A HYDROLOGICAL INVESTIGATION OF THREE DEVON SAND DUNE SYSTEMS; BRAUNTON BURROWS, NORTHAM BURROWS AND DAWLISH WARREN
type: CreativeWork
description: In 1993 concerns were expressed by English Nature that Devon's three largest sand dune systems Braunton Burrows, Northam Burrows and Dawlish Warren were drying out to the detriment of the dune habitat flora and fauna. Research was therefore required to understand how these systems functioned hydrologically, to determine whether they were drying out and if so to recommend sustainable management options aimed at reinstating former water levels, or preventing any further lowering of the water tables. At Braunton water table elevations have been monitored on a monthly basis by the Nature Conservancy, the Nature Conservancy Council and English Nature since 1972. These data were invaluable in describing the spatial and temporal hydrological characteristics and functioning of the groundwater system. Braunton Burrows was the main study site of the research. At both Northam and Dawlish, at the start of the fieldwork programme a dipwell monitoring network was installed and water table elevations were recorded weekly. Hydrological characteristics of each dune system were related to temporal variability in effective precipitation, the tide, the underlying geology and sediment properties. The groundwater system at Braunton was mounded, with effective inputs accumulating over an impermeable basal layer close to mean sea level. The system was very sensitive to seasonal variability in effective precipitation. At the centre of the groundwater mound, during the winter months, the elevation of the water table was 10 m above OD. The groundwater mound was asymmetric, with the highest water table elevations occurring along the eastern margin of the system. The transitional zone from dune sands to marshland, of a lower permeability, was restricting the inland lateral drainage regime and was controlling both the shape and elevation of the water table. At Northam the groundwater system was also mounded and again the shape and elevation of the water table were dependent upon effective precip…
abstract: In 1993 concerns were expressed by English Nature that Devon's three largest sand dune systems Braunton Burrows, Northam Burrows and Dawlish Warren were drying out to the detriment of the dune habitat flora and fauna. Research was therefore required to understand how these systems functioned hydrologically, to determine whether they were drying out and if so to recommend sustainable management options aimed at reinstating former water levels, or preventing any further lowering of the water tables. At Braunton water table elevations have been monitored on a monthly basis by the Nature Conservancy, the Nature Conservancy Council and English Nature since 1972. These data were invaluable in describing the spatial and temporal hydrological characteristics and functioning of the groundwater system. Braunton Burrows was the main study site of the research. At both Northam and Dawlish, at the start of the fieldwork programme a dipwell monitoring network was installed and water table elevations were recorded weekly. Hydrological characteristics of each dune system were related to temporal variability in effective precipitation, the tide, the underlying geology and sediment properties. The groundwater system at Braunton was mounded, with effective inputs accumulating over an impermeable basal layer close to mean sea level. The system was very sensitive to seasonal variability in effective precipitation. At the centre of the groundwater mound, during the winter months, the elevation of the water table was 10 m above OD. The groundwater mound was asymmetric, with the highest water table elevations occurring along the eastern margin of the system. The transitional zone from dune sands to marshland, of a lower permeability, was restricting the inland lateral drainage regime and was controlling both the shape and elevation of the water table. At Northam the groundwater system was also mounded and again the shape and elevation of the water table were dependent upon effective precip…
author: BURDEN, RACHEL JANE
language: eng
date published: 1998-01-01T08:00:00Z
date modified: 2026-07-24T03:49:27Z
provider: University of Plymouth
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Plymouth