Article Title: Hillslope gullying in the Solway
Firth - Morecambe Bay region, Great Britain: Responses to
human impact and/or climatic deterioration?
Authors: Chiverrell,
RC;Harvey, AM;Foster, GC
Journal: GEOMORPHOLOGY
Volume: 84
Issue: 3-4
Page: 317-343
Year: FEB 28 2007
* Univ Liverpool, Dept Geog, Roxby Bldg, Liverpool L69 3BX,
Merseyside, England.
* Univ Liverpool, Dept Geog, Liverpool L69 7ZT, Merseyside,
England.
Why do you think your paper is highly cited, and
would you summarize the significance of your paper in layman's
terms?
The paper examines an issue identified in the geomorphological development
of upland northwest Britain, in which there appears to have been a
significant increase in hillslope instability in the last 3,000 years. The
paper presents new data that place this interpretation on a firmer
chronological footing, through the wider application of radiocarbon dating
to the alluvial fan sediments that have accumulated at the base of
hillslope gully networks.
These radiocarbon ages constrain these episodes of instability to four
300-200-year-duration phases after 2,500–2,200, 1,300–1,000,
1,000–800 and 500 years ago. This instability is strongly linked to
the lowering of landscape erosion thresholds due to increases in
human-mediated land pressure (agriculture). Nevertheless, high magnitude
rainfall events (storms) are the mechanism for gully inception.
"Wider implications of this work
stem largely from the importance of land-use
in conditioning the geomorphological regime
and sediment flux from upland
regimes."
The paper has significance perhaps in that it expands the database upon
which these findings are based and refines the previous work both in the
region and on this topic. The paper also draws together paleoecological
data that show how land-cover (vegetation) and climatic wetness have varied
during this time period in order to better understand the factors
responsible for landscape instability in upland UK during the last 3,000
years.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
This paper presents new data, as well as refining the existing body of
knowledge and it also presents a synthesis of available data for the
uplands of northwest England and southwest Scotland.
How did you become involved in this research, and were
there any problems along the way?
Originally, this work commenced owing to collaboration with
Prof. Adrian Harvey of the University of Liverpool,
who had been engaged in this type of research since the 1980's. The
process of combining his geomorphological interests with my background,
then in paleoecology—the use of pollen records to understand
changes vegetation cover and the mire surface wetness indications
preserved in peat deposits—coupled with a NERC-funded program of
radiocarbon dating, led to the advances in our understanding presented
in this paper.
Where do you see your research leading in the
future?
I have continued to refine this work expanding the database of radiocarbon
dated alluvial fan/gully locations. I also changed focus in order to
examine the connectivity between hillslope instability and process response
in down-system lake basins and rivers. In essence, this focuses on the
landform (geomorphological) response of rivers and lake basins to increases
and declines in sediment supply. This has led to a series of papers
published in Earth Surface Processes and Landforms, The
Holocene, and Catena.
These are as follows: Chiverrell, R.C., et al., "Late Holocene
environmental change in the Howgill Fells," Northwest England
Geomorphology 100, 41-69, 2008; Chiverrell, R.C., et al.,
"Evidence for changes in Holocene sediment flux in Semer Water and Raydale,
North Yorkshire, UK," Geomorphology 100, 70-82, 2008; Chiverrell,
R.C., et al., "Robust chronologies for landform development in
fluvial environments," Earth Surface Processes and Landforms,
2008; Foster, G.C., et al., "Catchment hydro-geomorphological
responses to environmental change in the Southern Uplands of Scotland"
The Holocene 18, 935-50, 2008; Foster GC, .et al.,
"Fluvial development and the sediment regime of the lower Calder, Ribble
catchment, northwest England" Catena, 2008; Shen, Z.X., et
al., "Holocene environmental reconstruction of sediment-source
linkages at Crummock Water, English Lake District, based on magnetic
measurements" The Holocene 18, 129–40, 2008.
Do you foresee any social or political implications for
your research?
Wider implications of this work stem largely from the importance of
land-use in conditioning the geomorphological regime and sediment flux from
upland regimes. Given the trajectories for land-use change implicit in UK
Government and European Agricultural Policies, an awareness of the
implications of reducing or increasing grazing pressure in the uplands of
temperate regions is important, particularly given the increased weight
placed on stewardship in the rural land management of conserved landscapes
(e.g., national parks and other areas of outstanding natural beauty).
Dr. Richard C. Chiverrell
University of Liverpool
Department of Geography
Liverpool, UK Web