Terrain sensitivity on high plateaux in the Scottish Highlands
Saved in:
| Title: | Terrain sensitivity on high plateaux in the Scottish Highlands |
|---|---|
| Authors: | Morrocco, Stefan M. |
| Summary: | Assessment of the sensitivity of high plateau terrain in the Scottish Highlands has been largely qualitative, thus hindering effective environmental management. This thesis (1) develops new quantitative methods to assess the mechanical sensitivity of high plateau geo-complexes; (2) produces a widely-applicable classification of terrain sensitivity; and (3) reconstructs past episodes of terrain disturbance. Measurement of terrain performance under stress was undertaken on ten widelydistributed high plateaux, covering five different lithologies. Statistical analyses reveal significant differences in shearing resistance (sensitivity) between and within different plant communities on all plateaux, and between some of the same communities on different plateaux due to differences in their species composition, proportional representation of dominant species, physiological condition and underlying soil types. Substrate strength measurements show large variability in the sensitivity of substrate to mechanical stress both within and between plateaux, with local controls, such as organic and moisture contents, grain-size variation and overburden pressure being most important, with no single dominant controlling factor. Assessment of the responses of different geo-complexes to footpath development on the western Mamores was employed to validate the use of measurements of vegetation and soil strength as proxy measures of sensitivity to physical stress. These tests have allowed the development of a terrain sensitivity classification based on the shear strength of the vegetation cover and the substrate. Terrain disturbance in the form of extensive aeolian reworking of vegetated sand sheets and aeolisols on some high plateaux is shown, by optically stimulated luminescence dating, to have occurred within the last 400 years or so, probably as a result of climatic deterioration during the Little Ice Age and possibly grazing pressure. These findings form a quantitative foundation for better informed management of sensitive high plateau areas. |
| URL: | https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.827883 |
| Database: | OpenDissertations |
| Abstract: | Assessment of the sensitivity of high plateau terrain in the Scottish Highlands has been largely qualitative, thus hindering effective environmental management. This thesis (1) develops new quantitative methods to assess the mechanical sensitivity of high plateau geo-complexes; (2) produces a widely-applicable classification of terrain sensitivity; and (3) reconstructs past episodes of terrain disturbance. Measurement of terrain performance under stress was undertaken on ten widelydistributed high plateaux, covering five different lithologies. Statistical analyses reveal significant differences in shearing resistance (sensitivity) between and within different plant communities on all plateaux, and between some of the same communities on different plateaux due to differences in their species composition, proportional representation of dominant species, physiological condition and underlying soil types. Substrate strength measurements show large variability in the sensitivity of substrate to mechanical stress both within and between plateaux, with local controls, such as organic and moisture contents, grain-size variation and overburden pressure being most important, with no single dominant controlling factor. Assessment of the responses of different geo-complexes to footpath development on the western Mamores was employed to validate the use of measurements of vegetation and soil strength as proxy measures of sensitivity to physical stress. These tests have allowed the development of a terrain sensitivity classification based on the shear strength of the vegetation cover and the substrate. Terrain disturbance in the form of extensive aeolian reworking of vegetated sand sheets and aeolisols on some high plateaux is shown, by optically stimulated luminescence dating, to have occurred within the last 400 years or so, probably as a result of climatic deterioration during the Little Ice Age and possibly grazing pressure. These findings form a quantitative foundation for better informed management of sensitive high plateau areas. |
|---|
