My investigation is a study of hydrology, as I want to find out how and why a rivers channel, flow and valley characteristics change as you move downstream from its upper course to its mouth. These changes are represented in the Bradshaw Model (fig 1), a fluvial model that describes changes in the river channel and flow characteristics between different courses along the river. Based on three factors, it is possible to infer information about the processes of river erosion, transportation and deposition that occurs along the river. I will use the Bradshaw Model to compare the river at Holford Combe with the characteristics that you would expect to happen and what impact these characteristics have on the formation of landforms along the course of the river.
Fig 1: The Bradshaw Model
Holford Combe is located in the Quantock hills, North Somerset (Fig2). The Village of Holford is about 14 miles from Bridgwater, on the A39 and 6 miles (10 km) east of Williton. The village is mainly situated on the left of the A39 whilst on the right there is the village hall and cricket field. Holford has been an area of outstanding natural beauty (AONB) since 1956. It is also a Site of Special Scientific Interest (SSSI).
The name of the river is The Holford Combe River (Fig 4). It is 7km long and the source of the river is at Lady’s Fountain Spring, Frog Combe (Fig 5) (Fig 3) which is near Halsway. It is 250m above sea level, and the Mouth is at Kilve Pill. The river flows northward through Holford and kilve villages. The land is used for agriculture for example Pepperhill is a beef herd farm on the slopes of the Quantocks and Durborough is a hill farm, on the edge of Quantock Common, keeping mainly sheep. Fig 2: Ariel map of
North Somerset, UK
Fig 3: Source of the River Holford.
Fig 5: OS map of Holford
Why the river Holford?
The Holford Combe river is ideal for my study because the river is short (7km) long, so we would have been able to collect more data in the time we were there. Also you can get a better overview of the general trends in a rivers processes and landforms over its full course. We can be more certain of our conclusions about the pattern along the Holford Combe River and how closely they relate to the Bradshaw Model (fig 1).
The length is very important because we were only aloud two days outside of school lessons to complete the data collection. The being short meant we were able to walk the length of the river from source to mouth and not waste time from travelling to different sites. It’s a good site choice from a health and safety perspective (fig 6) as the river is not to wide or deep and being short as well. Also erosional processes haven’t had much time to act against the river channel, to make sure it didn’t make it dangerously deep or wide. The river was very accessible to us from school (only 47 miles, South west of Bristol), so it was very easy to get to and realistic and cost effective for the site there.
Fig 6: Risk Assessment
Risk assessments are important because then you know of any potential dangers of where you are going and to avoid any potential incidents and so you are prepared in an unlikely event of an accident. Bibliography
The websites I have used to get my information that i needed were: http://www.quantockonline.co.uk/quantocks/villages/holford/holford1.html http://en.wikipedia.org/wiki/River_Holford http://www.quantockhills.com/education/Qpedia/Topics/Place/People/Land-Use/Far