Remediation of the Right Bank of the Neretva River : Undergraduate Thesis

Za potrebe dimenzioniranja zahvata sanacije kritičnih profila desne obale Neretve na dionici od 7+210.16 km do 7+709.00 km potrebno je odrediti računski model tla te izvršiti analizu stabilnosti pokosa za projektne situacije: stalno opterećenje i stalno opterećenje+potres.For the purpose of geotechnical designing for remediation of critical profiles of the right bank of the river Neretva on the section of 7 + 210.16 km to the 7 + 709.00 km it is necessary to determine the computational model of soil and analyze slope stability for the design situations: permanent load and permanent load + earthquake

Remediation of the Right Bank of the Neretva River : Undergraduate Thesis

Za potrebe dimenzioniranja zahvata sanacije kritičnih profila desne obale Neretve na dionici od 7+210.16 km do 7+709.00 km potrebno je odrediti računski model tla te izvršiti analizu stabilnosti pokosa za projektne situacije: stalno opterećenje i stalno opterećenje+potres.For the purpose of geotechnical designing for remediation of critical profiles of the right bank of the river Neretva on the section of 7 + 210.16 km to the 7 + 709.00 km it is necessary to determine the computational model of soil and analyze slope stability for the design situations: permanent load and permanent load + earthquake

Hindcast of Significant Wave Heights in Sheltered Basins Using Machine Learning and the Copernicus Database

Long-term time series of wave parameters play a critical role in coastal structure design and maritime activities. At sites with limited buoy measurements, methods are used to extend the available time series data. To date, wave hindcasting research using machine learning methods has mainly focused on filling in missing buoy measurements or finding a mapping function between two nearshore buoy locations. This work aims to implement machine learning methods for hindcasting wave parameters using only publicly available Copernicus data. Ensemble regression and artificial neural networks were used as machine learning methods and the optimal hyperparameters were determined by the Bayesian optimization algorithm. As inputs, data from the MEDSEA reanalysis wave model were used for the wave parameters and data from the ERA5 atmospheric reanalysis model were used for the wind parameters. The results of this study show that the normalized RMSE of the test data improved by 29% for Rijeka and 12% for Split compared to the original MEDSEA wave hindcast at buoy locations. The proposed method was extremely efficient in removing bias in the original MEDSEA hindcasts (e.g., NBIAS = -0.35 for Rijeka) to negligible values for both Split and Rijeka (NBIAS < 0.03)

Application of agent-based modelling for selecting configuration of vertical slot fishway

Uspostavljen je fizikalni i 3D numerički model strujanja te model baziran na agentima (eng. Agent-Based Model - ABM) za potrebe praćenja prolaska ribe kroz dvije konfiguracije riblje staze s vertikalnim otvorima. Potrošnja vlastite energije ribe pri prolasku kroz riblju stazu predstavlja ključni parametar ocjene o kvaliteti pojedine konfiguracije riblje staze. Modelska riba prepoznaje okolišne uvjete pomoću svojih senzorskih sposobnosti te donosi kognitivne zaključke o promjeni smjera kretanja prema zoni manje turbulentne kinetičke energije. Rezultati provedenog istraživanja pokazali su da riblja staza s duljim bazenima omogućuje prolazak ribe s manjim utroškom energije.Physical and 3D numerical hydrodynamic flow models and an agent-based model are developed with the principal objective of analysing fish behaviour in two vertical slot fishway configurations. Fish energy consumption due to swimming represents a crucial criterion for selecting an appropriate fishway configuration. The modelled fish detects ambient flow conditions, makes decisions based on its sensing and cognitive abilities, adapts to the changes in its environment, and moves toward the regions of less turbulent kinetic energy. The results show that fishways with longer pools enable passage of fish at a lower energy consumption

A numerical analysis of pollutant dispersion from the chimney of the medical waste incinerator in the urban environment

Provedene su numeričke analize širenja onečišćenja iz dimnjaka spalionice medicinskog otpada u urbaniziranom okruženju. Istraživanje je usmjereno na iznalaženje pozicije i visine dimnjaka čime se osigurava da poniranje oblaka onečišćenja prema tlu pri opstrujavanju zgrade s dimnjakom (tzv. downwashing) posljedično ne ugrožava zdravlje ljudi u neposrednoj blizini dimnjaka. Analiziran je slučaj prisutnosti objekta-zgrade idealizirane geometrije (uz varijaciju visine i duljine zgrade) ispred objekta tipske spalionice s dimnjakom (fiksnih dimenzija), te slučaj izvedbe dimnjaka na vrhu zgrade idealizirane geometrije (uz varijaciju pozicije i visine dimnjaka) bez zasebnog objekta spalionice. Praćene su koncentracije onečišćenja na dva metra iznad tla. Rezultati provedenog istraživanja pokazali su da u realnim uvjetima izgradnje (prisutnost zgrada uokolo objekta spalionice) i okoliša (brzina i smjer vjetra) dimnjak treba biti viši za 20 metra od obližnjeg objekta-zgrade ili izveden na sredini krovne konstrukcije u visini 20 metra, a ne uz tehnološku zgradu za postupanje s otpadom (spalionica) sa visinom 2,5 puta većom od same spalionice.Numerical analyses were carried out on the dispersion of pollution from the chimney of a medical waste incinerator in an urban environment. The research focused on determining the location and height of the chimney to ensure that the descent of pollution plumes towards the ground, known as “downwashing”, does not pose a health risk to people in the immediate vicinity of the chimney. Two scenarios were investigated in the study: the presence of a building with idealized geometry (with height and length variations) in front of a typical waste incinerator with a fixed size chimney and the case of a chimney on top of a building with idealized geometry (with position and height variations) without a separate waste incinerator. The pollutant concentrations were monitored at a height of 2 meters above the ground. The results of the study show that under realistic design conditions (presence of surrounding buildings) and environmental factors (wind speed and direction), the chimney should be positioned 20 meters higher than the adjacent building or in the middle of the roof structure at a height of 20 meters. This is better than a chimney next to the waste disposal facility (incinerator) that is 2.5 times higher than the incinerator itself

Numerische Analyse der Wirkung der Schleuse auf die Verhinderung von Salzwasserintrusion entlang des Flusses Neretva

3D numeričkim modelom provedena je numerička analiza dinamike pronosa slane vode u koritu rijeke Neretve na dionici 0+000.0 m - 25+000.0 m. Osim postojećeg stanja korita rijeke analizirane su i hipotetske situacije sa izvedbom jedne brane u profilu 2+000.0 m (velika dubina i mala širina) ili 4+000.0 m (mala dubina i velika širina), te izvedbom 4 brane u profilima 2/4/6/8+000.0. Regulacija podizanja i spuštanja brane vezana je uz srednji izmjereni protok na mjernoj postaji Metković u prethodnom razdoblju od 24 h (QSR-24) ili 6 h (QSR-6). U situacijama QSR-24 > 300 i 350 m3/s, odnosno QSR-6 > 300 m3/s, brana je potpuno spuštena, dok se za manje srednje vrijednosti protoka brana podiže do određene razine (od -2 m do -5 m) kroz jedan sat. Korišten je 3D numerički model Mike 3fm, zasnovan na metodi konačnih volumena. Za kalibraciju numeričkog modela korišteni su izmjereni protoci, razine i salinitet na monitoring postajama u 2018. godini, dok su za validaciju modelskih rezultata korišteni podaci iz 2017. godine. Podaci o temperaturi i salinitetu mora u akvatoriju ušća Neretve preuzeti su iz nacionalnih programa praćenja morskog okoliša. Modelska dinamika uzvodno-nizvodne translacije slanog klina u nestacionarnim uvjetima strujanja u suglasju je s mjerenjima. Modelska debljina razdjelne zone između slatke i slane vode veća je od izmjerene, kao posljedica numeričke difuzije i usvojene proračunske diskretizacija u vertikalnom smjeru od 1 m. Mjerene vrijednosti i rezultati modeliranja upućuju na zaključak da pri nestacionarnim protocima većim od 700 m3/s dolazi do potpunog istiskivanja slanog klina iz riječnog korita, dok pri protoku manjem od 150 m3/s slani klin napreduje do uzvodne stacionaže 20+909.0 m (Metković) i dalje uzvodnije. Ukoliko se želi spriječiti intruzija slanog klina uzvodno od stacionaže brane (2+000.0 m ili 4+000.0 m) potrebno je izvesti branu s podizanjem do dubine -2 m, uz uvjet podizanja brane QSR-24 300 and 350 m3/s and QSR-6 > 300 m3/s, the dam was fully lowered whereas at smaller mean discharge values the dam is lifted up to a certain level (from -2 m to -5 m) during one hour. The 3D numerical model Mike 3fm, based on the finite volume method, was implemented. The discharges, levels and salinity measured at monitoring stations in 2018 were used for the model calibration and the 2017 data for the model results validation. Data on the sea temperature and salinity in the waters of the Neretva river mouth were taken from the national marine environment monitoring programmes. The model dynamics of the upstream-downstream translation of the salt “wedge” in non-stationary circulation conditions is in line with the measurements. The model thickness of the dividing zone between the freshwater and saltwater is larger than the one measured as a result of the numerical diffusion and adopted discretization of the calculation in the vertical direction of 1 m. The measured values and modeling results point to the conclusion that a complete extrusion of the salt “wedge” from the riverbed occurs at non-stationary discharges larger than 700 m3/s whereas the salt “wedge” advances upstream to 20+909.0 m (Metković) and further at discharges lower than 150 m3/s. If the intrusion of the salt “wedge” upstream of the dam (2+000.0 m or 4+000.0 m) is to be prevented, a dam with a lifting to the depth of -2 m, under the condition of dam lifting at QSR-24 300 und 350 m3/s, bzw. QSR-6 > 300 m3/s, ist die Schleuse geschlossen, während im Falle von niedrigeren mittleren Durchflusswerten die Schleuse bis zu einer bestimmten Höhe (von -2 m bis -5 m) auf eine Stunde geöffnet wird. Das numerische 3D-Modell Mike 3fm, das auf der Methode der finiten Elemente gründet, wurde eingesetzt. Zur Kalibrierung des numerischen Modells wurden die in 2018 an Überwachungsstationen gemessenen Werte von Durchflüssen, Wasserständen und Salinität genutzt, während zur Validierung der Modellergebnisse die Angaben aus dem Jahr 2017 genutzt wurden. Die Angaben zur Temperatur und Salinität an der Mündung der Neretva wurden aus den nationalen Programmen zur Überwachung der Meeresumwelt übernommen. Die Modelldynamik des Vordringens des Salzkeils flussaufwärts und flussabwärts bei der nichtstationären Strömung stimmt mit den Messungen überein. Die Modelldichte der Übergangszone zwischen Süßwasser und Salzwasser ist höher als die gemessene Dichte, was als Folge der numerischen Diffusion und angenommenen Diskretisierung in der vertikalen Richtung von einem Meter gesehen wird. Die gemessenen Werte und die Ergebnisse der Modellierung weisen auf die Schlussfolgerung hin, dass bei nichtstationären Durchflüssen, die großer als 700 m3/s sind, zu einer völligen Verdrängung des Salzkeils aus dem Flussbett kommt, während bei dem Durchfluss unter 150 m3/s der Salzkeil bis zur Stationierung 20+909.0 m (Metković) und weiter flussaufwärts vordringt. Wenn man die Intrusion des Salzkeils flussaufwärts von der Stationierungsschleuse (2+000.0 m oder 4+000.0 m) verhindern will, sollte eine Schleuse gebaut werden, die bis zur Tiefe -2 m unter der Bedingung der Schleusenöffnung QSR-24 < 300 m3/s geöffnet wird

Analyse des Larventransportes aus dem Ballastwasser im Hafengebiet Ploče

Za akvatorij Luka Ploče uspostavljen je 3D numerički model cirkulacije mora i pronosa ličinki unesenih na fiksnoj poziciji lučkog terminala uslijed ispuštanja balastnih voda iz brodskih tankova. Modelske čestice ličinki nisu pasivne, već imaju senzoričku sposobnost prepoznavanja okolišnih uvjeta i kognitivne reakcije u vidu promjene smjera i intenziteta svoga kretanja (ABM, eng: agent based model) u smjeru optimalnog intenziteta svjetlosti i temperature mora. Modelske simulacije su provedene za razdoblje 12.3.2008.-10.5.2008., uz primjenu izmjerenog protoka i temperature rijeke Neretve na postaji Žitomislići (polusatna rezolucija), modelskih rezultata brzine i smjera vjetra iz numeričkog modela Aladin-Hr (trosatna rezolucija), satne dinamike morskih razina i izmjerene vertikalne raspodjele temperature i saliniteta mora na otvorenoj granici modela (CTD sonda). Čestice ličinki unose se u 4 termina (14.3., 22.3., 7.4. i 20.4.2008.), na početku situacija sa registriranom karakterističnom kombinacijom okolišnih uvjeta („mali“ ili „veliki“ protok Neretve sa „malom“ ili „velikom“ brzinom vjetra iz smjerova ENE, SW, S i E). Rezultati provedenih simulacija pokazuju da u situaciji većeg protoka Neretve i manjih brzina vjetra (prosječno za 7 dana nakon termina unosa ličinki QSR-7dana = 490 m3/s i WSR-7dana = 2.9 m/s) dolazi do najizraženije sedimentacije ličinki u zatvorenom dijelu lučkog bazena. S druge strane, u slučaju manjeg protoka Neretve i većih brzina vjetra (QSR-7dana = 114 m3/s i WSR-7dana = 3.7 m/s u rasponu smjerova S-SW) ličinke se intenzivno pronose u SE smjeru pružanja neretvanskog kanalaA 3D numerical model of sea circulation and transport of larvae introduced at a fixed position of the port terminal due to discharges of ballast water from ship tanks for the Port of Ploče waters was established. The model larvae particles are not passive but have sensory capacity to recognize environmental conditions and cognitive reaction regarding direction change and their movement intensity (ABM, agent based model) in view of optimal light intensity and sea temperature. The model simulations were conducted for a period from 12.3.2008 to 10.5.2008, using the measured discharges and temperatures of the Neretva River at the station Žitomislići (half-hour resolution), model results of wind speed and direction from the numerical model Aladin-Hr (three-hour resolution), hourly dynamics of sea levels and measured vertical distribution of sea temperatures and salinity at the open boundary of the model (CTD probe). The larvae particles were introduced at 4 dates (14.3., 22.3., 7.4. and 20.4.2008), at the start of situations with a registered characteristic combination of environmental conditions (“low“ or “high“ discharges of the Neretva with “low“ or “high“ wind speeds from the ENE, SW, S and E directions). The results of conducted simulations indicate that in a situation of higher Neretva discharges and lower wind speeds (on average in 7 dana after the larvae introduction QSR-7days = 490 m3/s and WSR-7days = 2.9 m/s), the most pronounced larvae sedimentation occurs in the closed part of the port basin. On the other hand, in case of lower Neretva discharges and higher wind speeds (QSR-7days = 114 m3/s and WSR-7days = 3.7 m/s in the S-SW direction range), the larvae are intensely transported in the SE direction of the Neretva channel.Für das Wassergebiet des Hafens Ploče wurde ein dreidimensionales numerisches Modell der Meereszirkulation und des Transportes von Larven erstellt, die an einem bestimmten Ort am Hafenterminal nach der Entleerung von Ballastwassertanks ins Meer eingeleitet werden. Die Modellpartikeln von Larven sind nicht passiv, sondern sie haben eine Sensorfähigkeit zur Wahrnehmung von Umweltbedingungen und eine kognitive Reaktion im Sinne der Änderung von Bewegungsrichtung und Bewegungsintensität (agentenbasiertes Modell; Engl. ABM – agent-based model) in der Richtung der optimalen Lichtintensität und Meerestemperatur. Die Modellsimulationen wurden für den Zeitraum zwischen 12. März 2008 und 10. Mai 2008 durchgeführt unter Anwendung des gemessenen Durchflusses und Temperatur des Flusses Neretva auf der Station Žitomislići (halbstündige Auflösung), der Modellergebnisse für Windgeschwindigkeit und Windrichtung aus dem numerischen Modell Aladin-Hr (dreistündige Auflösung), der einstündigen Dynamik von Meeresebenen sowie der gemessenen vertikalen Temperaturverteilung und Salinität an den offenen Modellrändern (die CTD-Rosette). Die Larvenpartikeln wurden an vier Terminen (14. März, 22. März, 7. April und 20. April 2008) eingeleitet, am Anfang von Situationen mit der registrierten charakteristischen Kombination von Umweltbedingungen (Kombinationen vom kleinen oder großen Durchfluss vom Fluss Neretva mit niedriger oder erhöhter Windgeschwindigkeit aus den Richtungen ONO, SW, S und O). Die Ergebnisse der durchgeführten Simulationen zeigen, dass in der Situation eines größeren Durchflusses von Neretva (Q = 490 m3/s) und niedrigerer Windgeschwindigkeit (W = 2.9 m/s) durchschnittlich sieben Tage nach der Einleitung von Larven zur ausgeprägtesten Bildung vom Larvensediment im geschlossenen Teil des Hafengebietes kommt. Andererseits werden in der Situation eines kleineren Durchflusses von Neretva (QSR = 114 m3/s) und erhöhter Windgeschwindigkeit (W = 3.7 m/s) im Windrichtungsbereich S-SW die Larven intensiv entlang des Neretva-Kanals in der südöstlichen Richtung transportiert

Remediation of the Right Bank of the Neretva River : Undergraduate Thesis

Za potrebe dimenzioniranja zahvata sanacije kritičnih profila desne obale Neretve na dionici od 7+210.16 km do 7+709.00 km potrebno je odrediti računski model tla te izvršiti analizu stabilnosti pokosa za projektne situacije: stalno opterećenje i stalno opterećenje+potres.For the purpose of geotechnical designing for remediation of critical profiles of the right bank of the river Neretva on the section of 7 + 210.16 km to the 7 + 709.00 km it is necessary to determine the computational model of soil and analyze slope stability for the design situations: permanent load and permanent load + earthquake