| Abstract [eng] |
Macrophytes are important for fish nurseries, also they stabilize ground sediment as well as reduce amounts of carbon dioxide, phosphorus, and methane in the atmosphere. One of the Marine Water Framework Directive criteria is diversity of species and habitats and their distribution. Currently macrophyte monitoring is done using in situ methods and that requires many resources and does not cover a lot of area. The aim of this work was to compose high quality maps of shallow water and shore macrophytes, describe change in these locations and evaluate most common problems that are faces using this method. The main aspects that are considered while mapping are hydro-meteorological conditions, technical equipment and used software. Also, ability to measure volume, area, and amount will be evaluated as well. Final orthophotos will be compared with in situ data and satellite images. In the end result, conditions to make high spatial resolution (up to 4 mm) orthophotos were described and evaluated. From orthophotos of Plateliai lake area where reed moving took place, reduction of 34 % reed area loss was calculated. Macrophyte cover correlation between in situ, drone and satellite images was around 0.5. Since visual assessment was similar with drone orthophotos using vegetation indices, this method could significantly improve (ability to cover larger area) macrophyte monitoring. |
