@article{KirchnerHerrmannMatrasetal.2022, author = {Kirchner, Andr{\´e} and Herrmann, Nico and Matras, Paul and M{\"u}ller, Iris and Meister, Julia and Schattner, Thomas G.}, title = {A pedo-geomorphological view on land use and its potential in the surroundings of the ancient Hispano-Roman city Munigua (Seville, SW Spain)}, series = {E\&G Quaternary Science Journal}, volume = {71}, journal = {E\&G Quaternary Science Journal}, number = {2}, doi = {10.5194/egqsj-71-123-2022}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300141}, pages = {123 -- 143}, year = {2022}, abstract = {This study investigates the surroundings of Munigua (municipium Flavium Muniguense), a small Roman town in the ancient province of Hispania Baetica (SW Spain). The city's economy was based primarily on copper and iron mining, which brought financial prosperity to its citizens. Local production of agricultural goods is thought to have been of little importance, as the regional soil conditions do not seem to be suitable for extensive agriculture. To evaluate the recent soil agro-potential and to find evidence for prehistoric and historic land use in the surroundings of Munigua, we applied a pedo-geomorphological approach based on the physico-chemical analysis of 14 representative soil and sediment exposures. Selected samples were analyzed for bulk chemistry, texture and phytoliths. The chronostratigraphy of the sequences was based on radiocarbon dating of charcoal samples. The site evaluation of the present-day soil agro-potential was carried out according to standard procedures and included evaluation of potential rootability, available water-storage capacity and nutrient budget within the uppermost 1 m. The results show that moderate to very good soil agro-potential prevails in the granitic and floodplain areas surrounding Munigua. Clearly, recent soil agro-potential in these areas allows the production of basic agricultural goods, and similar limited agricultural use should also have been possible in ancient times. In contrast, weak to very weak present-day soil agro-potential prevails in the metamorphic landscape due to the occurrence of shallow and sandy to stony soils. In addition, the study provides pedo-geomorphological evidence for prehistoric and historic land use in pre-Roman, Roman and post-Roman times. Catenary soil mapping in the vicinity of a Roman house complex reveals multi-layered colluvial deposits. They document phases of hillslope erosion mainly triggered by human land use between 4063 ± 82 and 3796 ± 76 cal BP, around 2601 ± 115 cal BP, and between 1424 ± 96 and 421 ± 88 cal BP. Moreover, geochemical and phytolith analyses of a Roman hortic Anthrosol indicate the local cultivation of agricultural products that contributed to the food supply of Munigua. Overall, the evidence of Roman agricultural use in the Munigua area indicates that the city's economy was by no means focused solely on mining. The production of basic agricultural products was also part of Munigua's economic portfolio. Our geoarcheological study thus supports the archeological concept of economically diversified Roman cities in the province of Baetica and in Hispania.}, language = {en} } @article{UllmannSauerbreyHoffmeisteretal.2019, author = {Ullmann, Tobias and Sauerbrey, Julia and Hoffmeister, Dirk and May, Simon Matthias and Baumhauer, Roland and Bubenzer, Olaf}, title = {Assessing Spatiotemporal Variations of Sentinel-1 InSAR Coherence at Different Time Scales over the Atacama Desert (Chile) between 2015 and 2018}, series = {Remote Sensing}, volume = {11}, journal = {Remote Sensing}, number = {24}, issn = {2072-4292}, doi = {10.3390/rs11242960}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193836}, pages = {2960}, year = {2019}, abstract = {This study investigates synthetic aperture radar (SAR) time series of the Sentinel-1 mission acquired over the Atacama Desert, Chile, between March 2015 and December 2018. The contribution analyzes temporal and spatial variations of Sentinel-1 interferometric SAR (InSAR) coherence and exemplarily illustrates factors that are responsible for observed signal differences. The analyses are based on long temporal baselines (365-1090 days) and temporally dense time series constructed with short temporal baselines (12-24 days). Results are compared to multispectral data of Sentinel-2, morphometric features of the digital elevation model (DEM) TanDEM-X WorldDEM™, and to a detailed governmental geographic information system (GIS) dataset of the local hydrography. Sentinel-1 datasets are suited for generating extensive, nearly seamless InSAR coherence mosaics covering the entire Atacama Desert (>450 × 1100 km) at a spatial resolution of 20 × 20 meter per pixel. Temporal baselines over several years lead only to very minor decorrelation, indicating a very high signal stability of C-Band in this region, especially in the hyperarid uplands between the Coastal Cordillera and the Central Depression. Signal decorrelation was associated with certain types of surface cover (e.g., water or aeolian deposits) or with actual surface dynamics (e.g., anthropogenic disturbance (mining) or fluvial activity and overland flow). Strong rainfall events and fluvial activity in the periods 2015 to 2016 and 2017 to 2018 caused spatial patterns with significant signal decorrelation; observed linear coherence anomalies matched the reference channel network and indicated actual episodic and sporadic discharge events. In the period 2015-2016, area-wide loss of coherence appeared as strip-like patterns of more than 80 km length that matched the prevailing wind direction. These anomalies, and others observed in that period and in the period 2017-2018, were interpreted to be caused by overland flow of high magnitude, as their spatial location matched well with documented heavy rainfall events that showed cumulative precipitation amounts of more than 20 mm.}, language = {en} } @article{TrappeKneisel2019, author = {Trappe, Julian and Kneisel, Christof}, title = {Geophysical and sedimentological investigations of Peatlands for the assessment of lithology and subsurface water pathways}, series = {Geosciences}, volume = {9}, journal = {Geosciences}, number = {3}, doi = {10.3390/geosciences9030118}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201699}, pages = {118}, year = {2019}, abstract = {Peatlands located on slopes (herein called slope bogs) are typical landscape units in the Hunsrueck, a low mountain range in Southwestern Germany. The pathways of the water feeding the slope bogs have not yet been documented and analyzed. The identification of the different mechanisms allowing these peatlands to originate and survive requires a better understanding of the subsurface lithology and hydrogeology. Hence, we applied a multi-method approach to two case study sites in order to characterize the subsurface lithology and to image the variable spatio-temporal hydrological conditions. The combination of Electrical Resistivity Tomography (ERT) and an ERT-Monitoring and Ground Penetrating Radar (GPR), in conjunction with direct methods and data (borehole drilling and meteorological data), allowed us to gain deeper insights into the subsurface characteristics and dynamics of the peatlands and their catchment area. The precipitation influences the hydrology of the peatlands as well as the interflow in the subsurface. Especially, the geoelectrical monitoring data, in combination with the precipitation and temperature data, indicate that there are several forces driving the hydrology and hydrogeology of the peatlands. While the water content of the uppermost layers changes with the weather conditions, the bottom layer seems to be more stable and changes to a lesser extent. At the selected case study sites, small differences in subsurface properties can have a huge impact on the subsurface hydrogeology and the water paths. Based on the collected data, conceptual models have been deduced for the two case study sites.}, language = {en} } @article{UllmannBuedelBaumhaueretal.2016, author = {Ullmann, Tobias and B{\"u}del, Christian and Baumhauer, Roland and Padashi, Majid}, title = {Sentinel-1 SAR Data Revealing Fluvial Morphodynamics in Damghan (Iran): Amplitude and Coherence Change Detection}, series = {International Journal of Earth Science and Geophysics}, volume = {2}, journal = {International Journal of Earth Science and Geophysics}, number = {1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147863}, pages = {007}, year = {2016}, abstract = {The Sentinel-1 Satellite (S-1) of ESA's Copernicus Mission delivers freely available C-Band Synthetic Aperture Radar (SAR) data that are suited for interferometric applications (InSAR). The high geometric resolution of less than fifteen meter and the large coverage offered by the Interferometric Wide Swath mode (IW) point to new perspectives on the comprehension and understanding of surface changes, the quantification and monitoring of dynamic processes, especially in arid regions. The contribution shows the application of S-1 intensities and InSAR coherences in time series analysis for the delineation of changes related to fluvial morphodynamics in Damghan, Iran. The investigations were carried out for the period from April to October 2015 and exhibit the potential of the S-1 data for the identification of surface disturbances, mass movements and fluvial channel activity in the surroundings of the Damghan Playa. The Amplitude Change Detection highlighted extensive material movement and accumulation - up to sizes of more than 4,000 m in width - in the east of the Playa via changes in intensity. Further, the Coherence Change Detection technique was capable to indicate small-scale channel activity of the drainage system that was neither recognizable in the S-1 intensity nor the multispectral Landsat-8 data. The run off caused a decorrelation of the SAR signals and a drop in coherence. Seen from a morphodynamic point of view, the results indicated a highly dynamic system and complex tempo-spatial patterns were observed that will be subject of future analysis. Additionally, the study revealed the necessity to collect independent reference data on fluvial activity in order to train and adjust the change detector.}, language = {en} } @article{Sponholz1994, author = {Sponholz, Barbara}, title = {Ph{\´e}nom{\´e}nes karstiques dans les roches siliceuses au Niger oriental}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86833}, year = {1994}, abstract = {Dans le Niger oriental, des ph{\´e}nomenes karstiques sont fr{\´e}quents dans les roches siliceuses: gres, silcretes, cro{\^u}tes ferrugineuses, roches cristallines. A partir des {\´e}tudes g{\´e}omorphologiques et micromorphologiques, on peut conclure a une kartsification, au sense de production de formes par dissolution. Les r{\´e}sultats permettent de dater du Tertiaire inf{\´e}rieur la principale p{\´e}riode de karstification. La r{\´e}partition r{\´e}gionale des formes induites par cette karstification indique une d{\´e}pendance probable des conditions pal{\´e}oclimatiques. Actuellement le karst influe encore sur le d{\´e}veloppement des autres formes de relief.}, language = {fr} } @phdthesis{Hipondoka2005, author = {Hipondoka, Martin H.T.}, title = {The development and evolution of Etosha Pan, Namibia}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-14351}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {This study explores and examines the geomorphology of a large endorheic basin, approximately twice the size of Luxemburg, situated in the Etosha National Park, Namibia. The main focus is directed on how and when this depression, known as Etosha Pan, came into being. Geomorphological investigation was complemented and guided primarily by the application and interpretation of satellite-derived information. Etosha Pan has attracted scientific investigations for nearly a century. Unfortunately, their efforts resulted into two diverging and mutually exclusive views with respect to its development. The first and oldest view dates back to the 1920s. It hypothesized Etosha Pan as a desiccated palaeolake which was abandoned following the river capture of its major fluvial system, the Kunene River. The river capture was assumed to have taken place in the Pliocene/Early Pleistocene. In spite of the absence of fluvial input that the Kunene contributed, the original lake was thought to have persisted until some 35 ka ago, long after the Kunene severed its ties with the basin. The current size of the basin and its playa status was interpreted to have resulted from deteriorating climatic conditions. The opposing view emerged in the 1980s and gained prominence in the 1990s. This view assumed that there were an innumerable number of small pans on the then surface of what later to become Etosha Pan. Since the turn of the Pliocene to Early Pleistocene, these individual pans started to experience a combined effect of fluvial erosion during the rainy season and wind deflation during the dry period. The climatic regime during that entire period was postulated to be semi-arid as today. This climatic status was used to rule out any existence of a perennial lake within the boundary of Etosha since the Quaternary. Ultimately, these denudational processes, taking place in a seasonal rhythm, caused the individual pans to deepen and widen laterally into each other and formed a super-pan that we call Etosha today. Thus the Kunene River had no role to play in the development of the Etosha Pan according to this model. However, proponents of this model acknowledged that the Kunene once fed into the Owambo Basin and assigned the end of the Tertiary to the terminal phase of that inflow. Findings of this study included field evidence endorsing the postulation that the Kunene River had once flowed into the Owambo Basin. Its infilled valley, bounding with the contemporary valley of the Kunene near Calueque, was identified and points towards the Etosha Pan. It is deliberated that a large lake, called Lake Kunene, existed in the basin during the time. Following the deflection of the Kunene River to the coast under the influence of river incision and neo-tectonic during the Late Pliocene, new dynamics were introduced over the Owambo Basin surface. After the basin was deprived of its major water and sediment budget that the Kunene River contributed, it was left with only smaller rivers, most notably the Cuvelai System, as the only remaining supplier. This resulted in the Cuvelai System concentrating and limiting its collective load deposition to a lobe of Lake Kunene basin floor. The accident of that lobe is unclear, but it is likely that it constituted the deepest part of the basin at the time or it was influenced by neo-tectonic that helped divert the Kunene River or both. Against the backdrop of fluvial action that was initiating the new lake, most parts of the rest of the basin, then denied of lacustrine activity, were intermittently riddled with a veneer of sediment, especially during phases of intensified aeolian activity. In the mean time, the area that was regularly receiving fluvial input started to shape up as a distinct lake with the depositions of sediments around the water-body, primarily via littoral action, serving as embankment. Gradually, a shoreline is formed and assisted in fixing and delineating the spatial extent of the new and much smaller lake, called Lake Etosha. That Lake Etosha is the predecessor of the modern day Etosha Pan. Indicators for a perennial lake found in this study at Etosha include fossil fragments of Clariidae species comparable to modern species measuring some 90 cm, and those of sitatunga dated to approximately 5 ka. None of these creatures exist today at Etosha because of their ecological requirements, which among others, include permanent water. The sitatunga, in addition, is known as the only truly amphibious antelope in the world. Since its inception, the new lake underwent a number of geomorphological modifications. A prominent character amongst these modifications is the orientation of the lake, which has its long-axis oriented in the ENE-WSW direction. It resulted from wave action affected by the prevailing dominant northeasterly wind, which is believed to have been in force since the Middle Pleistocene. Lake Etosha has also witnessed phases of waning and waxing under the influence of the prevailing climatic regime. Over the last 150 ka, the available data intercepted about seven phases of high lake levels. These data are generally in agreement with regional palaeoclimatic data, particularly when compared with those obtained from neighbouring Makgadikgadi Pans in Botswana. The last recorded episode of the wet phase at Etosha was some 2,400 years before the present.}, subject = {Etoschapfanne}, language = {en} }