e. illegal waste dumps) and
identification of water-surface river blockages. We used medium to
high-resolution multispectral satellite imagery as our data source, especially
focusing on the Tisza river as our study area. We found that using satellite
imagery and machine learning are viable to locate and to monitor the change of
the previously detected waste.
