Utjecaj izgradnje hidroelektrana na rijeku Dravu Benković, Robert; Japundžić-Palenkić, Božica; Mirosavljević, Krunoslav ...
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12/2022, Letnik:
43, Številka:
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Journal Article
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Rijeke su integralni dio tla, nastale u turbulentnim vremenima oblikovanja Zemlje, i mijenjale su se tijekom njezine povijesti. Raznolikost rijeka ne odražavaju samo različiti tipovi tla kroz koje ...one protječu nego ta raznolikost ovisi i o promjeni godišnjih doba i razlika između vlažnih i suhih godina. Drava je srednjoeuropska rijeka i jedna od najvažnijih pritoka Dunava. U prirodnim uvjetima pronos sedimenta u Dravi je uravnotežen, što znači da se na određenom području odnesena količina sedimenta nadomjesti istom količinom s uzvodnih dijelova sliva. Na svom toku kroz Hrvatsku Drava je tri puta pregrađena na dijelu toka uzvodno od ušća Mure, dok je prije ulaska u Hrvatsku čak dvadeset puta pregrađena. Izgradnjom hidroakumulacijskih jezera u sklopu hidroeneregetskih objekata mijenja se prirodni režim protoka, javljaju se značajne hidrološke i morfološke promjene na mjestu pregrada, kao i na dijelu toka uzvodno i nizvodno od pregrada. Izgradnja brana na rijekama smanjuje broj vrsta biljnoga i životinjskoga svijeta mijenjajući lokalne stanišne uvjete. Izgradnjom hidroelektrana dolazi i do kanaliziranja pojedinih dijelova vodotoka, gdje se mijenjaju erozijsko-sedimentacijski procesi u samom koritu. Rijeka koja je u prirodnom stanju sa svim svojim elementima najbolja je obrana od sezonskih poplava. Izgradnjom hidroenergetskih objekata mijenja se hidrološki režim, odnosno uvelike osciliraju vrijednosti protoka na pojedinim dijelovima rijeke Drave, što ima utjecaja na poplavne nizine nizvodno te na biljne vrste karakteristične za tu vrstu staništa. Glavnina biljnih vrsta koje su prilagođene poplavnim stanišnim uvjetima izgradnjom akumulacije izgubile bi većinu tla koje je pogodno za naseljavanje.
Rivers are an integral part of the soil, formed during the turbulent times of the formation of the planet Earth and have changed throughout its history. The diversity of rivers is not only reflected in the different types of soil through which they flow, but this diversity also depends on the changes in seasons and the differences between wet and dry years. The Drava River is a Central European river and one of the most important tributaries of the Danube. Under natural conditions, the transport of sediment in the Drava River is balanced, which means that in a certain area the amount of sediment carried away is replaced by the same amount from the upstream parts of the basin. Flowing through Croatia, the Drava River was dammed three times upstream of the mouth of the Mura River, while before entering Croatia it was dammed as many as 20 times. The construction of hydroaccumulation lakes, as part of hydropower facilities, changes the natural flow regime, causing significant hydrological and morphological changes at dam sites, as well as upstream and downstream of dams. The construction of dams on rivers reduces the number of plant and animal species by changing local habitat conditions. The construction of hydroelectric power plants leads to the canalization of certain parts of the watercourse, thus changing the erosion-sedimentation processes in the riverbed. A river in its natural state with all its elements is the best defense against seasonal floods. The construction of hydropower facilities changes the hydrological regime, that is, large fluctuations occur in the flow values in certain parts of the Drava River, which has an impact on the floodplains downstream and on the plant species characteristic of that type of habitat. Most of the plant species that are adapted to flood habitat conditions would lose most of the soil that is suitable for settlement with the construction of the reservoir.
Description: Scheme of the riparian zone in the Mura-Drava-Danube Transboundary Biosphere Reserve–the largest riverine protected area in south-eastern Europe–covering a gradient of softwood, ...transition and hardwood forests. Softwood floodplain forests grow in the lower parts of floodplains, they are hygrophilous, regularly flooded forests dominated by willow and poplar, while hardwood floodplain forests occur in the higher parts of current or former floodplains, dominated by elm, ash, or oak. The average lying deadwood volume per forest type ranges from 55 m3ha−1 in hardwood forests to 94 m3ha−1 in softwood forests. As distance from the river edge increased, the volume of lying deadwood decreased, ranging from 0.7 to 990 m3ha−1 in total. Deadwood in fresher decay stages was found mainly at greater distances to the river, while advanced decay stages dominated close to the river.
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•With increasing distance from the river edge, both the occurrence and volume of lying deadwood in riparian forests of south-eastern Europe decreased significantly.•High stand basal area had a positive effect on the volume of lying deadwood, while extensive silvicultural management practices increased the occurrence probability of lying deadwood.•Moist and warm climatic conditions led to a larger amount of deadwood in advanced decay stages.
Riparian forests are among the most diverse terrestrial ecosystems, yet their biodiversity is increasingly threatened by habitat degradation, climate change, river regulation and invasive species. We investigated deadwood, widely recognized as an indicator for forest biodiversity, in riparian forests of the Mura-Drava-Danube Transboundary Biosphere Reserve. The Biosphere Reserve is a conservation area that spans five countries and three rivers located in south-eastern Europe. In detail, we analyzed the drivers of lying deadwood volume, occurrence and decay related to floodplain type, silvicultural management, and climatic conditions using regression models. Lying deadwood occurrence and volume significantly decreased as distance from the river edge increased, indicating that river dynamics likely play a role in deadwood accumulation in riparian forests. Deadwood volume was also positively influenced by stand basal area, a parameter that can be directly addressed by silvicultural management. Deadwood decay was affected positively by temperature and negatively by precipitation, highlighting the importance of climatic conditions on decay progression. However, in order to draw more accurate conclusions about the drivers and dynamics of deadwood in riparian forests, further monitoring efforts that consider river flooding and flow regime, deadwood transport and saproxylic organism activity in addition to forest management and site conditions, are needed.
•Large-scale international survey of a protected riparian forest in Central Europe.•Every biotic threat needs their own measures.•Tree diversity negatively affects fungi leave damage.
In a changing ...world, riparian forests are coming under more and more stress from biotic threats. This impacts all stages from saplings to older trees. One of the most dominant biotic threats are alien species and eruptive pest species. Sustainable silvicultural methods are required to reduce the risk of such biotic threats. We investigated the influence of climate, site, tree, and silvicultural characteristics on leaf damage by insect pests or fungal pathogens, herbaceous alien plant species, browsing, and the abundance of native tree saplings. Transects across the Danube-Mura-Drava biosphere reserve from Austria in the northwest to Serbia in the southeast, each containing 7–8 plots, were established to assess tree and site characteristics, regeneration, as well as fungal and insect leaf damage. We found that the horizontal stand structure affected insect leaf damage in different ways. Insect leaf damage was positively correlated with fungal leaf damage and tree height, and negatively correlated with intensity of forest management (from natural forests to coppice/plantations), temperature and precipitation during the vegetation season. Fungal leaf damage was negatively associated with intensity of forest management, and negatively with public ownership and tree species richness. Browsing was positively influenced by the number of saplings. The abundance of alien herbaceous plant species was negatively associated with distance to the watercourse, mean tree height, mean temperature of the vegetative period (MTVP), competition level, and the number of trees per layer, and positively associated with the DBH.
Climate change is expected to have a significant impact on changing the flow regime of the lower Drava River. Four flume experiments were run to see how stabilized, increased and decreased flow and ...the occurrence of a series of floods affect channel planform evolution. Constant discharge produced alternate bars that subsequently merged into bigger bedforms, bedform migration, and a higher sinuosity of the channel. While merging and migration of bedforms may happen in the lower reaches of Drava, its sinuosity is unchanged due to river regulation. Reduced flow initiated transition from a braided to incised single-thread planform, with the formation of dormant channels. Drava already has a single-thread planform (because of dikes) and, in cases of flow reduction, will have the remnant of inactive channels. Increased discharge showed greater erosion and reworking of channel banks, a decrease of sinuosity ratio and active high bluff zones. On Drava sinuosity ratio is more difficult to change because of levees, but erosion, reworking of banks, and increased high bluff risks are possible. Floods simulation generated the construction of an anabranching planform alongside the incised main channel with terraces along banks (active during floods), bars, alluvial islands, and side channels (active during low flows). On the lower Drava River, this situation correlates with past floods.
Measurements made in the past few decades undeniably indicate change in the climate. The most visible sign of global climate change is air temperature, while less visible indicators include changes ...in river water temperatures. Changes in river temperature can significantly affect the environment, primarily the biosphere. The physical, biological and chemical characteristics of the river are directly affected by water temperature, although estimation of this relationship presents a complex problem. Although river temperature is influenced by hydrological and meteorological factors, the purpose of this study is to model daily water temperature using only one known parameter, mean air temperature. The relationship between the daily mean air and daily water temperature of the River Drava in Croatia is analysed using linear regression, stochastic modelling or nonlinear regression and multilayer perceptron (MLP) feed-forward neural networks. The results indicate that the MLP models are much better models which can be used for the estimation and prediction of daily mean river temperature.
The Drava Basin in the SW Pannonian Basin System (PBS) was initially formed by passive rifting with accompanying sedimentary infill. Although this has been the subject of much previous work, an ...account of tectonic control has been lacking. Based on cores, wire logging, and seismic data, the tectonostratigraphic interpretation, depositional systems, and control on depositional systems of the syn-rift infill of the eastern part of the Drava Basin were studied. The rifting phase is characterised by the formation of half-grabens, grabens, a sag, and supradetachment basin structures with structural ramp and structural highs. The syn-rift infill can be divided into second-order tectonostratigraphic sequences corresponding to the early and late rift stages. The second-order sequences are further subdivided into third-order tectonostratigraphic sequences formed in response to higher-order tectonic events associated with local rift migration. In contrast to the early-stage structures, the late-stage rift structures are primarily controlled by extensional detachments that represent parts of the Drava Rift Fault System (DRFS). The early syn-rift is characterised by continental deposition through alluvial fans, fan deltas, and lacustrine environments. The late syn-rift stage is characterised by marine deposition in shallow water, fan deltas, and submarine slope-aprons, with deep marine sedimentation and intense volcanic activity. The ramp, basin slopes, and fault scarp slopes represent the major sediment transport pathways involved in the formation of alluvial fans, fan deltas, or submarine slope-aprons. Basinal sedimentation and major depocenters are located within synforms formed by structural lows in the geometry of extensional detachments. This study gives an example of syn-rift tectonic control for the SW part of the PBS and the influence of detachment geometry on basin fill. We have presented an approach based on 3D seismostratigraphic interpretation of tectonostratigraphic sequences, and the correlation of seismic facies with depositional environments developed in a back-arc setting.
•The syn-rift infill of the Drava Basin is characterised by seismic facies and facies associations analysis.•The early rift stage is characterised by continental deposition and the late rift stage is by marine deposition.•Second-order and third-order sequences depict rift infill architecture.•Tectonic forces were the main controlling factors during sedimentation.
Biosphere reserves are protected areas vital for the preservation of living and inanimate nature, including the protection of anthropogenic values and cultural heritage. The basins of the Mura, ...Drava, and Danube rivers stretch through Slovenia, Croatia, Austria, Hungary, and Serbia and form a unique spatial unity. The Biosphere Reserve concept defines about 300,000 hectares of core and buffer zones and around 700,000 hectares of transition zones. This large, primarily marshy area is rich in natural and cultural heritage. This area is called “the Amazon of Europe” and represents the world’s first Transboundary UNESCO Biosphere Reserve, “Mura-Drava-Danube,” among five countries. This biosphere reserve is important for the preservation of the natural and cultural values of the entire region. Especially rare plant and animal representatives live in this unique geographical unity. Some species inhabit only this area. A total of 900,000 people living around this reserve have a rich cultural tradition and heritage that needs to be protected. The objective of the research is to examine the function that the selected protected areas have in the sustainable development of tourism. Quantitative methodology was used in the research. An analysis of the conducted questionnaire was performed using the SPSS v.21 software, as well as a comparative analysis of the attitudes of 1295 residents from three countries. Residents’ attitudes refer to the level of ecological, economic, socio-cultural, and institutional sustainability of this biosphere reserve as a tourist destination. The research results indicate that the four dimensions of sustainability have significant values and that the selected areas have an important function in the sustainable development of tourism.
U radu je primijenjena metodologija matematičkog programiranja AOMP (analiza omeđivanje podataka) modela analize u evaluaciji i mjerenju efikasnosti i uspješnosti hrvatskih županija. Temeljni je cilj ...ovog članka prikazati i analizirati efikasnost i uspješnost županija uz rijeku Dravu (Koprivničko-križevačke, Virovitičko-podravske i Međimurske županije) te dati zaključke o ovoj regiji i njezinoj regionalnoj efikasnosti. Ostali se ciljevi referiraju na korištenje i tumačenje teoretske pozadine AOMP metodologije. Riječ je o jednoj od najpopularnijih ne parametarskih metoda u evaluaciji efikasnosti od njenog uvođenja u revolucionarni rad Charnesa, Coopera i Rhodesa 1978. godine. U radu se koristi opsežni pregled literature o studijama primjene AOMP metodologije te dubinska evaluacija učinkovitosti hrvatskih županija. Autori su pregledali baze podataka Scopus, Web of Science (SSCI i SCI radovi) i CROSBI (Hrvatska znanstvena bibliografija) koristeći ključne riječi »CROATIA«, »COUNTY« i »DATA ENVELOPMENT ANALYSIS« kao ključne riječi za istraživanje. Pronađeno je sedam radova u Scopusu, petnaest na Web of Science i jedanaest na CROSBI-u, što je u konačnici rezultiralo pronalaskom dvanaest relevantnih radova za ovu analizu. Nadalje, ova studija analizira dosadašnji rad na području učinkovitosti županija u podravskoj regiji, kao i dubinsku analizu korištenih modela, skupa varijabli i njihovih nalaza. Rezultati analize otkrivaju različite aspekte evaluacije efikasnosti hrvatskih županija s posebnim naglaskom na županije uz rijeku Dravu. Koprivničko-križevačka i Virovitičko-podravska županija pokazale su visoku ekološku i ukupnu energetsku učinkovitost, ali su bile najmanje učinkovite u poduzetništvu i socijalnim uslugama za starije osobe, sukladno. Prema dobivenim rezultatima, Međimurska županija je najneučinkovitija županija u analiziranoj regiji. Štoviše, tri analizirane podravske županije u većini studija pokazuju tehničku neučinkovitost te ispodprosječnu učinkovitost. U tom kontekstu, županije trebaju uzeti u obzir dobivene rezultate te usporediti i primijeniti najbolje prakse iz visoko učinkovitih hrvatskih županija. Ovaj bi rad mogao poslužiti kao poticaj za veću upotrebu AOMP metodologije kao vrlo relevantne tehnike za ocjenu učinkovitosti i izvedbe, kao i alata za usporedbu u različitim regijama.
Diamondoid hydrocarbons were investigated in gas-condensates reservoirs from the Drava Depression, Croatian part of the Pannonian Basin, to define thermal maturity of condensates. The largest gas and ...gas-condensate fields in Croatia are Molve, Kalinovac, and Stari Gradac, located in the northwestern part of the Drava Depression. This area has extremely complex structural, lithological, and stratigraphic features that have resulted in the specific physical characteristics of the discovered hydrocarbon fluids. Bulk properties reveal that samples have high concentration of light aromatic hydrocarbon (BTEX) and low sulphur, and some of them are waxy; Stari Gradac and Severovci. Origin and maturity parameters of condensate were investigated and correlated based on gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS) techniques. The value of diamondoid based maturity parameters, like methydiamantane index 40–50 % indicate high level of thermal maturity corresponding to vitrinite reflectance 1.1–1.6 %. Condensate samples were not biodegraded, as shown by high API density values and the absence of unresolved complex mixture (UCM).
