Abiotic typology of Polish lakes

According to the requirements of the Water Framework Directive 2000/60/EC, all member states of the EU have to establish the typology of their surface waterbodies. The typology is aimed at defining the type-specific reference conditions against which the ecological state of waters can be assessed. The abiotic typology of Polish lakes of an area greater than 50 ha was established based on morphometric, hydrographic and physico-chemical data taken from the Polish national monitoring dataset. The current dataset comprises 749 out of a total of 1042 lakes with an area greater than 50 ha in Poland. Lake types were identified based on a combination of abiotic characteristics of lakes specified in Annex II of the Water Framework Directive such as ecoregions, size, altitude, mean depth, geology and an additional factor - Schindler's ratio. Altogether 13 abiotic lake types were established.