Departmental Research Projects
Accelerated Upland Erosion Following Recent Wildfire Damage, Northern Lake District
A research project of the Department of Geography.
Although the ecological effects of wildfires are understood for some environments in the UK, fires on steep mountainous terrain have not been investigated. Little is known about the hydrological and geomorphological consequences of such events in the UK. A large wildfire in Easter 2003 at Barrow Fell in the northern Lake District devastated more than 100 hectares of open moorland. Concerns about potential accelerated erosion, following the event prompted a field monitoring programme designed to investigate soil loss following the fire.
The aim of this project was to measure runoff and sediment dynamics in a recently burnt mountain catchment in the Northern Lake District.
Direct measurements of erosion were carried out at 18 sites on the mountain covering both disturbed areas (n = 13) and undisturbed sites (n= 5). This included a range of topographic settings (slope angles ranging between 15 and 32°) and different cover types. Monitoring was carried out between November 2003 and May 2005 and sediment traps were initially emptied every two weeks. Additional observations of local meteorological conditions, surface vegetation and soil characteristics were also made.
- Over the period of monitoring rates of soil loss were generally low but spatial and temporal variability was very marked
- As vegetation became more established erosion rates generally began to decline
- Local meteorological conditions particularly rainfall intensity, and also ground disturbance by frost action are important in conditioning the sediment yield
- An extreme event in January 2005 produced yields which were as great as the maximum yields observed in the first winter following the burn
It is concluded that although soil erosion rates following the burn are elevated, large scale severe soil loss did not occur and the area recovered well without the intervention of active management. The relative stability of the area (resistance to large scale erosion) relates to the simple slope geometry at Barrow Fell which does not greatly concentrate runoff into hollows. Furthermore, the intact surface crust had relatively low runoff rates (partly due to surface cracking) and was quickly revegetated in the aftermath of the fire.
For further information, please contact Professor Jeff Warburton.