Contribution of archaeobotany to understand taphonomic phenomena. The case of a Preboreal oxbow lake of Autrecourt-et-Pourron (Ardennes, France).

By analyzing the mechanisms that govern the interactions between environmental factors and ecosystems, paleoecology refines our knowledge of the mechanisms that are structuring plant communities, helping us to understand the complexity of past environments. While undertaking palaeoecological analyses, it is necessary to analyze and to understand the taphonomic phenomena influencing plant macrofossil assemblages. Indeed, the evaluation of under- and over-representation of taxa makes it possible to judge the interest and quality of the retained data set as a source of paleo-ecological information. The French National Centre for Archaeological Research (CNRA) recommends "refining taphonomic modelling in different aspects: accumulation and modification processes by biological agents, natural ageing processes of taphocenoses" (National Research Programming 2016, p. 35). The inability to reconstruct the diagenetic history of sedimentary layers can sometimes lead to erroneous palaeoecological interpretations. Like all archaeological documents, macrofossil plant assemblages come to us distorted by the taphonomic processes involved in the formation of sediment layers. The study of waterlogged plant macrofossils preserved in the wet sediments of an oxbow lake of the river Meuse (Autrecourt-et-Pourron, Ardennes, France) aims to analyze these taphonomic processes. This archaeobotanical study focusing on a river wall dated to the Preboreal period (11.7 ̵ 10.7 ka BP) allows establishing a taphonomic reference frame. We applied a correspondence analysis to establish links between criteria preservation and the analyzed sediment samples. We observed differences in preservation conditions depending on the stratigraphy and nature of the sediments. Before conducting archaeobotanical studies in natural contexts, an assessment of the taphonomic state of the retrieved plant macrofossils is highly recommended.

Limes en landschap

Summary From the AD 40s onwards a dense Roman military system was established along the Oude Rijn in the Netherlands. It has long been questioned why this system was established in a wetland area, and how it went on to become the northwest frontier or limes of the Roman Empire. In order to shed new light on this longstanding historical debate a detailed paleogeographical map was constructed. From the information assembled in this new map it can be concluded that this military system, which comprised a combination of forts and watchtowers, was established to watch over the river Rhine and its traffic, and to guard all waterways that gave access to the Rhine from the Germanic territories further north, and to and from the river Meuse further south to the delta. It is clear that strategic and logistical motives determined the size and location of all of the forts and military installations in this fortified transport corridor. The construction of the series of forts from the early 40s AD onwards has been correlated with the conquest of Britain from AD 43 onwards, but the building project was initiated in the reign of Caligula (AD 37-41).

Navigation simulations as support to lock approaches design. Application to Ampsin-Neuville new lock, Meuse, Belgium

The existing 136 × 16 m lock at Ampsin-Neuville, on River Meuse, Belgium, is close from saturation. A new lock, sized 225 × 25 m, has been designed in order to increase the capacity and will soon be built. Site constraints are significant: existing lock on the outer side of a river bend, limited space between existing lock and weir, hydropower station on the left bank, etc. Two layouts were successively tested in details: (1) replacing the right hand pass of the weir by the new lock, and building a new spillway around the hydropower station; and (2) building the new lock on the location of the existing 136 × 16 m lock, with use of a secondary lock to maintain navigation during works. Civil engineering studies were supported by different nautical simulations. Fast-time simulations were used in a first stage, with the ClusterTool software (DST), to check the availability of waiting berths in each design, with no current. In a second stage, real-time simulations were performed on the SANDRA simulator at DST, to check manoeuvrability with current. Lastly, manoeuvring times were used in capacity simulations, using IMDC-Locks software (IMDC). In particular, the capacity of the secondary lock of the second layout had to be tested. All the results collected helped to choose the appropriate design for the new lock, and to optimize future operation rules.

Removal of pharmaceuticals by a surface water treatment plant

Several pharmaceuticals were followed through a drinking water production process on the river Meuse. Tramadol and levetiracetam were the most common compounds while cytostatics were not detected. All compounds found at that intake point had an annual consumption greater than 90 mg/inhabitant. The tracer substance 1,2,3-benzotriazole allowed estimation of the maximal concentration of pharmaceuticals and the evolution profile for tramadol and sotalol. After pre-ozonation of raw water, most pharmaceuticals were completely removed, except levetiracetam and irbesartan, confirming the efficiency of this advanced oxidation process. Irbesartan and levetiracetam were completely removed by granular activated carbon filtration. Levetiracetam was the most reluctant compound. A conventional multi-barrier treatment combining ozone and activated carbon, already used for several decades before implementation in wastewater treatment, can completely remove most pharmaceuticals. Therefore, drinking water without any significant health-related amount of these pharmaceuticals can be produced from surface water.

Archaeological heritage management in the Meuse valley (Limburg, the Netherlands) from a national perspective: aims, methods and results

Numerous archaeological investigations have been performed along the river Meuse in the Netherlands’ southeastern province of Limburg as part of the major ‘Maaswerken’ infrastructural project. To improve flood risk management and navigability, and for the purpose of gravel production and nature development, several areas of land covering a total of almost 2000 ha are being excavated to a great depth. In anticipation of this, archaeological research was performed for the purposes of recording and documenting archaeological remains in the most important areas and locations. From 1998 to 2015 the Cultural Heritage Agency of the Netherlands (Amersfoort) was in charge of the investigations, and acted as adviser to national public works agency Rijkswaterstaat.The archaeological research connected with the Maaswerken project differed from regular, site-based investigations in terms of the landscape archaeology perspective on which it was based. The research themes and principles associated with this perspective were published in several documents, including a scientific policy plan published in 2004, and presented in further detail in area programmes and project briefs. The policy plan assigned each project area to one of five value assessment categories, based on the intactness of the landscape and the archaeological potential for addressing the research questions. In areas of high landscape intactness and great archaeological potential (category 1) the Agency selected zones to be surveyed and assessed, and for archaeological excavation. Though most of the fieldwork, including specialist analysis, was performed in these zones, other category project areas have also been the subject of archaeological fieldwork, including borehole surveys, site-oriented research and watching briefs, but on a more incidental basis. Observations were also made in the river Meuse itself and in the river's winter bed.The archaeological investigations resulted in a large number of standard reports of desk studies and fieldwork, including reports of specialist analyses. A considerable proportion of these refer to the large-scale investigations at Borgharen and Itteren to the north of Maastricht, and at Lomm and Well–Aijen to the north of Venlo. The results of the investigations suggest the archaeological record here is rich and varied, with a time depth of c. 11,500 years, and traces of occupation and land use ranging from the Early Mesolithic (Well–Aijen, Borgharen) to the Second World War (Lomm).This paper reflects on almost 20 years of archaeological research in the project areas of the Maaswerken and on the principles and methods used in the field research. The common thread is the results of landscape and archaeological studies and the relationship between them. Examples are used to illustrate results that can be regarded as important from a national perspective, and in terms of archaeological heritage management.