A simulation-optimisation methodology for designing the operation of emergency reservoirs in the Hungarian Tisza basin

This work reports the results of an investigation of reservoirs that were selected in Hungary in the framework of a new flood control strategy for the River Tisza, the largest tributary of the River Danube. Through a comprehensive analysis the optimal operation mode was identified, which would need to be applied to achieve the maximum decreasing effect on peak water levels. The flood waves were simulated using a 1D hydrodynamical model, which is based on the Saint-Venant equations. Both measured and synthetic discharge data were used as boundary conditions. The time lead as compared to the flood peak was determined for the reservoir system. On the Upper-Tisza the figures exceed the order of magnitude of the possible time lead of the realistic forecast, meaning that further research of the reconditioned discharge forecast is necessary. The investigation results of the interaction of two reservoirs showed that the sum of the decreasing effects on water levels when separated reservoirs work independently approac hes the decreasing effect of the jointly operating reservoirs reasonably well. Therefore the joint impacts can be estimated using quick linear programming methods

Áramlási holtterek eloszlása és ökológiai jelentősége a Tisza magyar szakaszán = Distribution and ecological significance of aggregated dead zones along the Hungarian section of River Tise

A Tisza magyar szakaszán a fitoplankton biomasszáját és összetételét alapvetően a Szamos fitoplanktonja határozza meg. A Tisza heterogén, ám szokatlanul mély medrében az áramlási holtterek hatása jelentéktelen. A tiszalöki és a kiskörei duzzasztás miatt lelassuló vízből a kovaalgák kiülepednek, az óriási kiterjedésű holttérként funkcionáló Tisza-tóból bemosódó Cryptophyta és zöldalgák ezt a biomassza veszteséget nem tudják pótolni. Az áramlási holtterek akkor tudják jelentősen befolyásolni a folyó fitoplanktonját, ha az aljzatra ülepedő algák számára elegendő fény áll rendelkezésre a fotoszintézishez. Ilyen viszonyok jellemzőek a Szamos romániai szakaszára - és feltevésünk szerint számos olyan nagy folyóra - melynek kisvízi medrét nem szabályozták. A sekély áramlási holtterekben a kiülepedés - felkeveredés - kiülepedés spirálja révén sokszorosára növekszik az algák tartózkodási ideje a vízhez képest. Ez a mechanizmus a nagyobb méretű, gyorsabban ülepedő fajokat részesíti előnyben. A hazai vízfolyásokon általánosságban is igazoltuk, hogy a fitoplankton bioamasszáját nem a tápanyag ellátottság, hanem a tartózkodási idő határozza meg. Ezért a tápanyag kibocsátás csökkentése önmagában nem hatékony beavatkozás a vízfolyások ökológiai állapotának javítására. A vízhálózat fitoplankton szempontból vett topológiai viszonyai azonban lehetnek olyanok, hogy a tápanyagterhelésen keresztül csökkenthessük a hálózat algatermő képességét. | The import of algae from the Szamos River is the major determinant of the biomass and composition of phytoplankton along the Hungarian Tisza River (from rkm 686 to rkm 177). The impact of aggregated dead zones is negligible in the highly heterogeneous but exceptionally deep channel of the latter. As a consequence of diminutive flow velocities upstream of the two dams (rkm 523 and 402), the dominant diatoms sediment rapidly. The mass export of crypto- and chlorophytes from the shallow floodplain complex created by Dam 2 (maximum area 104 km2) cannot compensate for the biomass loss. To significantly influence the dynamics of riverine phytoplankton, the bottom of dead zones must be illuminated and sustain photosynthesis by sedimented algae. Such shallows are characteristic of the Romanian Szamos and presumably of several large rivers that escaped regulation of their low water channel. Repeated sedimentations and resuspensions ensure manifold longer residence time for phytoplankton relative to water. The mechanism selectively favors larger cells that sediment faster. Statistical analysis of long-term water quality data from Hungarian running waters revealed that algal biomass was independent of nutrient availability and was related to water residence time. Consequently, emission control is an inefficient measure to improve the trophic status of streams and rivers, unless the topology of the whole fluvial network is considered with respect to phytoplankton growth

A magyarországi akusztikai járműkategóriák megfeleltetése a CNOSSOS-EU módszer járműosztályainak

A közúti stratégiai zajtérképek előállítása során a hazai forgalomszámlálási gyakorlat nem teszi lehetővé a „szóló nehéz tehergépkocsi”, valamint a „motorkerékpár és segédmotoros kerékpár” forgalmi kategóriába tartozó járművek egyértelmű besorolását a CNOSSOS-EU módszer járműosztályaiba. Eltérő besorolási változatok zajkibocsátásra gyakorolt hatását elemezve előbbi kategóriára általánosan, utóbbira pedig a belterületi útszakaszokra vonatkozóan igazoltuk a probléma akusztikai relevanciáját

A Kárpát-medence déli (Dél-Magyarország, Bácska, Horvátország) és az ÉNY-Mediterrán térség löszeinek vizsgálata és kapcsolatuk az Emilian (tengeri) -pencki (alpi) pleisztocén kronológiával = Investigations into loess sequences in the southern part of the Carpathian Basin (Southern Hungary, Bachka, Croatia) and in the northeast Mediterranean and their relationship with the Emilian (marine) and Penckian (alpine) pleistocene chronology

A Kárpát-medence D-i peremvidékén végzett vizsgálatok jelentősen hozzájárulnak a terület negyedidőszaki fejlődése és környezetváltozásai egyre pontosabb megismeréséhez. Négy típusterületen - 1. az Isztriai-félsziget É-i és D-i peremvidékén, 2. a Bácskai-löszplató K-i peremvidékén, 3. az Erdődi-rög Duna alámosta szakaszán, valamint a Duna-Tisza torkolatvidéke környezetében végeztünk kutatásokat abból a célból, hogy az alsó-, középső- és felsőpleisztocén lösz- és talajsorozatok, ill. egyes helyeken az aljzatban található pliocén rétegek egységes környezetjelző módszerrel történő vizsgálatával olyan őskörnyezet változásokra vonatkozó alapinformációk birtokába juthassunk, amelyek a korábbiaknál jóval több, pontosabb és gyorsabb ismeret-anyag megszerzését teszi lehetővé a vizsgált terület fejlődéstörténetéről, ősföldrajzi- és őskörnyezet változásairól. Az őskörnyezet változásokra vonatkozó adatok a lehető legegyszerűbb és leggyorsabb módon leolvashatók az adatbázisokból és a szelvény mellé szerkesztett grafikonokról a feltárás minden mérési adatára vonatkozóan. Vizsgált feltárásaink (1. Titel, 2. Vörösmart, 3. Velica Stancia, 4. Szuliman, 5. Marlera, 6. Erdőd, 7. Stari Slankamen) magukba foglalják a fiatal lösz- és talajsorozatot, az öreg löszök és fosszilis talajaik sorozatát és a lösz alatti szubaerikus formációt, a "dunaföldvári összletet". A kapott eredmények alapján sok, a Kárpát-medence üledékeire vonatkozó - párhuzamosítási lehetőség birtokába jutottunk. | Studies conducted in the southern peripheral loess regions of the Carpathian basin have contributed to a more exact knowledge of the Quaternary evolution and environmental changes of the area. Investigations were carried out in four key regions: 1 Northern and southern margins of the Istrian Peninsula, 2 Eastern edge of Bácska Loess Plateau, 3 Along the section of Erdőd Massive underwashed by the Danube, and 4 Tributary of Tisza into the Danube. They included analyses of loess-paleosol sequences formed in early, middle and late Pleistocene and in some places Pliocene formations in the basement using uniform methods of environmental indication and were aimed to rapidly obtain exact and comprehensive basic information concerning the evolution, paleogeographic and paleoenvironmental changes in the study area. A simple and rapid method was find to deduce information from the databases and diagrams drawn parallel with the profiles. The sampling and analyses included the following sections: 1 Titel, 2 Vörösmart, 3 Velica Stancia, 4 Szulimán, 5 Marlera, 6 Erdőd, 7 Stari Slankamen. At these type localities young loesses and soils, old loess-paleosol series and a subaerial formation underlying loess (the so called Dunaföldvár series) were investigated. Results obtained this way offer opportunities for the correlation between sediments of the Carpathian basin

Effects of Anthropogenic Activities on the Elemental Concentration in Surface Sediment of Oxbows

The Upper Tisza floodplain region provides a mosaic of aquatic habitats including a series of oxbows. Inorganic contaminants can accumulate in the sediment; thus, the sediment is good indicator of the contamination of these oxbows. Our aim was to explore the effects of anthropogenic activities on the concentration of ele- ments and also to study the influence of vegetation types on the element in surface sediment of oxbows. We studied eight oxbows: two of them were protected, four of them were used for fishing and two of them were contaminated with domestic sewage. The following el- ements were measured with MP-AES in surface sedi- ment: Al, Cr, Cu, Fe, Mn, Pb and Zn. The elemental concentration was compared to the toxicity classes of Environmental Protection Agency (EPA), and the as- sessment of the level of toxicity was based on this comparison. We found that studied oxbows were differ- ent from each other based on the elemental concentra- tions of sediment using canonical discriminant analysis and analysis of variance. Based on the elemental con- centration in surface sediment of oxbows, separation was also found among vegetation types. But significant difference was not found in the concentrations of ele- ments based on vegetation types. Our results demon- strated that the anthropogenic activities had remarkable effects on the elemental concentration of surface sedi- ment in oxbows. Our findings suggest that the sediment is useful to assess the effects of anthropogenic activities on elemental concentrations of oxbows

Cladocera remains and vegetation types to assess the state of oxbows

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Exploring river pollution based on sediment analysis in the Upper Tisza region (Hungary)

We assessed contamination in the Upper Tisza region (Hungary, Central Europe), analyzing the elemental concentrations in sediment cores of oxbows. Our hypothesis was that the metal contamination which occurred in the year 2000 and which came from the mining area in Transylvania (Romania) may be detected even 15 years after the contamination, based on the vertical profile of sediment cores. Sediment cores were collected from five oxbows, and the following elements were measured with microwave plasmaatomic emission spectrometry (MP-AES): Cu, Cr, Ba, Fe, Mn, Pb, Sr, and Zn. Among the oxbows studied, there was one protected oxbow, three were used for fishing, and one was contaminated with sewage. Our results indicated that the year of contamination is still observable in the vertical profile of the sediment cores. The pollution index (PI) was used to characterize the sediment enrichment of metal elements in the sediment cores. In the case of Cu, Pb, and Zn, the contamination which originated in the year 2000 was detected in the layers of the sediment cores. The contamination levels of Cu, Pb, and Zn were high or moderate in the studied oxbows. All oxbows were moderately contaminated by Mn, while a moderate level of contamination was found for Fe in the protected oxbow, one fishing oxbow, and the sewage-contaminated oxbow. In the fishing oxbows, a low level of contamination was found for Fe. The contamination level of Sr was low in the protected oxbow and in the two fishing oxbows, while in one of the fishing oxbows and in the sewage-contaminated oxbow, a moderate level of Sr contamination was found. The pollution index scores indicated that the contamination level for Ba and Cr was low in the sediment cores of the oxbows studied. Our results indicated that the contamination of the Tisza River from the mining area in Northern Romania has been continuous and is still ongoing

SURFACE LAYER’S SOUND SPEED PROFILES: CLIMATOLOGICAL ANALYSIS AND APPLICATION FOR THE CNOSSOS-EU NOISE MODEL

Noise pollution and exposure are important environmental issues that need to be investigated and regulated. To do this,we need to know about micrometeorology to figure out how noise travels from the source to the receiver. Accordingly, the sound propagation part of the common noise assessment methods (CNOSSOS-EU) developed by the European Commission for different sources of noise needs detailed meteorological databases. Using data from the SYNOP stations maintained by the Hungarian Meteorological Service (HMS) and the ERA5 meteorological reanalysis database, the standard noise propagation conditions are determined. The primary objective of this study is to ascertain the probability distribution of stability classes for a variety of source-receiver orientations, utilizing either 25 or 2 stability classes, and several different aggregation levels. Relative frequencies and year-to-year variability have been calculated for favourable noise propagation conditions where the sound speed profile grows with height (downward refraction condition) and unfavourable noise propagation conditions where the sound speed profile constant or decreases with height (so-called homogeneous conditions). Favourable noise propagation occurs in approximately one-third of cases during the daytime while in approximately two-third of cases during the evening and night-time where the noise exposure is increasing. Furthermore, using the SoundPLANnoise software, sound propagation model calculations were performed on a study area near Budapest, using different values of parameter pf describing the probability of occurrence of favourable conditions on sound propagation during different periods of the day. This area is crossed by Highway 4, which is a major road according to the 49/2002 EU Directive, as it has more than three million vehicles passing on the examined section every year. The results show considerable deviations in annual average A-weighted sound levels calculated using different versions of parameter pf. The largest difference between the A-weighted sound levels calculated with the highest and lowest generated annual pf values was 1.65 dB(A); 1.42 dB(A) and 0.75 dB(A) for day, evening and night periods, respectively.&nbsp

Stabilizing effect of WWTP discharge on water quality and fish assemblage structure

We examined the effluent from a municipal (Nyiregyhaza, Hungary) wastewater treatment plant (WWTP) on hydrophysicochemical properties and on diversity, community structure, and stability of fish assemblages at the recipient low flow channel system during a two-year period. The WWTP outflow increased significantly the nutrient concentrations (e.g. NO2 and NO3 concentrations increased to 4x and 8x respectively), and the regime (with the permanent ~0.23m3/s load) at the recipient channel sections. The wastewater outflow not only altered, but stabilized the physico-chemical variables measured, and the water regime in the recipient channels. Thus the natural, periodic fluctuation of the environmental variables was diminished in the study period. The WWTP outflow caused significant changes in the fish fauna as well. High abundances and taxa richness were found in the stocks inhabiting the charged watercourse sections. At the same time, species composition and relative abundances of fish stocks proved to be more constant at the impaired sites. Our results show that the WWTP outflow caused altered, but significantly more stable environmental conditions. These alterations were favourable for the emergence of a more diverse and more stable fish community on the recipient channel sections. Hence, the dynamic variability in fish assemblage structure that is characteristic of natural lowland stream was not apparent in these perturbed, semi natural habitats

Novel genetic sex markers reveal unexpected lack of, and similar susceptibility to, sex reversal in free-living common toads in both natural and anthropogenic habitats

Anthropogenic environmental changes are affecting biodiversity and microevolution worldwide. Ectothermic vertebrates are especially vulnerable because environmental changes can disrupt their sexual development and cause sex reversal, a mismatch between genetic and phenotypic sex. This can potentially lead to sex‐ratio distortion and population decline. Despite these implications, there is scarce empirical knowledge on the incidence of sex reversal in nature. Populations in anthropogenic environments may be exposed to sex‐reversing stimuli more frequently, which may lead to higher sex‐reversal rate or, alternatively, these populations may adapt to resist sex reversal. We developed PCR‐based genetic sex markers for the common toad (Bufo bufo) to assess the prevalence of sex reversal in wild populations living in natural, agricultural and urban habitats, and the susceptibility of the same populations to two ubiquitous oestrogenic pollutants in a common garden experiment. We found negligible sex‐reversal frequency in free‐living adults despite the presence of various endocrine‐disrupting pollutants in their breeding ponds. Individuals from different habitat types showed similar susceptibility to sex reversal in the laboratory: all genetic males developed female phenotype when exposed to 1 µg L(−1) 17α‐ethinylestradiol (EE2) during larval development, whereas no sex reversal occurred in response to 1 ng L(−1) EE2 and a glyphosate‐based herbicide with 3 µg L(−1) or 3 mg L(−1) glyphosate. The latter results do not support that populations in anthropogenic habitats would have either increased propensity for or higher tolerance to chemically induced sex reversal. Thus, the extremely low sex‐reversal frequency in wild toads compared to other ectothermic vertebrates studied before might indicate idiosyncratic, potentially species‐specific resistance to sex reversal