Southern African Geomorphology

This book covers the geomorphology and landscape evolution of South Africa, focusing on arid landscapes, fluvial systems, karst, Quaternary landscapes, macro-scale geomorphic evolution, coastal geomorphology and applied geomorphology. It would appeal to postgraduate students in Physical Geography (Geomorphology) and Physical Geology and all academics in the earth sciences

Southern African Geomorphology

This book covers the geomorphology and landscape evolution of South Africa, focusing on arid landscapes, fluvial systems, karst, Quaternary landscapes, macro-scale geomorphic evolution, coastal geomorphology and applied geomorphology. It would appeal to postgraduate students in Physical Geography (Geomorphology) and Physical Geology and all academics in the earth sciences

Densification of spatially-sparse legacy soil data at a national scale: a digital mapping approach

Digital soil mapping (DSM) is a viable approach to providing spatial soil information but its adoption at the national scale, especially in sub-Saharan Africa, is limited by low spread of data. Therefore, the focus of this thesis is on optimizing DSM techniques for densification of sparse legacy soil data using Nigeria as a case study. First, the robustness of Random Forest model (RFM) was tested in predicting soil particle-size fractions as a compositional data using additive log-ratio technique. Results indicated good prediction accuracy with RFM while soils are largely coarse-textured especially in the northern region. Second, soil organic carbon (SOC) and bulk density (BD) were predicted from which SOC density and stock were calculated. These were overlaid with land use/land cover (LULC), agro-ecological zone (AEZ) and soil maps to quantify the carbon sequestration of soils and their variation across different AEZs. Results showed that 6.5 Pg C with an average of 71.60 Mg C ha–1 abound in the top 1 m soil depth. Furthermore, to improve the performance of BD and effective cation exchange capacity (ECEC) pedotransfer functions (PTFs), the inclusion of environmental data was explored using multiple linear regression (MLR) and RFM. Results showed an increase in performance of PTFs with the use of soil and environmental data. Finally, the application of Choquet fuzzy integral (CI) technique in irrigation suitability assessment was assessed. This was achieved through multi-criteria analysis of soil, climatic, landscape and socio-economic indices. Results showed that CI is a better aggregation operator compared to weighted mean technique. A total of 3.34 x 106 ha is suitable for surface irrigation in Nigeria while major limitations are due to topographic and soil attributes. Research findings will provide quantitative basis for framing appropriate policies on sustainable food production and environmental management, especially in resource-poor countries of the world

Approaching Reality: Integrating Image-based 3D Modelling and Complex Spatial Data in Archaeological Field Recording

This thesis finalises a 5+3 PhD project within the joint doctoral programme in Digital Heritage established in collaboration between History, Archaeology and Classical Studies, Graduate School, the Faculty of Arts, Aarhus University and the University of York. The thesis deals with the overarching theme of spatial data in archaeological excavation recording. Spatial data are at the core of all archaeological observations, and are expressed in numerous ways, ranging from traditional hand drawings to digital two- and three-dimensional representations in Geographic Information Systems and proprietary 3D software. Yet, despite technological advances, state-of-the art digital spatial data are almost equally detached from textual archaeological interpretation as they were using conventional tools decades ago. The thesis presents a study of how technological advances influence archaeological excavation traditions and methodologies. Special emphasis is directed at exploring how the increased use of image-based 3D documentation may contribute to increased quality of field recording and, in particular, what theoretical conceptualisations and technical developments are needed to harness its full potential. The thesis is composed of four articles, which constitute individual chapters (2-5). Each chapter covers a theme within the underlying topic of integrating spatial data in archaeology, supplemented by an introductory chapter (1), a synthesis (6) and a conclusion (7). The first article (chapter 2) provides an introduction to the overarching research questions and their methodological and historical background. It offers some rudimentary impressions of differing excavation and recording traditions in Britain and Denmark, to critically assess the use of GIS in archaeology and the negotiation between state-of-the-art technology and archaeological practice. The article discusses how the adaptation of GIS may have contributed significantly to the detrimental effect of creating stand-alone silos of spatial data that are rarely fully integrated with non-spatial, textual data, and has acted to stifle the development of digital standards of recording by perpetuating outmoded analogue recording conventions from a previous century. The chapter outlines the potential of born-digital 3D recording technologies such as Structure From Motion (SFM), GPS, and laser scanning in current practice, while advocating for a conceptualisation of new types of data and data representation in archaeological documentation. This, however, requires changes in archaeological methodologies and workflows and that we redefine more explicitly what we actually want to do with spatial data in archaeology. The second article (chapter 3) seeks to advance the conceptual framework of 3D models within archaeological excavation recording. 3D documentation advocates for a new workflow with a more three-dimensional reasoning, allowing for the utilisation of 3D as a tool for continuous progress planning and evaluation of an excavation and its results. Just like the general use of models to form hypotheses, it is possible to use 3D models as spatial hypotheses of an ongoing excavation. This allows us to visually realise or spatially conceptualise our hypotheses as a virtual reconstruction and to combine it with our observational data. The article presents first-hand experiences of working with 3D reconstruction and visualisations during the excavations at Viking Age site Jelling, and explores how the concept of authenticity may facilitate negotiations between visualising what we know, and what we think we know. The third article (chapter 4) further addresses the challenges inherent to the integration of 3D documentation: specifically its inability to convey archaeological interpretations. Image-based 3D modelling is generally considered a superior tool for generating geometrically accurate and photo-realistic recording of an excavation, but does not immediately encourage reflexive or interpretative practice. This is a direct consequence of the technical limitations of currently available tools, but also reflects an archaeological methodology and spatial conceptualisation based on two-dimensional abstractions. Using the example of the excavations at the Iron Age site Alken Enge, this article takes a more technical approach to exploring how new tools developed for segmenting field-recorded 3D geometry allow embedding archaeological interpretations directly in the 3D model, thereby augmenting its semantic value considerably. This is considered a precondition for the successful integration of 3D models as archaeological documentation. Furthermore, the article explores how web-based 3D platforms may facilitate collaborative exchange of 3D excavation content and how the integration of spatial and attribute data into one common event-based data model may be advantageous. The event-based approach is used for conceptualising how digital spatial data are created, derived and evolve throughout the documentation and post-excavation process. This effectively means building a conceptualisation of excavation recording procedures and seeing them through to the data model implementation itself. The fourth and last article (chapter 5) further explores the technologies outlined in chapters two and four. In particular, it focuses on evaluating analytical capabilities and alternative visualisation end-goals for 3D excavation recording. The chapter presents a simple case study, demonstrating the pipeline from excavating an archaeological feature, through image-based documentation and processing, to volumetric visual representation, while exploring the potential of machine learning to aid in feature recognition and classification. Chapter six acts as a synopsis, which provides added context to the results of the preceding chapters and furthermore discusses archaeological data models in general, conceptual reference models and, finally, presents the data model and implementation developed during the research project. The research introduces several novel approaches and technical developments aimed at aggregating the fragmented excavation data throughout the archaeological sector. This includes developing software for harvesting 2D GIS data from file storage at local archaeological institutions, functions for 3D semantic segmentation, automated processes for pattern recognition (SVM), machine learning and volumetric visualisation, and database mappings to web-services such as the MUD excavation database - all of which feed into the development of the Archaeo Framework. The online database \url{www.archaeo.dk} provides an implementation of the proposed data model for complex spatial field recorded data, and demonstrates the achieved data management capabilities, analytical queries, various spatial and visual representations and data interoperability functions. The Archaeo Framework acts as a data repository for excavation data, and provides long-awaited integration of spatial and textual data in Denmark. The benefits of spatial integration are clearly evident, notably having all information in one system, available online for research, dissemination and data re-use. For the first time, it is possible to perform large-scale validation of digital excavation plans against the written record, and perform complex spatial queries at a much deeper level than merely a site on a map. This research frames the basis for further developments of dynamic data management approaches to the integration of complex spatial data in field archaeology. The data model is expected to assist archaeologists in implementing better conceptualised excavation data models, and to facilitate a better understanding and use of 3D for archaeological documentation and analysis. Ultimately, the implementation provides access to the inaccessible dimensions of archaeological recording by joining hitherto isolated and fragmentary archaeological datasets - spatial and textual. Future areas of investigation should seek to advance this further in order to facilitate the persistence of complex spatial data as integrated components of archaeological data models

Acoustic data optimisation for seabed mapping with visual and computational data mining

Oceans cover 70% of Earth’s surface but little is known about their waters. While the echosounders, often used for exploration of our oceans, have developed at a tremendous rate since the WWII, the methods used to analyse and interpret the data still remain the same. These methods are inefficient, time consuming, and often costly in dealing with the large data that modern echosounders produce. This PhD project will examine the complexity of the de facto seabed mapping technique by exploring and analysing acoustic data with a combination of data mining and visual analytic methods. First we test the redundancy issues in multibeam echosounder (MBES) data by using the component plane visualisation of a Self Organising Map (SOM). A total of 16 visual groups were identified among the 132 statistical data descriptors. The optimised MBES dataset had 35 attributes from 16 visual groups and represented a 73% reduction in data dimensionality. A combined Principal Component Analysis (PCA) + k-means was used to cluster both the datasets. The cluster results were visually compared as well as internally validated using four different internal validation methods. Next we tested two novel approaches in singlebeam echosounder (SBES) data processing and clustering – using visual exploration for outlier detection and direct clustering of time series echo returns. Visual exploration identified further outliers the automatic procedure was not able to find. The SBES data were then clustered directly. The internal validation indices suggested the optimal number of clusters to be three. This is consistent with the assumption that the SBES time series represented the subsurface classes of the seabed. Next the SBES data were joined with the corresponding MBES data based on identification of the closest locations between MBES and SBES. Two algorithms, PCA + k-means and fuzzy c-means were tested and results visualised. From visual comparison, the cluster boundary appeared to have better definitions when compared to the clustered MBES data only. The results seem to indicate that adding SBES did in fact improve the boundary definitions. Next the cluster results from the analysis chapters were validated against ground truth data using a confusion matrix and kappa coefficients. For MBES, the classes derived from optimised data yielded better accuracy compared to that of the original data. For SBES, direct clustering was able to provide a relatively reliable overview of the underlying classes in survey area. The combined MBES + SBES data provided by far the best accuracy for mapping with almost a 10% increase in overall accuracy compared to that of the original MBES data. The results proved to be promising in optimising the acoustic data and improving the quality of seabed mapping. Furthermore, these approaches have the potential of significant time and cost saving in the seabed mapping process. Finally some future directions are recommended for the findings of this research project with the consideration that this could contribute to further development of seabed mapping problems at mapping agencies worldwide

Remote Sensing and Geosciences for Archaeology

This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications

Science handbook

2005 handbook for the faculty of Scienc

Science handbook

2005 handbook for the faculty of Scienc

Science handbook

2006 handbook for the faculty of Scienc

Science handbook

2006 handbook for the faculty of Scienc