Human History and Digital Future

Korrigierter Nachdruck. Im Kapitel "Wallace/Moullou: Viability of Production and Implementation of Retrospective Photogrammetry in Archaeology" wurden die Acknowledgemens enfternt.The Proceedings of the 46th Annual Conference on Computer Applications and Quantitative Methods in Archaeology, held between March 19th and 23th, 2018 at the University of Tübingen, Germany, discuss the current questions concerning digital recording, computer analysis, graphic and 3D visualization, data management and communication in the field of archaeology. Through a selection of diverse case studies from all over the world, the proceedings give an overview on new technical approaches and best practice from various archaeological and computer-science disciplines

Changes in the Building Stock of Da Nang between 2015 and 2017

This descriptor introduces a novel dataset, which contains the number and types of buildings in the city of Da Nang in Central Vietnam. The buildings were classified into nine distinct types and initially extracted from a satellite image of the year 2015. Secondly, changes were identified based on a visual interpretation of an image of the year 2017, so that new buildings, demolished buildings and building upgrades can be quantitatively analyzed. The data was aggregated by administrative wards and a hexagonal grid with a diameter of 250 m to protect personal rights and to avoid the misuse of a single building’s information. The dataset shows an increase of 19,391 buildings between October 2015 and August 2017, with a variety of interesting spatial patterns. The center of the city is mostly dominated by building changes and upgrades, while most of the new buildings were constructed within a distance of five to six kilometers from the city center

Satellitengestützte Charakterisierung der Stadtmorphologie in Kigali (Ruanda) und Verknüpfung mit einer transsektoralen Verbrauchsanalyse

Basisdaten zur Stadtmorphologie sowie Daten über die spezifischen Bedarfe und Verbräuche der Sektoren wie Energie, Wasser und Abwasser, sind für die Stadtplanung und die Planung von Infrastruktur wichtig. Gerade in sich dynamisch entwickelnden urbanen Regionen des Globalen Südens liegen diese Daten zumeist nicht vor. Die vorliegende Studie zeigt, dass mittels Satelliten-Fernerkundung und Haushaltsbefragungen diese Informationslücken geschlossen werden können. Mittels Pléiades- und RapidEye-Aufnahmen konnten für die Stadt Kigali die Stadtmorphologie und die Anzahl von Gebäuden erhoben sowie eine Typisierung der Gebäude durchgeführt werden. Die Haushaltsbefragung zeigt einen direkten Zusammenhang zwischen Stadtstruktur/Gebäudetyp und nutzerspezifischen Verbrauchs- und Bedarfswerten

The development of an innovative computer-based Integrated Water Resources Management System for water resources analyses

International audienceThe European IWRMS (Integrated Water Resources Management System) project is dedicated to developing a toolset for a sustainable use and distribution of water resources in souther African countries. This system integrates various scientific components: remote sensing, information systems, database management, and hydrological modelling. This paper is mainly related to the remote sensing contribution of the project. Two points are discussed: land cover classification and the spatio-temporal processing of remote sensing data to extract hydrological parameters

Geomorphology of the upper Mkhomazi River basin, KwaZulu-Natal, South Africa, with emphasis on late Pleistocene colluvial deposits

We present a 1:50 000 scale geomorphological map of the upper Mkhomazi River basin, located in the foothills of the Drakensberg mountains in KwaZulu-Natal Province, South Africa. The sub-horizontal strata of the Permo-Triassic Beaufort Group forms plateau interfluves with a concave valley slope morphology. Locally, thick sequences of late Pleistocene colluvial deposits and associated buried paleosols (Masotcheni Formation) infill first-order tributary stream valleys and extend across the adjacent lower slopes. Surface runoff processes preferentially incise into the poorly consolidated, highly erodible sediments causing severe gully erosion that is responsible for widespread land degradation and desertification phenomena. The main purpose of this work is to derive a geomorphological map of the study area focussing on the erosional landforms to understand their spatial distribution and their relation to the colluvial deposits. Finally, a local and regional stratigraphic correlation of colluvial deposits and associated buried palaeosol profiles is proposed

Geomorphological processes, forms and features in the surroundings of the Melka Kunture Palaeolithic site, Ethiopia

The landscape of the surroundings of the Melka Kunture prehistoric site, Upper Awash Basin, Ethiopia, were studied intensively in the last decades. Nonetheless, the area was mainly characterized under a stratigraphic/geological and archaeological point of view. However, a detailed geomorphological map is still lacking. Hence, in this study, we identify, map and visualize geomorphological forms and processes. The morphology of the forms, as well as the related processes, were remotely sensed with available high-resolution airborne and satellite sources and calibrated and validated through extensive field work conducted in 2013 and 2014. Furthermore, we integrated multispectral satellite imagery to classify areas affected by intensive erosion processes and/or anthropic activities. The Main Map at 1:15,000 scale reveals structural landforms as well as intensive water-related degradation processes in the Upper Awash Basin. Moreover, the map is available as an interactive WebGIS application providing further information and detail (www.roceeh.net/ethiopia_ geomorphological_map/)

Remote sensing for characterisation and kinematic analysis of large slope failures : Debre Sina landslide, Main Ethiopian Rift Escarpment

This study was carried out in the framework of the German Science Foundation (DFG) project “Integrated assessment of geomorphological process dynamics on different spatio-temporal scales in the Ethiopian Highlands using remote sensing and advanced modelling approaches” (HO1840/11-1) and the Czech Science Foundation (GAČR) project “Mass wasting and erosion as an indicator of morphotectonic activity in the Ethiopian Highlands based on remote sensing approaches” (P209/12/J068). The ALOS/PRISM data were provided by the ESA in the framework of the project ID13160. The aerial photographs were provided by the Ethiopian Mapping Agency. We would like to thank the Gesellschaft für Erd- und Völkerkunde, Stuttgart, Germany for supporting the field campaign in 2015.Frequently occurring landslides in Ethiopia endanger rapidly expanding settlements and infrastructure. We investigated a large landslide on the western escarpment of the Main Ethiopian Rift close to Debre Sina. To understand the extent and amplitude of the movements, we derived vectors of horizontal displacements by feature matching of very high resolution satellite images (VHR). The major movements occurred in two phases, after the rainy seasons in 2005 and 2006 reaching magnitudes of 48 ± 10.1 m and 114 ± 7.2 m, respectively. The results for the first phase were supported by amplitude tracking using two Envisat/ASAR scenes from the 31 July 2004 and the 29 October 2005. Surface changes in vertical direction were analyzed by subtraction of a pre-event digital elevation model (DEM) from aerial photographs and post-event DEM from ALOS/PRISM triplet data. Furthermore, we derived elevation changes using satellite laser altimetry measurement acquired by the ICESat satellite. These analyses allowed us to delineate the main landslide, which covers an area of 6.5 km2, shallow landslides surrounding the main landslide body that increased the area to 8.5 km2, and the stable area in the lower part of the slope. We assume that the main triggering factor for such a large landslide was precipitation cumulated over several months and we suspect that the slope failure will progress towards the foot of the slope.Publisher PDFPeer reviewe

Identifying Droughts Affecting Agriculture in Africa Based on Remote Sensing Time Series between 2000-2016: Rainfall Anomalies and Vegetation Condition in the Context of ENSO

Droughts are amongst the most destructive natural disasters in the world. In large regions of Africa, where water is a limiting factor and people strongly rely on rain-fed agriculture, droughts have frequently led to crop failure, food shortages and even humanitarian crises. In eastern and southern Africa, major drought episodes have been linked to El Niño-Southern Oscillation (ENSO) events. In this context and with limited in-situ data available, remote sensing provides valuable opportunities for continent-wide assessment of droughts with high spatial and temporal resolutions. This study aimed to monitor agriculturally relevant droughts over Africa between 2000-2016 with a specific focus on growing seasons using remote sensing-based drought indices. Special attention was paid to the observation of drought dynamics during major ENSO episodes to illuminate the connection between ENSO and droughts in eastern and southern Africa. We utilized Tropical Rainfall Measuring Mission (TRMM)-based Standardized Precipitation Index (SPI) with 0.25° resolution and Moderate-resolution Imaging Spectroradiometer (MODIS)-derived Vegetation Condition Index (VCI) with 500 m resolution as indices for analysing the spatio-temporal patterns of droughts. We combined the drought indices with information on the timing of site-specific growing seasons derived from MODIS-based multi-annual average of Normalized Difference Vegetation Index (NDVI). We proved the applicability of SPI-3 and VCI as indices for a comprehensive continental-scale monitoring of agriculturally relevant droughts. The years 2009 and 2011 could be revealed as major drought years in eastern Africa, whereas southern Africa was affected by severe droughts in 2003 and 2015/2016. Drought episodes occurred over large parts of southern Africa during strong El Niño events. We observed a mixed drought pattern in eastern Africa, where areas with two growing seasons were frequently affected by droughts during La Niña and zones of unimodal rainfall regimes showed droughts during the onset of El Niño. During La Niña 2010/2011, large parts of cropland areas in Somalia (88%), Sudan (64%) and South Sudan (51%) were affected by severe to extreme droughts during the growing seasons. However, no universal El Niño- or La Niña-related response pattern of droughts could be deduced for the observation period of 16 years. In this regard, we discussed multi-year atmospheric fluctuations and characteristics of ENSO variants as further influences on the interconnection between ENSO and droughts. By utilizing remote sensing-based drought indices focussed on agricultural zones and periods, this study attempts to contribute to a better understanding of spatio-temporal patterns of droughts affecting agriculture in Africa, which can be essential for implementing strategies of drought hazard mitigation