Gregory, K.J. (ed.). 1997. Fluvial Geomorphology of Great Britain. Geological Conservation Review Series, No. 13, JNCC, Peterborough, ISBN 0 412 78930 2.

The original source material for these web pages has been made available by the JNCC under the Open Government Licence 3.0. Full details in the JNCC Open Data Policy

Figures

(Figure 1.1) (a) Annual precipitation for the whole of Britain (after Ward, 1981). (b) The discharge ratio for the whole of Britain (after Ward, 1981).

(Figure 1.2) The original drainage pattern for England and Wales as initiated by Early Tertiary uplift of the late Cretaceous sea floor (Brown, 1960), and the initial watersheds and initial drainage of Scotland (after Sissons, 1967).

(Figure 1.3) Rainfall magnitude-duration relationships for the world and the UK. The largest falls (from Rodda, 1970) and magnitude-duration relationships of geomorphologically significant UK floods, where known, are given.

(Figure 1.4) (a) The sequence of environmental and palaeohydrological change in the Severn basin (after Gregory and Lewin, 1987). (b) The sequence of palaeohydrological changes in the Severn basin (after Gregory and Lewin, 1987).

(Figure 1.5) (a) An idealized section showing the relationship between river profile, channel materials and channel pattern. (After Smith and Lyle, 1979.) (b) Map showing 'surveyed' rivers in Great Britain. (After Smith and Lyle, 1979.)

(Figure 1.6) A map of England and Wales showing rivers channelized, 1930–80. (After Brookes, et al., 1983.)

(Figure 1.7) A map of Great Britain showing the classification of GCR fluvial geomorphology sites. See also (Table 1.1).

(Figure 2.1) Mean annual flood scaled by drainage area for Scottish rivers.

(Figure 2.2) Drainage prior to the glacial stages of the Pleistocene. (After Sissons, 1967.)

(Figure 2.3) An idealized downstream sequence of bar types in a gravel-bed river. (After Bluck, 1976.)

(Figure 2.4) The distinction between 'robust' and 'responsive' behaviour and the two types of geomorphic threshold. A,C: Robust behaviour — the river repeatedly crosses intrinsic thresholds, but the overall response is stable within limiting thresholds; negative feedback regulates change; landforms retain stable identity as they form and reform. B: Responsive behaviour–in response to externally imposed change, the river moves across the extrinsic threshold to a new process regime; landforms in original regime A are destroyed and replaced by new landforms created in regime C. (After Werritty and Brazier, 1994.)

(Figure 2.5) The fluvial geomorphology sites selected for the GCR in Scotland. Sites are as numbered in (Table 2.1), together with four sites featured in (Table 2.2): 25 Allt Coire Gabhail; 26 Findhorn Terraces; 27 North Esk and West Water palaeochannels; and 28 Glen Roy, Glen Spean and Glen Gloy.

(Figure 2.6) The Falls of Measach on the River Droma in Corrieshalloch Gorge. The character of the slot-gorge is evident from the near vertical walls, the very steep gradient and the cascading nature of the water flow. (Photo: L.J. McEwen.)

(Figure 2.7) The flood stage on 4 August 1829 on the River Findhorn at Randolph's Leap. The river rose 15 m above its normal level at the entrance to this severely constricted bedrock gorge. (Source: Lauder, 1830.)

(Figure 2.8) The River Findhorn at Randolph's Leap: the inner channel cuts into schist, displaying polished bedrock surfaces, potholes and bedrock ribs. (Photo: A. Werritty.)

(Figure 2.9) General view of the Falls of Dochart. (Photo: A. Werritty.)

(Figure 2.10) The Grey Mare's Tail in Moffatdale. (a) The Tail Burn descends from the plateau via a 200 m high waterfall in a series of cascades and plunge pools (photo: A. Werritty). (b) Detail of the first cascade and plunge pool on Tail Burn, showing the impact of the more resistant gritty conglomerates (cascade), the less resistant shales and the mudstone beds (plunge pool) on the detailed morphology of the waterfall (photo: A. Werritty).

(Figure 2.11) River Clyde meanders. The channel (April 1991) is shown along with the floodplain sediments and landforms worked by the River Clyde and Medwin Water since 1848. Palaeochannels are now partly filled, but can still be identified on the floodplain surface. This site at present comprises six major meanders on the River Clyde and five smaller meanders on the Medwin Water. The Clyde meanders within the site extend over 3.2 km and include bends at various stages of development from gently curved to highly tortuous with incipient cutoffs. The, meanders on the Medwin Water are, by contrast, much smaller in scale (channel widths typically <10 m) but display patterns of development similar to those on the Clyde. (After Brazier et al., 1993.)

(Figure 2.12) River Clyde meanders: the progressive migration of meander bends since 1848 based on mapped positions of the active channel in 1848, 1858, 1909 and 1977. Note the downstream migration of most bends, and cutoffs to form oxbow lakes. (After Brazier et al., 1993.)

(Figure 2.13) Irregular meanders developed on the River Glass. The channel is characterized by a sequence of irregular meanders and associated slackwater areas plus numerous palaeochannels of contrasting ages embedded within the floodplain. (Photo: Royal Commission on the Ancient and Historical Monuments of Scotland; print 4188, 61489; flown May 1989: Crown Copyright.)

(Figure 2.14) The River Glass in Strathglass: a comparison of the planforms in 1876 and 1901. Channel stability increases in the downstream direction. A number of abandoned channels and infilled palaeochannels occupy the floodplain. (Source: First and Second Edition 1 : 10 560 scale Ordnance Survey maps.)

(Figure 2.15) A well-developed meander bend and point bar on the Abhainn an t-Srath Chuileannaich. (Photo: W. McEwen.)

(Figure 2.16) Abhainn an t-Srath Chuileannaich. Changing channel patterns mapped in successive editions of Ordnance Survey large-scale maps: the first edition survey of 1875, the second edition resurvey of 1903, and the metric edition survey of 1971.

(Figure 2.17) Endrick Water: a geomorphological map of point bars, overbank sedimentation, point bar scrolls, oxbow lakes and palaeochannels. (Based on 1988 aerial photographs.)

(Figure 2.18) A recent meander cutoff on the Endrick Water (October 1983). The abandoned channel has been plugged by sediment at the downstream end (A). The neck of the former floodplain (B) is now a riffle between a point bar (C) and a concave bench (D). (Photo: Royal Commission on the Ancient and Historical Monuments of Scotland; print 048, 514 88; flown June 1988: Crown Copyright.)

(Figure 2.19) Deny Burn: a downstream reach displaying tortuous meanders and numerous abandoned channels. The alluvial basin is terminated by a bedrock control (to the bottom left of the photograph). (Photo: Royal Commission on the Ancient and Historical Monuments of Scotland; print 4188, 106G/SCOT/UK/58: Crown Copyright.)

(Figure 2.20) The River Balvag delta: a narrow spit-shaped delta prograding into Loch Lubnaig (to the bottom of the picture) with upstream strathlochans in various stages of development. (Photo: Royal Commission on the Ancient and Historical Monuments of Scotland; print 018, 51188; flown June 1988: Crown Copyright.)

(Figure 2.21) The tree-lined channel of the River Balvag and the delta prograding into Loch Lubnaig: (Photo: U. McEwen.)

(Figure 2.22) The geomorphology of the Lower Spey.

(Figure 2.23) The dissected diagonal bar within the highly-active braided channel of the lower River Spey. Many of the smaller-scale sedimentological features (chutes incised within the bar and marginal sand sheets) are very ephemeral, being formed and destroyed by successive floods. (Photo: U. McEwen.)

(Figure 2.24) The drainage basin of the River Feshie, with sites referred to in the text. A, Allt Garbhlach alluvial fan and river terraces; B, Allt Lorgaidh alluvial fan; C, Upper Glen Feshie debris cones; D, River Feshie upper braided reach; E, River Feshie lower braided reach; F, River Feshie confluence alluvial fan.

(Figure 2.25) The geomorphology of the Allt Garbhlach–Allt Fhearnagan area of Glen Feshie. (From Robertson-Rintoul, 1986a; Werritty and Brazier, 1991a.)

(Figure 2.26) The upper braided reach in Glen Feshie. The Allt Lorgaidh descends from the Gaick plateau across a terraced alluvial fan (A). The 2 km long braided reach of the River Feshie (B) is the most active section of a gravel-bed river in Britain. (Photo: Cambridge University Collection AGJ 36 (23/7/62): Copyright Cambridge University.)

(Figure 2.27) (a) The surveyed section across the base of the Glen Feshie debris cones, showing boundaries between individual debris flow units. (b) Detailed sections at sampling sites 1-4. (After Brazier and Ballantyne, 1989.)

(Figure 2.28) The upper braided reach, 1869–1971. Changing channel patterns mapped in successive editions of Ordnance Survey large-scale maps: (a) First edition survey, 1869; (b) Second edition resurvey, 1899; (c) Metric edition survey, 1971. (After Werritty and Ferguson, 1981.)

(Figure 2.29) The geomorphology of the confluence of the River Feshie with the River Spey: based on aerial photograph of July 1991. (After Werritty and Brazier, 1991b.)

(Figure 2.30) Allt Dubhaig from its emergence from hummocky moraine to its diversion into Loch Garry. The distances recorded provide reference points for features reported in the text. (After Ferguson et al., 1996.)

(Figure 2.31) (a) Upper Allt Dubhaig, illustrating the character of the near-braided channel (A), a meandering channel with active point bars (B) and palaeochannels on the adjacent floodplain (C). (b) Lower Allt Dubhaig, illustrating the character of the stable sinuous channel (A) with fixed point bars (B), levees (C) and flood basins (D). (Photos: A. Werritty.)

(Figure 2.32) (a) Long profile of Allt Dubhaig. (b) Downstream fining on the Allt Dubhaig for D50 and D84.

(Figure 2.33) Dorback Burn: a small wandering gravel-bed river in which an actively braided channel is reworking the valley floor. (Photo: Royal Commission on the Ancient and Historical Monuments of Scotland; F 22543/RAF/1428; flown August 1961: Crown Copyright.)

(Figure 2.34) Dorback Burn: the highly divided sandur-like channel in October 1978 following the flood of 4 July 1978, contrasted with the simpler channel pattern in May, 1979. (After Werritty, 1984.)

(Figure 2.35) A geomorphological map of Glen Coe: slope forms below the Aonach Eagach ridge, including the Chancellor debris cone (1), the Coire nan Lochan fan (2), and the, River Coe valley floor (3). (After Brazier, 1987.)

(Figure 2.36) Glen Coe: changing channel planforms for 1875 and 1988 of the River Coe. The composite diagram indicates the location of the main channel at different dates between 1875 and 1988. (After McEwen, 1994b.)

(Figure 2.37) Luibeg Burn. (a) Bouldery flood deposits (0.5–1.0 m b axes) reworked in the 1956 flood (flow direction towards camera). (b) A detail of the flood deposits, showing imbrication — flow direction right to left. (Photos: A. Werritty.)

(Figure 2.38) Allt Mor (River Nairn). (a) The upper reach, boulder-bed mountain torrent, highly divided flow around unstable bars. (b) The lower reach, stable sinuous channel in Strath Nairn. The two reaches are only 2 km apart, illustrating the 'discordance' and rapid change in channel morphology. (Photos: L J. McEwen.)

(Figure 2.39) The geomorphology of the Allt Mor (River Nairn).

(Figure 2.40) The Lost Valley. (a) A general view of the alluviated valley surrounded by talus slopes: note the highly divided channel planform on the valley floor. (b) The major rock slope failure which has piled up as a talus cone, blocking the mouth of the alluviated valley. (Photos: A. Werritty.)

(Figure 2.41) The geomorphology of the Allt Coire Gabhail (The Lost Valley).

(Figure 2.42) Allt Mor (River Druie) maps, showing the location of the catchment and general characteristics. (a) The location of the site; (b) the lower reaches of Allt Mor; (c) the topography; (d) the solid and drift geology. (After McEwen and Werritty, 1988.)

(Figure 2.43) The Allt Mor channel immediately upstream of the Coronation Bridge, 24 hours after the 3 August 1978 flash flood. (Photo: R.I. Ferguson.)

(Figure 2.44) The Quoich Water alluvial fan. The currently unstable braided channel has been recently dredged. Palaeochannels from the 1829 flood are well developed on the fan surface to the left of the active channel. (Photo: A. Werritty.)

(Figure 2.45) A geomorphological map of Allt a' Choire.

(Figure 2.46) Allt a' Choire. (a) Actively gullied and deeply dissected till in the eastern headwater. (b) An alluvial fan with three distinct surfaces to the left of the currently active channel which flows into the River Findhorn. (Photos: A. Werritty.)

(Figure 2.47) The geomorphology of Allt Coire Chailein.

(Figure 2.48) The Allt Coire Chailein alluvial fan: the section eroded by the currently active channel on the eastern side of the fan. Coarse fluvial deposits are visible at the base of the section, with stratified organics and debris flow deposits above. (Photo: A. Werritty.)

(Figure 2.49) (a) A schematic section along the length of Eas na Broige debris cone. (b) A detail of the section at the sampling sites (after Brazier et al., 1988).

(Figure 2.50) Oldhamstocks Burn. Active gullies producing 'badland' topography in Yearn Hope valley. (Photo: A Werritty.)

(Figure 2.51) The Findhorn terraces at Ballachrochin (British Geological Survey photograph C1415, reproduced by permission of the Director, British Geological Survey. © NERC. All rights reserved).

(Figure 2.52) The terraces of the River North Esk and West Water in the Edzell area. (After Maizels, 1983a.)

(Figure 2.53) The Parallel Roads of Lochaber. T, M, B and G identify the final positions of the ice-fronts damming the 355 m, 325 m, 260 m and Glen Gloy lakes respectively. (After Peacock and Cornish, 1989.)

(Figure 2.54) The landforms and deposits of the Treig–Laggan area. (After Sissons 1977b; Peacock and Cornish, 1989.)

(Figure 2.55) The geomorphology of the northern part of upper Glen Roy. (After Sissons and Cornish, 1983.)

(Figure 2.56) The fans and river terraces of the southern part of upper Glen Roy. (After Sissons and Cornish, 1983.)

(Figure 2.57) The geomorphology of the Spean Bridge–Gairlochy area: see the text for an explanation of the letters. (After Sissons, 1979c.)

(Figure 2.58) The Loch Lomond Readvance ice limits and associated ice-dammed lakes in the Glen Roy–Glen Spean area. (After Sissons, 1981b.)

(Figure 3.1) The Pleistocene legacy in upland geomorphology: block diagram showing typical slope and valley morphology and deposits. Fluvial activity is seen as superimposed on the morphology and deposits of glaciation and periglaciation. (After Lewin, 1981.)

(Figure 3.2) At this GCR site, there is an assemblage of characteristic fluvial landforms within a small area, representing the response of the Afon Llugwy to the headward extension of the River Conway, associated with glacial deepening. (Photo: S. Campbell.)

(Figure 3.3) The Afon Uugwy: capture of the proto-Dee by the Afon Conwy.

(Figure 3.4) Pistyll Rhaeadr. With a drop of 75 m from a sandstone precipice, this waterfall is the highest in Wales. (Photo: S. Campbell.)

(Figure 3.5) A section through Pistyll Rhaeadr, at [SJ 073 295].

(Figure 3.6) A steep-sided gorge section of the Afon Cynfal. (Photo: S. Campbell.)

(Figure 3.7) The Afon Twymyn: drainage changes near Dylife.

(Figure 3.8) Steep-gradient rapids on the Afon Glaslyn. (Photo: S. Campbell.)

(Figure 3.9) The lower Teifi Valley and the overflow channels of the.Teifi lakes. (After O.T. Jones, 1965.) 1964).

(Figure 3.10) A narrow incised section of the Afon Teifi. (Photo: S. Campbell.)

(Figure 3.11) The Afon Teifi: a geological map of the area around Cenarth. (After O.T. Jones, 1965.)

(Figure 3.12) General view of the River Dee at Llangollen. (Photo: S. Campbell.)

(Figure 3.13) A diagrammatic geological map of the neighbourhood of Ystradfellte. The 'solid' rock outcrops are shown. They are largely and irregularly covered by superficial deposits.

(Figure 3.14) The disappearance and reappearance of the Afon Hepste near Penderyn.

(Figure 3.15) Sequential diagrams illustrating stages in the formation of Scwd-yr-Eira. This fall owes its origin to a fault, which has retreated upstream as a result of the erosion of some beds of shale that occur near its base. (After North, 1962.)

(Figure 3.16) The Afon Mellte: the origin of Porth-yr-Ogof. Stages (a), (b) and (c) are sequential. The sections represent three stages, and are drawn downstream from north to south (from right to left). By the occupation of a long underground channel and the collapse of all but one section of the roof, the river enters and emerges from cave mouths. (After North, 1962.)

(Figure 3.17) The Afon Mellte. (Photo: S. Campbell.)

(Figure 3.18) The Afon Mellte: waterfalls and their relation to faults.

(Figure 3.19) Diagrams illustrating the lateral migration of a waterfall. The water tends to collect on one side of the gorge owing to the inclination of the hard rocks over which it flows, and the valley grows wider, principally by erosion of the softer shales on one side. (After North, 1962.)

(Figure 3.20) Diagrams illustrating stages in the formation of Scŵd Clyngwyn. The fall has resulted from the removal of comparatively soft shale. (After North, 1962.)

(Figure 3.21) A geomorphological map of the Afon Dyfi: see (Figure 3.22) for sections. (After Thomas et al., 1982.)

(Figure 3.22) The Afon Dyfi: cross-sections through the terrace. (After Thomas et al., 1982.)

(Figure 3.23) The Afon Rheidol: the sedimentology of the Rheidol terraces. (After Macklin and Lewin, 1986.)

(Figure 3.24) The Afon Rheidol: metals (lead and zinc) in river sediments. (After Macklin and Lewin, 1986.)

(Figure 3.25) The Afon Vyrnwy: a geomorphological map. (After Lewin, 1992.)

(Figure 3.26) The Afon Ystwyth: (a) the channel at various dates; (b) the floodplain profiles at Grogwynion in 1969. (After Lewin et al., 1977.)

(Figure 3.27) The study reach on the Afon Elan [SN 864 748]. (After Lewin and Brindle, 1977.)

(Figure 3.28) Bank deposition (positive values) and erosion (negative values) between April 1974 and May 1975. (After Lewin and Brindle, 1977.)

(Figure 3.29) The River Severn, at Caersws, showing active erosion of the outer bank of a meander, and deposition on the other. (Photo: S. Campbell.)

(Figure 3.30) A location map of the upper Severn, showing the positions of the measurement stations and survey sections.

(Figure 3.31) The meander history of the Upper Severn: (a) Llanidloes; (b) Llandinam; (c) Caersws.

(Figure 3.32) The upper Severn catchment: downstream flood frequency variations. (After Hey, 1975.)

(Figure 3.33) The outer bank of a meander of the River Dee, between Holt and Worthenbury. (Photo: S. Campbell.)

(Figure 3.34) The capture of the upper Afon Teifi by the Rheidol and Ystwyth. (After Howe and Thomas, 1963.)

(Figure 3.35) The Afon Teifi: the southeastern raised bog at Tregaron, central Wales. Stratigraphic section established by borings between the hillside and Afon Teifi. The division of the peat and the domed shape of the bog are quite distinct. (After Godwin and Mitchell, 1938.)

(Figure 3.36) Drainage networks in the Maesnant experimental basin.

(Figure 3.37) Mynydd Du (Black Mountain): (a) Location; (b) scars. (Photos: S. Campbell.) escarpment of Old Red Sandstone, the geological

(Figure 3.38) Black Mountain: (a) a block diagram of the scarp; (b) a plane table survey of three debris-flow gullies. (After Statham, 1976.)

(Figure 3.39) Black Mountain: a profile of a typical gully-flow cone system. (After Statham, 1976.)

(Figure 4.1) A location map showing the fluvial geomorphology GCR sites in the north-west England GCR Block. 1 Langstrathdale (potential GCR site); 2 Wasdale (potential GCR site); 3 Buttermere and Crummock Water (potential GCR site); 4 Carlingill Valley; 5 Langdale and Bowerdale; 6 Langden Brook; 7 River Dane.

(Figure 4.2) Langstrathdale: a geomorphological map.

(Figure 4.3) Langstrathdale, looking upstream from Blackmoss Pot. Note the braided channel upstream of the rock-cut reach. (Photo: A.M. Harvey.)

(Figure 4.4) Wasdale: a geomorphological map.

(Figure 4.5) Wasdale, looking across Wastwater from near Over Gill towards the fan delta (f) of Lingmell Gill. Note the gullied slopes of Lingmell Gill valley. (Photo: A.M. Harvey.)

(Figure 4.6) Buttermere: a geomorphological map.

(Figure 4.7) Buttermere, looking across the fan delta of Hassnesshow Beck to that of Comb Beck. Note the lake shore reworking of Hassnesshow fan delta sediments into a small spit. (Photo: A.M. Harvey.)

(Figure 4.8) Carlingill: (a) geomorphological map. (After Harvey, 1992.) (b) Stratigraphic and geomorphic relationships of features in middle Carlinghill. (After Harvey et al., 1984.)

(Figure 4.9) Carlingill, in Middle Carlingill valley. Note the hillslope cut by older, now stable gullies (h); the high terrace (I); the fan segment (f) grading into the main terrace (t); the younger fan segment (y) grading to the low terrace; the modern valley floor (m) and the unstable braided channel. (Photo: A.M. Harvey.)

(Figure 4.10) Carlingill, looking up Grains Gill fan towards the active gully site at Grains Gill. Note the hill slope cut by older, now stable gullies (h); the active gullies (g); the high terrace (P set below the solifluction surface (s); the fan segment (f) grading into Carlingill main terrace; and the modern unstable cobble-bed channel. (Photo: A.M. Harvey.)

(Figure 4.11) Langdale and Bowderdale geomorphological map. The inset shows stratigraphic relationships of the dated sediments in Middle Langdale. (After Harvey et al., 1981.)

(Figure 4.12) Middle Langdale, showing now stable hillslope gullies (h) which fed debris cone (d). Note the pre-1970 meandering channel on the valley floor (p) and the post-1982 braided channel (b). (Photo: A.M. Harvey.)

(Figure 4.13) Bowderdale, showing 1982 sediments on Lodge Gill fan (s) and the old fan surface (f). Note the 1982 gravel deposits on valley floor. (Photo: A.M. Harvey.)

(Figure 4.14) Langden (a) geomorphological map. (b) Sequence of channel change upstream of Little Hareden, 1968–90. (After Thompson, 1987.) (c) Stratigraphic relationships of dated sediments at Little Hareden Fan. (After Harvey and Renwick, 1987.)

(Figure 4.15) Langden Valley, looking across the braided channel of Langden Brook to Little Hareden Fan. (Photo: A.M. Harvey.)

(Figure 4.16) The braided cobble-bed channel of Langden Brook. (Photo: A.M. Harvey.)

(Figure 4.17) River Dane: (a) geomorphological map. (From mapping by J.M. Hooke and A.M. Harvey.) (b) Stratigraphic relationships of dated site downstream Swettenham Bridge. (After Hooke et al., 1990.)

(Figure 4.18) The River Dane near Holly Banks, showing the main terrace (I), the low terrace (t), the modern flood-plain (f) and the meandering channel with a well developed pool–riffle sequence. (Photo: A.M. Harvey.)

(Figure 4.19) The River Dane near Somerford Hall, showing a very tight meander bend that has since developed into a cutoff. (Photo: A.M. Harvey.)

(Figure 5.1) The major river systems and relief of north-east England. GCR Sites: 1 Harthope Burn; 2 Low Prudhoe; 3 Blackett Bridge; 4 Blagill; 5 The Islands, (Alston Shingles); 6 Black Burn; 7 Garrigill; 8 Shaw Beck. Other sites descibed in the text: 9 Farnley Haughs; 10 Lambley; 11 Thinhope Burn.

(Figure 5.2) Black Burn: geomorphological features and dated sedimentary units, with cross-sectional profiles.

(Figure 5.3) Black Burn, looking downstream in a northeasterly direction, showing well-developed palaeochannels on low river terrace surfaces. (Photo: M.G. Macklin.)

(Figure 5.4) Black Burn, looking upstream in a southerly direction, showing prominent meander cutoffs dated to between 1900 and 1957. (Photo: M.G. Macklin.)

(Figure 5.5) Channel change at Black Burn, 1859–1980.

(Figure 5.6) Garrigill, River South Tyne: (a) alluvial landforms, palaeochannels and sediment units and (b) cross-sections of the valley floor. (After Aspinall et al., 1986.)

(Figure 5.7) Blagill, River Nent, looking upstream in a southwesterly direction, showing an abandoned braided channel system dating from c. 1896–1950 which is currently being entrenched by the present river. (Photo: M.G. Macklin.)

(Figure 5.8) Nent valley at Blagill: (a) alluvial landforms, sediment units and metal concentrations in the historical floodplain and earlier alluvial sediments; (b) cross-sections. (After Macldin, 1986).

(Figure 5.9) An up-section plot of metal concentrations in the low alluvial terrace at Blagill. The location of the section is shown in (Figure 5.8). (After Macklin, 1986.)

(Figure 5.10) Channel change at Biagill, River Nent, 1775–1984. (After Macklin, 1986.)

(Figure 5.11) The Islands, River South Tyne: (a) alluvial landforms and palaeochannels and metal concentrations in historical and earlier alluvial units; (b) cross-sections and lead and zinc concentrations.

(Figure 5.12) The Islands, River South Tyne, looking upstream in a southeasterly direction from Brown Ghyll, showing a late 19th century braided channel belt to the left of the drystone wall and a pre-19th century terrace to the right. (Photo: M.G. Macklin.)

(Figure 5.13) Channel change at the Islands, River South Tyne, 1860–1975. (After Macklin and Lewin, 1989.)

(Figure 5.14) Changes in the height of bed material sedimentation at the Islands, 1858–1987.

(Figure 5.15) (a) Blackett Bridge, River West Allen. Floodplain and valley floor morphology, cross profiles and metal concentrations for alluvial units. (After Macklin and Aspinall, 1986.) (b) Blackett Bridge, River West Allen. Cross-sections. (After Macklin and Aspinall, 1986.)

(Figure 5.16) River channel change at Blackett Bridge, River West Allen, 1859–1983 (after Macklin and Aspinall, 1986.)

(Figure 5.17) Blackett Bridge, River West Allen, looking downstream in a northerly direction, showing a late Roman age terrace on the left of the present channel and a 19th century terrace on the right. (Photo: M.G. Macklin.)

(Figure 5.18) (a) Maps showing channel change at Low Prudhoe between 1860 and 1978, and the location of the sections. (b) Valley floor and channel cross-sections upstream and downstream of Ovingham bridge: the relative heights of the 1771 and 1815 floods are indicated. (After Macklin et al., 1992c.)

(Figure 5.19) Low Prudhoe, River Tyne: a section of the late 19th and early 20th century fine-grained alluvium. Lighter layers are sand units representing major flood events. Scale: 0.2 m. (Photo: M.G. Macklin.)

(Figure 5.20) Metal concentrations and organic matter content in vertically accreted alluvium at Low Prudhoe, showing major flood units with their probable dates. (After Macklin et al., 1992c.)

(Figure 5.21) A comparison of floods documented in the lower Tyne valley and the sedimentary flood record at Low Prudhoe between 1890 and 1989. (After Macklin et al., 1992c.)

(Figure 5.22) The Harthope study reach: (a) the channel position in 1897 and 1976, and (b) the present valleyside and floodplain features. (After Milne, 1982).

(Figure 5.23) The plan (a) and sections (b) of the Hurricane Charley and historical flood sediments in Shaw Beck, Arkengarthdale, North Yorkshire. (After Newson and Macklin, 1990.)

(Figure 5.24) Shaw Beck: historical coarse-grained flood deposits overlying bedrock terrace. (Photo: M.G. Macklin.)

(Figure 5.25) Pleistocene and Holocene river terraces and palaeochannel sequences at Lambley, River South Tyne, Northumberland. (After Passmore, 1994.)

(Figure 5.26) Successive maps of channel and bar morphology at Lambley and Featherstone, River South Tyne, derived from cartographic, aerial photograph and field mapping (1990) sources. (After Passmore et al., 1993).

(Figure 5.27) Lambley, River South Tyne, looking downstream in a northeasterly direction, showing the unstable near-braided channel at the northern end of the study reach. (Photo: M.G. Macklin.)

(Figure 5.28) (a) A surveyed longitudinal profile of the study reach in Thinhope Burn, showing the positions, heights and sequence of dated Holocene alluvial fills and river terraces in relation to the present stream bed. (b) A time-level diagram for Holocene alluvial units in the Thinhope Burn study reach. (After Macklin et al., 1994b.)

(Figure 5.29) Thinhope Burn, looking upstream in a southwesterly direction, showing late Holocene river terraces and historical coarse-grained flood deposits. (Photo: M.G. Macklin.)

(Figure 5.30) Thinhope Burn: historical flood deposits overlying a bedrock terrace. (Photo: M.G. Macklin.)

(Figure 5.31) Late Pleistocene and Holocene river terrace morphologies at Farnley Haughs, Northumberland. (After Passmore and Macklin, 1994.)

(Figure 5.32) Sedimentary sequences at Farnley Haughs, Northumberland. (After Passmore and Macklin, 1994.)

(Figure 5.33) Farnley Haughs, River Tyne: fine-grained alluvium in Styford unit, showing lateral accretion features. Scale: 2 m. (Photo: D.G. Passmore.)

(Figure 6.1) The extent of the terrace deposits at Beckford: a map showing the distribution of terrace outcrops in the Beckford area.

(Figure 6.2) Sedimentary sequences at Beckford: vertical sections showing sedimentology and facies associations through terrace. (After Dawson, 1986.)

(Figure 6.3) The exposure of terrace deposits at Beckford. (Photo: R.J. Davis.)

(Figure 6.4) The pool–riffle sequence on valley bends of the Osage river, derived from aerial photographs. (After Duly, 1970.)

(Figure 6.5) A section of lake sediments at Preston Montford. (After Jones, 1982.)

(Figure 6.6) The distribution of channel movement along the River Axe. (After Hooke, 1977.)

(Figure 6.7) The changing channel pattern along the River Axe, near Whitford. (After Hooke, 1977).

(Figure 6.8) The changing channel pattern along the River Axe, near Axminster. (After Hooke, 1977.)

(Figure 6.9) River channel change on the River Exe at Brampford Speke. (Modified from Hooke and Kain, 1982.)

(Figure 6.10) A temporary sign alongside the Exe. "This site is part of New Sowdens Farm and is situated in the middle reaches of the Exe Valley, which is of particular geomorphological interest, with good examples of oxbow formations, hence its designation as a site of special scientific interest. Evidence of the former Exe Valley Railway can be seen which cuts through the site on an embankment and was in use until 1963'. (Photo: K.J. Gregory.)

(Figure 6.11) The River Ter, showing relationship between the bankfull recurrence interval and the catchment area. (After Harvey, 1969.)

(Figure 6.12) The River Ter, showing (a) the correlation of discharge frequency (Q20) to median riffle spacing, and (b) the correlation of channel width at Q20 to median riffle spacing. (After Harvey, 1975.)

(Figure 6.13) The River Derwent at Hathersage: the distribution of river terraces.

(Figure 6.14) A schematic diagram indicating bench formation and the relationship between water level and tree growth. (Derived from data in Petts, 1977.)

(Figure 6.15) The influence of River Noe sediments on channel substrate downstream of the Noe confluence. (After Petts, 1988b.)

(Figure 6.16) An active debris dam on the Highland Water, New Forest. (Photo: K.J. Gregory.)

(Figure 6.17) Millyford Bridge reach, illustrating changes in debris location and channel morphology.

(Figure 6.18) The distribution of vegetation — soil moisture categories (a) and runoff contributing areas at different levels of baseflow (b) in the Withybed subcatchment. (After Gurnell et al., 1985.)

(Figure 6.19) The development of seepage steps: cross-sections showing incipient gullies and headstep. (After Tuckfield, 1964.)

(Figure 6.20) Topographical features of Cannon Hill Valley, Exmoor. (After Anderson and Calver, 1977.)

(Figure 6.21) A channel (flowing top right to bottom left) incised into peat deposits, Cannon Hill Valley. (Photo: RJ. Davis.)

(Figure 6.22) Channel changes on the River Lyn after the 1952 flood: plans of Lynmouth: (a) before the flood, (b) today. (After Dobbie and Wolf, 1953.)

(Figure 6.23) Alluvium-filled palaeochannels on the River Itchen, Warwickshire. (After Dury, 1954.)

(Figure 6.24) The palaeochannel of the Eydon Brook, looking upstream to section C (of (Figure 6.25)). (Photo: R.J. Davis.)

(Figure 6.25) Palaeohydrological features of the River Cherwell and Eydon Brook. (After Dury, 1953.)

(Figure 6.26) Ashmoor Common: location and sub-peatcontours. (After Brown, 1982.)

(Figure 6.27) Ashmoor Common: cross-sections. contours. (After Brown, 1982.)

(Figure 6.28) General view of Ashmoor Common. (Photo: R.J. Davis.)

(Figure 6.29) Fan gravels at the top of the Buildwas quarry section.

(Figure 6.30) The Alport Valley illustrates the morphology of upland channels where, with limited sediment supply, the river cuts into bedrock. (Photo: R.J. Davis).

(Figure 6.31) Moorland areas undergoing peat erosion; Laund Clough, Bleaklow GCR site. (Photo: R.J. Davis.)

(Figure 6.32) Simulated and actual streams on Bleaklow: (a,b) convex slopes; (c,d) concave slopes; (e,f) straight slopes. (After Mosley, 1972.)

(Figure 6.33) Chart showing Featherbed Moss peat changes over time. (After Tallis, 1985.)

(Figure 6.34) Lydford Gorge: the site of the Lyd-Burn river capture.

(Figure 6.35) Lyd Gorge waterfall. (Photo: K.J. Gregory.)

(Figure 6.36) Potholes in Lydford Gorge. (Photo: K.J. Gregory.)

(Figure 6.37) Land use in the Mimmshall Brook catchment. (After Darby and Thorne, 1992.)

(Figure 6.38) Water End swallow hole. (Photo: R.J. Davis.)

(Figure 6.39) Lower Force, Aysgarth Falls. (Photo: I.D. Hooper.)

(Figure 6.40) A cross-section of the meander bend on Dovedale Griff, and the schematic stratigraphy of the cut bank deposits. (After Richards, 1981.)

(Figure 6.41) Dovedale: a morphological map of the terrace and fan fragments based on air photograph analysis and field survey. (After Richards, 1981.)

(Figure 6.42) The low-angle fan of sediment at the junction between Jugger Howe Beck and Hollin Gill. (Photo: R.J. Davis.)

(Figure 6.43) Culm River and floodplain. (Photo: H. Rowlands.)

(Figure 6.44) Conveyance loss and flood attenuation, River Culm. (After Lambert and Walling, 1987.)

(Figure 6.45) Microtopography and excess caesium-137, River CuIm floodplain at Rewe. The contours on (a) refer to heights in centimetres above an arbitrary datum representing the lowest point on the floodplain surface within the sampled area. (b) The pattern of excess caesium-137. (After Walling and Bradley, 1989.)

(Figure 6.46) The re-profiled floodplain section, River Lugg. (After RSPB et al., 1994.)

(Figure 6.47) Flood alleviation work combined with channel stabilization activities, River Lugg. (After RSPB et al., 1994.)

(Figure 6.48) River Lugg: a typical cross-section at a re-profiled meander. (After Lewis and Williams, 1984.)

(Figure 6.49) River Lugg: a plan view of a typical weir. (After Lewis and Williams, 1984.)

(Figure 6.50) River Lugg: a long sectional view of a typical weir. (After Lewis and Williams, 1984.)

(Figure 6.51) Upstream of the weirs on the River Lugg, slower-flowing water has allowed new habitats (reed and 'withy' beds, marginal wetlands and backwaters) to develop. (Photo: R.J. Davis.)

Tables

(Table 1.1) Key to the sites shown on (Figure 1.7), including classifications used in (Table 1.2)

(Table 1.2) Numbers of GCR sites representing the categories shown on (Figure 1.7)

(Table 2.1) GCR site selection criteria for fluvial geomorphology in Scotland: channel and planform typology. (After Kellerhals et al., 1976.)

(Table 2.2) Geomorphologically distinct characteristics of fluvial geomorphology GCR sites in Scotland.

(Table 3.1) Confinement materials on an 8 km reach of the Upper Elan. (After Lewin and Brindle, 1977.)

(Table 3.2) Threshold discharges for bed material movement and type of reach (E = erosional; D = depositional; S = stable).

(Table 3.3) Input and output of sediment from debris-flow gullies. Yearly sediment derived from sides of gully B, 30 September 1971–29 September 1972.

References