Abstract: The aim of the study was to identify changes in agricultural practices and periods of agricultural expansion and regression during the last 1,300 years in the South-Swedish Uplands. Sediments from the small lake of Skarpingsgolen (1.2 ha) were used to quantify land-cover at a local scale (c. 1 km radius) in 50-year intervals based on pollen analysis and the LOVE model (Local Vegetation Estimates). The results showed a dramatic change in land-cover, starting c. ad 1150, from a grazed, deciduous woodland, dominated by Corylus, Betula and Quercus, to a semi-open landscape dominated by Picea and open agricultural land. A hamlet, situated next to the lake, was probably established during the 12th century, abandoned during the late medieval crisis (late 14th century) and re-colonized during the 16th century. High values of Cannabis-type pollen (up to 10% of the pollen sum) suggest that hemp retting was carried out in the lake from the 13th to the 17th centuries, while elevated levels of microscopic charcoal indicate that slash-and-burn cultivation was practiced during the early 14th and the 16th–18th centuries. The LRA-based estimates of vegetation show that the modern landscape, dominated by managed coniferous woodlands, is very different from the landscape only 50–100 years ago. This type of study is useful for comparisons with historical and archaeological records, and provides sufficient temporal and spatial resolution to identify short-lived abandonments and shifts in agricultural practices.

Abstract: La degradation de l’obscurite sous l’effet des usages de lumiere artificielle nocturne dans et aux abords des infrastructures humaines est appelee pollution lumineuse. Liee a l’urbanisation, cette pollution deborde les espaces urbains pour affecter les espaces ruraux et les aires protegees. La lutte contre la pollution lumineuse s’organise dans plusieurs pays, dans lesquels des territoires experimentent des politiques environnementales de protection de l’obscurite. L’enjeu porte a la fois sur la preservation de la biodiversite et la transition energetiques. En France, quelques territoires ruraux pionniers experimentent des dispositifs integrant ce double enjeu. Deux d’entre eux constituent les cas d’etude de cet article. Nous montrons comment ces territoires font de l’obscurite une ressource specifique. Nous identifions trois processus de specification. Le premier, suivant une logique utilitariste anthropocentree, releve de l’economicisation de l’environnement dans la lignee de la shallow ecology. Le deuxieme, suivant une logique de conservation ecocentree, releve de l’ecologisation radicale de l’economie, dans la lignee de la deep ecology. Le troisieme suit une logique socioecosystemique integree consacrant l’interdependance entre le developpement, l’amenagement, la preservation de la biodiversite et la sobriete energetique. Les controverses de specification travaillent les territoires. Ceux-ci deviennent des territoires d’incubation, c'est-a-dire des espaces de resolution de ces controverses qui se traduisent dans un operateur de transition permettant au territoire d’emprunter une nouvelle trajectoire de developpement et d’amenagement.

Abstract: Land use and land cover change (LUCC) models are increasingly being used to anticipate the future of territories, particularly through the prospective scenario method. In the case of so-called trend or Business-as-Usual (BAU) scenarios, the aim is to observe the current dynamics and to extend them into the future. However , as they are implemented as baseline simulation in most current software packages , BAU scenarios are calibrated from a training period built from only two dates. We argue that this limits the quantitative estimation of future change intensity, and we illustrate it from a simple model of deforestation in Northern Ecuadorian Amazon using the Land Change Modeler (LCM) software package. This paper proposes a contribution to improve BAU scenarios calibration by mainly two enhancements: taking into account a longer calibration period for estimating change quantities and the integration of thematic data in change probabilities matrices. We thus demonstrate the need to exceed the linear construction of BAU scenarios as well as the need to integrate thematic and particularly socio-demographic data into the estimation of future quantities of change. The spatial aspects of our quantitative adjustments are discussed and tend to show that improvements in the quantitative aspects should not be dissociated from an improvement in the spatial allocation of changes, which may lead to a decrease in the predictive accuracy of the simulations. 2

Abstract: Land use and land cover change (LUCC) models are increasingly being used to anticipate the future of territories, particularly through the prospective scenario method. In the case of so-called trend or Business-as-Usual (BAU) scenarios, the aim is to observe the current dynamics and to extend them into the future. However , as they are implemented as baseline simulation in most current software packages , BAU scenarios are calibrated from a training period built from only two dates. We argue that this limits the quantitative estimation of future change intensity, and we illustrate it from a simple model of deforestation in Northern Ecuadorian Amazon using the Land Change Modeler (LCM) software package. This paper proposes a contribution to improve BAU scenarios calibration by mainly two enhancements: taking into account a longer calibration period for estimating change quantities and the integration of thematic data in change probabilities matrices. We thus demonstrate the need to exceed the linear construction of BAU scenarios as well as the need to integrate thematic and particularly socio-demographic data into the estimation of future quantities of change. The spatial aspects of our quantitative adjustments are discussed and tend to show that improvements in the quantitative aspects should not be dissociated from an improvement in the spatial allocation of changes, which may lead to a decrease in the predictive accuracy of the simulations. 2

Abstract: The Bronze Age decorated cave of Les Fraux (Dordogne, France) combines cave art and evidence for domestic and symbolic activities. The interdisciplinary research which has been conducted on the site since 2007 attempts to untangle the interwoven uses of this cave for later prehistoric communities, during short but regular human visitations, by combining chronology, interactions between individuals and their environment, and emerging technologies. The cave seems first to have been characterised by symbolic activity (cave art, votive deposits), becoming increasingly used for domestic activities. One aim of the research was the interpretation of archaeological data within a framework which combined space and time, from data acquisition, implementation of site monitoring, experimentation and simulation to reconstruction. We employed an integrative research approach based on new technologies, involving full 3D documentation of the entire site and processing of interdisciplinary data according to accurate 3D models of the cave, which provided a common framework for the various studies and partners involved. The difficulty of our study, however, lies in the definition and the meaning of ritual or symbolic gesture, as practiced in a cave context.

Abstract: The invention relates to a device (11) for capturing multiple images of an object, comprising an assembly of light-emitting units (51) arranged on a flat surface (31), at least one image-capturing unit (41), and a control unit (21) for controlling the assembly of light-emitting units in such a way as to carry out the illumination for each light-emitting unit with at least one light characteristic determined according to the distance between the illuminating position of the light-emitting unit and a reference position (PR).

Abstract: The emergence of quantum technologies, including cold atom based accelerometers, offers an opportunity to improve the performances of space geodesy missions. In this context, CNES initiated an assessment study called GRICE (GRadiometrie a Interferometres quantiques Correles pour l’Espace) in order to evaluate the impact of cold atom technologies to space geodesy and to the end users of the geodetic data. In this paper, we present a specific mission scenario for gravity field mapping based on a twin satellite concept. The mission uses a constellation of two satellites each equipped with a cold atom accelerometer. A laser link measures the distance between the two satellites and couples these two instruments in order to produce a correlated differential acceleration measurement. The main parameters, determining the performances of the payload, have been investigated. In addition, a preliminary study of mass, consumption and volume has been conducted to ensure the onboard feasibility of these instruments. A general study of the satellite architecture, including all the subsystems, has also been realized and is presented here.

Abstract: Quantitative reconstruction of past plant abundance from fossil pollen data is still a challenging task for palynologists. During the last decades, mechanistic methods have been developed to conver...

Abstract: Horizontal wells with multiple hydraulic fractures have become a standard completion for the development of tight oil and gas reservoirs. Successful optimization of multiple-fracture design on horizontal wells began empirically in the Barnett Shale in the late 1990s (Steward 2013; Gertner 2013). More recently, research has focused on further improving fracturing performance by developing a model-derived optimum. Some researchers have focused on an economic optimum on the basis of multiple runs of an analytical or numerical model (Zhang et al. 2012; Saputelli et al. 2014). With such an approach, a new set of model runs is necessary to optimize the design each time the input parameters change significantly. Running multiple simulations for every optimization case might not always be practical. An alternative approach is to develop well-performance curves with dimensionless variables on the basis of the performance model. Such an approach was the basis for unified fracture design (UFD) for a single fracture in a vertical well (Economides et al. 2002). However, a similar systemized method to calculate the optimum for a horizontal well with multiple hydraulic fractures was missing. The objective of this study was to develop a rigorous and unified dimensionless optimization technique with type curves for the case of multiple transverse fractures in a horizontal well—an extension of UFD. The mathematical problem was solved in dimensionless variables. Multiple fractures include the proppant number (NP), penetration ratio (Ix), dimensionless conductivity (CfD), and aspect ratio (yeD) for each fracture, which is inversely proportional to the number of fractures. The direct boundary element (DBE) method was used to generate the dimensionless productivity index (JD) for a given range of these parameters (28,000 runs) for the pseudosteady-state case. Finally, total well JD was plotted as a function of the number of fractures for various NP. The effect of minimum fracture width was studied, and the optimization curves were adjusted for three cases of minimum fracture width. The provided dimensionless type curves can be used to identify the optimized number of fractures and their geometry for a given set of parameters, without running a more complicated numerical model multiple times. First, the proppant mass (and hence, NP) used for the fracture design can be selected on the basis of economic or other considerations. For this purpose, a relationship between total JD and NP, which accounts for the minimum fracture width requirement, was provided. Then, the optimal number of fractures can be calculated for a given NP using the generated type curves with minimum width constraints. The following observations were made during the study on the basis of the performed runs: For a given volume or proppant, NP, total JD for multiple fractures increases to an asymptote as the number of fractures increases. This asymptote represents a technical potential for multiple fractures and for high proppant numbers (NP≥100), with a technical potential of 3πNP. Below this asymptote, the more fractures that are created for a fixed NP, the larger the JD. In practice, minimum fracture width constrains the fracture geometry, and therefore maximum JD. For the case when 20/40 sand is used for multiple hydraulic fracturing of a 0.01-md formation with square total area, the optimal number of factures is approximately NP25. Application of horizontal drilling technology with multiple fractures assumes the availability of high proppant numbers. It was shown mathematically that the alternative low proppant numbers (NP≤20 for the previous case) are impractical for multiple fractures, because total JD cannot be significantly higher than JD for an optimized single fracture in the same area. This means that low formation permeability and/or high proppant volumes are needed for multiple fracture treatments.