György Sipos

Holocene landscape dynamics at the tell Arslantepe, Malatya, Turkey – Soil erosion, buried soils and settlement layers, slope and river activity in a middle Euphrates catchment

Alluvial and colluvial sequences were studied around the prehistoric tell Arslantepe in 11 exposures and additional auger cores. The chronology is based on 11 optically stimulated luminescence (OSL) ages, four radiocarbon ages, and the embedded artifacts. Sediments contained wood charcoals, providing information on former vegetation. Fluvial activity is documented during Late Glacial times (15.4 ± 2.5, 12.8 ± 3.1 kyr) and frequently after Roman times. Slope and soil erosion occurred in the early (10.6 ± 1.4, 8.2 ± 0.7 kyr) and mid–late Holocene (6.7 ± 0.9, 5.4 ± 0.7–4.7 ± 0.7, 2.6 ± 0.2–2.5 ± 0.2, 1.9 ± 0.2–1.8 ± 0.2 kyr, and during the last 1000 years). The early Holocene erosion phases pre-date the so far established onset of settlement at the tell. This either indicates an earlier onset of agricultural land use than assumed or climatic influence on erosion, such as the 10.3 and 8.2 kyr climate events known from Western Europe. The erosion phases at around 5.0 and 2.6 kyr could reflect geomorphic responses to societal collapse (Late Chalcolithic state, Neo-Hittite kingdom) at Arslantepe. Most intensive Holocene soil erosion and landscape degradation occurred after occupation of the region by the Roman Empire. This is paralleled by the onset of river activity. A part of the lower neo-Hittite town as well as an early Holocene Terra Rossa–like soil that had formed rapidly were found buried. So far, no indication for mid–late Holocene fluvial activity of the adjacent creeks until Roman times has been found. Our results illustrate the large potential of slope deposits for long term reconstructions of human induced landscape transformation in Anatolia.

Investigation of Holocene blown-sand movement based on archaeological findings and OSL dating, Danube-Tisza Interfluve, Hungary

Abstract Please click here to download the map associated with this article. The largest blown-sand area of Hungary is located on the Danube-Tisza Interfluve. Here the most significant aeolian activity took place in the Pleistocene, however the aeolian rework of the forms occurred also in the Holocene and even during historical times. The aims of the research were: (1) to map the geomorphology of the study area at the eastern border of the interfluve (2) to determine the periods of sand remobilisation during historical times (3) to identify the possible types of human activities enabling aeolian activity. In order to determine the exact time of blown-sand movement OSL measurements were applied. Maps (scale 1:10,000) were made in order to analyze the geomorphological setting of the area and to represent the spatial distribution of archaeological findings. Based on the results, the studied sand dune area was occupied mainly by groups grazing large livestock. The archaeology of the territory reflects that settlements were primarily established in the border zone of dry dunes and wet, marshy interdune areas. Animal breeders with large populations meant an intensive burden on the environment and the chance for over-grazing increased during their inhabitance. For these reasons, aeolian activity reoccurred several times on the territory: at the beginning of the Late Bronze Age (1400-800 y BC), in the Sarmatian period (100–500 y AD), during the realm of the Avars (500–900 y AD) and when the Cumanians inhabited the region (1200–1500 y AD).

Recent Landform Evolution in Hungary

Fluvial geomorphic processes (channel and floodplain evolution) are widespread in the extensive lowlands of Hungary. Since flow regulation in the nineteenth century, river channels have shown adjustments of considerable degree. Some agricultural areas in hills and low mountain basins are seriously affected by water erosion, particularly gully development on loess. Although all sand dunes have been stabilized by now, historically wind erosion has also been a major geomorphic agent in blown-sand areas. The areas affected by mass movements and karst processes are limited but their processes still operate – partly in function of the changing climatic conditions. Applied geomorphological research focuses on ever intensifying human impact on the landscape (particularly in mining districts), which has become the primary driver of recent geomorphic evolution in Hungary, too.

Effect of Climate Change on the Hydrological Character of River Maros, Hungary-Romania

Abstract It is highly probable that the precipitation and temperature changes induced by global warming projected for the 21st century will affect the regime of Carpathian Basin rivers, e.g. that of River Maros. As the river is an exceptionally important natural resource both in Hungary and Romania it is necessary to outline future processes and tendencies concerning its high and low water hydrology in order to carry out sustainable cross-border river management. The analyses were based on regional climate models (ALADIN and REMO) using the SRES A1B scenario. The modelled data had a daily temporal resolution and a 25 km spatial resolution, therefore beside catchment scale annual changes it was also possible to assess seasonal and spatial patterns for the modelled intervals (2021- 2050 and 2071-2010). Those periods of the year are studied in more detail which have a significant role in the regime of the river. The study emphasizes a decrease in winter snow reserves and an earlier start of the melting period, which suggest decreasing spring flood levels, but also a temporally more extensive flood season. Changes in early summer precipitation are ambiguous, and therefore no or only slight changes in runoff can be expected for this period. Nevertheless, it seems highly probable that during the summer and especially the early autumn period a steadily intensifying water shortage can be expected. The regime of the river is also greatly affected by human structures (dams and reservoirs) which make future, more detailed modelling a challenge.

Constraining the Age of Floodplain Levels Along the Lower Section of River Tisza, Hungary

Abstract During the Late Pelistocene-Holocene transition the fluvial landscape of the Great Hungarian Plain changed considerably as a consequence of tectonic, climatic and geomorphological factors. Geochronology, and especially luminescence dating, is a very important tool in reconstructing these changes. The present study focuses on the Lower-Tisza region and addresses the timing of the development of different floodplain levels. In the meantime the luminescence characteristics of the investigated alluvial sediments were also assessed, with a special emphasis on the comparison of silty fine grain and sandy coarse grain results, as in the given medium and low energy environment fine grain sediments are more abundant, however, based on the literature, coarse grain samples are more reliable in terms of luminescence dating. Measurements were performed on 12 samples originating from the point bars of two large palaeo-meanders, representing different floodplain levels along the river. Results indicate the applicability of both grain size fractions for dating purposes, though fine grain subsamples overestimate in average by 1.5 ka the ages yielded by coarse grain subsamples. Consequently, fine grain samples can be used for outlining only general trends, and results need to be controlled by coarse grain measurements where possible. Based on the ages received, the upper floodplain was actively formed until 13-15 ka, when incision and the development of an intermediate floodplain level started. The meander on the intermediate flood plain level developed then very actively until 9 ka. As indicated by the received age information the intensity of meander formation could be highly affected by climatic and especially vegetation control. However, reconstruction can be refined later by further sampling and the application of the results of the present paper.

Factors triggering landslide occurrence on the Zemun loess plateau, Belgrade area, Serbia

Among the numerous factors that trigger landslide events, the anthropogenic impact caused by inadequate planning and faulty land use in urban areas is increasing. The Zemun settlement on the northern outskirts of Belgrade has experienced a number of landslides in the last three decades, endangering buildings and roads, and claiming human lives, particularly in the case of the 2010/2011 landslides. Selected meteorological parameters were used to calculate rainfall erosivity indices such as Precipitation Concentration Index and Modified Fournier Index over the period 1991–2015. Drought indices, Lang aridity index and Palfai Drought Index were calculated as well. Mann–Kendall trend test was applied to identify potential rising and/or declining trends both in meteorological parameters and calculated indices. Trend analysis of the annual and seasonal scales yielded a statistically significant trend in the spring time series. Stable arid and pronounced drought conditions were recorded. The modified Fournier index based on monthly mean values yields moderate aggressiveness, with several extreme values indicating very high erosivity classes, especially for 2010/2011. The geological substrate is predominantly loess and hence highly susceptible to erosion and slope failure when climatological conditions are suitable. Accelerated urbanization at the end of the last century reduced vegetation cover, intensified pressure on the vertical loess slope, and lacked suitable rain drainage systems so that surface-water runoff was directed into the porous loess, thereby endangering slope stability. We proposed a geomorphic model to describe the nature of the erosional processes on the loess cliffs of the Zemun loess plateau. Results from this study have implications for mitigation strategies.

Public Perception on Hydro-Climatic Extremes and Water Management Related to Environmental Exposure, SE Hungary

Increasing climate extremities, as consequences of climate change, highly affect the public and farmers in the SE Carpathian Basin. Our research aimed at the investigation of the perceptions and experiences of public, farmers and decision-makers on drought and inland excess water problems on the Hungarian part of this region, since their knowledge and cooperation are essential in the future planning of sustainable water management. Their opinions were explored by 481 questionnaires and 52 in-depth interviews addressing the perceived climate change impacts in everyday life and agriculture, causes of drought and inland excess water, possibilities of mitigation and adaptation, and sustainability of the present farming structure. The spatial distribution of the answers was compared with the spatial pattern of drought and inland excess water sensitivity based on environmental indicators. The results confirmed their high correspondence reflecting a realistic knowledge on severity, significance and the contributing factors. Individual responsibility, the lack of financial resources and an uncertain vision of public were considered as major weak points that could be improved to foster the implementation of an effective water management strategy. High efforts are necessary to outline the framework of inclusive planning processes with exact roles of all actors and find ways to motivate co-operation willingness and increase individual responsibility.

Assessment of possible uncertainties arising during the hydromorphological monitoring of a Sand-Bedded Large River

Abstract The riverbed morphology of sand-bedded rivers is dynamically changing as a consequence of quasi continuous bedload transport. In the meantime, the dimension, size and dynamics of developing bedforms is highly depending on the regime of the river and sediment availability, both affected by natural and anthropogenic factors. Consequently, the assessment of morphological changes as well as the monitoring of riverbed balance is challenging in such a variable environment. In relation with a general research on the longer term sediment regime of River Maros, a fairly large alluvial river in the Carpathian Basin, the primary aim of the present investigation was to assess uncertainties related to morphological monitoring, i.e. testing the reproducibility of hydromorphological surveys and digital elevation model generation by performing repeated measurements among low water conditions on selected representative sites. Surveys were conducted with the combination of an ADCP sonar, GPS and total station. The most appropriate way of digital elevation modelling (DEM) was tested and 30-point Kriging was identified to be optimal for comparative analysis. Based on the results, several uncertainties may affect the reproducibility of measurements and the volumetric deviation of DEM pairs generated. The mean horizontal difference of survey tracks was 3-4 m in case of each site, however this could not explain all the DEM deviation. Significant riverbed change between measurements could also be excluded as the main factor. Finally, it was found that results might be affected greatly by systematic errors arising during motor boat ADCP measurements. Nevertheless, the observed, normalised and aggregated DEM uncertainty (600-360 m3/rkm) is significantly lower than the changes experienced between surveys with a month or longer time lag. Consequently, the developed measurement strategy is adequate to monitor long term morphological and sediment balance change on sand bedded large river.

Dating the Holocene Incision of the Danube in Southern Hungary

Abstract The alluvial development of the Great Hungarian Plain has greatly been determined by the subsidence of different areas in the Pannonian Basin. The temporal variation of subsidence rates significantly contributed to the avulsion and shifting of main rivers. This was the case in terms of the Hungarian Lower Danube when occupying its present day N-S directional course. The considerable role of tectonic forcing is also supported by the presence of different floodplain levels. Although, several channel forms are identifiable on these the timing of floodplain development has been reconstructed up till now mostly by the means of geomorphological analysis, and hardly any numerical dates were available. The main aim of this study is to provide the first OSL dates for palaeo-channels located on the high floodplain surface of the Hungarian Lower Danube, and to determine the maximum age of low and high floodplain separation on the Kalocsa Plain. For the analysis two meanders were sampled close to the edge of the step slope between the two levels. According to the results, the development of the investigated palaeo-meanders could be rapid. The formation of the older meander was dated to the Late Atlantic, while the possible separation of the high and low floodplain surfaces could start in the beginning of the Subboreal Phase.

Towards a continuous inland excess water flood monitoring system based on remote sensing data

Abstract Inland excess water (IEW) is a type of flood where large flat inland areas are covered with water during a period of several weeks to months. The monitoring of these floods is needed to understand the extent and direction of development of the inundations and to mitigate their damage to the agricultural sector and build up infrastructure. Since IEW affects large areas, remote sensing data and methods are promising technologies to map these floods. This study presents the first results of a system that can monitor inland excess water over a large area with sufficient detail at a high interval and in a timely matter. The methodology is developed in such a way that only freely available satellite imagery is required and a map with known water bodies is needed to train the method to identify inundations. Minimal human interference is needed to generate the IEW maps. We will present a method describing three parallel workflows, each generating separate maps. The maps are combined to one weekly IEW map. At this moment, the method is capable of generating IEW maps for a region of over 8000 km2, but it will be extended to cover the whole Great Hungarian Plain, and in the future, it can be extended to any area where a training water map can be created.