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  • 1. Abawallo, S. S.
    et al.
    Brandimarte, L.
    Maglionico, M.
    Analysis of the performance response of offline detention basins to inlet structure design2013In: Irrigation and Drainage, Vol. 62, no 4, p. 449-457Article in journal (Refereed)
  • 2. Ahlers, R.
    et al.
    Brandimarte, L.
    Kleemans, I.
    Sadat, S. H.
    Ambitious development on fragile foundations: Criticalities of current large dam construction in Afghanistan2014In: Geoforum, Vol. 54, p. 49-58Article in journal (Refereed)
  • 3.
    Andersson, Elin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Hietala, Sofia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Application of a new method to improve river cross sections derived from satellite images2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In hydrological and hydraulic modelling, river geometry is a crucial input data. Recent investigations have been looking at methods to improve the description of cross sections extracted by DEM derived by satellite images. SRTM derived DEM are often lacking precise information as the sensors cannot detect the submerged river parts, but, on the other hand, it is available on a global scale which makes it very attractive and useful, especially in data scarce regions. This study aims at applying the so called “slope break” method to improve river cross section geometry extracted from SRTM DEM. The report is divided into three parts: a) The making of a Matlab-code to improve cross sections geometry extracted by satellite derived DEM; b) an application of the code to real cross-sections from the river Po in Italy and c) hydraulic simulations with and without SRTM modified cross sections to test the performance of the method, in collaboration with senior colleagues. The Matlab successfully performs the slope break point and finds, when appropriate, the approximated lowest point zmin of the cross section below the water surface. The comparison of the river geometry of the modified SRTM cross sections versus LiDAR available cross sections show the good performance of the method in improving the river geometry description. This code can simplify the work and improve many SRTM river cross sections in an effective way. The hydraulic simulations performed with and without the modified cross sections show how the modified SRTM model improves when compared to LiDAR results 

  • 4.
    Andersson, Kjell
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Hagnestål, Anders
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Sellgren, Ulf
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Design of a flexible chain for winch based point absorbers2018In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018, 2018Conference paper (Refereed)
  • 5. Bandeira, Jefferson Vianna
    et al.
    Salim, Lecio Hannas
    Bomtempo, Virgilio Lopardi
    Moreira, Rubens Martins
    Brisset, Patrick
    Hughes, Catherine E.
    Pant, Harish Jagat
    Thereska, Jovan
    Wörman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Nuclear Techniques for Monitoring Sediment Dynamics in the Coastal Zone2014In: ENGINEERING GEOLOGY FOR SOCIETY AND TERRITORY, VOL 4: MARINE AND COASTAL PROCESSES, CHAM: SPRINGER INT PUBLISHING AG , 2014, p. 151-155Conference paper (Refereed)
    Abstract [en]

    The knowledge of sediment transport in the coastal region is of vital importance to the management of this critical interface between land and sea, where most of the world population lives. For the assessment of sediment behaviour, hydraulic and sediment measurements, bathymetric survey, mathematical and physical models, are applied. Sediment tracers provide a unique capability for understanding sediment transport assisting in sediment management which cannot be obtained any other way, whether conventional monitoring or physical and numerical models because tracers integrate all the hydrodynamic actions in time and space. Computational fluid dynamics (CFD) is now an essential tool for the management of the natural systems and is increasingly used to study the fate and behaviour of particulates and contaminants. Tracer techniques are often employed to validate hydrodynamic models to enhance confidence in the predictive value of the models. In-situ detection afforded by the use of a radioactive tracer allows accurate quantitative determination of the rate of sediment transport, compared with other tracer methods. Also, it is cost effective and safe: its radiological impact to the environment is minimal. Several case studies, performed in different regions of the world, are presented.

  • 6.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Combined role of advective pumping and mechanical dispersion on time scales of bed form-induced hyporheic exchange2010In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 46, p. W08518-Article in journal (Refereed)
    Abstract [en]

    This study analyzes the effect of advective pumping and pore scale dispersion on bed form-induced hyporheic exchange. Advection and dispersion play a competitive role in the exchange dynamics between the porous medium and the overlying stream: Advective fluxes first lead solutes deep into the bed and then back to the stream water, whereas dispersive fluxes favor the transfer of solutes deep into the bed leading to a permanent mass retention. The combined effect of advective exchange and dispersive fluxes produces complexity in the shape of the tails of the residence time distributions (RTDs), which follow at various stages of the process either a power law or an exponential decay. The seepage velocity induced by the stream gradient and, in case of a moving bed, the celerity of the translating bed forms limit the thickness of the advective hyporheic zone, inducing the RTDs to decrease rapidly at late time. This rapid decay can be preceded by a temporal region where the probability density functions (pdf's) tend to be inversely proportional to the square of time, and is followed by a region dominated by dispersion where the pdf's tend to be inversely proportional to the 3/2 power of time. The process shows distinct temporal ranges identified here by appropriate dimensionless parameters. Because of this complex exchange dynamics, models considering pure advection in the porous medium can significantly underestimate solute transfer at long time scales, whereas purely diffusive models of hyporheic exchange appear inadequate to represent the physical processes at an intermediate stage.

  • 7.
    Bottacin-Busolin, Andrea
    et al.
    WET Engn Srl, I-31033 Castelfranco Veneto, TV, Italy.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Musner, Tommaso
    Univ Padua, Dept Chem Proc Engn, I-35131 Padua, Italy.
    Tregnaghi, Matteo
    WET Engn Srl, I-31033 Castelfranco Veneto, TV, Italy.
    Zaramella, Mattia
    WET Engn Srl, I-31033 Castelfranco Veneto, TV, Italy.
    Evidence of distinct contaminant transport patterns in rivers using tracer tests and a multiple domain retention model2011In: Advances in Water Resources, ISSN 0309-1708, E-ISSN 1872-9657, Vol. 34, no 6, p. 737-746Article in journal (Refereed)
    Abstract [en]

    Solute transport in rivers is controlled by surface hydrodynamics and by mass exchanges with distinct retention zones. Surface and hyporheic retention processes can be accounted for separately in solute transport models with multiple storage compartments. In the simplest two component model, short term storage can be associated to in-channel transient retention, e.g. produced by riparian vegetation or surface dead zones, and the long-term storage can be associated to hyporheic exchange. The STIR (Solute Transport In Rivers) multiple domain transport model is applied here to tracer test data from three very different Mediterranean streams with distinctive characteristics in terms of flow discharge, vegetation and substrate material. The model is used with an exponential residence time distribution (RTD) to represent surface storage processes and two distinct modeling closures are tested to simulate hyporheic retention: a second exponential RTD and a power-law distribution approximating a known solution for bedform-induced hyporheic exchange. Each stream shows distinct retention patterns characterized by different timescales of the storage time distribution. Both modeling closures lead to very good approximations of the observed breakthrough curves in the two rivers with permeable bed exposed to the flow, where hyporheic flows are expected to occur. In the one case where the occurrence of hyporheic flows is inhibited by bottom vegetation, only the two exponential RTD model is acceptable and the time scales of the two components are of the same magnitude. The significant finding of this work is the recognition of a strong signature of the river properties on tracer data and the evidence of the ability of multiple-component models to describe individual stream responses. This evidence may open a new perspective in river contamination studies, where rivers could possibly be classified based on their ability to trap and release pollutants.

  • 8.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Zaramella, Mattia
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Modellazione a tempi di residenza del trasporto di soluti nei corsi d'acqua: Applicazione al fiume Yarqon, Israele2008Conference paper (Other academic)
    Abstract [it]

    Il trasporto di soluti nei corsi d’acqua è controllato dall’idrodinamica superficiale e da scambi di massa con distinte zone di ritenzione. La propagazione a valle delle sostanze trasportate è generalmente ritardata dall’immagazzinamento temporaneo in zone morte superficiali, tipicamente zone vegetate o sacche di ritenzione laterali, e nei sedimenti sottostanti, nella cosiddetta zona iporeica. In questo articolo viene presentato un modello concettuale per il trasporto di soluti nei corsi d’acqua (STIR, Solute Transport In Rivers) nel quale i singoli processi di scambio sono rappresentati separatamente da una probabilità di “uptake” e da un’appropriata distribuzione dei tempi di residenza. Ciò rende il modello flessibile e modulare, e consente di incorporare l’effetto di una varietà di processi d’immagazzinamento e reazioni chimiche in modo dettagliato. La capacità del modello di rappresentare situazioni reali è qui dimostrata dall’applicazione al fiume Yarqon, in Israele.

  • 9.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Singer, Gabriel
    Univ Vienna, Dept Freshwater Ecol.
    Zaramella, Mattia
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Battin, Tom
    Univ Vienna, Dept Freshwater Ecol.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Effects of Streambed Morphology and Biofilm Growth on the Transient Storage of Solutes2009In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 43, no 19, p. 7337-7342Article in journal (Refereed)
    Abstract [en]

    Microbial biofilms are the prime site of nutrient and contaminant removal in streams. It is therefore essential to understand how biofilms affect hydrodynamic exchange, solute transport and retention in systems where geomorphology and induced hydrodynamics shape their growth and structure. We experimented with large-scale streamside flumes with streambed landscapes constructed from graded bedforms of constant height and wavelength. Each flume had a different bedform height and was covered with a layer of gravel as substratum for benthic microbial biofilms. Biofilms developed different biomass and physical structures in response to the hydrodynamic conditions induced by the streambed morphology. Step injections of conservative tracers were performed at different biofilm growth stages. The experimental breakthrough curves were analyzed with the STIR model, using a residence time approach to characterize the retention effects associated with biofilms. The retained mass of the solute increased with biofilm biomass and the biofilm-associated retention was furthermore related to bedform height We tentatively relate this behavior to biofilm structural differentiation induced by bed morphology, which highlights the strong linkage between geomorphology, hydrodynamics, and biofilms in natural streams and provide important clues for stream restoration.

  • 10.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Tait, Simon
    Univ Bradford, Sch Engn Design & Technol.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Chegini, Amir
    Univ Guilan, Dept Civil Engn, Fac Engn.
    Tregnaghi, Matteo
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Probabilistic description of grain resistance from simultaneous flow field and grain motion measurements2008In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 44, no 9, p. W09419-Article in journal (Refereed)
    Abstract [en]

    Experiments were carried out using a mobile gravel bed placed in a tilting flume with a modified particle image velocimetry (PIV) system. Individual grain movements were surveyed using data from time series of images. Near-bed velocity flow field measurements were made simultaneously above the same area of the sediment surface by applying cross-correlation techniques to the collected plan view images. Statistics of grain motions were collected through a semiautomatic procedure. Significant changes in the flow field were observed in the proximity of the entrained or deposited particles. A strong correlation is shown between the changes in the local streamwise and lateral velocity and the movement of the grains. The theory of Grass is revisited and developed based on the experimental results. The probability distribution of individual grain resistance has been derived from the statistics of the near-bed velocity field and of the entrainment risk.

  • 11.
    Bottacin-Busolin, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Tregnaghi, Matteo
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Marion, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Tait, Simon
    Univ Bradford, Sch Engn Design & Technol, Bradford BD7 1DP, W Yorkshire, England.
    Misurazioni del campo di moto in prossimità di grani in movimento2006Conference paper (Refereed)
    Abstract [it]

    È stata condotta una serie di esperimenti utilizzando una canaletta di laboratorio a fondo inclinabile ed un avanzato sistema PIV (Particle Image Velocimetry). L’apparato sperimentale ha permesso un’indagine a scala di grano delle condizioni di movimento incipiente. Sul fondo della canaletta si è disposto un letto di materiale granulometrico uniforme, che nelle prove è stato sottoposto all’azione continua di una portata d’acqua costante. Il regime idrodinamico approssima il moto uniforme della corrente e la condizione di incipiente movimento dei grani. Ciascun test è stato condotto per una durata di 10 – 18 ore, durante la quale sono state registrate misurazioni per periodi di circa cinque minuti ad intervalli regolari. Il campo di moto istantaneo è stato misurato all’interno di un’area di circa 400 cm2, posta su un piano inizialmente parallelo al letto, ad una distanza da esso di circa 5 mm. Un apposito software ha consentito la costruzione delle matrici del campo di velocità istantaneo, tramite la tecnica di cross-correlazione delle immagini applicata a particelle traccianti. Mediante una fotocamera digitale si sono ottenute, inoltre, delle sequenze di foto della superficie dei sedimenti, ognuna delle quali è contemporanea ad una misura del campo di moto. Tramite una procedura semi-automatica di elaborazione dei dati è stata prodotta una statistica riguardante il moto dei sedimenti. Analizzando le sequenze è stato possibile riconoscere lo spostamento dei grani superficiali; in seguito, osservando l’andamento temporale delle velocità in prossimità delle particelle in movimento, sono stati individuati dei cambiamenti del campo di moto locale che si verificano contemporaneamente alla loro rimozione o deposizione. Tali variazioni di velocità, che possono interessare la componente longitudinale e laterale o le rispettive fluttuazioni dalla media, appaiono una diretta conseguenza del moto delle particelle. È inoltre rilevante la correlazione tra “salti” positivi di velocità in corrispondenza di un grano che viene mosso e “salti” negativi nel caso di un grano che si deposita.

  • 12. Brandimarte, L.
    et al.
    Brath, A.
    Castellarin, A.
    Baldassarre, G. D.
    Isla Hispaniola: A trans-boundary flood risk mitigation plan2009In: Physics and Chemistry of the Earth, Vol. 34, no 4-5, p. 209-218Article in journal (Refereed)
  • 13. Brandimarte, L.
    et al.
    Di Baldassarre, G.
    Uncertainty in design flood profiles derived by hydraulic modelling2012In: Hydrology Research, Vol. 43, no 6, p. 753-761Article in journal (Refereed)
  • 14. Brandimarte, L.
    et al.
    Di Baldassarre, G.
    Bruni, G.
    D'Odorico, P.
    Montanari, A.
    Relation Between the North-Atlantic Oscillation and Hydroclimatic Conditions in Mediterranean Areas2011In: Water Resources Management, Vol. 25, no 5, p. 1269-1279Article in journal (Refereed)
  • 15. Brandimarte, L.
    et al.
    Paron, P.
    Di Baldassarre, G.
    Bridge pier scour: A review of processes, measurements and estimates2012In: Environmental Engineering and Management Journal, Vol. 11, no 5, p. 975-989Article in journal (Refereed)
  • 16. Brandimarte, L.
    et al.
    Popescu, I.
    Neamah, N. K.
    Analysis of fresh-saline water interface at the Shatt Al-Arab estuary2015In: International Journal of River Basin Management, Vol. 13, no 1, p. 17-25Article in journal (Refereed)
  • 17. Brandimarte, L.
    et al.
    Woldeyes, M. K.
    Uncertainty in the estimation of backwater effects at bridge crossings2013In: Hydrological Processes, Vol. 27, no 9, p. 1292-1300Article in journal (Refereed)
  • 18. Brandimarte, Luigia
    The seventh facet of uncertainty: wrong assumptions, unknowns and surprises in the dynamics of human–water systems2016In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 61, no 9, p. 1748-1758Article in journal (Refereed)
  • 19. Castellarin, A.
    et al.
    Galeati, G.
    Brandimarte, L.
    Montanari, A.
    Brath, A.
    Regional flow-duration curves: Reliability for ungauged basins2004In: Advances in Water Resources, Vol. 27, no 10, p. 953-965Article in journal (Refereed)
  • 20.
    Dargahi, Bijan
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Flow characteristics of bottom outlets with moving gates2010In: Journal of Hydraulic Research, ISSN 0022-1686, E-ISSN 1814-2079, Vol. 48, no 4, p. 476-482Article in journal (Refereed)
    Abstract [en]

    This study investigates the discharge characteristics of a bottom outlet with a moving gate by Flow3D. Experimental results for a scale model outlet of the Aswan Dam, Egypt, were used. Two different flow features were found. Pressurized flow established if the flume was filled and then the gate was slowly opened. However, a free surface flow occurred if the gate was fully opened and the entire flume was slowly flooded with water. The numerical simulations successfully captured the two flow patterns as well as the discharges and water surface profiles. The discharges were predicted with sufficient accuracy using the first-order momentum advection scheme. In comparison with the k-epsilon turbulence model, the Re-Normalization Group model yields the best agreement with the experiments. The model performed with similar accuracy for both model and prototype cases.

  • 21. Di Baldassarre, G.
    et al.
    Montanari, A.
    Lins, H.
    Koutsoyiannis, D.
    Brandimarte, L.
    Blschl, G.
    Flood fatalities in Africa: From diagnosis to mitigation2010In: Geophysical Research Letters, Vol. 37, no 22, article id L22402Article in journal (Refereed)
  • 22. Di Baldassarre, G.
    et al.
    Schumann, G.
    Brandimarte, L.
    Bates, P.
    Timely Low Resolution SAR Imagery To Support Floodplain Modelling: A Case Study Review2011In: Surveys in Geophysics, Vol. 32, no 3, p. 255-269Article in journal (Refereed)
  • 23. Di Baldassarre, G.
    et al.
    Viglione, A.
    Carr, G.
    Kuil, L.
    Yan, K.
    Brandimarte, L.
    Blöschl, G.
    Debates - Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes2015In: Water Resources Research, Vol. 51, no 6, p. 4770-4781Article in journal (Refereed)
  • 24. Di Baldassarre, G.
    et al.
    Yan, K.
    Ferdous, M. R.
    Brandimarte, L.
    The interplay between human population dynamics and flooding in Bangladesh: A spatial analysis2014Conference paper (Refereed)
  • 25. Domeneghetti, A.
    et al.
    Gandolfi, S.
    Castellarin, A.
    Brandimarte, L.
    Di Baldassarre, G.
    Barbarella, M.
    Brath, A.
    Flood risk mitigation in developing countries: Deriving accurate topographic data for remote areas under severe time and economic constraints2015In: Journal of Flood Risk Management, Vol. 8, no 4, p. 301-314Article in journal (Refereed)
  • 26.
    Fabian, Mark
    et al.
    SUNY Coll Environm Sci & Forestry, Dept Environm Resources Engn, Baker Labs 423, Syracuse, NY 13210 USA.
    Endreny, Theodore
    SUNY Coll Environm Sci & Forestry, Dept Environm Resources Engn, Baker Labs 423, Syracuse, NY 13210 USA.
    Bottacin-Busolin, Andrea
    Water & Environm Technol Engn Srl, I-31033 Treviso, Italy.
    Lautz, Laura
    Syracuse Univ, Dept Earth Sci, Heroy Geol Lab 204, Syracuse, NY 13244 USA.
    Seasonal variation in cascade-driven hyporheic exchange, northern Honduras2011In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, Vol. 25, no 10, p. 1630-1646Article in journal (Refereed)
    Abstract [en]

    A characterization of hyporheic exchange for dry and wet season baseflow, as well as partially dewatered discharge, was done in Prieta Creek, a first-order cascade in northern Honduras. The cascade had discharges from 1 to 15 1 s(-1), had average slopes of 12%, pool spacing of 3 m, and shallow substrate of sand and gravel. Tracer tests were conducted in a 15-m sub-reach, a length considered to be adequate for the experiment based on the DaI test, a ratio of exchange and transport processes. In the three tests, between 9 and 18% of tracer was not recovered, possibly due to entrainment in flowpaths passing beneath the downstream monitoring location. Tracer data were analysed by the one-dimensional transport with inflow and storage (OTIS) transient storage model (TSM) to derive standard exchange parameters, and by the solute transport in rivers (STIR) model to examine hyporheic residence time distributions (RTDs). The best fit of the observed tracer breakthrough curves was obtained by using the STIR model with a combination of two exponential RTDs to represent hyporheic retention. With increasing discharge, the OTIS model predicted increasing storage exchange fluxes and exchange coefficients and decreasing storage zone areas and transient storage times, which are trends supported by riparian and streambed piezometric head data. Riparian water levels rose during the transition from the dry to wet season, which could constrict the hyporheic storage zone. Thirteen of the 19 streambed piezometers recorded seasonal changes in hydraulic gradients and flux direction, with fewer yet stronger upwelling zones during higher discharges. The MODFLOW model missed the observed seasonal changes, possibly due to subtle changes in the seasonal change in water surface profiles. We conclude that partially dewatered dry season exchange, compared to wet season exchange, was initiated and terminated with smaller pressure gradients and, in different streambed locations, was smaller in volume, had longer residence times, and may connect with deeper and longer flow paths.

  • 27. Gandolfi, S.
    et al.
    Castellarin, A.
    Barbarella, M.
    Brath, A.
    Domeneghetti, A.
    Brandimarte, L.
    Di Baldassarre, G.
    Rio soliette (Haiti): An international initiative for flood-hazard assessment and mitigation2013Conference paper (Refereed)
  • 28.
    Gröndahl, Fredrik
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Chemical Analysis of Water and Sediments - Coastman - Estonia, Fauna and Flora2005In: Report to the Department of Environmental Engineering, Tallinn, Technical University, Estonia: European Comission in Estonia , 2005Chapter in book (Refereed)
  • 29. Gulbinskas, Saulius
    et al.
    Mileriene, Rosita
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Blažauskas, Nerijus
    Beach nourishment for shore protection in the Lithuanian Baltic sea coast2011In: Artificial beaches, artificial islands and other structures in the coastal and offshore areas: Proceedings of the 2nd International Conference 'Construction of the Artificial Lands in the Coastal and Offshore Areas' / [ed] Khabidov, A.Sh., Publishing House of the Siberian Branch of Russian Academy of Sciences , 2011Conference paper (Refereed)
  • 30.
    Gustafsson, David
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Ahlberg, Jesper
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Environmental Physics.
    Granlund, Nils
    Luleå University of Technology.
    Lindström, Göran
    Sveriges meteorologiska och hydrologiska institut.
    Wetterhall, Fredrik
    Sveriges meteorologiska och hydrologiska institut.
    Lundberg, Angela
    Luleå University of Technology.
    Distribuerade system för förbättrade snö- och avrinningsprognoser. Integration i hydrologiska modeller: Delrapport 12009Report (Other academic)
  • 31. Hailemariam, F. M.
    et al.
    Brandimarte, L.
    Dottori, F.
    Investigating the influence of minor hydraulic structures on modeling flood events in lowland areas2014In: Hydrological Processes, Vol. 28, no 4, p. 1742-1755Article in journal (Refereed)
  • 32.
    Hellmér, Elin
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Using eDNA to improve environmental monitoring for water bodies effected by hydropower in Sweden2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this report is to contribute to the base of knowledge on environmental monitoring by increasing understanding of how eDNA, electrofishing and sampling fishing may be used to examine fish biodiversity. It also aims at understanding if fish indexes developed within the Water Framework Directive reflect biodiversity, as well as the potential of eDNA data to serve as input to these indexes. This was done by using three different approaches.

    Firstly, in order to establish which of the methods eDNA, electrofishing and sampling fishing is more suitable to measure the different dimensions of biodiversity (species richness, species evenness and genetic diversity), a literature review comparing the different methods was carried out. It was found that eDNA yields a more detailed results for species richness, electrofishing yields better results for species evenness and sampling fishing is outperformed by eDNA and electrofishing alike. Both electrofishing and sampling fishing may collect data for genetic diversity analysis, however electrofishing outperforms sampling fishing with regards to amount of species caught, making electrofishing a more suitable data collection method.

    Secondly, in order to gain insight on practical usage of eDNA, a case study of Spjutmo (Dalarna county) was reviewed. It was established that eDNA generated more detailed information of species richness in the case of Spjutmo (as compared to electrofishing). The relative abundance data generated by the eDNA study might be seen as a measure of species evenness. However, electrofishing yielded data which may serve as input to species evenness indices. To the best knowledge of the author, none of the methods generated data on genetic diversity in this specific case.

    Officials from the energy company Fortum and the county board of Dalarna were also interviewed in order to get insight on what potential they see for eDNA to contribute to environmental monitoring. Both officials point at the ability to estimate abundance as a desired feature, hence a better understanding of what the relative abundance results indicates is wanted. The two interviews indicate that this understanding is an important feature to develop in order to make metabarcoding studies effective in current environmental monitoring.

    Thirdly, in order to understand if fish indexes developed within the Water Framework Directive reflect biodiversity, a literature review was performed. It was found that, all but one of the compared indexes incorporates or somewhat incorporates species richness. However, only five indexes are indicative or somewhat indicative of species richness. Species evenness is incorporated or somewhat incorporated by two indexes, which are also indicative or somewhat indicative of species evenness. None of the indexes incorporate or indicate genetic diversity.

    Within the third literature review, the potential of eDNA data to serve as input to current fish-based indexes developed within the Water Framework Directive, was studied. It was found that eDNA data may serve as input to only one index in its present form. However, five indexes also use proportional information (e.g. proportion of tolerant species), which possibly could be provided by eDNA data. The index where usage of eDNA data is currently possible uses presence-absence information.

  • 33.
    Ivansen, Anders
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Hydrauliska effekter av avbördade extremflöden: Fallstudie på en damm i Norrland2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Flödesdimensionering är något som används världen över när det kommer till konstruktionen och hanteringen av byggnader i vattendrag. I Sverige har flödeskommitén, bestående av SMHI och intressenter från vattenkraftsindustrin, tagit fram flödesdimensioneringsriktlinjerna som blivit praxis för svenska dammägare. Utifrån dessa riktlinjer får dammar olika flödesdimensioneringsklassningar beroende på vad konsekvenserna blir av olika högflöden. Detta arbete bygger på en nyligt genomförd konsekvensutredning på en av Jämtkrafts dammar i mellersta Norrland. Dammen, som går under namnet Damm B i denna rapport, har tidigare haft flödesdimensioneringsklass II men bedöms nu tillhöra flödesdimensionerings klass I. Dammen ska utifrån detta kunna avbörda ett klass I-flöde på 1690 m3/s till skillnad från det tidigare kravet på 1035 m3/s (klass II-flöde). Syftet med denna rapport äratt undersöka vilka effekter den naturliga tillrinningen av dessa och mellanliggande flöden har på olika objekt och områden nedströms Damm B. Med modelleringsverktyget MIKE 11 konstrueras en en-dimensionell flödesmodell för flödessimuleringar och avläsning av vattennivåer. Simuleringarna visar att den största delen av nedströms undersökta objekt påverkas mellan flödena 1100 m3/s och det så kallade 1000-års flödet på 1376 m3/s där risken för människoliv börjar vid det senare. Redan under klass II-flödet sker viss översvämning på de strandnära vägarna i området. Mellan 1100 m3/s samt 1200 m3/s börjar den mindre dammen nedströms (Damm C) riskera att gå till brott för att sedan överströmmas vid 1400 m3/s. Uträkning av skjuvspänningen berättar att det finns erosionsrisker för korndiametrar på upp till ca 2 cm i vissa erosionsbenägna områden. Denna erosionsbenägenhet inträffar för flöden under 1300 m3/s innan dammbrott har skett i Damm C. Vattenytans lutning minskartill följd av en större motdämning vilket därefter orsakar att minskningen av skärspänningen sker snabbare än den ökning som uppkommer till följd av ett stigande vattendjup. Vattenytan stiger dock och berör områden som inte brukar ligga under vatten. Detta kan leda till kornfraktioner som inte har transporteras bort vid tidigare flöden nu riskerar göra detta vilket bland annat kan bilda drivgods. Flödesdimensioneringsriktlinjerna som har tagits fram i Sverige bygger på miljöbalkens allmänna hänsynsregler vilket gör dem till en bra mall för dammägare att följa. När funderingar dock finns att inte bygga ut avbördningskapaciteten helt behöver det funderas på hur mycket ett eventuellt dammbrott skulle påverka den egna anläggningen och förtroendet från myndigheter samt allmänheten. I fallet med Damm B kommer de flesta objekten som undersöks att beröras vid en naturlig tillrinning på 1400 m3/s. Det är därför av intresse att genomföra noggrannare dammbrotts simuleringar för att hitta ett flöde mellan 1400 m3/soch 1690 m3/s där inga större ytterligare konsekvenser från ett dammbrott uppstår. Till följd av de svårheter och osäkerheter som valetav en lägrea vbördningskapacitet medför motiverar denna rapport dock till en utökad kapacitet för ett klass I-flöde i Damm B och undersöka möjligheterna för ökad avbördning vid Damm C. Detta kan även kompletteras med en omfattande samordnad beredskapsplan längs med älven och ett utökat översvämnings-/erosionsskydd på utsatta områden. 

  • 34.
    Johansson, Emilia
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Ericsson, Emma-Helena
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Quantification for the Flow of Microplastic Particles in Urban Environment: A Case of the Chao Phraya River, Bangkok Thailand: A Minor Field Study2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Plastic, including microplastic, is a common product in the society today and is starting to be more common in oceans where it can stay for a long time. Microplastic is defined usually in the size range five millimeter and smaller and together with the important Chao Phraya river in Bangkok, Thailand, the main subject of this paper is described. More clearly, the aim of this paper is to provide a first-hand quantification of microplastics flowing into the Chao Phraya River. Samples were taken at upstream, middle and downstream locations in the river with a pump-system and were then analyzed in a lab. The result showed an increasing load of microplastic entering the river from Bangkok, for example the result for size range five to one millimeter showed a six times increase of microplastic between the upstream and downstream point.

  • 35. Lin, C.
    et al.
    Kao, M. -J
    Wong, W. -Y
    Tsai, C. -P
    Chang, K. -T
    Yang, James
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Characteristics of flow separation and hydraulic jump during run-down motion of shoaling solitary wave traveling over steep sloping bottom2016In: Proceedings of the International Offshore and Polar Engineering Conference, International Society of Offshore and Polar Engineers , 2016, p. 724-731Conference paper (Refereed)
    Abstract [en]

    The features of velocity fields for the evolution of shoaling solitary wave, having a wave-height to water-depth ratio of 0.363 and propagating over a 1:3 sloping bottom, are investigated experimentally. A flow visualization technique using particle trajectory method and a high-speed particle image velocimetry (HSPIV) system employing a high-speed digital camera were used. This study mainly focuses on the occurrence of separated shear layer from the sloping bottom, evolved vortex structure, subsequent hydraulic jump, and curling jet of the backward breaking wave impinging upon the free surface of retreated flow during the run-down motion of the shoaling solitary wave.

  • 36.
    Marion, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Bottacin-Busolin, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Tait, Simon
    Univ Bradford, Sch Engn Design & Technol, Bradford BD7 1DP, W Yorkshire, England.
    Tregnaghi, Matteo
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn, I-35131 Padua, Italy.
    Near-bed flow field measurements at threshold of sediment motion2007In: PROCEEDINGS OF THE CONGRESS - INTERNATIONAL ASSOCIATION FOR HYDRAULIC RESEARCH, 2007, p. 401-Conference paper (Refereed)
    Abstract [it]

    Several experimental tests were carried out using a gravel bed tilting flume and an ad­vanced Particle Image Velocimetry (PIV) system. Sediment movement at the threshold was surveyed at the grain scale under uniform flow conditions. A natural river gravel with well sorted sediment was used. Flow field measurements were made over an area of approximately 400 cm2, on a plane located at 5 mm above the original sediment bed. Image processing and cross-correlation techniques were used to obtain flow velocities. Sequences of images of the bed surface were taken simultaneously with the measurements of the flow field. Statistics of the movements of the grains were collected through a semi-automatic procedure. Significant changes in the local flow field were observed in the proximity of the entrained or deposited particles. Such variations of velocity, which can be either in terms of the longitudinal and la­teral components or in terms of the relevant fluctuations from the time average, appear as a direct effect of the removal or deposition of individual grains. A strong correlation is shown between the changes in the streamwise velocity and the movement of the particles: local ve­locity increases were observed to correspond with the entrainment of grains, while local ve­locity reductions occurred as a grain was deposited.

  • 37.
    Marion, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotechn Engn.
    Packman, Aaron
    Northwestern Univ, Dept Civil & Environm Engn, Evanston.
    Zaramella, Mattia
    Univ Padua, Dept Hydraul Maritime Environm & Geotechn Engn.
    Bottacin-Busolin, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotechn Engn.
    Hyporheic flows in stratified beds2008In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 44, no 9, p. W09433-Article in journal (Refereed)
    Abstract [en]

    Surface-subsurface exchange fluxes are receiving increasing interest because of their importance in the fate of contaminants, nutrients, and other ecologically relevant substances in a variety of aquatic systems. Solutions have previously been developed for pore water flows induced by geometrical irregularities such as bed forms for the cases of homogeneous sediment beds and idealized heterogeneous beds, but these solutions have not accounted for the fact that streambed sediments are subject to sorting processes that often produce well-defined subsurface structures. Sediments at the streambed surface are often coarser than the underlying material because of size-selective sediment transport, producing relatively thin armor layers. Episodic erosional and depositional processes also create thick layers of different composition within the porous medium, forming stratified beds. A series of experiments were conducted to observe conservative solute transport in armored and stratified beds. An analytical solution was developed for advective exchange with stratified beds and provides appropriate scaling of the physical variables that control exchange flows. The results show that armor layers are too thin to significantly alter the advective pumping process but provide significant solute storage at short time scales. Stratified beds with layers of significant thickness favor development of horizontal flow paths within the bed and change the rate of solute transfer across the stream-subsurface interface compared to homogeneous beds.

  • 38.
    Marion, Andrea
    et al.
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Zaramella, Mattia
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Bottacin-Busolin, Andrea
    Univ Padua, Dept Hydraul Maritime Environm & Geotech Engn.
    Solute transport in rivers with multiple storage zones: The STIR model2008In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 44, no 10, p. W10406-Article in journal (Refereed)
    Abstract [en]

    Solute transport in rivers is controlled by surface hydrodynamics and by mass exchanges between the surface stream and distinct retention zones. This paper presents a residence time model for stream transport of solutes, Solute Transport in Rivers (STIR), that accounts for the effect of the stream-subsurface interactions on river mixing. A stochastic approach is used to derive a relation between the in-stream solute concentration and the residence time distributions (RTDs) in different retention domains. Particular forms of the RTD are suggested for the temporary storage within surface dead zones and for bed form-induced hyporheic exchange. This approach is advantageous for at least two reasons. The first advantage is that exchange parameters can generally be expressed as functions of physical quantities that can be reasonably estimated or directly measured. This gives the model predictive capabilities, and the results can be generalized to conditions different from those directly observed in field experiments. The second reason is that individual exchange processes are represented separately by appropriate residence time distributions, making the model flexible and modular, capable of incorporating the effects of a variety of exchange processes and chemical reactions in a detailed way. The capability of the model is illustrated with an example and with an application to a field case. Analogies and differences with other established models are also discussed.

  • 39. Mazzoleni, M.
    et al.
    Barontini, S.
    Ranzi, R.
    Brandimarte, L.
    Innovative probabilistic methodology for evaluating the reliability of discrete levee reaches owing to piping2015In: Journal of Hydrologic Engineering, Vol. 20, no 5, article id 04014067Article in journal (Refereed)
  • 40. Mazzoleni, M.
    et al.
    Dottori, F.
    Brandimarte, Luigia
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    Tekle, S.
    Martina, M. L. V.
    Effects of levee cover strength on flood mapping in the case of levee breach due to overtopping2017In: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 62, no 6, p. 892-910Article in journal (Refereed)
    Abstract [en]

    The reliability of a levee system is a crucial factor in flood risk management. In this study we present a probabilistic methodology to assess the effects of levee cover strength on levee failure probability, triggering time, flood propagation and consequent impacts on population and assets. A method for determining fragility curves is used in combination with the results of a one-dimensional hydrodynamic model to estimate the conditional probability of levee failure in each river section. Then, a levee breach model is applied to calculate the possible flood hydrographs, and for each breach scenario a two-dimensional hydrodynamic model is used to estimate flood hazard (flood extent and timing, maximum water depths) and flood impacts (economic damage and affected population) in the areas at risk along the river reach. We show an application for levee overtopping and different flood scenarios for a 98 km reach of the lower Po River in Italy. The results show how different design solutions for the levee cover can influence the probability of levee failure and the consequent flood scenarios. In particular, good grass cover strength can significantly delay levee failure and reduce maximum flood depths in the flood-prone areas, thus helping the implementation of flood risk management actions.

  • 41. Palomino Cuya, D. G.
    et al.
    Brandimarte, Luigia
    , Institute for Water Education, Westvest 7, PO Box 3015, 2601 DA Delft, Netherlands.
    Popescu, I.
    Alterach, J.
    Peviani, M.
    A GIS-based assessment of maximum potential hydropower production in La Plata basin under global changes2013In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 50, p. 103-114Article in journal (Refereed)
    Abstract [en]

    Population growth, economic development, urbanization, changes in hydrological regimes and land use are the main drivers affecting allocation and exploitation of water resources. The pressure exerted by these global changes on the five countries -Argentina, Bolivia, Brazil, Paraguay and Uruguay- located in La Plata Basin over the last decades has raised the need for assessing trends in future electricity demand and energy production in the basin.The aim of this research is to assess whether (and when) shortage and vulnerabilities in terms of hydropower generation are to be expected in La Plata basin in the next decades. The methodology proposed has focused on two aspects to reach the objectives: 1) assessment of hydropower production and electricity demand in the basin over the last twenty years (1987-2008), in order to establish growing trends for the next thirty years; 2) computation of maximum potential hydropower using the newly developed Arc-GIS based tool VAPIDRO-ASTE. The assessment and calculation have been applied to La Plata River and its main tributaries: Paranaiba, Grande River, Tiete, Paranapanema, Iguaçu, Uruguay, Negro River, Paraguay and Paraná. The first outcomes of this research show that La Plata Basin has high hydropower potential. About 40% of the hydropower potential is already used to produce and supply energy. Out of the remaining 60% potential, about 25% could hardly be exploited because of environmental issues or low cost/benefit ratio. Thus, the estimated residual potential hydropower is about 35% of the maximum potential hydropower calculated.

  • 42. Popescu, I.
    et al.
    Brandimarte, Luigia
    UNESCO, IHE Institute for Water Education, Delft, Netherlands.
    Perera, M. S. U.
    Peviani, M.
    Assessing residual hydropower potential of the la Plata Basin accounting for future user demands2012In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 16, no 8, p. 2813-2823Article in journal (Refereed)
    Abstract [en]

    La Plata Basin is shared by five countries (Argentina, Bolivia, Brazil, Paraguay and Uruguay), which have fast growing economies in South America. These countries need energy for their sustainable development; hence, hydropower can play a very important role as a renewable clean source of energy. This paper presents an analysis of the current hydropower production and electricity demand in La Plata Basin (LPB), and it analyses the maximum and residual hydropower potential of the basin for a horizon of 30 yr (i.e. year 2040). Current hydropower production is estimated based on historical available data, while future energy production is deduced from the available water in the catchment (estimated based on measured hydrographs of the past years), whereas electricity demand is assessed by correlating existing electricity demand with the estimated population growth and economic development. The maximum and residual hydropower potential of the basin were assessed for the mean annual flows of the present hydrological regime (1970-2000) and topographical characteristics of the area. Computations were performed using an integrated GIS environment called VAPIDRO-ASTE released by the Research on Energy System (Italy). The residual hydropower potential of the basin is computed considering first that the water supply needs for population, industry and agriculture are served, and then hydropower energy is produced. The calculated hydropower production is found to be approximately half of the estimated electricity demand, which shows that there is a need to look for other sources of energy in the future.

  • 43. Popescu, Luigia
    et al.
    Brandimarte, Luigia
    UNESCO-IHE, Delft, Netherlands.
    Peviani, M.
    Effects of climate change over energy production in La Plata Basin2014In: International Journal of River Basin Management, ISSN 1571-5124, E-ISSN 1814-2060, Vol. 12, no 4, p. 319-327Article in journal (Refereed)
    Abstract [en]

    The population growth and the economic development that the five Countries (Argentina, Bolivia, Brazil, Paraguay and Uruguay) located in La Plata Basin (LPB) have gone through over the last decades have risen the necessity to assess the current and future electricity demand and compare it to the energy production. In this region, the water resources of LPB are one of the most important sources of energy. In this context, the CLARIS EU (European Union) FP7 project has carried out an extensive research work which, in terms of investigating hydropower potential and vulnerability, has produced the following outcomes: assessment of current hydropower production and electricity demand; calculation of the maximum potential hydropower in order to establish whether and when shortage in terms of hydropower generation is to be expected; analysis of potential residual hydropower taking into account future user demands and analysis of hydropower production taking into account climate change scenarios, in order to identify potential vulnerabilities under variable input and/or needs for other sources of energy.

    This paper focuses on the outcomes of the climate change scenario analysis and its impacts on hydropower production in the basin. This has been investigated by (1) assessing the current hydropower production and electricity demand over the last 20 years (1991–2010), in order to establish growing trends in the short-term (2031–2040) and at the end of the century (2079–2098); (2) estimating maximum potential hydropower under present hydrological conditions; (3) analysis of potential vulnerability, by combining the first two research steps and (4) analysing the impact of climate change scenarios on hydrological variability and thus on hydropower production.

    The assessment of hydropower production and electricity demand determined that the current hydropower production represents about 73% of the electricity demand. Analysing the trends for the electricity produced by hydro-plants and the electricity demand, it is evident that the increment rate for the hydroelectricity production is lower than the increment rate of the electricity demand. Although, the maximum theoretically available energy at the basin level is about 683 GWh, the maximum feasible available energy (taking into account environmental flow requirements and financial constraints) will be of about 514 GWh per year.

    The climate change analysis shows an opposite trend at the sub-basin level, but overall, at the basin scale, the hydropower production is expected to increase because of changes in the hydrological variables.

  • 44.
    Reinius, E.
    KTH. VBB, SWECO, Sweden.
    Method To Reduce The Groundwater Flow Around A Subsurface Storge Of Nuclear Waste1981In: Subsurface Space: Environmental Protection Low Cost Storage Energy Savings, Elsevier, 1981, Vol. 2, p. 977-982Chapter in book (Other academic)
    Abstract [en]

    Ground water flow through an underground repository for nuclear waste located 500 m below the ground surface as proposed by Swedish authorities may be considerably reduced by surrounding the repository with a zone of constant potential like Faraday's cage in electricity. The zone consists of tunnels and boreholes between them.

  • 45. Schmadel, Noah M.
    et al.
    Neilson, Bethany T.
    Heavilin, Justin E.
    Stevens, David K.
    Worman, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Hydraulic Engineering.
    The influence of spatially variable stream hydraulics on reach scale transient storage modeling2014In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 50, no 12, p. 9287-9299Article in journal (Refereed)
    Abstract [en]

    Within the context of reach scale transient storage modeling, there is limited understanding of how best to establish reach segment lengths that represent the effects of spatially variable hydraulic and geomorphic channel properties. In this paper, we progress this understanding through the use of channel property distributions derived from high-resolution imagery that are fundamental for hydraulic routing. We vary the resolution of reach segments used in the model representation and investigate the minimum number necessary to capture spatially variable influences on downstream predictions of solute residence time probability density functions while sufficiently representing the observed channel property distributions. We also test if the corresponding statistical moments of the predictions provide comparable results and, therefore, a method for establishing appropriate reach segment lengths. We find that the predictions and the moment estimates begin to represent the majority of the variability at reach segment lengths coinciding with distances where observed channel properties are spatially correlated. With this approach, reach scales where the channel properties no longer significantly change predictions can be established, which provides a foundation for more focused transient storage modeling efforts.

  • 46.
    Setegn, Shimelis Gebriye
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Melesse, A. M.
    Abbaspour, K.
    Dargahi, Bijan
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Srinivasan, R.
    Effect of Downscaling Methods on the Assessment of the Impact of Climate Change in Watershed Scale Management Models2009In: Proceedings of the American Water Resources Association - AWRA 2009: Spring Specialty Conference: Managing Water Resources Development in a Changing Climate/TPS-09-1, 2009Conference paper (Refereed)
  • 47.
    Setegn, Shimelis Gebriye
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Melesse, A. M.
    Dargahi, Bijan
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Srinivasan, R.
    Water Resources Variability as a Result of Changing Climate: A Case Study in the Lake Tana Basin, Blue Nile Ethiopia2009In: Proceedings of the American Water Resources Association (AWRA) 2009: Spring Specialty Conference: Managing Water Resources Development in a Changing Climate /TPS-09-1, 2009Conference paper (Refereed)
  • 48. Taddele, Y. D.
    et al.
    Setegn, Shimelis Gebriye
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering, Hydraulic Engineering.
    Berndtsson, R.
    Hydrological Response of Gilgel Abay River Flow to Climate Change, Lake Tana Basin, Ethiopia2009In: Proceedings of the 5th International SWAT Conference, 2009Conference paper (Refereed)
  • 49.
    Thunqvist, Eva-Lotta
    KTH, School of Technology and Health (STH), Centres, Centre for Health and Building, CHB.
    Enskilda brunnar och saltvatteninträngning på Ornö2011Report (Other academic)
    Abstract [sv]

    Haninge kommun är en kustkommun i en storstadsregion. Befolkningen i Stockholms län ökar kontinuerligt och så även inflyttningen till i Haninge kommun. Fritidsboende övergår i permanentboende och särskilt attraktivt är det att bo vid kusten. Även på öar i skärgården med fast båtförbindelse ökar befolkningen. I skärgården sker vattenförsörjningen oftast med enskilda brunnar. Ett kustnära läge för en brunn innebär en ökad risk för saltvatteninträngning vid stora uttag.

    Syftet med denna studie är att kartlägga förekomsten av enskilda brunnar på Ornö samt att utreda om kustnära brunnar har förhöjda kloridhalter till följd av saltvatteninträngning. Ornö, är en ö belägen i Stockholms skärgård i Haninge kommun, med en yta av nästan 5000 ha och med 279 permanentboende. På sommaren ökar dock siffran markant då det finns ett stort antal fritidsboende på ön.

    År 2009 skickades 762 enkäter ut till Ornös fastighetsägare. Totalt erhölls 606 svar, dvs en 80% svarsfrekvens. 349 fastighetsägare uppgav att de tog sitt vatten från en enskild brunn, 212 fastigheter var anslutna till en gemensam brunn. Uppgifter om brunnars djup visade sig vara svåra att erhålla. I den databas som upprättades av Haninge kommun framgår endast vilka fastigheter som har en brunn, inte var på fastigheten brunnen ligger.

    I augusti 2010 provtogs 42 brunnar. Sju av brunnarna hade en kloridhaltkoncentration av 100mg/l eller mer. Nio brunnar hade en natriumkoncentration av 100mg/l eller mer.

    Saltvattenpåverkan av brunnsvatten förekommer främst när grundvattenuttagen överstiger grundvattenbildningen inom ett område. Detta kan ske vid ökande grundvattenuttag och/eller perioder med dålig grundvattenbildning. Salthalten i brunnsvatten varierar därför med tiden. Studien visade att det fanns brunnar med höga klorid

    och natriumhalter i områdena Ornöboda, Hässelmara, Långviksholmen och Brevik. De högsta halterna fanns på Långviksholmen som också har ett mycket begränsat tillrinningsområdet. Två av brunnarna tillhörde samfälligheter och har troligen stora uttag vilket kan öka risken för saltvatteninträngning.

    Även fortsättningsvis bör information om brunnars läge och kemiska data (i det fall fastighetsägaren genomför en analys av brunnsvattnet) samlas i en brunnsdatabas hos Haninge kommun. Genom brunnsdatabasen får kommunen ett relevant beslutsunderlag för planering och uppföljning. Det fortsatta arbetet bör omfatta utformning av rutiner för att sammanställa och i framtiden införa data om enskilda brunnar i en GIS

    databas. Denna databas kan tillsammans med data från SGUs brunnsarkiv ge ett underlag för kartor som visar områden för ökad risk för saltvatteninträngning. Vidare bör det ske en uppföljning och återkommande analys av brunnar i områden där kloridhalterna är höga. Det är också viktigt att informera fastighetsägare om risken för saltvatteninträngning beskrivs samt utfärda rekommendationer om vattenanvändning tex med hänvisning till SGUs rapporter om grundvattennivåer.

  • 50. Toth, E.
    et al.
    Brandimarte, Luigia
    UNESCO-IHE, Institute for Water Education, Westvest, 7, Delft, Netherlands.
    Prediction of local scour depth at bridge piers under clear-water and live-bed conditions: Comparison of literature formulae and Artificial Neural networks2011In: Journal of Hydroinformatics, ISSN 1464-7141, E-ISSN 1465-1734, Vol. 13, no 4, p. 812-824Article in journal (Refereed)
    Abstract [en]

    The scouring effect of the flowing water around bridge piers may undermine the stability of the structure, leading to extremely high direct and indirect costs and, in extreme cases, the loss of human lives. The use of Artificial Neural Network (ANN) models has been recently proposed in the literature for estimating the maximum scour depth around bridge piers: this study aims at further investigating the potentiality of the ANN approach and, in particular, at analysing the influence of the experimental setting (laboratory or field data) and of the sediment transport mode (clear water or live bed) on the prediction performances. A large database of both field and laboratory observations has been collected from the literature for predicting the maximum local scour depth as a function of a parsimonious set of variables characterizing the flow, the sediments and the pier. Neural networks with an increasing degree of specialization have been implemented - using different subsets of the calibration data in the training phase - and validated over an external validation dataset. The results confirm that the ANN scour depths' predictions outperform the estimates obtained by empirical formulae conventionally used in the literature and in the current engineering practice, and demonstrate the importance of taking into account the differences in the type of available data - laboratory or field data - and the sediment transport mode - clear water or live bed conditions.

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