Sediment Loss from a Waste Rock Dump,ERA Ranger Mine,Northern Australia

During the 1994/95 wet season, runoff, suspended load and bedload loss from large scale erosion plots under natural rainfall events were measured at three sites with different treatments on the Energy Resources of Australia Ranger waste rock dump (cap, soil, fire). The fire site has well established trees, the soil site smaller shrubs and the cap site minimal vegetation. All three sites are located on the flat areas of the waste rock dump with similar slopes and cap, fire and soil are local names for the sites. The quantity of bedload eroded from the soil and fire sites decreased during the monitoring period, however, the same trend was not observed on the cap site. Bedload loss from the fire and soil sites is significantly log‐linear with time and reduces at a decreasing rate until becoming statistically constant toward the later part of the first half of the wet season. For corresponding storms at each site, bedload erosion was highest from the unvegetated and unripped cap site and lowest from the well vegetated fire site. Site specific linear relationships between bedload and total sediment load have been derived and can be used to derive total sediment load in the absence of measured suspended load.     

Erosion and Errors: Testing the Use of Repeated LIDAR Analyses and Erosion Modelling for the Assessment and Prediction of Erosion of Archaeological Sites?

Slope soil erosion is one of the main threats to archaeological sites. Several methods were applied to establish the erosion rates at archaeological sites. Digital elevation models (DEMs) from three different dates were used. We compared the elevations from these three models to estimate erosion. We also applied the landscape evolution model LAPSUS with the available DEMs as basis. Spatial processing errors and effects of tillage and harvesting practices explain most of the DEM elevation differences between the recordings. Increased DEM resolution does not result in more precise or reliable erosion. The present technological level of landscape evolution modelling makes it possible to indicate areas most vulnerable to soil displacement by surface runoff erosion and tillage. Future research, using sediment and surface dating techniques such as deposit of radionuclides, heavy metals and OSL dating will provide a more accurate estimation of erosion rates and the subsequent impact on archaeological sites.     

NEOLITHIC SOILS, MIDDENS AND ALLUVIUM IN THE LOWER WELLAND VALLEY

Summary. The soil micromorphological analysis of buried soils and probable 'midden' deposits buried beneath alluvium from six sites in the lower Welland valley between Maxey and Etton (Cambridgeshire) has revealed a deforested early Neolithic landscape which quickly became subject to seasonal alluviation. This paper suggests that the Neolithic/Bronze Age use of this landscape is directly related to its interpretation as an alluviated floodplain rather than an alluviated, former dry-land landscape.     

Establishing Stage‐Discharge Relationships in Multiple‐Channelled,Ephemeral Rivers: a Case Study of the Diamantina River,Australia

The method for deriving a stage‐discharge relationship has a significant impact on the shape of the river's rating curve. We compare rating curves for a single gauging station on a mutiple‐channelled river in Australia compiled using three different methods – the Urban Runoff and Basin Systems (URBS) rainfall‐runoff model, an empirically‐based velocity‐area method, and the predictive Hydrologic Engineering Centre‐River Analysis System (HEC‐RAS) computer model. The rainfall‐runoff model was found to predict lower discharges for stage heights over 3.5 m than both the empirically‐based velocity‐area method and the HEC‐RAS model. The empirically‐based velocity‐area model predicts similar discharges to the rainfall‐runoff model for stage heights less than 3 m but much higher discharges for larger flood events. The HEC‐RAS model predicts higher discharges than both other rating curves at all stage heights probably due to under‐estimation of the impact of surface roughness on flow velocity. The three models are discussed with particular reference to their use on multiple‐channelled rivers.     

Ancient soil resources of the Usumacinta River Region,Guatemala

In this study we present the results of a combination of methods used to identify possible agricultural activity of the ancient Maya in the Usumacinta River Basin in Guatemala. These methods included stable carbon isotope analysis of bulk soil organic matter, soil profile investigations and a spatial model of gentle slopes and well-drained soils to identify favorable agricultural conditions. Stable carbon isotope analysis of bulk soil organic matter in particular offers potentially direct evidence of agricultural activity. The δ¹³C results suggest that there is a strong signature of C₄ plants, such as maize and tropical grasses, throughout the study area. Further, the current soil conditions and extent of relatively gently sloped areas are favorable to agriculture. Overall, the results are supportive of the hypothesis that the area, located between the polities of Piedras Negras and Yaxchilán, was agriculturally important to surrounding areas.     

A comparison between the Mediterranean climates of Eurasia and the Americas

On the 19th and 20th September 1981 heavy rain fell throughout Scotland. Almost 140mm was recorded for the 24 hours up to 9.00 am on the 20th at Dundonnell in Wester Ross, an event with a recurrence interval of approximately 120 years. The storm generated a peak discharge of c.60m³ s‐¹ on the Ardessie Burn which drains a 13.3km² catchment on the northwestern slopes of An Teallach. The resulting flood caused severe localised bank erosion and partially destroyed a fish farm. The total volume of measured flood deposits exceeded 1800 tonnes, approximately equal to 14 years normal average annual non‐dissolved sediment output. The identification of specific sediment source areas and deposition sites allows an assessment of geomorphic work in terms of direct landscape adjustment in response to extreme rainfall. The flood stresses the importance of rare events in the landscape evolution of upland environments and the influence of antecedent catchment conditions.     

The Role of Fire Disturbance on Runoff and Erosion Processes – a Long‐Term Approach,Mt. Carmel Case Study,Israel

The Mediterranean ecosystem of Mt. Carmel, Israel, is subjected to an increasing number of forest fires of various extents and severities. The impacts of forest fires on runoff and erosion are widely documented and include increased peak flows and soil loss until the return of a vegetation cover. Most studies, however, treat fire as a single event, whereas the present study is aimed at exploring the long‐term effects of repeated forest fires on eco‐geomorphic processes. The study integrates the results of plot‐based, detailed analysis of post‐fire runoff and erosion with vegetation recovery analysis, at a temporal‐spatial scale which includes the effect of reburning. Our results indicate that forest fires lead to a significant increase in runoff and sediment yields, particularly during the first two years following the disturbance, up to five orders of magnitude higher than from the adjacent unburnt control plots.     

Hydrothermal control on organic matter alteration and illite precipitation, Mt Isa Basin, Australia

Abundant illite precipitation in Proterozoic rocks from Northern Lawn Hill Platform, Mt Isa Basin, Australia, occurred in organic matter‐rich black shales rather than in sandstones, siltstones and organic matter‐poor shales. Sandstones and siltstones acted as impermeable rocks, as early diagenetic quartz and carbonate minerals reduced the porosity–permeability. Scanning and transmission electron microscopy (SEM and TEM) studies indicate a relation between creation of microporosity–permeability and organic matter alteration, suitable for subsequent mineral precipitation. K–Ar data indicate that organic matter alteration and the subsequent illite precipitation within the organic matter occurred during the regional hydrothermal event at 1172 ± 50 (2σ) Ma. Hot circulating fluids are considered to be responsible for organic matter alteration, migration and removal of volatile hydrocarbon, and consequently porosity–permeability creation. Those rocks lacking sufficient porosity–permeability, such as sandstones, siltstones and organic matter poor shales, may not have been affected by fluid movement. In hydrothermal systems, shales and mudstones may not be impermeable as usually assumed because of hydrocarbons being rapidly removed by fluid, even with relatively low total organic carbon.     

HOLOCENE ACCUMULATION OF COLLUVIAL AND ALLUVIAL SEDIMENTS IN THE WEIßE ELSTER RIVER VALLEY IN SAXONY,GERMANY*

Geoarchaeological investigations at two archaeological excavation sites lead to new results with respect to the Holocene landscape development of an archaeologically important loess landscape of Central Europe. Colluvial and alluvial sediments were sampled during archaeological excavations on the valley edge of the Weiße Elster and dated by means of ¹⁴C, TL and dendrochronology, and on the basis of archaeological finds. Thus, for the first time, the development of a valley edge of a river in the Leipzig area, which has been continuously settled for 7300 years, can be reconstructed. The first soil erosion on the valley edge is established towards the end of the Atlantic period. During the High Middle Ages, a colluvial sediment developed. Its deposition time can be limited to between ad 1000 and 1100. The flood loam near Großstorkwitz, which can be stratified by means of the soil and colluvial deposits, originated in the late Sub‐Boreal and early Sub‐Atlantic, as well as after ad 1100. During the first millennium ad, a soil developed in the older flood loam, which indicates a phase of reduced flood loam sedimentation.     

‘Torrents of Terror’: the August 1998 Storm and the Magnitude,Frequency and Impact of Major Floods in the Illawarra Region of New South Wales

The Illawarra Region some 80 kilometres south of Sydney is characterised by a prominent coastal escarpment that rises to 700 m within 12 km of the coast and forms a locus for frequent, high intensity rainfall events. One of the most recent recorded events occurred on 17 August 1998 with rainfall intensities at several pluviometers exceeding 120 mm hr^‐1 over a duration of one hour, with up to 249 mm falling in 3.5 hours during the main storm burst. Detailed pluviometer data indicate that the storm was non‐stationary and moved down catchment producing a widespread zone of 120 mm hr^‐1 intensity rainfall over a 30 minute duration across mid‐lower catchment areas after similar intensity but longer duration rainfall in catchment headwaters. Slope‐area reconstructions of peak discharge indicate that small catchments on the escarpment within the zone of maximum intensity experienced close to 100% rainfall‐runoff relationships, with peak discharges correlated to short duration (<1 hr) peak rainfall intensities. Widespread erosion occurred particularly where urban development had encroached on natural water courses. Debris/hyperconcentrated flows originating from both anthropogenic and natural sediment sources caused damage to urban areas. This paper provides an overview of the spatial and temporal characteristics of the 17 August 1998 storm, the hydrologic and geomorphic response of the streams, and the nature of damage to urban areas. It reassesses the frequency of recent high‐magnitude rainfall/flood events in the region, discussing the relationships between rainfall intensities, estimates of flood magnitudes and stormwater channel capacities.     

Crop marks and soils at two archaeological sites in Britain

The factors which create crop marks at two archaeological sites, at Glenlochar, Kirkcudbrightshire and at Fisherwick, Staffordshire, are examined in some detail. Marks are best recorded at these places in cereals and show earliest over the shallowest soils. They appear when the potential soil moisture deficit, which occurs when water transpired by a crop exceeds rainfall, is greater than the amount of water in the soil available to the plant. Marks only show in grassland when the deficit is about 40 mm more than that calculated for cereals. Marks also appear in very wet years, but are fainter than those caused by a moisture deficit, and are probably caused by waterlogging in the soil. At both sites the soils are moderately stony and shallow over terrace sands and gravels, except for soils in infilled ditches over which crop growth is better.     

Faeces deposition on Amazonian Anthrosols as assessed from 5β-stanols

In the Amazon Basin, within a landscape of infertile soils, fertile Anthrosols of pre-Columbian origin occur (Amazonian Dark Earths or terra preta de Índio). These soils are characterized by high amounts of charred organic matter (black carbon, biochar) and high nutrient stocks. Frequently, they were considered as sign for intensive landscape domestication by way of sedentary agriculture and as sign for large settlements in pre-Columbian Amazonia. Beyond the archaeological interest in Amazonian Dark Earths, they increasingly receive attention because it is assumed that they could serve as a model for sustainable agriculture in the humid tropics (terra preta nova). Both questions lack information about the pre-Columbian practices which were responsible for the genesis of Amazonian Dark Earths. It has often been hypothesized that deposition of faeces could have contributed to the high nutrient stocks in these soils, but no study has focussed on this question yet. We analyzed the biomarkers for faeces 5β-stanols as well as their precursors and their 5α-isomers in Amazonian Dark Earths and reference soils to investigate the input of faeces into Amazonian Dark Earths. Using Amazonian Dark Earths as example, we discuss the application of threshold values for specific stanols to evaluate faeces deposition in archaeological soils and demonstrate an alternative approach which is based on a comparison of the concentration patterns of 5β-stanols with the concentration patterns of their precursors and their 5α-isomers as well as with local backgrounds. The concentration patterns of sterols show that faeces were deposited on Amazonian Dark Earths.     

Methods for assessing stormwater management at archaeological sites: Copan Ruins case study

Archaeological sites may be discovered by fortuitous soil erosion, but their protection requires deliberative stormwater management plans and estimates of runoff volumes. This paper uses the Maya site of Copan, Honduras to demonstrate widely applicable methods to estimate runoff, including use of satellite rainfall data processed by single parameter models. Our analysis compares present day estimates of runoff and erosion with those of two historic periods, 900 A.D during peak Maya occupation of the Great Plaza, and 1800 A.D. prior to excavation when the site was mostly forest covered. For each period, the watershed area, soil, land cover, and rainfall data were used with a single parameter Curve Number model to estimate the runoff volume for annual to decadal storms. The maximum runoff depth and erosive potential in conveyance channels was then computed with the HEC-RAS model. The models did not predict runoff would occur for the forested period of 1800 A.D., but predicted that runoff for 900 and post-1800 A.D was large enough to cause the erosion observed in the drainage channel today. Our results provide runoff magnitudes that demonstrate the need for Copan Maya designed stormwater removal infrastructure described in earlier archaeological analysis. The need for stormwater removal was also designed into the wet Maya site of Palenque, while stormwater capture and storage was designed into the Maya sites of Tikal, a drier site due to local drainage characteristics and water availability. Methods used in stormwater runoff analysis can empower communities and managers to develop scientifically and culturally appropriate non-structural management methods to conserve archaeological sites.     

Pits,mounds, and vernal ponds in a Tasmanian subalpine grassland

Falling trees commonly turbate soils in primary forest, creating characteristic edaphic patterns related to pit and mound topography. Vernal ponds with associated mounds were observed in mineral soils on a treeless plain in subalpine Tasmania, Australia. The hypothesis that paired ponds and mounds on the plain originated as pit and mound features in forests that were later destroyed by fire was tested by comparing the soils and landforms caused by recent tree falls in adjacent forest with those on the plain. The soil characteristics, orientations, and dimensions of the ponds and mounds were consistent with a tree fall origin, although rare secondary ponds on the tops of mounds may derive from the burrowing activities of the medium‐sized marsupial, Vombatus ursinus (common wombat). The characteristics of pond and mound soils suggested that most were hundreds to thousands of years old, with the ponds persisting because of differences in deflation, deposition, and organic matter formation between themselves and adjacent persistently dry land.     

Rugged Plateaus and Extensive Floodplains — Modelling Landform Evolution in a Northern Australian Catchment

Medium to large natural catchments are often more spatially heterogeneous than small catchments or single landforms. Attempting to model landform evolution of large areas is consequently more complex. This paper demonstrates that modelling landform evolution in medium to large catchments can be improved by calibrating the model to smaller, more geomorphologically homogenous sub‐catchments. The paper investigates landform evolution in the Ngarradj catchment in the Northern Territory of Australia (a medium scale catchment of approximately 67 km²). The catchment is complex and contains two distinct landform regions; an upland plateau region with highly dissected sandstone and shallow, sandy soils, and a lowlands region with gentle, wooded slopes and floodplains with deep, sandy soils. The SIBERIA landform evolution model is calibrated and applied to the Ngarradj catchment. The complexity of the Ngarradj catchment is incorporated into the modelling by dividing the catchment into three sub‐catchments (Swift Creek (SC), Upper Main (UM) and East Tributary (ET)) which are relatively homogeneous and for which hydrology and sediment transport data are available. A discharge‐area relationship and long‐term, sediment loss rates for the catchment are derived based on an annual series flood frequency analysis of a 20 year runoff record predicted in a previous study. Sediment transport modelling incorporates both suspended and bedload sediment loss. The denudation rates derived using these data are 37, 63 and 77 mm kyr^?1 for the SC, UM and ET sub‐catchments, respectively. Model predictions indicate that the UM sub‐catchment will have the greatest mean erosion. This is balanced by the large amount of deposition that will occur in the upper Ngarradj valley of the UM sub‐catchment. Further deposition occurs on the floodplain of Ngarradj, with the area between the SC and ET/UM (up‐stream) sub‐catchments experiencing a small net accretion of sediment (15 mm kyr^?1).     

Landscape and Soil Development on Monaro Basalt West of Nimmitabel,New South Wales

Prolonged stability of the southern tableland of NSW, developed on early Tertiary Monaro basalt, is evident from weak landscape dissection and numerous small lakes. However, poorly developed soils and weathered zones are inconsistent with prolonged Cainozoic weathering or formation under climates substantially different to the present. Thin Holocene sediments are also at variance with the sizes of the lake basins. Low depositional landforms, termed ‘lake shadows’, occur on the eastern perimeters of most lakes, and comprise clay pellets blown from basin floors during dry phases. Deflation, dominantly during Quaternary glacial periods, and reactivated today, is responsible for the thin soils and sediment cover. The lake basins are partly solutional and partly deflational features. The modern soil cover reflects the modern climate.     

Mobile Cartographies and Mobilized Ideologies: The Visual Management of Jerusalem

This article analyses a recent ideological shift in the visual management of Jerusalem. Through two case studies in the real estate and tourism industries we show how mobile technologies are shaping both actual settings in, and visual consumption of, Jerusalem. The analysis points at the creation of a “tunnel vision” for consumers and visitors, which promotes Jewish hegemony in the city and simultaneous detachment from Palestinian spaces and histories. This tunnel vision situates the viewers in physical and simulated enclaves within the city, creating a relationship of distance and elevation to promote their embodied identification with Israel's Judaizing mission for the area, primarily the Holy Basin. This mode of viewing Jerusalem is evocative of Israel's post‐second intifada policies and the concurrent rise of right‐wing ideologies, which relegate to the margins alternative readings of the contested urban landscape.     

A Survey of Soil Erosion in Australia using Caesium‐137

A survey of soil erosion was conducted in Australia using the fallout radioisotope caesium‐137 as an indicator of topsoil redistribution. Two hundred and six sites were sampled, 100 within rotational cropping and horticultural use, 52 within uncultivated permanent pasture and forest, and 54 in rangelands. Average net soil losses were approximately equal for cultivated cropping lands and rangelands (ca. 5.5 t ha^?1 yr^?1), and just over 1 t ha^?1 yr^?1 for pasture and forest. The Mann Whitney U Test revealed that losses under cropping and rangeland conditions were significantly higher (p < 0.05) than under uncultivated pasture and forest. Soil loss was negatively correlated with mean annual rainfall and slope gradient, and positively correlated with slope length (Spearman's rank correlation). There was no correlation between rates of soil loss and a rainfall erosi‐vity index. An assessment of erosional events was provided by landholders for 104 sites, with their ranking being weakly but significantly correlated with soil loss estimates (r =+0.35). Sixty percent of sites had net soil losses greater than 1 t ha^?1 yr^?1, and 74% of sites had losses of more than 0.5 t ha^?1 yr^?1. This latter rate may be regarded as a limit for a tolerable level of soil loss. These high rates of soil loss have occurred since the mid‐1950s despite there being significant landholder awareness of the soil erosion hazard.     

Soil fertility and slope processes in the Western Cumberland Escarpment of Kentucky: influences on the development of horticulture in the Eastern Woodlands

The archaeological record of dry rockshelters in the Red River Valley of eastern Kentucky contains botanical remains of several weedy annual seed-bearing plants that point to the independent development of agriculture during the Late Archaic and Early Woodland Period. The objective of this study is to gather quantitative data through the chemical and physical analysis of soils collected within a valley transect to gain insights into landscape processes and soil fertility that may have played a role in the early development of plant domestication and the location of garden plots in relation to rock shelter sites in the upper Cumberland Plateau region of eastern Kentucky. Soils on upland benches formed in limestones have soil fertility values that are comparable to fertile floodplain soils. Upslope outcrops of calcareous bedrock are contributing basic cations to these bench soils. Additionally, in comparison to other landscape positions these upland soils have high levels of organic carbon, available P and greater C:N ratios. Soil morphology, radiocarbon dates, and archaeological evidence indicate that many of the numerous earthflows and debris flows within the region are Early to Middle Holocene in age. These slides were likely generated by Mid-Holocene climatic shifts in which the frequency and intensity of summer precipitation increased across the southeastern United States. These slope failures may have contributed to the development of plant domestication by creating forest canopy gaps and disturbed soils in which weedy plants thrived.