The Norwegian area frame survey of land cover and outfield land resources

Abstract

There is a growing demand for reliable information about land cover and land resources. The Norwegian area frame survey of land cover and outfield land resources (AR18X18) is a response to this demand. AR18X18 provides unbiased land cover and land resource statistics and constitutes a baseline for studying changes in outfield land resources in Norway and a framework for a national land resource accounting system for the outfields. The area frame survey uses a systematic sampling technique with 0.9 km 2 sample plots at 18 km intervals. A complete wall-to-wall land cover map of an entire plot surveyed is obtained in situ by a team of fieldworkers equipped with aerial photographs. The use of sample plots with extended coverage (0.9 km 2 ) ensures that the survey also deals with local variation, thus strengthening the estimates well beyond simple point sampling. The article documents the methodology used in the survey, followed by a discussion of issues raised by the choice of methodology. These issues include the problem of calculating uncertainty and a confidence interval for the estimates, the focus on common rather than rare land cover categories, and the prospect of downscaling the results in order to obtain statistics for subnational regions.

Spatial Transferability of Vegetation Types in Distribution Models Based on Sample Surveys from an Alpine Region

“…The focus on the chosen vegetation type data, DM method, EVs and spatial scale however, provides only a certain part of the challenges involved in DM transferability. Nevertheless, as high quality vegetation maps remain a key tool for nature management [43], and fieldwork mapping is time-consuming and expensive, we need a better understanding of how to model the distribution of vegetation types from existing data, such as area frame surveys [21]. Spatial modelling techniques, such as the DM methods (e.g.…”

“…This grid is in accordance with the Norwegian area frame survey of land cover and outfield land resources [21]. The three vegetation types were treated independently throughout the study.…”

Distribution modelling of vegetation types based on area frame survey data

“…RS‐based maps can be obtained for the entire landmass of the world, but are burdened with inherent limitations, e.g., on the number of types into which vegetation or land cover can be correctly classified (Franklin & Wulder, ). RS‐based maps are therefore typically used when broad‐scale or coarse patterns are required (Achard, Eva, Mayaux, Stibig, & Belward, ; Bartholome & Belward, ; Tuanmu & Jetz, ), while RS data have so far not proven useful when higher thematic accuracy is required, e.g., for many research and management purposes (Bekkby, Rinde, Erikstad, & Bakkestuen, ; Strand, ). In order to meet the increasing demand for land use and land cover information, the European Statistical Agency initiated the LUCAS (Land Use/Cover Agricultural Survey) program, organised as a sample‐based area frame field survey, to obtain area‐representative data (Eurostat, ).…”

Composition and spatial structure of dwarf shrub heath in Norway

“…A wall-to-wall vegetation map of each PSU was compiled according to the system for vegetation and land cover mapping at intermediate scale (1: 20,000-1:50,000) (abbreviated VK50) (Rekdal & Larsson 2005). The VK50 nomenclature consists of 45 vegetation types and 9 other land cover types, and operates with a minimum mapping unit (MMU) of 1000 m 2 for rare or especially important vegetation types and 5000 m 2 for common types (Strand 2013). The description of the vegetation classes is mainly based on physiognomy, as it appears from dominant species or species groups, and secondly by characteristic species.…”

“…Data from the area frame survey of land cover and outfield land resources in Norway -the 'Norwegian land cover and land resources of the outfields' (Areal regnskap for utmark, abbreviated to AR18X18) (Strand 2013) -were used as a 'test bed'. The survey combines a wall-to-wall mapping of vegetation types with point sampling of detailed vegetation subtypes in the same area.…”