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Geomorphology Project Ideas
Glacier reconstruction in Cwm Llydaw and Cwm Dyli, Snowdonia, North Wales
An assessment of the effectiveness of river restoration works, River Crane, West London
Palaeo-environmental reconstruction of fluvioglacial sediments in Glen Brittle, Isle of Skye
Palaeo-environmental reconstruction of Craig cerrig-gleisiad, Brecon Beacons, mid-Wales
A study of the geomorphology and sedimentology of point bars along a lowland meandering river
A comparison of (lowland) pool-riffle and (upland) step-pool channels
The effects of reservoirs on river systems
Glacier reconstruction in Cwm Llydaw and Cwm Dyli, Snowdonia, North Wales
The mapping of glacial limits using erosional (e.g. glacial striae) and depositional evidence (e.g. moraines) can reveal detail about ice thickness, extent and direction of flow. The cwms of Snowdonia were last occupied by Younger Dryas (Loch Lomond) Stadial glaciers, and dated between 11-11 ka BP. However, there has been much debate over the actual extent of the glaciers in Cwm Llydaw and Cwm Dyli. This project re-assesses the glacial limits mapped by Gray (1992) and Addison (1987) and evaluates which is most likely to be correct. As part of the project you will reconstruct the form and shape of the glacier and, by comparing with present-day valley glaciers, calculate its Equilibrium Line Altitude (the line separating the zones of accumulation and ablation on a glacier) and the palaeotemperature.
Addison K (1997) Classic Glacial Landforms of Snowdonia. Geographical Association (Sheffield).
Addison K, Edge MJ and Watkins R (eds.) (1990) North Wales Field Guide. Quaternary Research Association (Coventry).
Gray JM (1982) The last glaciers (Loch Lomond Advance) in Snowdonia, North Wales. Geological Journal, 17, 111-133.
Sissons JB (1974) A late-glacial ice cap in the central Grampians, Scotland. Transactions of the Institute of British Geographers, 62, 95-114.
Sissons JB (1979) Palaeoclimatic inferences from former glaciers in Scotland and the Lake District. Nature, 278, 518-521.
Reconstruction of the palaeo-environmental history of a peat bog, Clogwyngarreg, Snowdonia, North Wales
Lake sediments frequently contain a history of deposition spanning many thousands of years. They are an ideal medium for preserving a range of micro- and macrofossils (e.g. pollen, larger plants, algal and insect remains). Fossil pollen and plants tell us about the vegetation that once grew in the lake and within the surrounding landscape. The aquatic flora and fauna (diatoms, invertebrates, etc.) provide information on the past status of the lake ecosystem itself and how it has changed over time. These sources provide a proxy (indirect) record of the climatic conditions that existed at the time the sediments were laid down. The type and character of the sediment that accumulates at the bottom of a lake also provides valuable palaeo-environmental information. Using a Russian corer to retrieve sediment sections down through 6-8 metres of peat bog (an infilled lake), followed by sediment description and microscope work to study the pollen preserved in the sediment, it is possible to study how climate has changed over possibly 10-15,000 years, during and even prior to the last stadial (the Younger Dryas or Loch Lomond). This will allow you to work out how the climate changed, when woodland developed, and possibly identify anthropogenic impacts on the lake from e.g. the Mesolithic period.
Ince J (1983) Two postglacial pollen profiles from the uplands of Snowdonia, Gwynedd, North Wales. New Phytologist, 95, 159-172.
Ince J (1996) Late-glacial and early Holocene vegetation of Snowdonia. New Phytologist, 132, 343-353.
Moore PD and Webb JA (1978) An Illustrated Guide to Pollen Analysis. Hodder and Stoughton (London).
An assessment of the effectiveness of river restoration works, River Crane, West London
In recent decades it has been acknowledged that river training (e.g. channelisation) has detrimental effects on the geomorphology and ecology of rivers. In recent years, there has been a shift towards the rehabilitation and restoration of rivers to a semi-natural state and to improve ecological habitats by working in combination with natural processes. One such river restoration scheme has been undertaken recently along the River Crane between Hounslow and Twickenham in west London. The placement of arcuate boulder berms at angles on alternate banks was designed to promote meandering within the confines of a channelised reach. This project maps the changes in erosion and deposition along the reach produced by “soft” river engineering measures. Particular attention is paid to the rates and distribution of sedimentation behind the berms, and also the invertebrates and wildlife along the reach, in order to evaluate the success of the scheme.
Brookes A (1995) River channel restoration: theory and practice. In: Gurnell, A. & Petts, G. (eds.). Changing River Channels. Wiley (Chichester), ch.17, pp.369-388.
De Waal L, Wade M and Large A (eds.) (1998) Rehabilitation of Rivers: Principles and Implementation. Wiley (Chichester).
Palaeo-environmental reconstruction of fluvioglacial sediments in Glen Brittle, Isle of Skye
A reconstruction of the environment of deposition of sediments laid down along the valley bottom, close to sea-level, of Glen Brittle will be undertaken by sedimentary logging and particle size analysis. The history of these fluvioglacial sediments, laid down in a proglacial environment, will be undertaken. For instance, it may be possible to document the advance or retreat of the Younger Dryas glacier that occupied the nearby Coire Lagan 11-10 ka BP by studying changes in particle size and shape through the sediment profile. Palaeodischarge estimates may also be possible. Finally, the relationship with the raised beach nearby, and glacio-isostatic changes, will also be considered.
Briggs D (1977) Sediments. Butterworths (London).
Gale SJ and Hoare PG (1991) Quaternary Sediments. Belhaven (New York). Ch.4, pp.56-101.
Lewis DW and McConchie D (1994) Analytical Sedimentology. Chapman & Hall (London). Ch.7, ‘Textures’, pp.92-129.
Lindholm R (1987) A Practical Approach to Sedimentology. Allen & Unwin (London). Chs. 5, 7 and 11, pp. 107-123; 154-183; 235-259.
Tucker M (1982) The Field Description of Sedimentary Rocks. Geol. Soc. Lond. Handbook, Wiley (Chichester). Chs.2 and 4, pp.11-18; 36-43.
Palaeo-environmental reconstruction of Craig cerrig-gleisiad, Brecon Beacons, mid-Wales
The cwm of Craig cerrig-gleisiad contains a diverse range of geomorphological features, including glacial moraines, peat bogs, meltwater channels, landslide deposits and scree slopes. Geomorphological mapping, both by field-walking and by using aerial photographs, of the distribution and extent of these features can provide valuable information for the palaeoenvironmental reconstruction of this complex site. Consideration will also be made of the continuing debate of the formation of mounds in many cwms in the Brecon Beacons: are they protalus ramparts (of periglacial origin) or are they moraines (of glacial origin)?
Campbell S and Bowen DQ (1989) The Quaternary of Wales. Geological Conservation Review Series, Nature Conservancy Council.
Ellis-Gruffydd ID (1977) Late Devensian glaciation in the Upper Usk Basin. Cambria, 4(1), 46-55.
Lewis CA (1970) The glaciations of the Brecknock Beacons, Wales. Brycheiniog, 14, 97-120.
Shakesby R (1992) Classic Landforms of the Brecon Beacons. Classic Landform Guides, no.13, The Geographical Association (Sheffield).
Thomas TM (1959) The geomorphology of Brecknock. Brycheiniog, 5, 55-156.
Channel change along a meandering river: the River Severn
The study of channel migration of meandering rivers is particularly important for buildings on floodplains and flood defence levees. Using tithe maps, different editions of OS maps and aerial photographs it is possible to document channel changes along a reach of a meandering river. In addition to identifying the types of channel change (e.g. expanding, translation, etc.) and rates of channel bank erosion over time, it is also possible to estimate sediment volumes eroded or accreted. This can be supported by lithological mapping and analysis of the channel bank and point bar deposits along the reach.
Hooke JM (1977) The distribution and nature of changes in river channel patterns. The example of Devon. In: Gregory KJ (ed.) River Channel Changes, 265-280. 551.483 GRE
Hooke JM (1984) Changes in river meanders: a review of techniques and results of analysis. Progress in Physical Geography, 8, 473-508.
Hooke JM (1993) Processes of channel planform change on meandering channels in the UK. In: Gurnell A and Petts G (eds.) Changing River Channels. Wiley (Chichester), ch.5, pp.87-115. 551.48 GUR
7. A study of the geomorphology and sedimentology of point bars along a lowland meandering river
Undertake a detailed geomorphological study of the morphology and sediments of a series of point bars along a meandering river (such as the River Severn, Exe or Usk). You will carry out surveying using a surveyor’s level or theodolite to produce a detailed topography map onto which you produce an overlay map of particle size distribution, floodwater depths and flow directions. This will allow you to model the processes operating. Comparison between different point bars as you go downstream can also be done.
Knighton D (1998) Fluvial Form and Processes. 2nd edition, Arnold (London).
A comparison of (lowland) pool-riffle and (upland) step-pool channels
Erosion-deposition units are fundamental features of all river channels, but their nature differs according to the environment. The substrate type, channel gradient, channel load and water discharge seem to be the main determining factors in determining the morphology and spacing of these units. For instance, steep, upland rivers flowing over bedrock are characterised by step-pool units, whilst low gradient, meandering lowland rivers have pool-riffle units. This project considers the factors influencing their formation and allows direct comparison of contrasting environments.
Knighton D (1998) Fluvial Form and Processes. 2nd edition, Arnold (London).
The effects of reservoirs on river systems
Reservoirs have major hydrological, geomorphological, sedimentological and ecological effects on river systems. A wide literature exists on this subject. Using a paired catchment approach (i.e. comparing an unimpacted neighbouring stream with the study river), you will study the cross-sectional shape of the channel and the channel sediments downstream. Alternatively you could look at water quality aspects by undertaking downstream sampling of invertebrates above and below the reservoir or in adjoining catchments.
Gregory KJ and Park C (1974) Adjustment of river channel capacity downstream from a reservoir. Water Resources Research, 10(4), 870-873.
Petts GE (1977) Channel response to flow regulation: the case of the River Derwent, Derbyshire. In: Gregory KJ (ed.) River Channel Changes. 145-164.
Petts GE (1979) Complex response of river channel morphology subsequent to reservoir construction. Progress in Physical Geography, 3, 329-362.
Petts GE (1984) Impounded Rivers: Perspectives for Ecological Management. Wiley (Chichester).
Petts GE (1984) Sedimentation within a regulated river. Earth Surface Processes and Landforms, 125-134.
Petts GE (1986) Water quality characteristics of regulated rivers. Progress in Physical Geography, 10(4), 492-516.
Petts GE and Lewin J (1979) Physical effects of reservoirs on river systems. In: Hollis GE (ed.) Man's Impact on the Hydrological Cycle in the United Kingdom. GeoBooks, ch.8.
