Landscape structure (patch pattern) of the Jorka river catchment (Masurian Lakeland Poland) : analysis of air photos / Joanna Rybak

The objective of the study was to identify components of the landscape of a selected lakeland catchment basin (river Jorka catchment, Masurian Lakeland, Poland), to asses their size and distribution with respect to their cover and use, and to evaluate their role as barries to nutrient inflow into lakes. Aerial photographs (1:10000) were applied to identify the use and cover of catchment. Vertical black and white photographs were recorded on negative infrared in 1997 and 1998. The air photos and topographical maps (1:10000, 1:25000) were used to identify objects (landscape patches) that differed with respect to their function as barries to nutrients. Each landscape patch was allocated to one of the eight categories of land cover and use: crop fields, forests (forests on mineral soils, oak-hornbeam forests, mixed coniferous forests), meadows and pastures, wasteland (permanently or temporarily excluded from agricultural use) lakes, wet forests (forests on hydrogenic soils, alder swamps, riparian carrs, and shrubberies), other wetlands (open wetlands, mid-field bodies of water), and built-up land. The identified objects were assigned to three categories with rrespect to their function as barriers: highly effective barriers (forested and non-forest wetlands, and lakes - 6% of Jorka river catchment); moderate effective barriers (forest, meadows and pastures, wasteland - 42%); and wwith no barrier function (arable land, built-up land - residential and industrial, tourist objects, etc. - 52%).