Olaf Bubenzer

An integrated approach for groundwater assessment at the Northwestern Coast of Egypt (Ras El Hekma area): case study

Ras El Hekma area was chosen for the present study due to its special conditions; the area lacks water for human and agriculture proposes. This area represents one of the main headlands along the southern Mediterranean coast, where population growth and agricultural activities require the corresponding development of groundwater. The main objective of this paper is to monitor and record data about the current groundwater as well as to have a systematic understanding of the hydrogeological setting in the area of study. Also, one of the study objectives is to identify and assess the factors which affect the groundwater occurrence and quality. This assessment will contribute to groundwater protection. The study area has three aquifers: Holocene, Pleistocene, and Middle Miocene aquifers. The recharge to these aquifers comes from the direct infiltration of rainfall and from the surface runoff. Rock–water interaction and the effect of solution and leaching processes on the mineralization of groundwater are studied using the PHREEQC model. Seawater intrusion contributes effectively to the increase in water salinity. The present study clarifies the relationship between the depth to water, the sea level and salinity of water. The groundwater in the area of study is evaluated for drinking, domestic, livestock and agricultural purposes. The present study suggests some recommendations for developing the groundwater in the study area.

Growth rate of Usnea aurantiacoatra (Jacq.) Bory on Fildes Peninsula, Antarctica and its climatic background.

The ages of a fruticose lichen of Usnea aurantiacoatra (Jacq.) Bory, from Fildes Peninsula, King George Island, Southwest Antarctic, were determined by radiocarbon (14C), and it is 1993–1996 at bottom and 2006–2007 at top of the lichen branch. The growth rates of U. aurantiacoatra calculated are 4.3 to 5.5 mm year−1 based on its length and ages. The comparisons show that the growth rates of U. aurantiacoatra are higher than those of U. antarctica (0.4 to 1.1 mm year−1). The growth rates of fruticose lichens are always higher, usually >2 mm year−1, than those of crustose ones, usually <1 mm year−1, in polar areas. A warming trend on Fildes Peninsula is recorded in the period from 1969 to 2010 obviously: the mean annual temperature rose from −2.75 to −1.9°C and the average temperature of summer months from 0.95 to 1.4°C, as well as the average temperature of winter months from −6.75 to −5.5°C. The alteration of lichen growth rates in polar areas may respond to the climatic and environmental changes, and the lichens may act as bio-monitor of natural condition.

Radiocarbon Dating of Agrarian Terraces by Means of Buried Soils

Soils buried under terrace fills have been widely used to date the construction of ancient agrarian terraces. The reliability of the obtained radiocarbon dates entirely depends on the degree of preservation and isolation of the Ab horizons and on the amount of embedded older carbon. To assess these caveats, we analyzed 14 C dates (11 on charred material and 3 on the bulk organic fraction) obtained from buried soils under Andalusi terrace fills in Ricote, Spain (AD 711–1492). The preservation of Ab horizons was assessed through bulk analyses [particle size distribution (PSD), carbon analyses, magnetic susceptibility (Mag Sus)] and statistics [Welch’s ANOVA, MANOVA (Wilk’s lambda) and effect size tests]. The effects of older carbon were quantified through the systematic dating of Ab horizons within the earliest terrace cluster of Ricote. Our results show that (1) Ab horizons were not disturbed nor mixed with the terrace fills above; (2) the dates determined from the bulk organic fraction were statistically significantly older than those provided by the charred material, probably due to the higher stability of the microcharcoal fraction; and (3) the earliest dates measured on charcoal clustered reliably around cal AD 989–1210, suggesting that the first Andalusi irrigated terraces of Ricote were built between the end of the 10th and the beginning of the 13th centuries AD.

Digital Geoarchaeology: Bridging the Gap Between Archaeology, Geosciences and Computer Sciences

Modern archaeology increasingly crosses academic boundaries by combining different new methodologies in order to answer research questions about ancient cultures and their remains. Above all, the geosciences became an indispensable counterpart of archaeology and cultural heritage management. As to the investigation of past archaeological landscapes and palaeoenvironments, the term Geoarchaeology is commonly used, representing the utilization of traditional and the development of new geoscientific applications for archaeological purposes. In addition, computationally engaged research became absolute state of the art in modern archaeology, in geoscientific landscape reconstructions and in the deciphering of spatio-temporal interactions between man and nature. Despite this multidisciplinary constellation, the thematic and methodological overlap of humanities, natural sciences and informatics is frequently disregarded. It is beyond debate that multidisciplinary approaches, which especially emerge at the interface of adjacent subjects, substantially contribute to a better understanding of ancient landscapes, their forming processes and the resulting cultural heritage. They allow fusing complementary perspectives for the first time and therefore go far beyond unilateral research designs. Digital Geoarchaeology, which is to be established in this chapter as a new concept for the first time, can therefore be regarded as an intersection of disciplines that contributes to the consolidation of different academic perspectives. It represents a novel approach in terms of computer scientific methods combined with geoscientific know-how and archaeological expertise to multi-methodically investigate past human-environmental relationships. Accessing this multidisciplinary interface helps overcome potentially restricted, monodisciplinary perceptions and provides new forms of unbiased approaches for investigating the interplay of man and nature. Thus, closer collaboration and dialogue across disciplinary boundaries will offer promising prospects for future research at the human-environmental interface.

Detection of sand encroachment patterns in desert oases. The case of Erg Chebbi (Morocco)

Desert oases are fragile agrarian areas, very vulnerable to sand encroachment by wind. Ensuring their conservation highly depends on our capacity to identify sand encroachment patterns, e.g. the origin of sand and its spatial distribution in the irrigated plots. Here we show how to tackle this issue using the case study of Erg Chebbi (Morocco), where two oases (Hassilabiad and Merzouga) are surrounded by dunes, Hamada and alluvial sediments from the Wadi Ziz. We combine field interviews with the study of wind dynamics, sediment sampling, Particle Size Distribution (PSD) tests and End-Member Modelling Analysis (EMMA). We observe that the most relevant contributor to sand encroachment is the Wadi Ziz (30%), followed by the Hamada (28%), an undetermined source of dust (25%), and the Erg dunes (16%). These genetically different sediments cluster unevenly in the oases, indicating the existence of areas with contrasting degrees of exposure to sedimentary sources. The results allow to define on solid grounds which sand source areas should be stabilized first in order to obtain the greatest reduction in sand encroachment. Our approach also provides policy-makers with better tools to identify which spots are specially vulnerable to accumulate a specific sediment, thus allowing for a more nuanced management of sand in oasis environments.

In Search of the Optimal Path to Cross the Desert: Geoarchaeology Traces Old Trans-Saharan Routes

Due to today’s broad and often free availability of detailed satellite data, it became possible to examine desert areas on a large scale and, ideally, down to tiny details for old trans-Saharan route systems, which are abandoned since centuries or even thousands of years ago. Additionally, digital elevation models (DEMs) can be used to evaluate the geomorphological situation. In conjunction with historical sources and ground-truth data, these data allow us to reconstruct the position of the desert routes with reasonable accuracy, here exemplified for the Western Desert of Egypt. On the central limestone plateau, where stony ground (hamada, serir) prevails, most of the routes can precisely been seen from space because of their specific natural preservation conditions. In contrast, sandy surfaces usually do not allow recognition of routes in the satellite image. Additionally, the quite narrow donkey tracks of the pharaonic routes are mostly invisible from space. On the other hand, DEMs (ASTER, SRTM) allow calculating ideal routes by means of geographical information systems (GIS), usually applied in cases were traditional routes have not survived. In the present study, we confront both methods using the example of the Darb el-Tawil to test the hypothesis that these old roads largely follow the ideal route. This 250 km long road has been one of the primary arteries between the Nile Valley and the Western Desert oases during the past 4000 years. Due to modern demographic and economic development, it has been selected for the construction of a new paved highway, which will irrevocably destroy the still existing tracks and archaeological objects.

New investigations at the Middle Stone Age site of Pockenbank Rockshelter, Namibia

In southern Africa, Middle Stone Age sites with long sequences have been the focus of intense international and interdisciplinary research over the past decade (cf. Wadley 2015). Two techno-complexes of the Middle Stone Age—the Still Bay and Howiesons Poort—have been associated with many technological and behavioural innovations of Homo sapiens. The classic model argues that these two techno-complexes are temporally separated ‘horizons’ with homogenous material culture (Jacobs et al. 2008), reflecting demographic pulses and supporting large subcontinental networks. This model was developed on the basis of evidence from southern African sites regarded as centres of subcontinental developments.

Heidelberger Geographen in Peru

Uber Forschungsarbeiten, die Geographen der Universitat Heidelberg in Peru durchgefuhrt haben, berichtet die Sendung von Campus-TV im November 2010. Wie ist die Landoberflache zu ihrer heutigen Form gelangt und was sagt dies uber das Klima in fruheren Zeiten aus? Diesen Fragen sind Heidelberger Geographen in Peru nachgegangen. Sie haben unterschiedliche Naturraume untersucht – mit dem Ziel, in Zusammenarbeit mit Archaologen und Forschern anderer Fachrichtungen zu verstehen, wie der Mensch mit einer Umwelt im Wandel umgeht.

Towards a Reconstruction of Land Use Potential

This chapter is situated in the field among archaeology, geomorphology, and ecology. Two case studies from different east-Saharan landscape units classify and analyse archaeological, geoscientific, and remote-sensing data of Early and Mid-Holocene archaeological sites. The section combines the approaches of landscape ecology and landscape archaeology. The aim is a parameterisation of the research areas with respect to structural and ecological features. The data were used within a Geographical Information System (GIS), a hydromodelling, and statistical software. The analysis allows an indication of the observed landscape parameters that are essential for the location of the sites within each time slice. Therefore, the study broadens the understanding of the man–environment relationships.With the help of this integral and autochthonous landscape inspection it is possible to reconstruct the past potential of the utilisation of such arid landscapes. Such an approach also helps in locating new archaeological sites within landscape units. At the end a first suggestion for a model of interacting key variables and the general landscape development of the Western Desert during the Early and Mid-Holocene is presented.

Landscape in Geography and Landscape Ecology, Landscape Specification and Classification in Geomorphology

At first, mainly with respect to the German literature but with comparisons to some recent Anglophone papers, an excursive overview of the development and the meaning of the term ‘landscape’ in geography and landscape ecology is given. This is followed by a description of how the surface of a given landscape can be specified and classified within geomorphology as a basis for further investigations in the natural sciences and humanities.