Breadcrumbs
NCAF4/4 Definitions for mapping access land
Background
2. This paper explains how the Agency intends to interpret the terms "mountain, moor, heath and down" for the purpose of mapping access land, and summarises the main datasets we intend to use to identify the relevant land. In doing so, it assumes that the legislation will not define mountain, moor, heath and down. The paper draws extensively on work undertaken for the Agency by W.S. Atkins and the GeoData Institute. It covers:
a. the working definitions of the various land types which we have used to date to identify relevant datasets (and which we propose to use in the future to refine the final selection of datasets and to assess the utility of new or revised datasets); and
b. our current assessment of the best available datasets to use for the production of consultation maps of access land, given the working definitions we have adopted.
3. At the third meeting of the NCAF, members received a presentation by the Geodata Institute on the availability and utility of existing datasets for the purpose of mapping access land. GeoData's study represented the first phase of the Agency's access mapping work. It concluded that, while there is no single dataset that will provide the information we need for all land types, there are a number of national and local datasets which, used in combination, will make a major contribution to the production of good quality consultation maps. While there are likely to be some areas where the paucity or poor quality of existing data will necessitate supplementary work using air photographs or limited field survey, we anticipate that this will be needed in relatively few areas.
Working definitions
4. We have adopted the following working definitions:
Mountain means:
a. all land over 600 metres; and
b. extensive areas of crag, scree or other mainly bare rock (but
not coastal cliffs).
Moor means land, usually in hill areas, with vegetation comprising mainly rough grasses, mosses, heather or bracken, or a patchwork of these. It sometimes includes scattered trees or scrub, streams, boggy areas, rock or other bare ground. Upland heath will frequently fall within the definition of moor.
Heath means land, usually in lower lying areas (typically below 300m), with vegetation comprising mainly rough grasses, heather, gorse, bracken or scrub, or a patchwork of these. It often includes trees, and sometimes includes streams, marshy areas, open water, carr, sand or other bare ground.
Down means natural or semi-natural grassland on calcareous soils, typically found on undulating ground in areas of chalk or limestone geology.
Best available datasets
5. Having adopted the working definitions above, we have sought to discover and use those datasets that best identify the land which meets the definitions. We anticipate that a wide range of data sources will ultimately contribute to the mapping of access land in England. These data sources employ a variety of classification systems, some of which have been modified over time and are therefore not homogeneous across the country. We remain open to the possibility of identifying alternative, and possibly better, datasets for some types of land as the second phase of mapping work progresses, or as new or revised data becomes available. The following is a summary of those darasets we have identified, through the work of the GeoData Institute, as the best currently available for the purpose of mapping mountain, moor, heath and down as defined at para 4 above:
Mountain and moor will be identified mainly by using the Moorland Map of England (ADAS 1993), supplemented by National Park Section 43/Section 3 maps and appropriate Environmentally Sensitive Area (ESA) data. We anticipate that all or most land over 600 metres will be included on the Moorland Map of England, but this will be checked by desk study against other available data sources.
Heath will be identified by using the relevant land cover classes within Phase 1 habitat survey, or equivalent classes within other data sources. Within Phase 1 habitat data there is no specific division between moor and heathland types, and thus some overlap is to be expected. Areas of naturally regenerating woodland or scrub encroaching onto heath may reasonably be included within the category of heath.
Down will be identified by using the relevant land cover classes within Phase 1 habitat survey, habitat inventory and Environmentally Sensitive Area mapping data sources, in conjunction with geological data. Areas of associated communities, such as unfenced scrub within natural or semi-natural calcareous grassland, may reasonably be included within the category of down. However, calcareous soils constituting dunes, base-rich wet meadows or areas on low-lying calcareous drift soils are likely to be excluded from the category of down.
Phase 2 Mapping
7. The Agency intends to use the working definitions and datasets described in this paper as the starting point for the second phase of its access mapping work - i.e testing and refining the mapping methodology developed by the GeoData Institute in two large test areas, and going on to produce consultation maps of access land in those two areas.
