Gábor Mezősi

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.

The Physical Geography of Hungary

In this chapter, the palaeo-geographical changes of the central part of the Carpathian Basin are described, since the Palaeozoic until nowadays. It analyses the evolution of the landscape based on plate tectonics, besides the main influencing factors of palaeo-geographical forms and processes are also studied in connection with climate and vegetation changes. The Quaternary landscape development processes and their consequences are described in detail. In Hungary, fluvial processes are dominant; therefore, the development of the fluvial network, the formation of terrace systems and their controlling factors (e.g. tectonic movements) are emphasized too. The other main form assemblage of the region is connected to blown sand and loess formation. In the mountainous areas, the dominant processes are the different development ways of karstic and non-karstic surfaces and the periglacial forms and processes. The summary of geomorphological, climatic, vegetational and hydrological processes follows a temporal order; thus, the chapter gives a detailed and complex analysis on the Pleistocene, Late Glacial and Holocene evolution of the region. 1.1 Paleozoic and Mesozoic Relief Evolution and Palaeo-Geography Paleozoic and Mesozoic palaeo-geographical history of the Carpathian Basin is quite complex, because the crust pieces currently located side by side and representing an integral unit may have been as far as thousands of kilometres from each other at the time of their evolution. Even though the climate was warmer and more uniform at that time, the different ecological conditions resulted in distinct surface evolution and sediment formation. The crust pieces forming the Carpathian Basin once were located at different places on Earth; thus, they will not be discussed in detail. The description follows the evolution of the micro-plates called ALCAPA (Pelso) and Tisia-Dacia, which came about as a result of subsequent evolution and fusion. However, it must be considered that the two micro-plates are separated along the Middle Hungarian structural line (lineament), which was active until the Miocene and only got into their current positions in the Mid-Tertiary.

Assessment of future scenarios for wind erosion sensitivity changes based on ALADIN and REMO regional climate model simulation data

Abstract The changes in rate and pattern of wind erosion sensitivity due to climate change were investigated for 2021–2050 and 2071–2100 compared to the reference period (1961–1990) in Hungary. The sensitivities of the main influencing factors (soil texture, vegetation cover and climate factor) were evaluated by fuzzy method and a combined wind erosion sensitivity map was compiled. The climate factor, as the driving factor of the changes, was assessed based on observed data for the reference period, while REMO and ALADIN regional climate model simulation data for the future periods. The changes in wind erosion sensitivity were evaluated on potentially affected agricultural land use types, and hot spot areas were allocated. Based on the results, 5–6% of the total agricultural areas were high sensitive areas in the reference period. In the 21st century slight or moderate changes of wind erosion sensitivity can be expected, and mostly ‘pastures’, ‘complex cultivation patterns’, and ‘land principally occupied by agriculture with significant areas of natural vegetation’ are affected. The applied combination of multi-indicator approach and fuzzy analysis provides novelty in the field of land sensitivity assessment. The method is suitable for regional scale analysis of wind erosion sensitivity changes and supports regional planning by allocating priority areas where changes in agro-technics or land use have to be considered.

Assessing Landscape Sensitivity Based on Fragmentation Caused by the Artificial Barriers in Hungary

Abstract Artificial barriers significantly disturb the landscape unit. Roads split the contiguous landscape units, thus basically modi fying their ecological characters. The more artificial barriers are constructed in the landscape, the more fragmented it is. Theref ore, the contiguous landscape unit is divided into two or more patches, weakening resilience and stability of ecological systems. During decrease in patch size, the stability reduces until the patch size is at its minimum viable or effective population size. In current study analysing the degree of fragmentation caused by artificial barriers in meso-scale landscape units (meso-regions) we can get an overall picture about changes in their stability and sensitivity. The major aims of this study is to investigate the fragmentation of landscape units caused by three types of artificial barriers (roads, railways and settlements) in micro-regions, and to measure the degree of fragmentation and its spatial-temporal (1990, 2011 and future scenario to 2027) changes using mathemat ical/ statistical analysis and landscape metrics (Number of Patches, Division, Landscape Splitting Index and Effective Mesh Size). By calculating landscape fragmentation metrics, the micro-regions are identified, which must be protected with high priority in the future. In the planning processes, type and position of artificial barriers could be more properly determined by calculation of these landscape metrics.

Climate of Hungary

The climate of the Carpathian Basin reflects the combined characteristics of the neighbouring regions. Despite of the small area and the modest orographic differences of the country, the climate elements (e.g. solar radiation, temperature or precipitation conditions) have distinctive spatial and temporal characters. The result of climatic measurements and the differences in the values will be described in this chapter. Besides, the agro-economical (e.g. drought hazard) and environmental resource potential of the climate (e.g. wind energy utilization) will be introduced. The latest will be described in detail (e.g. recreational potentials and skiing, are limited in natural conditions), as well as the renewable energy sources. Based on estimations, the potential amount of solar radiation (72 PJ,), wind energy (46 PJ), geothermal energy (50 PJ) and biomass (120 PJ) is far higher than the actual usage of these energy resources, which altogether is lower than 10 PJ, if the biomass usage (ca. 52 PJ) is not accounted. In this chapter, the special climate characters of the cities will be analysed too. Slightly detailed description is provided on the potentials (mountainous medical locations) and hazards of the climate (e.g. rainstorm hazard, heat stress, increasing extremities). The past and future climate changes of the Basin are also analysed.

Estimation of the Changes in the Rainfall Erosivity in Hungary

Abstract According to the forecasts of numerous regional models (eg. REMO, ALADIN, PREGIS), the number of predicted rainfall events decreases, but they are not accompanied by considerably less precipitation. It represents an increase in rainfall intensity. It is logical to ask (if the limitations of the models make it possible) to what extent rainfall intensity is likely to change and where these changes are likely to occur in the long run. Rain intensity is considered to be one of the key causes of soil erosion. If we know which areas are affected by more intense rain erosion, we can identify the areas that are likely to be affected by stronger soil erosion, and we can also choose effective measures to reduce erosion. This information is necessary to achieve the neutral erosion effect as targeted by the EU. We collected the precipitation data of four stations every 30 minute between 2000 and 2013, and we calculated the estimated level of intensity characterizing the Carpathian Basin. Based on these data, we calculated the correlation of the measured data of intensity with the values of the MFI index (the correlation was 0.75). According to a combination of regional climate models, precipitation data could be estimated until 2100, and by calculating the statistical relationship between the previous correlation and this data sequence, we could estimate the spatial and temporal changes of rainfall intensity.

Granite Weathering in the Velence Hills

The landforms of granite weathering in the Velence Hills are unique in Central Europe. Through intensive weathering since the end of the Permian the exposed granite mass was transformed to saprolite. Weathering combined with sheet wash worked on the Eocene andesite too and resulted in heavy denudation. Since the Late Tertiary tectonic movements also contributed to the fragmentation of the granite mass, which was accompanied by the decay of the surface saprolite. The Velence Hills are best known for granite ridges and tors (balanced rocks). Tectonics had a fundamental contribution to the development of landforms. The water entering from both below and above to the joint network had a significant weathering effect on the one hand through its hydrothermal effect and on the other hand (from the other direction) through hydrolysis (both affected the feldspars and talcs of the granite). The landscape on surfaces decomposed hydrothermally or through hydrolysis are clearly distinguishable from the land form related to the intact granite surfaces.

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.

Division of the Natural Landscape Regions

This chapter describes the hierarchic system of the Hungarian landscape units and its structure. The smallest unit is the ecotope, and the group of ecotopes forms the micro-region, which constitute meso- and macro-regions. This system is the basis of the regional description of Hungary, introduced in Part II of the book. Based on the accepted Hungarian classification of regions, the regions are determined by their physical geographical factors, but in connection with them, social (and economical) processes also modify their structure, function and characteristics. Therefore, in the regional descriptions, some environmental values and conflicts of each macro-region are highlighted. Besides the structural analysis of the regions, some landscape historical data are described.

Natural Vegetation of Hungary

The species composition of the vegetation in the Carpathian Basin is determined by the climate, relief, lithology/soil and hydrological conditions. Two main zonal vegetation types appear in Hungary: the zone of deciduous forests, which is dominated by oak and beech (especially in hilly and mountainous areas), and its most widespread forest type is the turkey oak–oak forest. The other zonal vegetation is the forest steppe on lowland areas, which includes different sand and loess forest steppes, and herbaceous associations (e.g. lossy and sandy steppe grasslands). Based on the reconstruction of potential vegetation, approximately 30–50 % of the Carpathian Basin was covered by forest before the intensive human impact, while just approx. 20 % of Hungary was covered by forest. The Carpathian Basin is very rich in species (ca. 3000 plant and 43,000 animal species), and it has colourful and various ecological systems; thus, it is one of the areas with the richest vegetation in Europe. Therefore, the questions of nature protection and conservation are highlighted in the chapter. Highly protected areas are the peatbogs, marshland forests, mixed oak forest and lowland oak forest, which are endangered by natural and human factors.