High-resolution digital elevation models, often derived from airborne lidar, are rapidly gaining importance in both archaeology and geomorphology, in particular where these two disciplines overlap in ...their interest in anthropogenic changes to the relief of the earth surface (“archaeogeomorphology”). Inter-group and inter-state conflict are one aspect of human behaviour which commonly causes such relief changes. Conflict archaeology and conflict geomorphology, which are both young sub-disciplines within their scientific fields, have until now only touched upon a small part of the wide range of issues which they can encompass. While conflict archaeology has for a long time been almost synonymous with battlefield archaeology, the few papers explicitly discussing conflict geomorphology are mainly concerned with the impact of bombing on soil geomorphology. The application of high-resolution digital elevation models in investigating past conflicts can and should, however, encompass all geomorphological traces of conflict. These include defensive structures such as earthworks, primary and secondary traces of warfare itself (e.g. bomb craters and rubble mountains), conflict-related traces associated with military training and weapons testing facilities as well as, potentially, traces of conflict sustenance (e.g. conflict-related mining and infrastructure). Examples highlight the potential of high-resolution digital elevation models for the detection, mapping and quantification of conflict-related relief changes and thus for the understanding of conflicts. As suitable data are becoming increasingly available, the study of prehistoric and historic conflicts will benefit across the discipline boundaries between archaeology and geomorphology. In the field of heritage management, the detection, visualisation and protection at landscape-scale of what is often seen as “dark” heritage is expected to gain importance.
•Geomorphological traces of past conflicts are widespread features.•Their recognition is facilitated by high-resolution digital elevation models.•An overview of common conflict-related archaeogeomorphological features is given.
Coppice dunes covered by epiarenic Tillandsia fog vegetation occur in the Peruvian coastal desert. To analyse the three-dimensional vegetation structure on such a coppice dune, a photogrammetric ...structure-from-motion approach is applied. A photogrammetric plant height map was derived from a digital surface model and a digital terrain model created by this approach. This plant height map is analysed in conjunction with stand-scale vegetation patterns, regional wind direction derived from migrating dunes, near-surface wind direction derived from the orientation of sand ripples and ground observations. Tillandsia vegetation patterns are non-random. Banded and reticulate patterns occur at stand scale. At metre to sub-metre scale, groups of tall plants occur in clusters as well as in rows aligned with air movement. While self-organisation processes related to maximising fog moisture capture by the plants and to coppice dune growth appear to control the development of the banded to reticulate pattern, retaining an upright growing position (and hence continued exposure to fog moisture on decadal time scales) by minimising aeolian erosion at the base of these rootless plants appears to control the development of rows and clusters at metre to sub-metre scale.
•A structure-from-motion approach is used to record 3D vegetation structure of sparse plant cover.•Sand ripples document the influence of dune topography and Tillandsia plants on near-surface air flow.•A plant height map is used to analyse the alignment of Tillandsia plants with respect to wind direction.•Alignment of plants in rows allows long-term upright growth due to reduced aeolian erosion at the plant base.
For millennia, humans have lived in regions which have been and/or are today characterised by arid environmental conditions. Many archaeological sites are therefore located in deserts where they are ...subjected to specific conditions regarding their preservation, vulnerability, visibility and accessibility. The aim of this paper is to show how data from high and intermediate resolution satellite sensors and ground-based multi-image photogrammetry (Structure-from-Motion) can be combined to document damage to spatially extensive archaeological heritage in arid environments. In this approach, high-resolution satellite images (QuickBird) are used to locate archaeological sites and to verify the type of disturbance. Multiple sequential intermediate resolution satellite images (Landsat 7 ETM+) are used to document the spatial extent and temporal development of surface disturbances at the site and in the surrounding area. Structure-from-Motion (SfM) is used to document damage to a small segment of the archaeological site by creating a very high resolution DEM and orthophoto which are used for detailed damage assessment. The approach is exemplified using damage by off-road vehicles to a large Nasca period geoglyph in the coastal desert of southern Peru. It can be applied to document threats to spatially extensive archaeological sites in arid environments, such as large-scale looting, agricultural expansion or urban and industrial sprawl.
A recently published paper proposing a “strict solar alignment” of figurative rock carvings in southern Sweden requires some critical and cautionary remarks. Using the paper “Strict solar alignment ...of Bronze Age rock carvings in SE Sweden” by N.-A. Mörner as a case study, various pitfalls and challenges in archaeoastronomical investigations are highlighted. Substantiating the idea of a relationship between the orientation of archaeological features such as rock carvings and astronomical events such as sunrise at winter solstice requires accurate and precise determination of (i) the orientation of the archaeological features and (ii) the azimuth of the astronomical event at the time of creation of the rock carvings, taking into account all influencing factors such as changes in Earth orbit parameters, surrounding topography and vegetation. Furthermore, possible motivations or intentions of Bronze Age rock carvers have to be considered. When trying to support a causal link between the orientation of archaeological features and astronomical events, it is indispensable to discuss and exclude possible alternative explanations, related to, for example, rock carving practice and visibility. Taking into account the above issues, there is no evidence for a solar alignment of the Järrestad rock carvings. The issues discussed using the Järrestad rock carvings as a case study are relevant to archaeoastronomical investigations in general.
► An assessment of “Strict solar alignment of rock carvings in SE Sweden” by N.-A. Mörner reveals numerous pitfalls. ► Accuracy and precision are indispensable for archaeoastronomical investigations. ► The orientations of rock carvings at Järrestad do not support an archaeoastronomical hypothesis. ► Several alternative explanations for the orientations of the rock carvings are discussed.
The SRTM data set is the highest resolution DEM with global or continental coverage. It is therefore the DEM of choice for continental-scale geomorphological mapping and quantitative analysis. In ...this study, SRTM data are used for the identification and characterisation of endorheic basins in southern South America (south of 19°S). The results show the feasibility of continental-scale quantitative geomorphology based on SRTM data and provide insights into the distribution of closed basins. The largest endorheic basin is located in the Puna region and consists of several interconnected sub-basins. This basin accounts for 38.6 % (7877 km3) of the total volume of the endorheic basins identified in this study. Analyses of the geographic distribution show a narrow longitudinal distribution between 64.5 and 71.5° W and a multimodal latitudinal distribution which is characterised by two groups of basins at 22.5-27.5°S and 37.5-50.0° S and an almost complete absence of basins between 27.5 and 37.5° S. Problems and sources of misinterpretation arising from data quality and resolution are discussed. Further research, targeting in particular the genesis and potential for paleoenvironmental reconstruction of closed basins in southern Argentina, is called for.
In the coastal desert of southern Peru, sequential high-resolution satellite images document the presence of short-lived and long-lived dust devil tracks. Dust devil tracks in the study region remain ...visible for less than 6 months in one area and for more than 4 years in another area. Short-lived tracks are generally darker than the surrounding ground surface. The brightness of long-lived tracks is often equal to that of their surroundings; they become visible due to a brighter edge along their margins. Different modes of formation related to ground surface properties are suggested to explain the differences in persistence and appearance. Dark, short-lived dust devil tracks are ascribed to the removal of silt-sized material from largely sand-sized surface materials. Long-lived tracks with bright margins are ascribed to coarser surface materials and the fallout of sand-sized particles along the track edges. Locating suitable areas on Earth for the study of dust devil tracks and distinguishing between different types of dust devil tracks is expected to further promote terrestrial analogue studies for Martian dust devil streaks.
Irrigation agriculture is an ancient and widespread feature in regions where allogenic rivers flow through arid landscapes. This paper reports the results of sedimentological–pedological ...investigations in the Palpa Valley in the coastal desert of southern Peru where sediment-laden river water is used for irrigation. An adapted facies classification is used to deduce a generalised stratigraphical sequence of the valley bottom sediments. Chronological constraints from radiocarbon dating and archaeological finds are used to reconstruct sedimentation rates for fossil to recent irragric anthrosols. Actualistic case studies are used to quantify present-day irrigation sedimentation. The investigations result in a clarification of the sedimentological and geomorphic history of this valley and a quantification of irrigation-related sedimentation. Irragric anthrosols date back more than 3500 years and provide direct evidence for the beginning of irrigation agriculture in this region. It is concluded that: (i) the up to approximately 4 m thick fine-grained sediments in the Palpa Valley bottom totaling a volume of 21.4 Mio. m
3 are a result of long-lasting human impact and have to be considered as artefacts of prehistoric and historic irrigation agriculture in the hyperarid coastal desert; (ii) the fine-grained sediments represent a geoarchive which holds information on the history of irrigation agriculture as well as information on possible natural disturbance by extreme fluvial events; (iii) the identification of irragric anthrosols has implications for archaeological and paleoenvironmental reconstructions.
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