Tim Stott

A comparison of stream bank erosion processes on forested and moorland streams in the Balquhidder Catchments, central Scotland

Stream bank erosion rates measured over a two-year period on a moorland and a forested stream in the Institute of Hydrologys Balquhidder Paired Catchments in central Scotland were compared. Bank erosion rates are generally higher on the mainstream of the moorland catchment and highest in wintger on both streams. Bank erosion is correlated with the incidence of frost: minimum temperatures measured on stream banks of the forested stream were an average of 3·7°C higher than on stream banks both outside the forest and on the moorland stream. This makes the incidence of frost on forested stream banks half as frequent. Volumes of material eroded from the mainstreams were combined with bulk density measurements and it is estimated that erosion of the mainstream banks is contributing 1·5 and 7·3 per cent of the sediment yield of the forested and moorland catchments, respectively. Analysis of the vertical distribution of erosion on the banks of both streams suggests an undercutting mechanism which is more pronounced in the moorland stream. The influence of trees on bank erosion and possible implications for the management of forest streams are discussed.

Estimation of error in bankfull width comparisons from temporally sequenced raw and corrected aerial photographs

This study investigates the propagation of error through image-to-image comparison of 285 river bankfull width measurements of the Afon Trannon, mid-Wales. Bankfull width is quantified from both aerial photographs analysed as rectified images in ERDAS Imagine OrthoMax and raw images in Paintshop Pro. A method for the robust estimation of bankfull width measurement error through temporal sequences of scanned aerial photographs is presented and the improvement in accuracy achieved using rectified imagery is quantified. Results from this study are placed in the context of previously published rates of bankfull width change, from a wide range of river scales, and the bankfull change rates for robust medium-term analysis using approximately 1:10,000 historical aerial photography are identified.

Plantation forestry impacts on sediment yields and downstream channel dynamics in the UK: a review:

The impact of coniferous plantation forest on erosion and sediment yields in the UK uplands over the past three decades is reviewed by examining background or natural suspended sediment yields (SSY), bed load yields (BLY) and bank erosion and comparing with studies of‘disturbed’catchments. This paper collates all the UK studies that have monitored changes in erosion and sediment yields at the forest establishment, mature forest and timber harvesting phases of the forest cycle. A simple model based on this comprehensive examination of studies to date suggests that mean sediment yields increase at the initial ground disturbance phase, recover as the forest matures and increase again more significantly at the timber harvesting phase. The likely downstream impacts of these changes in sediment yields on channel dynamics and management is discussed, introducing sediment wave theory with particular reference to the generation of bed load waves downstream of forested catchments. Modelling of downstream changes in unit stream power has implications for the accumulation of nonpoint source sediment in sediment waves. Published studies in which channel changes have resulted from the passage of sediment waves are collated and it is concluded that the translating wave model is best supported. The paper concludes with a discussion of the broader implications for river management and presents advice for river managers.

Student Engagement Patterns over the Duration of Level 1 and Level 3 Geography Modules: Influences on Student Attendance, Performance and Use of Online Resources

Greater flexibility in delivery resulting from increased use of e-learning will inevitably change the way university students approach studying. Recent studies have examined relationships between attendance, online learning and performance but findings are inconclusive. One concern is that an unintended consequence of placing lecture resources online may be increased absenteeism possibly leading to decrease in performance. This study explores patterns of student engagement across two geography courses. Findings corroborate the importance of attendance as a predictor of performance, demonstrate how assessment influences study behaviour, particularly online, and provide evidence for a need for integrated blended learning designs.

Forestry effects on suspended sediment and bedload yields in the Balquhidder catchments, Central Scotland

Outputs of suspended sediment and bedload from the 7·7 km 2 moorland Monachyle basin and the 6·8 km 2 , 40%-forested Kirkton basin near Balquhidder, and inputs from tributary streams and mainstream bank erosion, are compared. Sediment yield is about three times higher in the forested basin and varies more sensitively with streamflow, suggesting greater availability of erodible sediment. The output is predominantly of suspended sediment and is derived mainly from tributary streams. Initial observations following partial moorland ploughing and forest clearfelling in 1986 indicate that erosion of timber loading areas and logging roads is the main sediment source.

Forestry effects on bedload yields in mountain streams

Abstract Bedload traps installed on headwater tributary streams in the Balquhidder catchments in central Scotland were operated over a 27-month period. Mean bedload yields measured in six forested tributaries ranged from 0.171 ± 0.103 to 25.259 ± 5.795 t km −2 yr −1 , with a mean of 9.321 ± 1.999 t km −2 yr −1 ( n = 86) and D 50 of 8 mm. In the paired moorland catchment, the range in mean bedload yield in three tributaries was from 0.901 ± 0.395 to 5.93 ± 1.645 t km −2 yr −1 with a mean of 2.869 ± 0.885 t km −2 yr −1 ( n = 36) and D 50 of 32 mm. This difference was statistically significant; bedload yields seem to increase in proportion to the area of the catchment under mature forest. Timber harvesting operations were associated with increases in bedload yields in two headwater streams but short trap records before and after forestry operations meant that changes were not statistically significant. Ploughing and drainage ditching of moorland caused tributary bedload yields to increase in one stream but to decrease in another; neither change, however, was statistically significant. Yields reported are generally lower than in other parts of upland Britain, though differences in measurement methods make direct comparisons difficult. Bedload makes up a relatively small proportion of the total sediment load at Balquhidder as compared with other studies in Ayrshire and mid-Wales. The dataset available from which to assess bedload yields in the British uplands is developing but further clarification of the delivery-ratio effect for bedload is needed from catchments with a wide range of geology, climate and catchment size.

Virtual Field Sites: Losses and Gains in Authenticity with Semantic Technologies.

The authors investigate the potential of semantic web technologies to enhance ‘Virtual Fieldwork’ resources and learning activities in the Geosciences. They consider the difficulties inherent in the concept of Virtual Fieldwork and how these might be reconciled with the desire to provide students with ‘authentic’ tools for knowledge construction evident in existing Virtual Field Sites. Following the progress in design and use of Virtual Field Sites in one UK university, the authors investigate how emerging technologies might produce a shift in thinking about the nature and role of Virtual Field Sites from being primarily visual representation tools to sites for the development of skills necessary in practice. This would represent the integration of such online tools into an expanding and evolving set of discourses and practices, rather than replacing or contributing to the loss of traditional disciplinary activities such as the collection by students of their own field data.

Stepping back to move forward? Exploring Outdoor Education students' fresher and graduate identities and their impact on employment destinations

This four-year mixed method longitudinal study utilises data collected from four cohorts of Outdoor Education (OE) students to compare ‘fresher’ and ‘graduate’ identities and to explore the impact of identity on graduate employment. Findings demonstrate that compared to other programmes, and the university as a whole, OE students had a very distinctive ‘fresher’ profile characterised by active pre-university engagement with the outdoor community of practice, clear vision of their future careers, and how university could contribute to their personal and professional development. Most OE students appear to maintain this strategic approach throughout the three years of their degree, which results, on one hand, in a relatively high employment rate, but on the other hand, in a limited engagement with other developmental opportunities that could enhance their employability if they had chosen a different career route.

SUSPENDED SEDIMENT DYNAMICS IN THE MORTERATSCH PRO-GLACIAL ZONE, BERNINA ALPS, SWITZERLAND

Abstract. Suspended sediment concentration (SSC) in the Ova da Morteratsch, Switzerland, measured during July 2007 was closely associated with discharge (Q) and showed statistically significant relationships at the p < 0.001 level at the proximal and distal ends of the 600 m pro‐glacial zone. SSC predicted from 10‐minute turbidity records gives a much more detailed insight into SSC fluctuations and identified SSC peaks which do not coincide with discharge peaks. Net (proximal – distal) 10‐minute suspended sediment loads (SSL) are predominantly positive (i.e. suspended sediment is being stored in the reach) for most of the 7–19 July 2007 record. Net (proximal – distal) SSLs correlate closely with discharge for the first part of the record (7–13 July) but from 14 to 19 July suspended sediment exhaustion is in evidence and discrete phases of negative net SSL (i.e. sediment flushing) are likely for up to six hours on three separate days which coincide with phases of high discharge and exhaustion of the glacial suspended sediment sources. Analysis of Q at the Berninabach–Pontresina gauging station (5 km downstream) for the past five years revealed that maximum monthly discharges capable of generating sediment flushing events occur in an average of four months each year. The study emphasises the rapid change in suspended sediment transport and yields with distance from the glacier snout and highlights the importance of measurements as close to the glacier snout as possible if data are to be representative of the glaciated land up‐valley. A better understanding of the processes of sediment exchange and the colonisation and stabilisation of sediment stores by vegetation in such pro‐glacial zones is essential if we are to improve predictions of the impacts of climate change on river sediment dynamics and the subsequent effects on aquatic ecology.

Study goals and procrastination tendencies at different stages of the undergraduate degree

Study goals and effective management of study time are both linked to academic success for undergraduates. Mastery goals in particular are associated with study enjoyment and positive educational outcomes such as conceptual change. Conversely, poor self-regulation, in the form of procrastination, is linked to a range of negative study behaviours. Many researchers have treated goal orientations and procrastination tendency as stable traits and few have examined differences across academic levels. This study reports a cross-sectional measure of study goal orientation and procrastination tendency profiles at different academic levels on two undergraduate programmes. Findings concur with other studies in revealing a significant decline in mastery goals, particularly between the first and second years of study. Procrastination tendency is significantly higher in the second year. Potential causes of these differences and their implications are discussed, alongside considerations for positive learning environments.