Aerial photo interpretation and GIS work in a method study:
Calculation economical compensation cultivation and conservation of cultural land.
To find a method to give the cultural land and its objects indicator values that expresses their ecological values. Indicator values will be given to the areas in the cultural land with adjacent landscape elements (e.g. stone walls, headlands and large deciduous trees). The indicator value is based on the cultural land areas’ and the adjacent elements’ type, degree of cultivation, accessibility, closeness to cultural objects etc. This value will later be used to calculate the level of economical compensation for the owner of the land.
Definition of the cultural land
The cultural land is in this project defined to include cultivated land, grasslands with trees and bushes covering less than 70% of the land, adjacent land with different use within 20 meters from the real cultural land (including forest edges) and field impediments smaller than half an hectare.
A detailed aerial photo interpretation of the cultural landscape has been made in two test areas, Vetlanda in Småland and Selaön in Södermanland ( Lake Mälaren ). The interpretation of infra red photos was directly digitalized on an analytic stereo plotter. Primary data for the mapping was digital topographic maps and data from The Swedish Board of Agriculture that’s been put together. An initial edition for mapping of field islets and for forest edges was made in this step. Initially starting data was controlled and, if in needed, adjusted. In the areas within the cultural landscape the following was mapped, property, land use, cultivation, tree- and bush coverage and kind of tree (coniferous or deciduous). Deciduous stands adjacent to cultural landscapes and three kinds of open forest edges were mapped to create the layer Forest Edge. Six different types of dot objects and nine different types of line objects were mapped. In the line objects attributes were added such as tree- and bush coverage and tree kind, level of overgrowth and vegetation strip. This was transferred to ArcGIS (ArcInfo) for error check, adjustments and GIS analysis. Each step in ArcGIS was performed automatically by software I made (so called ALM’s). Cultural landscape objects within specified distances from cultural objects in the topographical data base (ancient monuments, gardens, churches etc.) were searched and later created new layers in the map data base. The map layer Visibility was created in more or less the same way which contains cultural landscape objects visible from larger roads. Dot-, line objects and forest edges were given and related to the nearest cultural landscape areas according to the specification. The indicator value for the cultural landscape areas could thereafter be summarized as the areas own values plus the values of nearby cultural landscape objects. The indicator value can finally be used to calculate the financial compensation the single objects or summarized on areas or summarized on land properties. The project is a part of a large EU research project AEMAC. The Swedish University of Agricultural Science in Uppsala is involved in the AEMAC and they gave this mission to NaturGis AB.