Sediment Transport Conditions Research Articles

Inferring pyroclastic density current flow conditions using syn-depositional sedimentary structures

The processes occurring in the basal region of concentrated pyroclastic density currents (PDCs) influence the mobility, runout distance, and damage potential of a current, but directly observing these processes is extremely difficult. Instead, we must investigate the deposits to glean information regarding the conditions of sediment transport and deposition. The PDC deposits of the May 18, 1980 eruption of Mount St. Helens (WA, USA) contain sedimentary structures consisting of bed material reworked into undulose structures and recumbent flame structures. The structures vary over two orders of magnitude in size with lengths ranging from 8 cm to 18 m and heights ranging from 4 cm to 1.8 m. Despite the large range in sizes, the structures remain self-similar in form, suggesting a common mechanism for formation. The structures are interpreted as the record of granular shear instabilities, similar to Kelvin-Helmholtz instabilities, formed at the interface between a shearing, high-concentration flow and the substrate in the moments just prior to deposition. The morphology of the structures suggests that the basal region of PDCs must be both highly concentrated and also highly mobile in the moments before final deposition, likely a result of elevated pore fluid pressures. We use a modified instability growth criterion to estimate PDC flow velocities at the time of formation; for the Mount St. Helens PDCs, the velocity estimates range from 0.2 to 7.5 m s−1 with larger structures requiring higher flow velocities. Combining the velocity estimates with the dimensions of the structures suggests deposition rates of 4 to 32 cm s−1. Such high deposition rates indicate that the deposits likely accumulated in a stepwise manner, rather than either progressively or en masse. The structures suggest that sections of the deposit accumulated during punctuated periods of high deposition lasting at most a few seconds followed by periods of bypassing (i.e., non-deposition) or erosion lasting minutes to tens of minutes. Our findings motivate continued experimental and numerical work to understand how the formation of recumbent flame (and similar) structures affects subsequent flow behavior in terms of runout distance and hazard potential.

Fluvial incision and coarse gravel redistribution across the modern Dead Sea shelf as a result of base‐level fall

AbstractGlobal eustatic lowstands can expose vast areas of continental shelves, and occasionally the shelf edge and the continental slope. The degree of fluvial connectivity to receding shores influences the redistribution of sediments across these emerging landscapes. Shelf and slope emergence in the Dead Sea since the middle of the 20th century, offers a rare opportunity to examine evolution of stream connectivity in response to continuous base‐level decline. We characterize the connectivity evolution of two streams, using high‐resolution time series of aerial imagery and elevation models, field mapping, and grain‐size analyses. Our rich spatiotemporal dataset of evolving channel geomorphology, sediment transport conditions, and sediment redistribution, allows calculating potential coarse sediment mobility in response to base level decline. Following shelf emergence, alluvial fans first prograded onto the low‐gradient shelf under unfavourable conditions for transporting coarse sediment to the regressing shoreline. Then, with shelf and slope emergence, the two adjacent streams evolved differently. The smaller, more arid watershed still maintains its highstand delta progradation on the shelf and is practically disconnected from the receding lake. The larger catchment, heading in wetter environments and having a narrower shelf, has incised the shelf and renewed and gradually intensified the sediment transport from the highstand to the lowstand delta. Sediment mobilization to lowstand shorelines is controlled by the evolution of the channel profile and by the average speed of gravel transport (10s‐100s m yr‐1). These findings from the Dead Sea are relevant to fluvial processes operating on continental shelves during glacial maxima. Streams would have commonly stored high proportions of their coarse sediment on the continental shelves rather than efficiently connecting with the lowstand level. Additionally, differences in sediment routing patterns should exist among nearby streams, primarily due to continental margin geometry and watershed hydrology. © 2019 John Wiley & Sons, Ltd.

Self‐cleansing design of sewers: Definition of the optimum deposited bed thickness

Sediment deposits may influence the performance of the sewer systems. Sediments are the main store of pollutants which causes sewer systems overflows. In order to prevent the deposition of sediment in sewer systems, self-cleansing design criteria are used. Among various criteria, "self-cleansing with deposited bed" criterion is found appropriate for designing of large sewers. Allowing small thickness of deposited bed in large sewers decreases the required channel bed slope and construction costs. This study presents a bed load self-cleansing model established on wide ranges of experimental data. Comparison of developed model with the existing models in the literature shows its higher performance on variety of data sources. Examples for the application of the model are presented, and design graphs and charts for different pipe sizes are proposed. As a result, the optimum deposited bed thickness is found 1%-5% of the pipe diameter; however, 1% is recommended for sewer pipes design. PRACTITIONER POINTS: Nondeposition sediment transport condition with a bed deposit criterion is found appropriate for large sewer pipe design. The precision of a model is linked to the ranges of experimental data and parameters used for the models development. The optimum range of deposited bed thickness can be adopted in the range of 1% to 5% of the pipe diameter.

Interaction between hydrokinetic turbine wakes and sediment dynamics: array performance and geomorphic effects under different siting strategies and sediment transport conditions

In-stream hydrokinetic energy conversion devices can be deployed in large scale rivers to produce energy with minimal infrastructure costs. They are however shown to actively interact with the channel bathymetry and sediment transport generating a scour and deposition pattern similar to bridge pier. Symmetric, streamwise, aligned turbine installations have shown to introduce only local effects, yet complex configurations may trigger non-local morphodynamic instabilities. Experimental investigations, based on continuous spatio-temporal measurements of bed topography, explore a number of inflow conditions and siting strategies for axial-flow hydrokinetic turbine models. Results show that asymmetric turbine installations in a portion of the channel cross section may introduce weak non-local deformation of the mean bed topography and alter bedform migration velocities. Geomorphic effects become stronger with increasing shear stress and with rotors deployed up to half of the channel width, resulting in mean flow distortion within the channel cross section and inducing an alternating scour-deposition pattern resembling the signature of steady, forced fluvial bars. Non-local effects can be mitigated, narrowing the turbine array, or amplified, distributing turbines in a vane-like installation, leading to different estimates of energy production averaged at the power plant scale. A discussion on the key quantities governing geomorphic effects and the potential benefits of asymmetric turbine deployments is provided as a preliminary guideline towards the expansion of Marine Hydrokinetic energy in rivers.

Numerical simulation of the lateral pipe intake: flow and sediment field

AbstractHydraulic characteristics of the flow and sediment transport conditions are among the most important issues in design of the lateral intakes in order to minimize the flow loss. In this study, a 3D numerical model has been employed in a parametric study to study the performance of a lateral pipe intake. Observations indicated that the flow was affected by the pipe intake so that the recirculation area was close to the wall of the main channel, the wall of the lateral pipe intake and back of the lateral pipe intake. The pipe intake in vertical direction to the main channel showed the highest performance, although sedimentation behind the pipe intake in this diversion angle was higher. In addition, pipe intake showed a quite acceptable performance for almost 40% intrusion to the main channel width. Relationships for the coefficient of discharge were also developed.

Experimental investigation on the flow behavior during the solid particles lifting in a micro-bubble generator type airlift pump system

The airlift pump system includes the both air and liquid inlet sections, and the vertical pipe as the transporting medium. The low performance of the concurrent airlift pump systems has promoted efforts to further improve performance in implementation of these devices in various conditions of real sediment transport on sea and lakebeds. In the present experimental study, we have modified the conventional airlift pump system by equipped our developed micro-bubble generators in the system. Here the three-phase flow behavior during the solid particle lifting of the micro-bubble generator type airlift pump system during the transient conditions is reported. The inner diameter of the vertical pipe of this airlift pump system was 50 mm. Several inclination angles of micro-bubble injection were used: 15°, 30°, and 45° from the horizontal. The working fluids were air and water. The tested solid particles were solid and coal with the averaged of particle diameters were 0.33 mm, 0.52 mm, and 0.81 mm. The ranges of supplied flow rates of liquid and air, QL and QG, were 7.0 m3/h–9.0 m3/h., 0.3 l/min–0.8 l/min, respectively. The obtained visualization images were analyzed by using the developed image processing technique.As a result, it was obtained that (1) the optimum solid lifting performance was found under the slug flow pattern due to their buoyancy force, (2) main parameters such as the injected inclination angle of the micro-bubble generator, the liquid and gas volumetric flow rates, the averaged particle diameters, and the density of the lifted particles affect the ability of the micro-bubble generator type of the airlift pump system, (3) The used of micro-bubble generators in the air lift pump system will increase their capability to bring the solid particles upward at least 17% compared to conventional airlift pump systems.

Particle transport mechanics and induced seismic noise in steep flume experiments with accelerometer‐embedded tracers

AbstractRecent advances in fluvial seismology have provided solid observational and theoretical evidence that near‐river seismic ground motion may be used to monitor and quantify coarse sediment transport. However, inversions of sediment transport rates from seismic observations have not been fully tested against independent measurements, and thus have unknown but potentially large uncertainties. In the present study, we provide the first robust test of existing theory by conducting dedicated sediment transport experiments in a flume laboratory under fully turbulent and rough flow conditions. We monitor grain‐scale physics with the use of ‘smart rocks’ that consist of accelerometers embedded into manufactured rocks, and we quantitatively link bedload mechanics and seismic observations under various prescribed flow and sediment transport conditions. From our grain‐scale observations, we find that bedload grain hop times are widely distributed, with impacts being on average much more frequent than predicted by existing saltation models. Impact velocities are observed to be a linear function of average downstream cobble velocities, and both velocities show a bed‐slope dependency that is not represented in existing saltation models. Incorporating these effects in an improved bedload‐induced seismic noise model allows sediment flux to be inverted from seismic noise within a factor of two uncertainty. This result holds over nearly two orders of magnitude of prescribed sediment fluxes with different sediment sizes and channel‐bed slopes, and particle–particle collisions observed at the highest investigated rates are found to have negligible effect on the generated seismic power. These results support the applicability of the seismic‐inversion framework to mountain rivers, although further experiments remain to be conducted at sediment transport near transport capacity. © 2018 John Wiley & Sons, Ltd.

Land Reclamation using Construction Waste for Offshore Gaza Fishery Port

The world experience rapidly growing in population density and lack of areas especially coastal areas, which is considered the most vital, economic and cultural areas around the world. This force the experts investigating different suggestions such as sea reclamation and its exploitation for many goals>In this study, it is proposed to relocate the construction features of the Gaza fishery port for better sediment transport and hydraulic conditions. Therefore, the study methodology started with estimation of the construction waste quantity resulted from 2014 aggression, then ensuring its testing results, specifications and possibility of using it in land reclamation. Furthermore, the existing Gaza fishery port sediment transportation and features were studied and its bathymetry was identified. As a result, the new proposed reclaimed area was identified in west of the existing western breakwater at Gaza fishery port and its area was estimated according to estimation the quantity of debris resulted from removing the existing breakwaters in addition to construction wastes resulted from 2014 aggression. The total estimated quantity of available debris is about one million cubic meters, which adequate to reclaim about 11 hectares. However, the new reclaimed area should be surrounded by sheet piles, so the sheet pile type is assumed to be PZC 28 and finally the total cost of the proposed reclaimed area was estimated as USD130 per square meter of reclaimed area. Finally, to facilitate transportation and movement through this reclaimed area, the bridge is recommended to be constructed. Finally, the cost of sea reclamation is feasible especially that Gaza fishery seaport is very vital and important place, which will be as a fishery port and for recreational activities.

EROSIVE PROCESS CONTROL IN THE BRAZILIAN SEMIARID REGION

ABSTRACT The adoption of measures to prevent and control erosive processes requires information about the factors affecting the erosion and the sediment transport conditions. However, the sediment yield of a basin depends on the availability of eroded material and the sediment transport capacity. Thus, the objective of this study was to identify the factors that affect the sediment transport capacity at different spatial scales in an area with caatinga vegetation. The study was carried out in the Iguatu Experimental Basin, in the state of Ceará, Brazil, from 2009 to 2014, by monitoring two scale levels: watershed with 2.06 ha, and erosion plot with 20 m². The variables evaluated for the rainfall events were precipitation, intensity of rainfall, antecedent soil moisture, precipitation of the antecedent five days, consecutive dry days, peak flow, runoff depth, and sediment yield. During the study period, 263 rainfall events (>2 mm) and 86 events generating runoff were recorded. Three Principal Components (PC) were developed using the Principal Component Analysis, which explained more than 79% of the total variance. Variables connected to the kinetic energy capacity of the rainfall to disaggregate soil particles, the energy for sediment transport, and the soil water content were framed in the CP1, CP2, and CP3, respectively. In the evaluated scales, the sediment yield presented a high correlation with the runoff depth, which indicates limiting conditions for sediment yield by the mass flow energy.

A new instability mechanism related to high-angle waves

Waves with a large incidence angle in deep water can drive a morphodynamic instability on a sandy coast whereby shoreline sand waves, cuspate forelands, and spits can emerge. This instability is related to bathymetric perturbations extending offshore in the shoaling zone. Here, we explore a different mechanism where the large incidence angle is supposed to occur at breaking and the bathymetric perturbations occur only in the surf zone. For wave incidence angles at breaking above ≈ 45∘, the one-line approximation of coastal dynamics predicts an unstable shoreline. This instability (EHAWI) is scale-free and the growth rate increases without bound for decreasing wavelength. Here we use a 2DH morphodynamic model resolving surf zone instabilities to investigate whether EHAWI could approximate a real instability in nature with a characteristic length scale. Assuming very idealized conditions on the bathymetric profile and sediment transport, we find a 2DH instability mode consisting of shore-oblique up-current bars coupled to a meandering of the longshore current. This mode grows for high-angle waves, above about 30∘ (offshore) and the maximum growth rate occurs for the angle maximizing the angle at breaking, about 70∘ (offshore). The dominant wavelength is of the order of the surf zone width. Interestingly, for long sand waves, the growth rate never becomes negative and it matches very well the anti-diffusive behavior of EHAWI. This distinguishes the present instability mode from other modes found in previous studies for other bathymetric and sediment transport conditions. Thus, we conclude that EHAWI approximates a real morphodynamic instability only for quite particular conditions. In such case, a characteristic length scale of the instability emerges thanks to surf zone processes that damp short wavelengths.

Depth-averaged modelling of granular dike overtopping

Failure of river dikes due to overtopping is a dangerous phenomenon to be avoided, and a complex unsteady sediment transport problem that is under intense scientific consideration. Mathematical modelling of these flows is conducted using one-dimensional families of models based on different conceptual approximations, including (i) a clear-water layer and bed-load layer approach; (ii) a mixture flow approach dividing the sediment transport into bed and suspended load transport modes; and (iii) a two-phase approach formulating the mass and momentum conservation equations for the water and sediment phases separately. These families of conceptual models involve a vertical momentum balance reducing to hydrostatic pressure distribution. As discussed in previous works, numerical results might be improved by relaxing this closure hypothesis. Herein, a vertically-averaged RANS model is presented for a water–sediment mixture, conceptually divided into suspended/bed-load layers, overtopping the erodible dike surface under non-equilibrium sediment transport and non-hydrostatic fluid pressure conditions. The model is critically compared with experimental data and Saint-Venant type simulations, resulting in improved predictions of the dike crest reach. However, the erosion at the dike toe is overpredicted, stating a limitation of depth-averaged modelling.

Responses of Riverbed Particles to Geomorphologic Processes in Aeolian-Fluvial Action Area: A Case Study of the Heilaigou Basin in Inner Mongolia of China

Abstract: The Heilaigou basin, located in the Inner Mongolia of China, is predominantly influenced by the aeolian-fluvial actions, with complicated sediment transport conditions on the mainstream riverbed. In order to identify the relationship between sedimentary particles and geomorphic processes, mechanisms for the formation of characteristics of grain size composition were investigated by analyzing grain size parameters and external dynamic geomorphologic features. Firstly, the grain size parameters of the riverbed, stream power, maximum grain size of the wind-blown particles and HI values of the mainstream channel were calculated and analyzed, and they were used to establish multiple regression functions of grain size parameters in order to determine the effects of wind and river actions on particles. The results show that sediments in different reaches are formed in different environments: the upper stream is controlled by fluvial and aeolian processes; the sorting properties of riverbed sediments in...

Effect of surface texture and structure on the development of stable fluvial armors

Stable fluvial armors are found in river systems under conditions of partial sediment transport and limited sediment supply, a common occurrence in nature. Stable armoring is also readily recreated in experimental flumes. Initially, this bed stabilizing phenomenon was examined for different flow discharges and solely related to surface coarsening and bedload transport reduction. The models developed suggest a specific armor composition (i.e., texture) dependent on the parent bed material and formative discharge. Following developments in topographic remote sensing, recent research suggests that armor structure is an important control on bed stability and roughness. In this paper, replicated flume runs during which digital elevation models (DEMs) were collected from both exposed and flooded gravel beds are used to interpret armoring manifestations and to assess their replicability. A range of methodologies was used for the analysis, providing information on (i) surface grain size and orientation, (ii) bed-elevation distributions, (iii) the spatial coherence of the elevations at the grain-scale, (iv) surface slope and aspect, (v) grain imbrication and (vi) the spatial variability in DEM properties. The bed-surface topography was found to be more responsive than bed-material size to changes in flow strength. Our experimental results also provide convincing evidence that gravel-beds' response to water-work during parallel degradation is unique (i.e., replicable) given the formative parameters. Based on this finding, relationships between the armors' properties and formative parameters are proposed, and are supported by adding extensive data from previous research.

Field data and regional modeling of sediment supply to Emilia-Romagna’s river mouths

The Fiumi Uniti and Savio rivers are two small sandy-bed river systems which sediment yield contributes feeds part of the Emilia-Romagna beaches (Italy). Since the twentieth century the northern Adriatic coast has been affected by well-known beach retreat phenomena. As the sediment supply of these local rivers is not well known, an analysis of bed-load transport rates for the last 10 kilometres of the river has been done. Multiple analysis, supported by direct field measurements of the 2005-06 and 2017 years (still ongoing) have been realized. Complementary hydraulic investigation and modelling have been performed. Repeated bed-material samplings have been carried out during different flood conditions, obtaining a significant number of observations. Aiming at defining the behaviour of sediment-transport in these two rivers, this paper focuses on the analysis of threshold sediment transport condition. Several formulae available in literature were used to test the field measurements. All these criteria seem inappropriate to predict the threshold conditions for bed particle entrainment in terms of the value of bed shear stress. The inaccurate estimation given by these formulae is due to the fact that they do not consider natural grain-shape factors or are mainly suitable for gravel-bed rivers.

Quasi-3D two-phase model for dam-break flow over movable bed based on a non-hydrostatic depth-integrated model with a dynamic rough wall law

The assumptions of equilibrium flow conditions neglecting the flow acceleration for vertical velocity distributions and of the equilibrium wall law applied to the bottom boundary condition, in which the flow acceleration is neglected in the vicinity of the bed, are questionable when used to calculate sediment transport for flows that vary rapidly over time and space. Examples of such flows include dam-break flows and flows around structures. This study proposes a two-phase depth-integrated model for large-scale geophysical flow applications involving sediment transport phenomena and bed morphology. The model for the fluid phase is based on the non-hydrostatic quasi-3D method, and uses a dynamic rough wall law that employs continuity and momentum equations for the bottom boundary conditions.It was confirmed that the proposed model reduces to the previous bedload formulae for uniform flow conditions under the weak sediment transport condition. The model was applied in an experiment involving a dam-break flow on a movable bed channel with a suddenly enlarged section. The comparison between the experimental results and the results calculated with the proposed model and previous models demonstrates the validity of the proposed model. The comparison also highlights the advantages of introducing a quasi-3D two-phase model to evaluate vertical velocity distributions and non-equilibrium sediment motions.

Image-based Lagrangian Particle Tracking in Bed-load Experiments

Image analysis has been increasingly used for the measurement of river flows due to its capabilities to furnish detailed quantitative depictions at a relatively low cost. This manuscript describes an application of particle tracking velocimetry (PTV) to a bed-load experiment with lightweight sediment. The key characteristics of the investigated sediment transport conditions were the presence of a covered flow and of a fixed rough bed above which particles were released in limited number at the flume inlet. Under the applied flow conditions, the motion of the individual bed-load particles was intermittent, with alternating movement and stillness terms. The flow pattern was preliminarily characterized by acoustic measurements of vertical profiles of the stream-wise velocity. During process visualization, a large field of view was obtained using two action-cameras placed at different locations along the flume. The experimental protocol is described in terms of channel calibration, experiment realization, image pre-processing, automatic particle tracking, and post-processing of particle track data from the two cameras. The presented proof-of-concept results include probability distributions of the particle hop length and duration. The achievements of this work are compared to those of existing literature to demonstrate the validity of the protocol.

Image-based Lagrangian Particle Tracking in Bed-load Experiments.

Image analysis has been increasingly used for the measurement of river flows due to its capabilities to furnish detailed quantitative depictions at a relatively low cost. This manuscript describes an application of particle tracking velocimetry (PTV) to a bed-load experiment with lightweight sediment. The key characteristics of the investigated sediment transport conditions were the presence of a covered flow and of a fixed rough bed above which particles were released in limited number at the flume inlet. Under the applied flow conditions, the motion of the individual bed-load particles was intermittent, with alternating movement and stillness terms. The flow pattern was preliminarily characterized by acoustic measurements of vertical profiles of the stream-wise velocity. During process visualization, a large field of view was obtained using two action-cameras placed at different locations along the flume. The experimental protocol is described in terms of channel calibration, experiment realization, image pre-processing, automatic particle tracking, and post-processing of particle track data from the two cameras. The presented proof-of-concept results include probability distributions of the particle hop length and duration. The achievements of this work are compared to those of existing literature to demonstrate the validity of the protocol.

LARGE-EDDY SIMULATION OF OSCILLATORY FLOW AND MORPHODYNAMICS OVER RIPPLES

The objective of the present study was to study the morphodynamical development of ripples in a movable bed. The methodology is based on the coupling of fluid flow, sediment transport and morphodynamics. A well-resolved large-eddy simulation (LES) is employed for the simulation of the three-dimensional turbulent oscillatory flow and the corresponding bed and suspended sediment transport over a rippled bed. The evolution of the bed form is obtained by the numerical solution of the Exner equation based on the spanwise-mean flow and sediment transport conditions. The Immersed Boundary method is implemented for the imposition of fluid and sediment boundary conditions on the moving bed surface. Results are presented for ripple creation and propagation from a quasi-flat bed, as well as results of initially sinusoidal ripples adapting to water conditions, based on the mobility number, ψ. The numerical model demonstrates phenomena of ripple creation, propagation and migration, resulting in ripple lengths in agreement with those predicted by empirical equations. It was shown that under the same hydrodynamic forcing, the bed tends to reach the same equilibrium state, regardless of the initial bed form.

Sediment carbon fate in phreatic karst (Part 2): Numerical model development and application

The authors develop a numerical model to elucidate time-distributed processes controlling sediment carbon fate in phreatic karst. Sediment carbon processes simulated in the new numerical model include in-conduit erosion and deposition, sediment carbon transport, surficial fine grained laminae evolution, carbon pool mixing, microbial oxidation, and the understudied process of sediment carbon exchange during equilibrium transport. The authors perform a model evaluation procedure that includes generalized likelihood uncertainty estimation to quantify uncertainty of the model results. Modeling results suggest that phreatic karst conduits sustain sediment transport activity long after surface storm events cease. The sustained sediment transport has the potential to shift the baseflow sediment yield of the phreatic karst to be on par with stormflow sediment yield. The sustained activity is suggested to promote the exchange of sediment carbon between the water column and subsurface karst deposits during equilibrium sediment transport conditions. In turn, the sediment carbon exchange impacts the mixing of new and old carbon pools and the flux of carbon from phreatic karst. Integrated numerical model results from this study support the concept that phreatic karst act as a biologically active conveyor of sediment carbon that temporarily stores sediment, turns over carbon at higher rates than surface streams, and recharges degraded carbon back to the fluvial system. The numerical modeling method adopted in this paper shows the efficacy of coupling carbon isotope fingerprinting with water quality modeling to study sediment carbon in phreatic karst.

Restoration of a boulder reef in temperate waters: Strategy, methodology and lessons learnt

Anthropogenic impacts on marine habitats are a global problem, particularly in coastal areas. While boulder reefs in temperate waters hold high biomass and biodiversity, and may be unable to recover from anthropogenic stressors without restoration efforts, little is known about how to restore and conserve this important marine habitat. Limited knowledge is a serious impediment to projects aimed at restoring boulder reefs that have been degraded or removed by substrate extraction. In 2008, a boulder reef was restored in Kattegat, the transitional waters between the North Sea and the Baltic Sea, using differently sized boulders. The restored reef covered approximately 27,600m2 seafloor and included 100,712 tons of boulders added at depths ranging between 4 and 11m. This paper describes methodology and lessons learned during the restoration project. Before the restoration, geological and geotechnical surveys confirmed that the sea bed could support added boulders, and high resolution bathymetric surveys provided input for the design of the reef, particularly for numerical modelling of the hydrographic and sediment transport conditions. Numerical modelling was used to derive hydrographic design conditions for boulder placements and further, to ensure that the restored reef would not affect the sea bed morphology and hydrographic conditions at a local harbour and at a protected habitat, both situated in the vicinity of the restoration area. Data on the physical structure of the restored boulder reef, collected in 2009, demonstrated that cavernous structures and shallow reef areas were restored. Moreover, data collected in 2012 confirmed the stability of the restored reef. Finally, results highlighted the importance of stakeholder mapping at the outset, appropriate timing of stakeholder involvement and ongoing consideration of stakeholder perceptions. Charting strategy and introducing a checklist for marine restoration projects, this paper outlines important considerations and methodology needed to ensure that restoration of temperate reef structures meet the objectives, without having undesirable effects on existing hydrographic and morphological conditions, including nearby coastal areas and protected marine habitats.