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Research and application in British geomorphology
Geofomm, Vol. 10, pp. 253-259,1979.
Pergamon Press Ltd. Printed in Great Britain.
Research and Application in British Geomorphology J.B. THORNES*,
London,
U.K.
Abstract: Three aspects of the application of geomorphological research are identified: direct application of principles, methods and techniques; research and development specifically for application and the recognition of potentially applicable research. Some recent British work in each of these areas is reviewed.
Introduction
British geomorphologists have become progressively more and more engaged in “applied geomorphology”. Some workers consider this to be “the application of geomorphological techniques and analysis to the solution of environmental management, engiplanning, neering or similar problems” (BRUNDSDEN, DOORNKAMP and JONES, 1978). Two other types of activity seem to be important in this context. The first of these is the development of new methods and techniques which are directed towards specific applications. The second lies in the recognition of particular research areas as having potential for application. In practice it is probably more useful to see the relationship as a continuum rather than to attempt to identify a specifically applicable component of the subject. The literature of applied geomorphology is quite large and two recent books give some idea of the scope. They are Geomorphology in Environmental Management (COOKE and DOORNKAMP, 1974) and Applied Geomorphology (HAILS, 1977). An attempt is made here to select but a few examples of recent British work which exemplify the relationships between research and application at the various levels, and which illustrate the more general trend of research activities.
within the universities and, to a lesser degree, in the polytechnics. It is mainly funded by the government, through the Natural Environmental Research Council (N.E.R.C.), by the universities themselves or by private sources. Individual geomorphologists have also been engaged as consultants by international and national agencies and by private companies. Following the Rothschild report (H.M.S.O., 1971) the British government adopted a “customer-contract” principle towards research in which the government acts as customer, commissioning research from the universities, from institutions and from other research bodies. This has led, in the N.E.R.C., to a somewhat more pragmatic attitude to wards the research activities which it supports. Moreover, the strengthening of the research institutions within the Council’s control, such as the Institute of Hydrology and the Institute of Geological Sciences has led to even greater competition for research funds. Basically, the funds available for geomorphological research remain very small and this has resulted in a concentration of effort in those areas requiring only modest sums of money. The Application of Geomorphological Methods and Techniques
Several steps are involved in direct application. These involve the precise identification of the problem, the specification of the information required for its solution, the collection of that information and the provision where possible of a set of alternative strategies leading to a
In Britain geomorphology is taught and researched mainly in Departments of Geography _____-_ * Dept. of Geography, London School of Economics, Houghton St., London WC2A 2AE. 253
254
solution. In this respect the methodology is similar to classical induction in science. By virtue of his training the geomorphologist emphasises the long term, complex structure of the problem rather than the immediate short-term technical problem. At the same time the shift towards greater interest in contemporary processes has led to a better training in the basic mechanics of the problem. It is this combination of historical perspective and technical competence which needs to be more fully developed and put to advantage. This point may be illustrated by reference to some recent work in Argentina. High-level, arid-zone basins in the province of Catamarca are undergoing severe desertification problems at the present time with extensive dune development and encroachment on cultivated land. In the short term the problem is viewed simply as one of dune stabilization using natural or artificial means (such as bitumens or special fencing) or the provision of smallof intensively irrigated land. scale “islands” Detailed field investigation however indicates a much more deeply rooted problem. This is a combination of deep-river trenching and the associated lowering of the water table together with extensive cutting of the native carob tree in the former bottomlands by the river and the grazing of unstable grasses on flat sandy areas. The problem may only be fully appreciated in the historical context and the solutions will involve economic and social as well as geomorphological measures (THORNES, 1978). Published British work has largely been concerned with the collection of geomorphological data, using geomorphological techniques to provide the information with which to develop management alternatives or choose between them. The work of Brunsden and his colleagues helps to illustrate these various types of activity with respect to fixed, topographic information. From their mapping of landslides in Dorset, BRUNSDEN and JONES (1972) were able to identify complex subsurface failure structures which in turn were producing surface-road construction and maintenance problems. In another study (BRUNSDEN et al., 1975) the geomorphological mapping of the land along the projected Dharan-Dhankuta highway in Nepal, with a length of 65 km, assisted engineers in choosing one of several alternative road alignments. In particular the utility of these investigations was in pointing
Geoforum/Volume lo/Number 3/1979
to likely sources of engineering problems which required further and much more detailed mechanical site analysis. In this sense the geomorphological information provides a first “filter”, thus lowering the cost of subsequent efforts. Sources of materials for construction and potential construction hazards arising from flooding and high salinity of groundwaters have also been the subject of investigation by this group (BRUNSDEN et al., 1976). Observational techniques and measurements have also been made of dynamic phenomena. In particular the recording of changes in hydrology and fluvial geomorphology reflects the overall resurgence of interest in fluvial processes. In Britain this work has been characterised by studies of the impact of urbanisation on hydrology and sediment production. A recent study by HOLLIS (1974) exemplifies this type of research. Investigations were made of the effects of progressive urbanisation around Harlow (Essex) on a local stream. Here a 16% urbanisation of the catchment led to an increase of the maximum monthly flood from 1.16 to 2.58 m3 /set over a period of 18 yr. GREGORY (1974) investigated the effects of building activity in a small drainage basin on the margin of Exeter, Devon, and showed that they have resulted in a doubling of peak discharge, a decrease of lag time to half its former value, and an increase in runoff varying between 1.1 and at least three times its former value. More recently GREGORY (1977) has edited a book on River Channel Changes, in which many papers describe short-, medium- or long-term changes in river channels and flood plains, some of which are of direct economic significance. Geomorphologists have also been involved in research designed to alleviate the magnitude of and losses incurred during floods. PENN INROWSELL and CHATTERTON (1977) attempt to relate flood damage costs to river stage and channel characteristics and geomorphological data has been employed in the estimation of discharge from unguaged catchments (N.E.R.C. 197.5). Water quality observations have been made to assess long-term changes superimposed on annual cyclical variations (EDWARDS and THORNES, 1973) or the impact of particular events such as the extremely dry English summer of 1976 on water quality (FOSTER and WALLING, 1978).
Geoforum/Volume IO/Number 311979
British geomorphologists have not generally been concerned with long-term monitoring of en~ronment~ systems even though various universities and polytechnics have maintained experimental catchments (e.g. ELLIS, 1977). The prevailing view in Britain has been that such investigations are best carried out by national bodies such as the Institute of Hydrology. This is because to be effective, such investigations usually need appreciable investments of time and money. There is, of course, some need to balance a few very well instrumented catchments, which can cover only a limited range of environments and problems, with a larger number which, although less well instrumented enable a larger range of conditions to be sampled. In any case nearly all the institutions concerned with long-term monitoring have geographers on their staff. There have also been some notable contributions from one or two research catchments (e.g. WEYMAN, 1974). Research for Application
One of the areas of overlap with direct application is the development of techniques, such as mapping, which will enhance the assessment of resources and change. Britain has a long history of such research (e.g. SAVIGEAR, 1958). Surprisingly, despite the existence of very active groups concerned with remote sensing in various departments in Britain, geomorphologists have, by and large, been slow to adopt the associated techniques. This is largely a reflection of the fact that reconnaissance survey has played a relatively minor role in the subject when compared with other countries. Nonetheless automated mapping is under development for geomorpholo~~al applications. An example of this is the work we have recently undertaken to provide a system of computer programmes for mapping soil erosion potential (MOORE and THORNES, 1976). This involves simple and easily obtainable field data in the form of spot heights or contours and uses a set of transport laws to generate erosion potential surfaces according to the type of processes or mixture of processes being considered. Similar work by KIRKBY (19761, and BEVAN and KIRKBY (1977), attempts to model the effects of drainage network and drainage basin topographic form respectively, on the spatial variability of the stream-flow hydrograph. This
255
work is particuiarly important in recognising the need to develop simple but physically wellfounded models of physical systems for which data can be easily obtained. Models which are less well based and require large amounts of historical data for their p~amete~zation are often of limited value, particularly in underdeveloped countries. A second important area of research for application is in the development of techniques for field measurement. The Technical Bulletins of the British Geo~~rpho~o~ical Research Group give some indications of developments in this field. In the fluvial field, for example, techniques for the monito~ng of suspended load (WALLING and TEED, 1971), bedload (ANDERSON, 1976) and water quality have been developed. Dr. P. McCullagh of the University of Nottingham has designed and developed a system of “wave posts” which give a signal whose frequency is a function of the height of water standing around the post. These were first developed for application in coastal studies but recently they have been successfully applied to the estimation of stage in ephemeral channel flows (BUTCHER and THORNES, 1978). They are particularly useful in this situation because, with very high sediment yield, conventional rating methods tend to cause very rapid ag~adation in the channel, do not allow for shifts in the main path of the stream, and impede the use of the channel bed for access. The most advanced and elaborate experimental work in Britain, both in equipment and field installation, is carried out at the Hydraulics Research Station at Wallingford. In particular, the experimental work on stream meanders by ACKERS and CHARLTON (1970 a, b) is well-known. Like the Institute of Hydrology, the Hydraulics Research Station is responsible to the Natural Environment Research Council. The development and use of climatic simulators for the exploration of the effects of temperature and humidity on weathering is also proving important. GOUDIE, COOKE and EVANS (1970), and GOUDIE (1974), have conducted simulations of salt-weathering on natural materials and show that it is extremely potent in comparison with other mechanical weathering processes. In areas of salt-rich groundwater, such as the semi-arid and arid countries of the Middle East, the implications
256
Geoforum/Volume lo/Number 3/1979
of this work for urban development important indeed (GOUDIE, 1977).
are very
A third type of research for application has been the investigation of statistical and mathematical models for forecasting change in environmental systems. The simplest cases involve empirical regression associations between an input to the system and a response variable. Discharge and river channel response provide a good example. PARK (1977) examined the regression relationship between drainage area to a point and channel capacity for a given frequency of discharge event. The channel capacity is the cross-sectional area of the water for a given event. He found that the gradient of this relationship is much steeper below reservoirs implying a sharper increase in channel capacity with discharge immediately below the reservoir. This effect is produced by the reduction in peak discharge as a result of reservoir construction and scour resulting from reduction in the stream load. Much more complex regression models have been constructed of channel geometry (e.g. BENNETT, 1976), though the utility of models based simply on the statistical description of channel morphology has, in my view, still to be demonstrated. A slightly different kind of model study is that recently carried out at the London School of Economics and Political Science (THORNES 1975). We investigated the and CLARK, statistical structure of water quality series using simple and seasonal autoregressive and movingaverage models. The objective was to assess the effects of missing data points on the structure and parameters of the models and to estimate how much data could be lost before the data set became useless for the specified purpose. For some water quality variables (such as electrical conductivity, temperature and pH) we found that the authorities could halve the amount of data collected without a serious loss of information. Although the use of experimental design and statistical techniques are now widespread in British geomorphology, insufficient attention has been paid to spatial variability and sampling procedures. These are especially important in applied work, for example in estimating groundwater conditions from point locations. The fourth
major thrust in research
for applica-
tion has come with the widespread adoption of the general framework of systems analysis. The work of CHORLEY and KENNEDY (197 1) has provided an impetus for this research and this has been reinforced by the Environmental publication of Systems (BENNETT and CHORLEY, 1978). One particular aspect of this has been to pay more attention to the general problem of budgeting. This work has so far largely emphasized water budgets and in particular their relation to land drainage. However, several recent papers have emphasized solute budgets and work is beginning to focus on geochemical cycles. One type of these studies is the mapping of solute concentrations in the catchment. WALLING and WEBB (1975) plotted variations in solute concentrations in the Exe catchment in southwest England. More work is needed in this field but also further investigations must be made of the detailed mechanisms involved in geochemical transfers. WAYLEN ‘(1976) has attempted to trace the geochemical budget of an entire small catchment on the Mendip Hills in Somerset and currently investigations of individual radioactive elements such as caesium are underway. This geochemical budgeting must be linked to hydrological hillslope data to provide information on the likely effects of forest removal and land management on soil chemistry. Some efforts along these lines are being made in a small tropical catchment near Manaus, Brazil. This involves observation of the hydrological and geochemical status of several sites over a period of some years prior to forest clearance (NORTCLIFF, THORNES and WAYLEN, 1979). Research with Application
Much of the research in British geomorphology is unfettered by the constraints imposed by the requirements of particular practical problems. At the same time much of it has great potential for application. Reviews of British research into mass movement (PRIOR, 1978), fluvial processes (GREGORY, 1978) and coastal phenomena (KING, 1978) have been published in the book Geomorphology: Present Problems and Future Prospects, edited by EMBLETON et al. At the very frontier of research a particular theme seems likely to prove important in the future relationship between research and
257
Geoforum/Volume 1O/Number 3/l 979
application. During the 1960s most British geomorphologists, following the North American example, came to believe that the most useful view of geomorphological systems was one that emphasized their short-term conditions of dynamic equilibrium. Accordingly, most basic research sought to emphasize equilibrium conditions and solutions. Most applications, on the other hand, are concerned with systems in dynamic disequilibrium and solutions which obtain over periods of the order of several decades. In the last few years there has been a shift towards the study of disequilibrium in geomorphic systems. In the 1960s the prevailing view was that the most important events were those of medium magnitude and frequency, in systems governed by self-regulation through negative feedback. In the 1970s more attention is being paid to transient behaviour during periods of relaxation after extreme events and to theoretical modelling of the stability-instability conditions which engender changes in the rate of operation of processes and the forms produced. Several papers have recently pointed out that periods of transient behaviour (recovery) between extreme events may be as important as the events themselves. This is most readily seen in semi-arid environments where low flows between large events recreate the channel, determining the nature of the response to succeeding large events (THORNES, 1977). However, the persistence of storm effects has also been studied in perennial channels. ANDERSON and CALVER (1977) for example have described the long-term effects of river channel response to the 1956 flood disaster at Lynmouth (Devon). Such observations need to be put on a firmer theoretical footing and the work of ALLEN (1974, 1976) is seminal in this respect. Much of applied work in fluvial and coastal environments involves protection for and recovery from the effects of extreme events.
analysis has been carried out with reference to changes in drainage density resulting from changes in the controlling variables. In the long term theoretical studies of this type will be needed to forecast the responses of rivers and hillslopes to changes produced by river management, deforestation and perhaps even climatic change. Finally, it is worth making the point that detailed studies of historical changes are important in the solution of practical problems even if they only demonstrate to us the complexity of responses to simple inputs in geomorphological systems. By understanding the extensive changes which have been caused by human activities in historic times and the anthropological responses to such changes, we will be in a stronger position to contend with future changes. This is well illustrated by the study of arroyo entrenchment in the southwest United States by COOKE and REEVES (1976) and by Mosley’s study of changes in the River Bollin, in Cheshire (England) (MOSLEY, 1975). In particular studies of known historical changes and their effects are important in the applied studies. It is not enough to investigate past changes and attempt to determine their causes. It would be a mistake to take too confined a view of applied geomorphology. Rather, what is needed is a wider appreciation of the practical importance of the research already being carried out and a recognition of the continuum between the basic description and assessment of geomorphological phenomena at one extreme and the theoretical modelling of the long-term behaviour of dynamic geomorphological systems on the other.
References
ACKERS P. and CHARLTON F.G. (1970a) MeanderOn the theoretical side, work in Britain is only just beginning. KIRKBY (1977) has attempted, following the work of Henderson and others to determine, theoretically, the stability conditions for the existence of different modal states (e.g. meandering or braiding) in river systems. In particular he has paid more attention to the role of sediment transport efficiency as a stability criterion. A similar
ing geometry 11. 230-252.
arising from varying~flows,‘.T, Hydrol.
ACKERS P. and CHARLTON F.G. (1970b) The geometry of small meandering streams, E3oc. Instn.
civ. Engn. Paper 73285 289-317. ALLEN J.R.L. (1974) Reaction, relaxation and lag in natural sedimentary systems: general principles, examples and lessons, Earth-Sci. Rev. 10, 263-342. ALLEN J.R.L. (1976) Bed forms and unsteady processes: some concepts of classification and response
258
illustrated by one-way types, Earth Surface Processes, 1,361-374. ANDERSON M.G. and CALVER A. (1977) On the persistence of landscape features formed by a large flood, Trans. inst. Br. Geogr. N.S. 2(2), 243-254. ANDERSON M.G. (1976) An inexpensive circuit design for the acoustic detection of oscillations in bedload transport in natural streams, Ewth Surface Processes, l(3), 213-219. BENNETT R.J. (1976) Adaptive channel geometry, Earth Surface Processes; 1, 13 l-l 50. BENNETT R.J. and CHORLEY R.J. (1978) Environmental Systems: Philosophy, Analysis and Control. Me~uen, London, 623 pp. BEVAN K.J. and KIRKBY M.J. (1976) Towards a simple physically based variable contributing model of catchment hydrology, University of Leeds, School of Geography, Working Paper No. 154. BUTCHER G.C. and THORNES J-B. (1978) Spatial variability of runoff processes in an ephemeral channel, Z. Geomorph. N.F., Suppl. Bd. 29, 83-92. BRUNSDEN D. and JONES D.K.C. (1972) The morphology of degraded landslide slopes in south west Dorset, Q. Jl. Engng. Geol. 5,205222. BRUNSDEN D., DOORNKAMP J.C., FOOKES P.G., JONES D.K.C. and KELLY J.M.H. (1975) The use of geomorphological mapping techniques in highway en~eer~g, J. Instn. Highw. Engng. 22,35-41. BRUNSDEN D., DOORNKAMP J-C. and JONES D.K.C. (1976) Summary and recommendations, Bahrain Surface Materials Resources Survey, 1. BRUNSDEN D., ~O~KAMP J.C. and JONES D.K.C. (1978) Applied geomorphology: a British view, In: Geomorphology: Resent Problems and Future Prospects, pp. 251-262, C.E. Embleton et al. (Ed). Oxford University Press, London. CHORLEY R.J. and KENNEDY B.A- (1971) Phys~al Geography: A Systems Approach. Prentice-Hall, Englewood Cliff, COOKE R.U. and DOORNKAMP J.C. (1974) Geomorphology in environmental M~age~ent. Oxford University Press, London. COOKE R.U. and REEVES R.W. (1976) Arroyos and Environmental Change in the American Southwest. Oxford University Press, London. EDWARDS A.M.C. and THORNES J.B.(1973),~nu~ cycle in river water quality: a time series approach, Wat.Resour. Res. 9,1286-1295. ELLIS J.B. (1977) The characterization of particulate solids and quality of water discharged from an urban cat&men& In: Effects of Urination and Industrialization on the Hydrological Regime and on Water Quality, Int. Assoc. for Scientific Hydrology. EMBLETON C., BRUNSDEN D and JONES D.K.C. (Ed.) (1978) Geomorphology: Present Problems and Future Prospects. Oxford University Press, London, 281~~. FOSTER I.D. and WALLING D.E. (1978) The 1976 drought and nitrate levels in the River Exe basin, J. Instn. Water Engn. Sci. 32,34I-35 1.
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IO~Number 311979
GOUDIE AS. (1974) Further experimental investigation of rock weathering by salt and other mechanical processes, Z. Geomorph. N.F. Suppl. 21, l-12. GOUDIE AS. (1977) Sodium sulphate weathering and the dis~tegration of Mohenjo-Daro, Pakistan, Earth Surface Processes, 2.75-86. GOUDIE A.S., COOKE R.U. and EVANS J.S. (1970) Experimental investigation of rock weathering by salts, Area, 4,42-48. GREGORY K.J. (1974) Streamflow and building activity, In: Fluvial Processes in Instrumented watersheds, Special Publication Vol. 6, pp. 107. 122, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers. GREGORY K-3. (1977) River Channel Changes. John Wiley, New York. GREGORY K.J. (1978) Fluvial processes in British basins, In: Geomo~holo~, Present ~oblems and Future Prospects, pp. 40-72, C.E. Embleton et al. (Ed.). Oxford University Press, London. HAILS J. (1977) Applied Geomorphology. Elsevier, Amsterdam. H.M.S.O. (1971) The organisation and management of government R and D, Framework for Government Research and Development, Cmnd. 4814, London. HOLLIS G.E. (1974) The effect of urbanization on floods in the Canon’s Brook, Harlow, Essex, In: F~v~l Processes in Ins~~nted ~tchments, Special Publication Vol. 6, pp. 123-139, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers. KING C.A.M. (1978) Coastal geomorpholo~ in the United Kingdom, In: Geomorphology, Present Problems and Future Prospects, pp. 224-250, C.E. Embleton et al. (Ed.). Oxford University Press, London. KIRKBY M.J. (1976) Tests of the random network model and its application to basin hydrology, Earth Surface Processes, 1, 197-2 13. KIRKBY M.J. (1977) Maximum sediment efficiency as a criterion for alluvial channels, In: River Channel Changes, pp. 429442, K.J. Gregory (Ed.). John Wiley , New York, MOORE R.F. and THORNES J.B. (1976) Leap a suite of Fortran lV programs for generating erosional potentials of land surfaces from topographic information, Computers Geosci. 2,493.499. MOSLEY M.P. (1975) Channel changes on the river Bollin, Cheshire, 1872-1973, E. Midld. Geogr. 6, 185199. NATURAL E~IRO~ENT RESEARCH CO~CIL (1975) Flood Studies Report. Five volumes, London. NORTCLIFF S., THORNES J.B. and WAYLEN M.J. (1979) Tropical forest systems: a hydrological approach, Amazoniana S(l), 65-72. PARK C.C. (1977) Man induced changes in stream channel capacity, In: River Channel Changes, pp. 121-144, K.J. Gregory (Ed.). John Wiley, New York.
Geoforum/Volume
lo/Number
3/1979
PENNING-ROWSELL E. and CHATTERTON J.B. (1977) The Benefits of Flood Alleviation. Saxon House, Farnborough. PRIOR D.B. (1978) Some recent progress and problems in the study of mass-movement in Britain, In: Geomorphology, Present fioblems and Future Prospects, pp. 84-106, C.E. Embleton et al. (Ed.). Oxford University Press, London. SAVIGEAR R.A.G. (1958) Morphological mapping, Geography 43, 10-17. THORNES J.B. (1977) Channel changes in ephemeral streams: observations, problems and models, In: River Channel Changes, pp. 317-335, K.J. Gregory, (Ed.). John Wiley, New York. THORNES J.B. (1978) Los Medanos de FiambalaTinogasta. U.N. Office of Technical Cooperation, New York. THORNES J.B. and CLARK M.W. (1975) Effects of missing data on autocorrelation and partial auto-
259
correlation functions, Working Paper 3, Water Quality Project, London School of Economics, London. WALLING D.E. and TEED A. (1971) A simple pumping sampler for research into suspended sediment transport in small catchments, J. Hydrol. 11, 129144. WALLING D.E. and WEBB B.W. (1975) Spatial variation of river water quality: a survey of the River Exe, Trans. Inst. Br. Geogr. 65,155-171. WAYLEN M.J. (1976) Aspects of the hydrochemistry of a small drainage basin, Unpublished Ph.D. Thesis, University of Bristol. WEYMAN D. (1974) Runoff processes, contributing area and streamflow in a small upland cat&men& In: Fluvial Processes in Instrumented Catchments, Special Publication, Vol. 6, pp. 3343, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers.
Pergamon Press Ltd. Printed in Great Britain.
Research and Application in British Geomorphology J.B. THORNES*,
London,
U.K.
Abstract: Three aspects of the application of geomorphological research are identified: direct application of principles, methods and techniques; research and development specifically for application and the recognition of potentially applicable research. Some recent British work in each of these areas is reviewed.
Introduction
British geomorphologists have become progressively more and more engaged in “applied geomorphology”. Some workers consider this to be “the application of geomorphological techniques and analysis to the solution of environmental management, engiplanning, neering or similar problems” (BRUNDSDEN, DOORNKAMP and JONES, 1978). Two other types of activity seem to be important in this context. The first of these is the development of new methods and techniques which are directed towards specific applications. The second lies in the recognition of particular research areas as having potential for application. In practice it is probably more useful to see the relationship as a continuum rather than to attempt to identify a specifically applicable component of the subject. The literature of applied geomorphology is quite large and two recent books give some idea of the scope. They are Geomorphology in Environmental Management (COOKE and DOORNKAMP, 1974) and Applied Geomorphology (HAILS, 1977). An attempt is made here to select but a few examples of recent British work which exemplify the relationships between research and application at the various levels, and which illustrate the more general trend of research activities.
within the universities and, to a lesser degree, in the polytechnics. It is mainly funded by the government, through the Natural Environmental Research Council (N.E.R.C.), by the universities themselves or by private sources. Individual geomorphologists have also been engaged as consultants by international and national agencies and by private companies. Following the Rothschild report (H.M.S.O., 1971) the British government adopted a “customer-contract” principle towards research in which the government acts as customer, commissioning research from the universities, from institutions and from other research bodies. This has led, in the N.E.R.C., to a somewhat more pragmatic attitude to wards the research activities which it supports. Moreover, the strengthening of the research institutions within the Council’s control, such as the Institute of Hydrology and the Institute of Geological Sciences has led to even greater competition for research funds. Basically, the funds available for geomorphological research remain very small and this has resulted in a concentration of effort in those areas requiring only modest sums of money. The Application of Geomorphological Methods and Techniques
Several steps are involved in direct application. These involve the precise identification of the problem, the specification of the information required for its solution, the collection of that information and the provision where possible of a set of alternative strategies leading to a
In Britain geomorphology is taught and researched mainly in Departments of Geography _____-_ * Dept. of Geography, London School of Economics, Houghton St., London WC2A 2AE. 253
254
solution. In this respect the methodology is similar to classical induction in science. By virtue of his training the geomorphologist emphasises the long term, complex structure of the problem rather than the immediate short-term technical problem. At the same time the shift towards greater interest in contemporary processes has led to a better training in the basic mechanics of the problem. It is this combination of historical perspective and technical competence which needs to be more fully developed and put to advantage. This point may be illustrated by reference to some recent work in Argentina. High-level, arid-zone basins in the province of Catamarca are undergoing severe desertification problems at the present time with extensive dune development and encroachment on cultivated land. In the short term the problem is viewed simply as one of dune stabilization using natural or artificial means (such as bitumens or special fencing) or the provision of smallof intensively irrigated land. scale “islands” Detailed field investigation however indicates a much more deeply rooted problem. This is a combination of deep-river trenching and the associated lowering of the water table together with extensive cutting of the native carob tree in the former bottomlands by the river and the grazing of unstable grasses on flat sandy areas. The problem may only be fully appreciated in the historical context and the solutions will involve economic and social as well as geomorphological measures (THORNES, 1978). Published British work has largely been concerned with the collection of geomorphological data, using geomorphological techniques to provide the information with which to develop management alternatives or choose between them. The work of Brunsden and his colleagues helps to illustrate these various types of activity with respect to fixed, topographic information. From their mapping of landslides in Dorset, BRUNSDEN and JONES (1972) were able to identify complex subsurface failure structures which in turn were producing surface-road construction and maintenance problems. In another study (BRUNSDEN et al., 1975) the geomorphological mapping of the land along the projected Dharan-Dhankuta highway in Nepal, with a length of 65 km, assisted engineers in choosing one of several alternative road alignments. In particular the utility of these investigations was in pointing
Geoforum/Volume lo/Number 3/1979
to likely sources of engineering problems which required further and much more detailed mechanical site analysis. In this sense the geomorphological information provides a first “filter”, thus lowering the cost of subsequent efforts. Sources of materials for construction and potential construction hazards arising from flooding and high salinity of groundwaters have also been the subject of investigation by this group (BRUNSDEN et al., 1976). Observational techniques and measurements have also been made of dynamic phenomena. In particular the recording of changes in hydrology and fluvial geomorphology reflects the overall resurgence of interest in fluvial processes. In Britain this work has been characterised by studies of the impact of urbanisation on hydrology and sediment production. A recent study by HOLLIS (1974) exemplifies this type of research. Investigations were made of the effects of progressive urbanisation around Harlow (Essex) on a local stream. Here a 16% urbanisation of the catchment led to an increase of the maximum monthly flood from 1.16 to 2.58 m3 /set over a period of 18 yr. GREGORY (1974) investigated the effects of building activity in a small drainage basin on the margin of Exeter, Devon, and showed that they have resulted in a doubling of peak discharge, a decrease of lag time to half its former value, and an increase in runoff varying between 1.1 and at least three times its former value. More recently GREGORY (1977) has edited a book on River Channel Changes, in which many papers describe short-, medium- or long-term changes in river channels and flood plains, some of which are of direct economic significance. Geomorphologists have also been involved in research designed to alleviate the magnitude of and losses incurred during floods. PENN INROWSELL and CHATTERTON (1977) attempt to relate flood damage costs to river stage and channel characteristics and geomorphological data has been employed in the estimation of discharge from unguaged catchments (N.E.R.C. 197.5). Water quality observations have been made to assess long-term changes superimposed on annual cyclical variations (EDWARDS and THORNES, 1973) or the impact of particular events such as the extremely dry English summer of 1976 on water quality (FOSTER and WALLING, 1978).
Geoforum/Volume IO/Number 311979
British geomorphologists have not generally been concerned with long-term monitoring of en~ronment~ systems even though various universities and polytechnics have maintained experimental catchments (e.g. ELLIS, 1977). The prevailing view in Britain has been that such investigations are best carried out by national bodies such as the Institute of Hydrology. This is because to be effective, such investigations usually need appreciable investments of time and money. There is, of course, some need to balance a few very well instrumented catchments, which can cover only a limited range of environments and problems, with a larger number which, although less well instrumented enable a larger range of conditions to be sampled. In any case nearly all the institutions concerned with long-term monitoring have geographers on their staff. There have also been some notable contributions from one or two research catchments (e.g. WEYMAN, 1974). Research for Application
One of the areas of overlap with direct application is the development of techniques, such as mapping, which will enhance the assessment of resources and change. Britain has a long history of such research (e.g. SAVIGEAR, 1958). Surprisingly, despite the existence of very active groups concerned with remote sensing in various departments in Britain, geomorphologists have, by and large, been slow to adopt the associated techniques. This is largely a reflection of the fact that reconnaissance survey has played a relatively minor role in the subject when compared with other countries. Nonetheless automated mapping is under development for geomorpholo~~al applications. An example of this is the work we have recently undertaken to provide a system of computer programmes for mapping soil erosion potential (MOORE and THORNES, 1976). This involves simple and easily obtainable field data in the form of spot heights or contours and uses a set of transport laws to generate erosion potential surfaces according to the type of processes or mixture of processes being considered. Similar work by KIRKBY (19761, and BEVAN and KIRKBY (1977), attempts to model the effects of drainage network and drainage basin topographic form respectively, on the spatial variability of the stream-flow hydrograph. This
255
work is particuiarly important in recognising the need to develop simple but physically wellfounded models of physical systems for which data can be easily obtained. Models which are less well based and require large amounts of historical data for their p~amete~zation are often of limited value, particularly in underdeveloped countries. A second important area of research for application is in the development of techniques for field measurement. The Technical Bulletins of the British Geo~~rpho~o~ical Research Group give some indications of developments in this field. In the fluvial field, for example, techniques for the monito~ng of suspended load (WALLING and TEED, 1971), bedload (ANDERSON, 1976) and water quality have been developed. Dr. P. McCullagh of the University of Nottingham has designed and developed a system of “wave posts” which give a signal whose frequency is a function of the height of water standing around the post. These were first developed for application in coastal studies but recently they have been successfully applied to the estimation of stage in ephemeral channel flows (BUTCHER and THORNES, 1978). They are particularly useful in this situation because, with very high sediment yield, conventional rating methods tend to cause very rapid ag~adation in the channel, do not allow for shifts in the main path of the stream, and impede the use of the channel bed for access. The most advanced and elaborate experimental work in Britain, both in equipment and field installation, is carried out at the Hydraulics Research Station at Wallingford. In particular, the experimental work on stream meanders by ACKERS and CHARLTON (1970 a, b) is well-known. Like the Institute of Hydrology, the Hydraulics Research Station is responsible to the Natural Environment Research Council. The development and use of climatic simulators for the exploration of the effects of temperature and humidity on weathering is also proving important. GOUDIE, COOKE and EVANS (1970), and GOUDIE (1974), have conducted simulations of salt-weathering on natural materials and show that it is extremely potent in comparison with other mechanical weathering processes. In areas of salt-rich groundwater, such as the semi-arid and arid countries of the Middle East, the implications
256
Geoforum/Volume lo/Number 3/1979
of this work for urban development important indeed (GOUDIE, 1977).
are very
A third type of research for application has been the investigation of statistical and mathematical models for forecasting change in environmental systems. The simplest cases involve empirical regression associations between an input to the system and a response variable. Discharge and river channel response provide a good example. PARK (1977) examined the regression relationship between drainage area to a point and channel capacity for a given frequency of discharge event. The channel capacity is the cross-sectional area of the water for a given event. He found that the gradient of this relationship is much steeper below reservoirs implying a sharper increase in channel capacity with discharge immediately below the reservoir. This effect is produced by the reduction in peak discharge as a result of reservoir construction and scour resulting from reduction in the stream load. Much more complex regression models have been constructed of channel geometry (e.g. BENNETT, 1976), though the utility of models based simply on the statistical description of channel morphology has, in my view, still to be demonstrated. A slightly different kind of model study is that recently carried out at the London School of Economics and Political Science (THORNES 1975). We investigated the and CLARK, statistical structure of water quality series using simple and seasonal autoregressive and movingaverage models. The objective was to assess the effects of missing data points on the structure and parameters of the models and to estimate how much data could be lost before the data set became useless for the specified purpose. For some water quality variables (such as electrical conductivity, temperature and pH) we found that the authorities could halve the amount of data collected without a serious loss of information. Although the use of experimental design and statistical techniques are now widespread in British geomorphology, insufficient attention has been paid to spatial variability and sampling procedures. These are especially important in applied work, for example in estimating groundwater conditions from point locations. The fourth
major thrust in research
for applica-
tion has come with the widespread adoption of the general framework of systems analysis. The work of CHORLEY and KENNEDY (197 1) has provided an impetus for this research and this has been reinforced by the Environmental publication of Systems (BENNETT and CHORLEY, 1978). One particular aspect of this has been to pay more attention to the general problem of budgeting. This work has so far largely emphasized water budgets and in particular their relation to land drainage. However, several recent papers have emphasized solute budgets and work is beginning to focus on geochemical cycles. One type of these studies is the mapping of solute concentrations in the catchment. WALLING and WEBB (1975) plotted variations in solute concentrations in the Exe catchment in southwest England. More work is needed in this field but also further investigations must be made of the detailed mechanisms involved in geochemical transfers. WAYLEN ‘(1976) has attempted to trace the geochemical budget of an entire small catchment on the Mendip Hills in Somerset and currently investigations of individual radioactive elements such as caesium are underway. This geochemical budgeting must be linked to hydrological hillslope data to provide information on the likely effects of forest removal and land management on soil chemistry. Some efforts along these lines are being made in a small tropical catchment near Manaus, Brazil. This involves observation of the hydrological and geochemical status of several sites over a period of some years prior to forest clearance (NORTCLIFF, THORNES and WAYLEN, 1979). Research with Application
Much of the research in British geomorphology is unfettered by the constraints imposed by the requirements of particular practical problems. At the same time much of it has great potential for application. Reviews of British research into mass movement (PRIOR, 1978), fluvial processes (GREGORY, 1978) and coastal phenomena (KING, 1978) have been published in the book Geomorphology: Present Problems and Future Prospects, edited by EMBLETON et al. At the very frontier of research a particular theme seems likely to prove important in the future relationship between research and
257
Geoforum/Volume 1O/Number 3/l 979
application. During the 1960s most British geomorphologists, following the North American example, came to believe that the most useful view of geomorphological systems was one that emphasized their short-term conditions of dynamic equilibrium. Accordingly, most basic research sought to emphasize equilibrium conditions and solutions. Most applications, on the other hand, are concerned with systems in dynamic disequilibrium and solutions which obtain over periods of the order of several decades. In the last few years there has been a shift towards the study of disequilibrium in geomorphic systems. In the 1960s the prevailing view was that the most important events were those of medium magnitude and frequency, in systems governed by self-regulation through negative feedback. In the 1970s more attention is being paid to transient behaviour during periods of relaxation after extreme events and to theoretical modelling of the stability-instability conditions which engender changes in the rate of operation of processes and the forms produced. Several papers have recently pointed out that periods of transient behaviour (recovery) between extreme events may be as important as the events themselves. This is most readily seen in semi-arid environments where low flows between large events recreate the channel, determining the nature of the response to succeeding large events (THORNES, 1977). However, the persistence of storm effects has also been studied in perennial channels. ANDERSON and CALVER (1977) for example have described the long-term effects of river channel response to the 1956 flood disaster at Lynmouth (Devon). Such observations need to be put on a firmer theoretical footing and the work of ALLEN (1974, 1976) is seminal in this respect. Much of applied work in fluvial and coastal environments involves protection for and recovery from the effects of extreme events.
analysis has been carried out with reference to changes in drainage density resulting from changes in the controlling variables. In the long term theoretical studies of this type will be needed to forecast the responses of rivers and hillslopes to changes produced by river management, deforestation and perhaps even climatic change. Finally, it is worth making the point that detailed studies of historical changes are important in the solution of practical problems even if they only demonstrate to us the complexity of responses to simple inputs in geomorphological systems. By understanding the extensive changes which have been caused by human activities in historic times and the anthropological responses to such changes, we will be in a stronger position to contend with future changes. This is well illustrated by the study of arroyo entrenchment in the southwest United States by COOKE and REEVES (1976) and by Mosley’s study of changes in the River Bollin, in Cheshire (England) (MOSLEY, 1975). In particular studies of known historical changes and their effects are important in the applied studies. It is not enough to investigate past changes and attempt to determine their causes. It would be a mistake to take too confined a view of applied geomorphology. Rather, what is needed is a wider appreciation of the practical importance of the research already being carried out and a recognition of the continuum between the basic description and assessment of geomorphological phenomena at one extreme and the theoretical modelling of the long-term behaviour of dynamic geomorphological systems on the other.
References
ACKERS P. and CHARLTON F.G. (1970a) MeanderOn the theoretical side, work in Britain is only just beginning. KIRKBY (1977) has attempted, following the work of Henderson and others to determine, theoretically, the stability conditions for the existence of different modal states (e.g. meandering or braiding) in river systems. In particular he has paid more attention to the role of sediment transport efficiency as a stability criterion. A similar
ing geometry 11. 230-252.
arising from varying~flows,‘.T, Hydrol.
ACKERS P. and CHARLTON F.G. (1970b) The geometry of small meandering streams, E3oc. Instn.
civ. Engn. Paper 73285 289-317. ALLEN J.R.L. (1974) Reaction, relaxation and lag in natural sedimentary systems: general principles, examples and lessons, Earth-Sci. Rev. 10, 263-342. ALLEN J.R.L. (1976) Bed forms and unsteady processes: some concepts of classification and response
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illustrated by one-way types, Earth Surface Processes, 1,361-374. ANDERSON M.G. and CALVER A. (1977) On the persistence of landscape features formed by a large flood, Trans. inst. Br. Geogr. N.S. 2(2), 243-254. ANDERSON M.G. (1976) An inexpensive circuit design for the acoustic detection of oscillations in bedload transport in natural streams, Ewth Surface Processes, l(3), 213-219. BENNETT R.J. (1976) Adaptive channel geometry, Earth Surface Processes; 1, 13 l-l 50. BENNETT R.J. and CHORLEY R.J. (1978) Environmental Systems: Philosophy, Analysis and Control. Me~uen, London, 623 pp. BEVAN K.J. and KIRKBY M.J. (1976) Towards a simple physically based variable contributing model of catchment hydrology, University of Leeds, School of Geography, Working Paper No. 154. BUTCHER G.C. and THORNES J-B. (1978) Spatial variability of runoff processes in an ephemeral channel, Z. Geomorph. N.F., Suppl. Bd. 29, 83-92. BRUNSDEN D. and JONES D.K.C. (1972) The morphology of degraded landslide slopes in south west Dorset, Q. Jl. Engng. Geol. 5,205222. BRUNSDEN D., DOORNKAMP J.C., FOOKES P.G., JONES D.K.C. and KELLY J.M.H. (1975) The use of geomorphological mapping techniques in highway en~eer~g, J. Instn. Highw. Engng. 22,35-41. BRUNSDEN D., DOORNKAMP J-C. and JONES D.K.C. (1976) Summary and recommendations, Bahrain Surface Materials Resources Survey, 1. BRUNSDEN D., ~O~KAMP J.C. and JONES D.K.C. (1978) Applied geomorphology: a British view, In: Geomorphology: Resent Problems and Future Prospects, pp. 251-262, C.E. Embleton et al. (Ed). Oxford University Press, London. CHORLEY R.J. and KENNEDY B.A- (1971) Phys~al Geography: A Systems Approach. Prentice-Hall, Englewood Cliff, COOKE R.U. and DOORNKAMP J.C. (1974) Geomorphology in environmental M~age~ent. Oxford University Press, London. COOKE R.U. and REEVES R.W. (1976) Arroyos and Environmental Change in the American Southwest. Oxford University Press, London. EDWARDS A.M.C. and THORNES J.B.(1973),~nu~ cycle in river water quality: a time series approach, Wat.Resour. Res. 9,1286-1295. ELLIS J.B. (1977) The characterization of particulate solids and quality of water discharged from an urban cat&men& In: Effects of Urination and Industrialization on the Hydrological Regime and on Water Quality, Int. Assoc. for Scientific Hydrology. EMBLETON C., BRUNSDEN D and JONES D.K.C. (Ed.) (1978) Geomorphology: Present Problems and Future Prospects. Oxford University Press, London, 281~~. FOSTER I.D. and WALLING D.E. (1978) The 1976 drought and nitrate levels in the River Exe basin, J. Instn. Water Engn. Sci. 32,34I-35 1.
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IO~Number 311979
GOUDIE AS. (1974) Further experimental investigation of rock weathering by salt and other mechanical processes, Z. Geomorph. N.F. Suppl. 21, l-12. GOUDIE AS. (1977) Sodium sulphate weathering and the dis~tegration of Mohenjo-Daro, Pakistan, Earth Surface Processes, 2.75-86. GOUDIE A.S., COOKE R.U. and EVANS J.S. (1970) Experimental investigation of rock weathering by salts, Area, 4,42-48. GREGORY K.J. (1974) Streamflow and building activity, In: Fluvial Processes in Instrumented watersheds, Special Publication Vol. 6, pp. 107. 122, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers. GREGORY K-3. (1977) River Channel Changes. John Wiley, New York. GREGORY K.J. (1978) Fluvial processes in British basins, In: Geomo~holo~, Present ~oblems and Future Prospects, pp. 40-72, C.E. Embleton et al. (Ed.). Oxford University Press, London. HAILS J. (1977) Applied Geomorphology. Elsevier, Amsterdam. H.M.S.O. (1971) The organisation and management of government R and D, Framework for Government Research and Development, Cmnd. 4814, London. HOLLIS G.E. (1974) The effect of urbanization on floods in the Canon’s Brook, Harlow, Essex, In: F~v~l Processes in Ins~~nted ~tchments, Special Publication Vol. 6, pp. 123-139, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers. KING C.A.M. (1978) Coastal geomorpholo~ in the United Kingdom, In: Geomorphology, Present Problems and Future Prospects, pp. 224-250, C.E. Embleton et al. (Ed.). Oxford University Press, London. KIRKBY M.J. (1976) Tests of the random network model and its application to basin hydrology, Earth Surface Processes, 1, 197-2 13. KIRKBY M.J. (1977) Maximum sediment efficiency as a criterion for alluvial channels, In: River Channel Changes, pp. 429442, K.J. Gregory (Ed.). John Wiley , New York, MOORE R.F. and THORNES J.B. (1976) Leap a suite of Fortran lV programs for generating erosional potentials of land surfaces from topographic information, Computers Geosci. 2,493.499. MOSLEY M.P. (1975) Channel changes on the river Bollin, Cheshire, 1872-1973, E. Midld. Geogr. 6, 185199. NATURAL E~IRO~ENT RESEARCH CO~CIL (1975) Flood Studies Report. Five volumes, London. NORTCLIFF S., THORNES J.B. and WAYLEN M.J. (1979) Tropical forest systems: a hydrological approach, Amazoniana S(l), 65-72. PARK C.C. (1977) Man induced changes in stream channel capacity, In: River Channel Changes, pp. 121-144, K.J. Gregory (Ed.). John Wiley, New York.
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lo/Number
3/1979
PENNING-ROWSELL E. and CHATTERTON J.B. (1977) The Benefits of Flood Alleviation. Saxon House, Farnborough. PRIOR D.B. (1978) Some recent progress and problems in the study of mass-movement in Britain, In: Geomorphology, Present fioblems and Future Prospects, pp. 84-106, C.E. Embleton et al. (Ed.). Oxford University Press, London. SAVIGEAR R.A.G. (1958) Morphological mapping, Geography 43, 10-17. THORNES J.B. (1977) Channel changes in ephemeral streams: observations, problems and models, In: River Channel Changes, pp. 317-335, K.J. Gregory, (Ed.). John Wiley, New York. THORNES J.B. (1978) Los Medanos de FiambalaTinogasta. U.N. Office of Technical Cooperation, New York. THORNES J.B. and CLARK M.W. (1975) Effects of missing data on autocorrelation and partial auto-
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correlation functions, Working Paper 3, Water Quality Project, London School of Economics, London. WALLING D.E. and TEED A. (1971) A simple pumping sampler for research into suspended sediment transport in small catchments, J. Hydrol. 11, 129144. WALLING D.E. and WEBB B.W. (1975) Spatial variation of river water quality: a survey of the River Exe, Trans. Inst. Br. Geogr. 65,155-171. WAYLEN M.J. (1976) Aspects of the hydrochemistry of a small drainage basin, Unpublished Ph.D. Thesis, University of Bristol. WEYMAN D. (1974) Runoff processes, contributing area and streamflow in a small upland cat&men& In: Fluvial Processes in Instrumented Catchments, Special Publication, Vol. 6, pp. 3343, K.J. Gregory and D.E. Walling (Ed.). Inst. British Geographers.