European Society for Soil Conservation

Workshop on
Long-term effects
of land-use on soil erosion in a historical perspective: European comparisons

  

 15-17 September 2000
University of Oxford, UK

 

 

Organisers: John Boardman (Oxford) and
 David Favis-Mortlock (Queen’s, Belfast)

  

Programme and Abstracts



INTRODUCTION

This workshop is the third in a series organised by the ESSC Task Force on Long-term effects of land-use on soil erosion in a historical perspective, and follows successful meetings in Müncheberg (September 1998) and Bonn (October 1999). The purpose of the workshop is to review current work on past land use and erosion in Europe, and to plan a future collaborative project provisionally titled Long-term soil erosion and soil conservation along the European ring.

John Boardman

David Favis-Mortlock


PROGRAMME

 

[Thursday 14th September

pm COST 623 Small Group WG3 meeting: Environmental Change Institute, 5 South Parks Road]

 

Friday 15th September

[am COST 623 Small Group WG3 meeting: Environmental Change Institute, 5 South Parks Road]

1.00 pm to 2.00 pm

Registration at St Edmund's Hall, Queen's Lane, Oxford

 

Paper Session 1 in Examination Schools Building, High Street, Oxford
(all invited papers 15 minutes + 5 minutes for discussion)

2.00 pm

John Boardman
(Oxford, UK)

Investigating past soil erosion: some questions and challenges

2.15 pm

Hans-Rudolf Bork
(Kiel, Germany)

Introduction to the ESSC Task Force

2.30 pm

Leszek Starkel
(Polish Academy of Sciences)

Effect of heavy downpours on forms and sediments

2.50 pm

Kazimierz Klimek
(Silesia, Poland)

Reflection of Neolithic and Early Mediaeval soil erosion in the alluvia of the Opava and Osobloga Rivers, northeastern foreland of the Sudety Mountains

3.10 pm

Friedhelm von Blankenburg
(Berne, Switzerland).
Co-authors:
M. Schaller, Niels Hovius and Peter Kubik

Large-scale, time-integrated erosion rates in Europe from cosmogenic nuclides in river sediments

3.30 pm

Timothy Beach
(Georgetown, Washington, USA).
Co-author:
Sheryl Luzzadder-Beach

Soil erosion and geoarchaeology in the eastern Mediterranean

3.50 pm

Dino Torri
(Firenze, Italy).
Co-authors:
C. Calzolari, G. Galardi and L. Rombai

Badland development and land mismanagement in Tuscany, Italy

4.10 pm

John Wainwright
(King's College London, UK)

The (pre-)history of erosion in the Mediterranean Basin

4.30 pm

Break (tea in St Edmund's Hall)

 

5.10 pm         

Tom Vanwelleghem
(Leuven, Belgium).
Co-authors: E. Vermaut, L. Umans, J. Deckers and J. Poesen

The human factor in gully development in Meerdal Forest, central Belgium

5.30 pm         

Birgit Kausch
(Trier, Germany).
Co-authors: Roland Baumhauer, Hartwig Löhr and Brigitta Schütt

The Gaugracht — a contribution to the erosional history of the lower Saar valley (Germany) since the Roman period

5.50 pm         

Markus Dotterweich
(Kiel, Germany).
Co-authors: Gabriele Schmidtchen and Hans-Rudolf Bork

Long-term effects of land use on soil erosion in a historical perspective: current investigations in Germany

6.10 pm

Andrey Panin
(Moscow, Russia)

Hierarchy of the Holocene hydrological rhythmicity on the East-European Plain

6.30 pm

End of session

 

 

 

 

7.00 pm

Dinner (in St Edmund's Hall)

 

 

Saturday 16th September

 

Discussion Session 1 in Examination Schools Building, High Street, Oxford

9.00 am

Discussion re. ESSC Ring Project including report-back of groups

10.30 am

Break (coffee in St Edmund's Hall)

 

 

Paper Session 2 in Examination Schools Building, High Street

11.10 am

Martin Bell
(Reading, UK)

Archaeological studies of the timescales of erosion

11.50 am

David Favis-Mortlock
(Queen's Belfast, UK).
Co-authors: John Boardman and Hans-Rudolf Bork

"Where has this colluvium come from?" Towards a modelling strategy which aims at an answer

 

12.30 pm

Poster session

 

 

Ian Foster
(Coventry, UK)

TBA

 

Brigitta Schütt
(Trier, Germany)

Historical weathering, erosion and accumulation in agricultural used area in southeastern Spain

 

Brigitta Schütt, Roland Baumhauer and Hartwig Löhr
(Trier, Germany)

Changing site-characters since Bronze age - the use of geographical information systems for analysing settlement preferences, a case study from the Bitburger Gutland/Germany

1.00 pm

Lunch (in St Edmund's Hall)

 

 

2.00 pm

Guided walk around Oxford (led by John Boardman)

 

 

3.30 pm

Break (tea in St Edmund's Hall)

 

Discussion Session 2 in Examination Schools Building, High Street

4.10 pm

Further discussion: papers from chairs and co-chairs

6.30 pm

End of discussion

 

 

7.00 pm

Conference Dinner (in St Edmund's Hall)
Further discussion over coffee (led by Hans-Rudolf Bork and John Boardman)

 

Sunday 17th September

9.00 am start

Field trip to the White Horse area, Berkshire Downs (led by Tom Evans, Oxford). We will aim to return to Oxford by 1.30 pm. Packed lunches are provided.

 


ABSTRACTS

Investigating past soil erosion: some questions and challenges

 

John Boardman

University of Oxford, UK

 

The reconstruction of past erosional patterns and events poses peculiar difficulties — as in other parts of the geological record the evidence is fragmentary, indeed the most interesting parts may be missing! Thus we must rely on an interpretation of extant paleo-landforms and deposits using the principle that the present is the key to the past.

In the last 30 years geomorphology has made significant advances in understanding many erosional processes such as crusting, ephemeral gullying and tillage erosion. Conceptual advances with respect to thresholds, feedbacks, spatial and temporal scale are also relevant. Allied to this, major developments in dating, modelling and the interplay between climate and land-use change have taken place. But still important challenges remain, for example:

1.     The present is an inadequate key to the past. Present day landscapes are often quite different from those of the past and scientific approaches to monitoring cover a very short period — therefore, by definition, the observed record is deficient in extreme events.

2.     Past landscapes are inadequately known and inadequately dated. Most of our information is from very limited areas - an archaeological dig or a soil profile. There is therefore a question of representativeness.

3.     Modelling offers an obvious way forward but is still crude and limited although the level of its technical sophistication may have us believe otherwise!

Significant advances will come from a combination of approaches and co-operative efforts: geomorphology, archaeology, anthropology and soil science working together to better understand and explain the partial record of the past.


Effect of heavy downpours on forms and sediments

 

Leszek Starkel

Polish Academy of Sciences, Cracow, Poland

 

The effects of short-lasting heavy downpours differ from the effects of continuous rains or snowmeltings. These are especially spectacular on the bare and steep slopes and show a great variety depending on the lithology of substratum.

The observations of particular events during last years and decades made in Southern Poland are very instructive. On the loessic plateaus and similar substratum the overland flow evoke the rill erosion and shallow soil flows and is frequently combined with piping and gully erosion as well as with aggradation in the first or second order valleys (combined deluvial, proluvial and colluvial deposition). On the steeper deforested slopes with shallow regolith are developing shallow earth flows or in the cryonival beltdebris flows. In the carstic areas may be observed reactivated carstic springs and deposition of coarser fractions combined with erosional transformation of valley floors.

In the case of downpours superimposed on the saturated substratum (after continuous rain or snowmelt period) the scale of debris flows formation, gullying and piping is much more intensive and extended.

In the sediments inherited from the Holocene may be recognised the effects of heavy downpours. Among them are proluvial and deluvial deposits up to several metres thick at the foot of slopes recorded from various foothill regions and loess plateaus. There are also gully systems mentioned in various sources and presented on the old maps. Especially valuable are the sequences of alluvial (proluvial) fans in which may be preserved the layers related to particular heavy downpour events.

In overbank deposits of second-third order streams such as extreme events are represented by the layers or lenses of coarser material with organic detritus. The surfaces of older debris flows in the high mountains are dated by lichenometric method and the coarser deposits in sequences of lake sediments correlate with them.

Only the application of actualistic approach can help to differentiate the recognition of geomorphic and sedimentological effects of heavy downpours from other meteorological events.


 Reflection of Neolithic and Early Mediaeval soil erosion in the alluvia of the Opava and Osobloga rivers, northeastern foreland of the Sudety Mountains

 

Kazimierz Klimek

University of Silesia, Sosnowiec, Poland

 

Eastern part of the Sudety Mountains takes shape of a mid-mountain massif (600 - 1400 m) made up of Palaeozoic gneiss and Devonian to Carboniferous greywackes and sandstone. During the cold periods of the Quaternary mountain slopes and valley sides were mantled by regoliths. The NE foreland of the Sudety Mountains (260- 320 m) is filled with heterogenous Quaternary deposits covered with a layer of loess deposited during the last Scandinavian glaciation. The Opava and Osoblaha/Osobloga rivers, tributaries of the upper Oder River are characterised by a high flood dynamics caused by both high precipitation in their headwater area and steep gradient in the upper valley sections.

Early farmers and breeders entered in the area from the Pannonian/Dabube Basin via the Moravian Gap beginning around 5400 - 5300 BC and are now known as the Linear Pottery culture. They settled mainly on the loess soils in the foreland of the Sudetes. That was the time of the first forest clearing and the beginning of man-induced soil erosion. Neolithic cultures that followed, until the Roman influences, kept stimulating soil erosion on the undulated loess plateau, thus leading to accumulation of alluvia in the main valley floors. Following a period of de-colonisation caused by a pause in tribal migration the area saw the beginning of an influx of Slavs. There are numerous archaeological sites that document this period and tribal castles in the area date as far back as to the 7th century. The second phase of the agricultural colonisation of the northeast foreland of the Eastern Sudetes began under the Greater Moravian State and was continued when the Opole Duchy replaced the former in 12th century. This, again, is documented by numerous settlements, later to become towns, cited to exist in the area since 11th and 12th centuries.

During that period, low yields from cultivated crops resulted in a situation whereby one family usually farmed one feud of land i.e. 15 - 30 ha. This led to overcultivation and forest clearing to gain more of fertile soil. As the result, runoff of rainwater and snowmelt water increased soil erosion. Population density of 30 persons per square kilometre on the loess-covered Glubczyce Plateau during the first half of 14th century illustrates the intensity of agricultural cultivation. Eroded material was deposited mainly within the footslopes or filled the secondary headwater valley floors; a portion was transported downstream and deposited in the main valley floors. Here, the development of the natural levees caused the origin of the backswamps in the middle course of the Opava and Osoblaha/Osobloga river valleys. These depressions are now filled up with non-carbonate silt of 0.05 - 0.002 mm with a significant content of clay < 0.002 mm (up to 30%). This indicates that the loess cover was the main source of these deposits. In the lower course of the Osoblaha/Osobloga valley, where vertical erosion prevailed, close to the present-day channel course, there are younger generations of fossil paleomeanders with organic infills, overlaid with 2 - 3 m thick silty overbank deposits. The oldest of these fossil organic intercalation is dated back to 1120±30 years BP, which would indicate that the overbank sedimentation was running faster during the early Middle Ages.


Large-scale, time-integrated erosion rates in Europe from cosmogenic nuclides in river sediments

 

Friedhelm von Blanckenburg1, M. Schaller1, Niels Hovius2 and Peter Kubik3

1Universität Bern, Switzerland

2University of Cambridge, UK

3Universität Zürich, Switzerland

 

Traditional estimates of large-scale, continental erosion rates are based upon measurements of solid and dissolved loads of rivers [1]. This method requires long-term (at least several decades), frequent (preferably daily) measurements, to account for temporal variability of water discharge and sediment transport. Even where these requirements are met, erosion rate estimates are not necessarily robust, because 1) they may not have captured rare, high-magnitude flood events, and 2) sediment transport rates may have been affected by river engineering works.

We have determined large-scale, continental erosion rates, using the concentration of the rare cosmogenic nuclide 10Be in quartz from the bedload of rivers. This technique exploits the continuous bombardment of the Earth's surface by cosmic rays which induce nuclear reactions in the upper meter of rocks. Nuclide concentration in the shallow subsurface is controlled by the surface erosion rate. It can be demonstrated that river sands contain a cosmogenic nuclide inventory that reflects the ensemble of erosion events distributed across a catchment. Assuming steady state erosion and nuclide production, the catchment-wide erosion rate, averaging over the time it takes to erode a layer of the uppermost 60cm (several kys) can be determined from a sample of well-mixed sand [2, 3].

We have tested this approach in four medium sized (103-104 km2) rivers draining the middle European uplands. The four test catchments are the Regen (SE Germany, crystalline bedrock), the Loire and Allier (France, crystalline bedrock), the Neckar (SW Germany, Mesozoic Sediments), and the Meuse (NE France, Belgium, Netherlands, Mesozoic sediments and Palaeozoic shists). Erosion rates were estimated from cosmogenic nuclide concentrations in river quartz, using the formalism developed by Lal [4]. Production rates have been scaled to the mean altitude of the upstream area of individual sampling locations. These estimates were compared with erosion rates calculated from suspended and dissolved loads measured during the last 30 years.

RIVER

RIVER LOAD

COSMOGENIC

Regen

7 mm/kyr (20 T/km2/yr)

35-45 mm/ka (100 T/km2/yr)

Loire/Allier

5-10 mm/kyr (20 T/km2/yr)

20-90 mm/ka (150 T/km2/yr)

Neckar

25-30 mm/kyr (75 T/km2/yr)

70-170 mm/ka (300 T/km2/yr)

Meuse

15-25 mm/kyr (55 T/km2/yr)

25-50 mm/ka (100 T/km2/yr)

There is good first-order agreement between river load-based and cosmogenic erosion rate estimates. However, close comparison between the methods shows that the river load-based rates are always 2-5 times lower than the cosmogenic rates. This difference may have at least three causes. First, the suspended loads do not necessarily include rare, high-magnitude events, such as centennial or millennial floods, which possibly carry the bulk of the sediment. In contrast, cosmogenic rates integrate over several kiloyears (5-10kyr Neckar; 10-30kyr Loire, 20-30kyr Regen, Meuse) and thus capture the full range of event magnitudes. Second, the steady-state assumption of homogeneous downwearing is violated by linear dissection processes such as rilling and gullying. Third, and most important, the cosmogenic rates carry a "memory" of past erosion rates that prevailed during the last cold period in Middle Europe. The latter possibility can be evaluated by application of the same approach to terrace deposits of the last climate cycle.

Observed spatial uniformity of erosion rates within catchments shows that the cosmogenic technique has considerable potential for the estimation of time-integrated denudation rates. Moreover, it might allow estimation of natural soil erosion (time-averaged cosmogenic erosion rates) vs. soil erosion induced by man (short-term rates from river gauging and estimates of historic soil erosion events), and could facilitate an evaluation of the effects of man, climate and climate change on continental erosion.

 

References

[1] M. A. Summerfield and N. J. Hulton (1994). J. Geophys. Res. 99, 13871-13883.

[2] D. E. Granger et al. (1996). J. of Geology 104, 249-257.

[3] P. Bierman and E. J. Steig (1996). Earth Surface Processes and Landforms 21, 125-139.

[4] D. Lal (1991). Earth Planet. Sci. Lett. 104, 424-439.



Soil erosion and geoarchaeology in the eastern Mediterranean

 

Timothy P. Beach1 and Sheryl Luzzadder-Beach1

1Georgetown University, Washington DC, USA

2George Mason University, Fairfax VA, USA

 

Questions of abiding interest in the Mediterranean world are the timing and causes of periods of soil erosion and aggradation. This paper is based on geoarchaeological field work over the last four years around and in Alanya and Kinet Höyük on Turkey's southern Mediterranean coast. Both regions have watersheds that rise in the Taurus or Ammanus Mountains and run through foothills and fans onto alluvial coastal plains. A legion of little-known environmental dynamics such as seismicity, climatic changes, sea-level changes, and millennia of human impacts complicate these landscapes. To investigate these complications we dated and characterized sediments, soil formation, and alluvial history, and correlated these with the regions’ environmental and archaeological records. We studied cutbank sediment sequences and paleosols across these watersheds’ valleys. In the watershed of the Ammanus Mountains, we found four salient paleosols that date from the Early Bronze Age, the Late Bronze Age, the Roman period, and the Ottoman Period. But there is greater diversity in the Taurus Mountains’ watershed. The presence of regional paleosols and their intervening episodes of sedimentation suggest possible periods of erosion and sedimentation. But despite the long human history of these regions the greatest changes have occurred in modern times. We are also studying the elemental chemistry of regional sediments and soils which will provide other sources of information for environmental change and past land uses. we will compare our field studies at these sites with previous and concurrent studies in the eastern Mediterranean to analyze earlier models of erosion & sedimentation hist across this whole region


Badland Development and Land Mismanagement in Tuscany (Italy)

 

C. Calzolari1, G. Galardi2, L. Rombai2 and D. Torri1

1CNR-IGES, Firenze, Italy

2Dipartimento di Studi Storici e Geografici, Firenze, Italy

 

Part of Tuscany (Italy) is characterised by Plio-Pleistocenic marine sediment outcrops that are generally overconsolidated but scarcely cemented, hence fairly erodible. The study area (podere Baccanello – podere=farm unit) is located in the valley of the river Orcia, Southeast Tuscany. The area of Baccanello and the surrounding sites are positioned over silty clay deposits, heavily dissected by badlands (biancana fields, Calzolari and Ungaro, 1998), now interspersed between land-levelled fields.

A thorough study of the spatial distribution of soil types within the biancana field surrounding the hill where the buildings of the podere Baccanello are located, showed that the better developed soils (Vertisols) are located on the top of small hills and on tallest biancana domes. Some spots of these soils are also found on the upper parts of presently cultivated slopes. The morphological position of these soils, together with the measured erosion rates (Torri and Bryan, 1998) indicate that the erosion events that lead to the badland formation must belong to a recent past.

The fortunate recovery of a cabreo (painting) dated 1837, which very precisely depicts the land use and some morphological features of the area, permitted us to verify the hypothesis on biancana field evolution and to start a research on the effects of past land (mis)management on soil erosion and landscape evolution. The research continued with an inquiry through documents preserved in the Italian State Archives, mainly in Florence.

The collected data describes two periods of major erosion which brought to the formation of biancana fields extended over some hundreds hectares. The first event took place during the eighteenth century and the second a century later. Both the events caused localised erosion of about 10m in some years (certainly less than 20). At present, erosion rates cannot be precisely determined nor the direct causative type of storm (or sequence of storms) due to still missing documents.

The evidences bring to the conclusion that the most important factor causing the badland formation was in both cases linked to mismanagement. Particularly, the documents relative to the first case were found as acts of the Florence Court. The Baccanello landlord invoked the Court in order to rescind the contract with which the Baccanello farm was rented. The allegation was that the tenant was mistreating the soil and causing farm degradation. The second case was just after a change in land use (recorded in the cabreo) from pasture to arable, that exposed some further hectares to intense erosion.



The (pre-)history of erosion in the Mediterranean Basin

 

John Wainwright

King's College, London, UK

 



The human factor in gully development in Meerdal Forest, central Belgium

 

Tom Vanwelleghem, E. Vermaut, L. Umans, J. Deckers and J. Poesen

Katholieke Universiteit Leuven, Belgium

 



The Gaugracht — a contribution to the erosional history of the lower Saar valley (Germany) since the Roman period

 

Birgit Kausch1, Roland Baumhauer1, Hartwig Löhr2 and Brigitta Schütt1

1University of Trier, Germany

2Rheinisches Landesmuseum, Trier, Germany

 

The Gaugracht is a gully with a partial wooded watershed in the lower Saar valley. The area totals about 2 km². Bedrock consists of mesozoic sediments covered by slope debris.

As cross profiles of the Gaugracht show there are several — minimum two — gully generations nested. In consequence of the youngest incision, which took place approximately during late Middle Ages, an alluvial fan has been formed at its base level. While most recently gullying processes in the watershed are of minor importance, the medieval alluvial fan was incised by a 3 m deep insection in the youngest past, yielding good profile conditions. At the mouth of the eroded indentation a younger small alluvial fan is building up today.

Utilisation of the area in earlier times can be proved by the "Altes Lager" (presumably a fortified roman estate of smaller dimension), grave-findings (early roman times) and the preservation of today wooded field terraces of high-medieval times in the headwater area of the watershed and its surroundings.

Investigations were made on various landform parameters by morphometry. The sediments of the alluvial fan were analysed on physical parameters and geochemically on main and trace elements in order to get information on the degree of environmental change and soil erosion in the drainage basin area of the Gaugracht in the past. Additionally, some of the adjacent sediments will be analyzed for the inclosed mollusc-association.

 


Long-term effects of land use on soil erosion in a historical perspective: current investigations in Germany

 

Markus Dotterweich, Gabriele Schmidtchen and Hans-Rudolf Bork

Christian-Albrechts-Universität zu Kiel, Germany

 

This paper will show the current projects of our working group about long-term effects of land use on soil erosion in a historical perspective in Germany.

This year we are investigating areas in northern Bavaria, Brandenburg, Schleswig-Holstein and in Lower Saxony. The research aim is to quantify soil losses caused by soil erosion due to intensive land use and heavy rainfalls. The investigation sites are slopes and gully-systems with their sediment traps and colluvial fans. The time scale of soil losses range from Iron Age until today. Here we will present new results from our research.

 


 Hierarchy of the Holocene hydrological rhythmicity on the East-European Plain

Andrey Panin

Moscow State University, Russia

 

In a wide geographical context erosion is a part of continental hydrological cycle. Changes of amount of surface flow that makes extrinsic control over erosion process, may be documented from functioning of river systems. Some examples of such changes have been found on the East-European Plain.

1. The Holocene hydrological cycle. The Holocene variations of river discharges are fixed in the size of palaeochannels preserved on river floodplains. Absolute dating of palaeochannels in a number of key sites reveals the general tendency of river runoff change: decline during the first half of the Holocene and subsequent rise in the late Holocene. Changes are not synchronous: in the north of the East-European Plain the lowest runoff is estimated in early Atlantic (6-8 ka BP), in the central part — in the late Atlantic (5-6,5 ka BP); no data exist for the southern regions. The late Sub-Atlantic is marked by growth of river channel size all over the territory.

2. Rise of peak discharges during the last millennium. Characteristic for river floodplains in the centre and south of the East-European Plain is distinct buried soil dated at 0,8 - 2,4 ka BP by 14C and archaeological methods. It is indicative of interrupt or at least of rare flooding. The soil is covered by up to 1-1,5 m thick laminated sediment with artefacts and organic matter dated at less than 1 ka BP. So, the Sub-Atlantic demonstrates a 2000-year climatic rhythm (“Shnitnikov cycle”) with the last millennium being its most humid part.

3. The last 2-2,5 centuries. Examination of old maps reveals a specific phenomenon - disappearance of small rivers. River sources shift downstream and upper stretches of river systems become dry valleys (“balkas”). Compared to the end of the XVIII century, river systems in semi-arid regions (steppes and forested steppes) have lost up to 50-60% of their total length. River disappearance was most rapid at the end of XVIII - first half of the XIX century and had stopped by the beginning - middle of the XX century. This phenomenon probably demonstrates evolution of humidity at the end and after Little Ice Age. It did not take place in humid regions (forest zone), that is why it is not known in Western Europe.

Intrinsic landscape control hinders clear coincidence between magnitude of erosion and hydrological rhythmicity. Nevertheless, the latter may serve, at least as a time scale, for inter-regional (long-distance) correlation of erosion history.



Archaeological studies of the timescales of erosion

 

Martin Bell

University of Reading, UK

 

This paper will evaluate the contribution which archaeology can make to a better understanding of the chronology of long-term soil erosion and the environmental and social context within which erosion occurred. The precision of a range of forms of archaeological and historical dating is considered. The most useful sequences will be obtained where there is detailed regional survey and a good existing knowledge of pottery fabrics, settlement and land-use history. Dendrochronology offers much greater chronological precision highlighting the potential for work at the colluvial wetland interface. Archaeological studies have tended to be somewhat site specific, often focusing on individual sections which makes quantification difficult. A more spatial view needs to be obtained mapping and quantifying dated sedimentary units in the landscape. There is also a case for working at a diverse range of spatial scales from individual field -> slope -> stream catchment -> river system -> estuarine interface. This point is developed by a comparison of erosion histories in the River Severn and Severn Estuary which highlights the contribution of dendrochronology to the development of more precise timescales.

The paper will also outline some of the main problems which archaeological soil erosion studies need to address including missing early Holocene woodland soils and the absence of Neolithic activity on the English chalk, contrasting perspectives on the date, extent and scale of erosion in the arid landscape of Almeria, south east Spain, and the problems of dating erosion history in landscapes which saw intensive prehistoric exploitation on Mallorca and Cyprus.

Future archaeological studies of soil erosion are likely to be most productive where they are integrated within interdisciplinary programmes of research using diverse timescales from present to past. Behind these issues is the question for discussion: 'to what extent is it possible, perhaps even necessary, to integrate these archaeological problems and criteria within the developing agenda for soil erosion studies in Europe and beyond?'

 


"Where has this colluvium come from?"
Towards a modelling strategy which aims at an answer

 

David Favis-Mortlock1, John Boardman2 and Hans-Rudolf Bork3

1Queen's University of Belfast, UK

2University of Oxford, UK

3Christian-Albrechts-Universität zu Kiel, Germany

 

In many areas of science, modelling approaches are widely used. The ability of models to assist in evaluating competing hypotheses is one of their most compelling attractions, particularly for situations where experimentation is difficult or impossible. It might therefore have been expected that models would by now have become a valuable tool for the study of past erosion. It is frequently necessary, for example, to weigh the merits of alternative hypotheses regarding the origin of colluvial sediment and the circumstances in which it was deposited. This might seem to be an ideal task for a model: yet model-based studies of past erosion remain a rarity. Why is this?

A partial answer is the mismatch between the capabilities of current models for soil erosion by water, and what they would need to be able to provide in order to be useful in studies of past erosion. As a result of increased understanding of erosional processes there have been great improvements in erosion models in recent years. However, there are still major weaknesses. In particular, current models have problems dealing with the spatial aspects of erosion, and with gullying.

This paper focuses on the spatial aspects of erosion models, from the perspective of their potential usefulness for modelling past erosion. First results are presented from a version of the WEPP Hillslope model which has been modified to improve its suitability for studies of past erosion. The paper also discusses potential strategies for model development within the context of the proposed ESSC collaborative project.

 


POSTERS


Historical weathering, erosion and accumulation in agricultural used area in southeastern Spain

Brigitta Schütt

University of Trier, Germany

 

The focus of the study is the investigation of the varying influence of climate and man on soil and relief forming processes in the semi-arid dryland zone of the upper Rio Guadalentin watershed (Prov. Murcia). It is proven whether the methodological approach gained from investigations of playa-lake-systems, using chemical characters of sediments as an indicator for the reconstruction of paleoenvironmental conditions (Schütt, 1998, 1999), can be transferred to predominantly detrital deposits caused by soil erosion processes. Object of the investigvation presented is a fan in the Cañada Hermosa, a hummocky area in the Subbetic zone between Lorca (Prov. Murcia) and Velez Blanco (Prov. Almeria). Three sedimentcores were taken along a transsect downslope from the vertex of the fan. For water harvesting effects the whole fan is terraced.

Laboratory analysis of the sediments included the detection of sediment structure and the analysis of chemical composition. Beside trace concentrations especially element ratios prove to be useful paleonenvironental indicators: distinct changes in sediment character point to the the initial terracing of the area, evident by marked changes in sediment’s nutrient concentration due to nutrient export by harvesting as well as by sediment structure caused by artificial earth movements.

Checking first the Mg-Ca-ratio of the sediments it can be concluded, that small Mg-Ca-ratios are due to relative dry phases with ephemeral rainfall and only short term ground humidity; the other way around, high Mg-Ca-ratios point to increased calcium mobilization and, thus, to longer lasting ground humidity, in general, coinciding with more rainfall and less evapotranspiration. At all, it has to be emphasized that these processes took place in the terrace environment after deposition and, thus, the Mg-Ca-ratio is an indicator quite different to the Si-Al-ratio, which points to the weathering conditions in the drainage basin environment. Checking the sediment’s Si-Al-ratio it can be concluded that increasing weathering intensities before and during terracing occured, while decreasing weathering intensities marked the environmental conditions during the Modern Times, interrupted by a short phase of moderate weathering intensities compared to the dry conditions with low weathering intensities in the most recent past.

Even still lacking data the sediments lead content gives us an idea about sediments age and sedimentation rates. So we can conclude preliminarily that the relative wet conditions in the recent past might correspond to the end of the Little Ice Age and that terracing took place during the Medieval.

References

Schütt, B. (1998). Chemical and mineralogical characters of lacustrine sediments as paleonvironmental indicators - An example from the Laguna Jabonera, Central Ebro Basin. -Terra Nostra, 98/6, 115-120.

Schütt, B. (1998). Reconstruction of Holocene Paleoenvironments in the Endorheic Basin of Laguna de Gallocanta, Central Spain by Investigation of Mineralogical and Geochemical Characters from Lacustrine Sediments. Journal of Paleolimnology 20, 217-234.

Schütt, B. (1998). Reconstruction of palaeoenvironmental conditions by investigation of Holocene playa-sediments in the Ebro Basin, Spain: Preliminary results. Geomorphology 23, 273-283.



Changing site-characters since Bronze age - the use of geographical information systems for analysing settlement preferences, a case study from the Bitburger Gutland/Germany

 

Brigitta Schütt1, Roland Baumhauer1 and Hartwig Löhr2

1University of Trier, Germany

2Rheinisches Landesmuseum, Trier, Germany

 

The region of the upper Mosel-valley with Trier as one of the oldest german towns in its center is because of it long and well documented history an especially suited region to recognize the changing perception of nature during history of manhood and to record and to understand the interdependance between human acting and natural processes in the past. Thus, a statistical study, linking information on historical and prehistorical findings and natural character of the site was implemented.

At the Rheinisches Landesmuseum Trier since World War II all historical and prehistorical findings are archived, including geographical coordinates, the kind, and the age of the findings assigned to periods. In this way a data-pool is available implying more than 25,000 findings all over the area of Trier.

The county of Bitburg, located in the northern part of the Trier area, is a rural area with only underdeveloped industrialization. Thus, most recent effects on landscape by accounts and sealing are relatively few. Accordingly, this area was selected for an initial statistical analysis combining information about the findings and natural site properties. Data about site properties include information on geology, diverse morphometric parameters, and soil characters like soil type, soil erodibility, and swampy areas. Using a geographical information system the different layers were linked and, that way, site properties of the findings were assembled.

In the following statistical analysis relationships between the kind resp. the age of the findings to site properties were checked. In doing so, changing preferences in location of settlements and graves over the history of man were acquired.


 LIST OF PARTICIPANTS

 

Dr Jussi Baade

Institut für Geographie, Friedrich-Schiller Universität, Löbdergraben 32, D-07743 Jena, Germany
Email cub@geogr.uni-jena.de

Dr Timothy Beach

Program in Science, Technology, and International Affairs, School of Foreign Service, Georgetown University, Washington DC 20057, USA
Email beacht@gunet.georgetown.edu

Dr Martin Bell

Department of Archaeology, University of Reading, PO Box 218, Whiteknights, Reading RG6 6AA, UK
Email m.g.bell@reading.ac.uk

Dr John Boardman

Environmental Change Institute, University of Oxford, 5 South Parks Rd, Oxford OX1 3UB, UK
Email john.boardman@eci.ox.ac.uk

Prof. Hans-Rudolf Bork

CAU Ökologie-Zentrum (ÖZK), Christian-Albrechts-Universität zu Kiel, Schaenburgerstr. 112, D-24118  Kiel, Germany
Email hrbork@ecology.uni-kiel.de

Mintae Choi

Environmental Change Institute, University of Oxford, 5 South Parks Rd, Oxford OX1 3UB, UK
Email mintae.choi@eci.ox.ac.uk

Dr Claus Dalchow

Zentrum für Agrarlandschafts- und Landnutzungsforschung (ZALF) e.V. Müncheberg, Eberswalder Str. 84, D-15374 Müncheberg, Germany
Email cdalchow@zalf.de

Prof. Richard Dikau

Rheinische Friedrich-Wilhelms-Universität Bonn, Geographisches Institut, Meckenheimer Allee 166, D-53115 Bonn, Germany
Email rdikau@slide.giub.uni-bonn.de

Dr Markus Dotterweich

CAU Ökologie-Zentrum (ÖZK), Christian-Albrechts-Universität zu Kiel, Schaenburgerstr. 112, D-24118  Kiel, Germany
Email dotter@ecology.uni-kiel.de

Dr David Favis-Mortlock

School of Geography, Queen's University of Belfast, Belfast BT7 1NN, Northern Ireland, UK
Email d.favis-mortlock@qub.ac.uk

Prof. Ian Foster

School of Natural and Environmental Sciences, University of Coventry, Priory Street, Coventry CV1 5FB, UK
Email i.foster@coventry.ac.uk

Birgit Kausch

Department of Physical Geography, Universität Trier, D-54286 Trier, Germany
Email kaus6101@uni-trier.de

Prof. Adam Kertesz

Department for Physical Geography, Hungarian Academy of Sciences, H - 1112  Budapest, Hungary
Email h3978ker@ella.hu

Prof. Kazimierz Klimek

Dept. of Quaternary Paleogeography and Paleoecology, University of Silesia, ul. Bedzinska 60, 41-200 Sosnowiec, Poland
Email: klimek@ultra.cto.us.edu.pl

Dr Andreas Lang

Geographisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 166, D-53115 Bonn, Germany
Email: alang@giub.uni-bonn.de

Dr Andrey Panin

Department of Geomorphology and Palaeogeography, Moscow State University, 119899, Moscow, Russia
Email: panin@morpho.geogr.msu.su

Prof. Jean Poesen

Laboratory for Experimental Geomorphology, Katholieke Universiteit Leuven, Redingenstraat 16bis, B-3000 Leuven, Belgium
Email Jean.Poesen@geo.kuleuven.ac.be

Nicholas Preston

Geographisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 166, D-53115 Bonn, Germany
Email: nick@slide.giub.uni-bonn.de

Dr Seppo Rekolainen

Impacts Research Division, Finnish Environment Institute, Kesäkatu 6, PO Box 140, FIN-00251 Helsinki, Finland
Email seppo.rekolainen@vyh.fi

Gabriele Schmidtchen

CAU Ökologie-Zentrum (ÖZK), Christian-Albrechts-Universität zu Kiel, Schaenburgerstr. 112, D-24118  Kiel, Germany
Email

Dr Brigitte Schütt

Department of Physical Geography, Universität Trier, D-54286 Trier, Germany
Email schuett@uni-trier.de

Prof. Leszek Starkel

Dept. Geomorphology and Hydrology, Institute of Geography, Polish Academy of Sciences, 31-018 Kraków, sw. Jana 22, Poland

Email: starkel@zg.pan.krakow.pl

Prof. Dino Torri

CNR-IGES, Piazzale delle Cascine 15, 50144 Firenze, Italy

Email dbtorri@iges.fi.cnr.it

Tom Vanwelleghem

Laboratory for Experimental Geomorphology, Katholieke Universiteit Leuven, Redingenstraat 16bis, B-3000 Leuven, Belgium
Email tvanwalleghem@hotmail.com

Dr Friedhelm von Blanckenburg

Isotopengeologie, Universität Bern, Erlachstrasse 9a, 3012 Bern, Switzerland
Email fvb@mpi.unibe.ch

Dr John Wainwright

Department of Geography, King's College London, Strand, London WC2R 2LS, UK
Email j.wainwright@kcl.ac.uk

Dr Jürgen Wunderlich

Institut für Physische Geographie, Universität Frankfurt, Postfach 11 19 32, D-60054 Frankfurt/Main, Germany

Email j.wunderlich@em.uni-frankfurt.de

 

Also attending the Conference Dinner:

Dr Brenda Boardman

Environmental Change Institute, University of Oxford, 5 South Parks Rd, Oxford OX1 3UB, UK
Email brenda.boardman@eci.ox.ac.uk

Tom Evans

Archaeology, University of Oxford

 

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Last modified 02/01/2001 15:34:13 GMT