WASER

International Journal of Sediment Research
Volume 32, No. 4, Pages 465-606 (December 2017)

Cover image International Journal of Sediment Research

Processes of dike-break induced flows: A combined experimental and numerical model study
Pages 465-471
Jian Sun, Lingwei Lu, Binliang Lin, Lu Liu

Maintaining the connected river-lake relationship in the middle Yangtze River reaches after completion of the Three Gorges Project
Pages 487-494
Xiuying Wang, Xiang Li, Baiyinbaoligao, Yihong Wu

Shoreline management plan for a protected but eroding coast along the southwest coast of India
Pages 495-505
Varangalil Noujas, Kachapally Varghese Thomas, Nalumakkal Raveendran Ajeesh

Impact of the Three Gorges Project operation on the water exchange between Dongting Lake and the Yangtze River
Pages 506-514
Minglong Dai, Jun Wang, Mingbo Zhang, Xi Chen

Predicting characteristics of dune bedforms using PSO-LSSVM
Pages 515-526
Kiyoumars Roushangar, Seyed Mahdi Saghebian, Dominique Mouaze

Predicting the effects of sediment based internal nutrient loads on eutrophication in Küçükçekmece Lagoon for rehabilitation planning
Pages 527-554
Cenk Gürevin, Ali Erturk, Meric Albay

Estimation of bedload discharge in sewer pipes with different boundary conditions using an evolutionary algorithm
Original research article
Kiyoumars Roushangar, Roghayeh Ghasempour

An analysis of shear stress distribution in circular channels with sediment deposition based on Gene Expression Programming
Pages 575-584
Zohreh Sheikh Khozani, Hossein Bonakdari, Isa Ebtehaj

Development and validation of a morphological model for multiple sediment classes
Pages 585-596
Guilherme Franz, Paulo Leitão, Lígia Pinto, Eduardo Jauch, ... Ramiro Neves

Geologic framework as a factor controlling coastal morphometry and dynamics. Curonian Spit, Lithuania
Pages 597-603
Darius Jarmalavičius, Gintautas Žilinskas, Donatas Pupienis

Full papers are available at ScienceDirect:

http://www.sciencedirect.com/science/journal/10016279, with free access of the abstracts.

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Processes of dike-break induced flows: A combined experimental and numerical model study
Pages 465-471
Jian Sun, Lingwei Lu, Binliang Lin, Lu Liu
Abstract
Dike breaking is a disaster that could cause extensive damage. It could lead to flood flows outside the dike and induce water level fluctuations in the main channel. Numerical models are increasingly used to simulate flood flows due to dike-break, because direct observations from field surveys and physical models are rather limited. Existing knowledge concerning dam-break flows cannot be applied directly to dike-break flows because the effect of channel discharge cannot be neglected in the latter. In this study, physical experiments are done in a large laboratory flume to simulate the process of dike-break induced flood wave propagation in the floodplain and flow fluctuations in the main channel. The variations of water levels and velocities are measured and recorded using an array of pressure sensors and two acoustic Doppler velocimetry devices. A numerical model has been set up according to the experimental layout. The experiments have high repeatability and the numerical model predictions agree closely with the physical model data. The experimental results provide reliable information for improving the understanding of dike-break flow dynamics and for the verification of numerical models.

Relationship between apparent redox potential discontinuity (aRPD) depth and environmental variables in soft-sediment habitats
Pages 472-480
Travis G. Gerwing, Alyssa M. Allen Gerwing, Kieran Cox, Francis Juanes, Sarah E. Dudas
Abstract
As global temperatures increase and dissolved oxygen (DO) content decreases in marine systems, indices assessing sediment DO content in benthic habitats are becoming increasingly useful. One such measure is the depth to the apparent redox potential discontinuity (aRPD), a transition of sediment color that serves as a relative measure of sediment DO content. We examined spatiotemporal variation of aRPD depth, and the nature of the relationships between aRPD depth and biotic (infauna and epibenthic predators) and abiotic variables (sediment properties), as well as the availability of resources (chlorophyll a concentration, and organic matter content) in the intertidal mudflats of the Bay of Fundy, Canada. aRPD depth varied significantly through space and time, and a combination of biotic (sessile and errant infauna, as well as epibenthic predators), and abiotic (exposure time of a plot, sediment particle size, penetrability, and water content) variables, as well as the availability of resources (sediment organic matter content, and chlorophyll a concentration) were correlated with aRPD depth. As such, knowledge of both biotic and abiotic variables are required for a holistic understanding of sediment DO conditions. Abiotic variables likely dictate a suite of potential aRPD depth conditions, while biota and resource availability, via bioturbation and respiration, strongly influence the observed aRPD depth. As DO conditions in marine systems will continue to change due to global climate change, elucidating these relationships are a key first step in predicting the influence decreasing DO content may have upon marine benthos.

Characterization of phosphorus interaction with sediments affected by acid mine drainage - relation with the sediment composition
Pages 481-486
Lamia Boukemara, Chahrazed Boukhalfa, Sarah Azzouz, Laurence Reinert, ... Anthony Szymczyk
Abstract
Phosphorus sorption capacity was investigated in surface sediments derived from an abandoned zinc-lead mine area located in northeastern Algeria. The forms and the distribution of phosphorus in the raw sediment were identified using the sequential chemical extractions method. Batch experiments were done to study the adsorption kinetics and isotherms. The pH effect was evaluated by macroscopic and infrared analyses. In raw sediment, speciation results show that phosphorus is dominantly bound to oxyhydroxides. Sorption experiments demonstrate that phosphorus uptake is principally related to sediment composition. The nature of the dominant iron oxyhydroxide has a substantial role in the adsorption capacity and the mechanism interaction. The adsorption kinetics can be described by the second order and Elovich models. The isotherms data are successfully modeled by the Temkin equation. The maximum phosphorus removal is reached under acidic pH. Spectroscopic analyses reveal that the predominance of jarosite implies electrostatic interaction with sediment particles. However, in the case of schwertmannite predominance, phosphate ions are adsorbed by the ligand exchange mechanism.

Maintaining the connected river-lake relationship in the middle Yangtze River reaches after completion of the Three Gorges Project
Pages 487-494
Xiuying Wang, Xiang Li, Baiyinbaoligao, Yihong Wu
Abstract
After operation of the Three Gorges Project (TGP), there is a new evolution tendency for rivers and lakes in the middle reaches of the Yangtze River (i.e. the Ching River reaches). In recent years, the weakening connection relationship between the Yangtze River and Dongting Lake has resulted in a series of problems for flood regulation, water resources utilization, and aquatic ecosystem protection in the river-lake joint area. In this paper, the hydrological characteristics and fluvial processes within the river-lake joint area are studied, and possible management strategies to maintain the connected river-lake relationship are proposed. To achieve this objective, the evolution tendency, such as the zero-flow problem and river regime for three major outlets (i.e. the Songzi Outlet, Taiping Outlet, and Ouchi Outlet) to Dongting Lake from the Yangtze River, is analyzed. It is believed that the Songzi Outlet has a comparative advantage in flow diversion over the other two outlets. The Range of Variability Approach is introduced to identify hydrological characteristics at the Songzi Outlet. Several characteristic values of flow diversion from this outlet during drought periods are determined. Then, the fluvial processes in the river-lake joint area are studied by comparing topographic maps and using control gauge station data of various years. The water and sediment flux are analyzed before and after operation of the TGP. Finally, based on the results obtained, two possible management strategies are recommended and corresponding parameters are estimated to strengthen and maintain the connected river-lake relationship. This analysis takes into account operation of the TGP, mainstream shift and increasing riverbed scour in the Ching River channel. To restore the flow diversion condition to that in the 1950s or 1960s (i.e. 140 m3/s of flow diversion corresponding to 5500 m3/s of flow at the Zhicheng station), it is estimated that the river channel around the Songzi Outlet should be dredged 1.4 m under the current riverbed situation, and other corresponding improvement measures for Songzi River channels should also be implemented.

Shoreline management plan for a protected but eroding coast along the southwest coast of India
Pages 495-505
Varangalil Noujas, Kachapally Varghese Thomas, Nalumakkal Raveendran Ajeesh
Abstract
Coastal erosion is a serious problem of concern along the southwest (SW) coast of India. Various coastal protection measures have been applied for the recovery of the coast, but the devastating effect of erosion still continues. The present study focuses on a coastal stretch situated on the southern sector of the SW coast of India, where Sundar and Sannasiraj (2006) proposed a groyne field along with an existing seawall to control severe erosion. In order to confirm the net littoral drift of this region and for a preliminary assessment of the performance of the groynes prior to construction of the proposed groyne field, two groynes were initially constructed as a pilot program in 2008-09. Periodic monitoring of shoreline position with the two groynes in place was carried out during 2009-14. A shoreline evolution model for the study region was setup, calibrated, and validated using field observations during 2010-11. In addition to traditional shoreline evolution modelling procedures, a profile simulation model was applied for simulating the shoreline behaviour during extreme monsoon seasons. The validated LITPACK model has been used to evaluate the performance of the proposed groyne field in controlling erosion, and the study also considered testing a modified transitional groyne field proposed as an alternative solution to the existing problem, and the modified transitional groyne field was found to be more effective than the prior design. A beach is expected to develop about 30–50 m within the groyne cells during the fair season which enhances the possibility of retaining a minimum beach width of 10 m during monsoon periods.

Impact of the Three Gorges Project operation on the water exchange between Dongting Lake and the Yangtze River
Pages 506-514
Minglong Dai, Jun Wang, Mingbo Zhang, Xi Chen
Abstract
The Three Gorges Project (TGP) is a world known project to utilize and manage the water resources of the Yangtze River. The reservoir stores water at the end of the flood season, and replenishes downstream reaches with water in dry seasons. In addition to such benefits, the TGP has irreversibly changed the hydrological process and the river-lake relation of the middle and lower reaches. In this paper, a hydrodynamic model was established to quantify the impact of the TGP׳s operation on the water exchange between Dongting Lake and the Yangtze River during 2009–2013. The results indicated that: the operation of the TGP has considerably reduced the peak discharge and the flood volume of the main stream and the Dongting Lake area. The inflow volume from the Yangtze River to Dongting Lake via three outlets decreased by 1.9–3.5 billion m3/yr, while the outflow volume from Dongting Lake to the Yangtze River at Chenglingji increased by 0.3–1.6 billion m3 in September and 0.4–0.6 billion m3 in October, respectively. This research provides valuable information for flood control, irrigation, and water allocation in the middle and lower reaches of the Yangtze River, and serves as a typical case for investigating the impact of other hydropower projects around the world.

Predicting characteristics of dune bedforms using PSO-LSSVM
Pages 515-526
Kiyoumars Roushangar, Seyed Mahdi Saghebian, Dominique Mouaze
Abstract
Dunes have a large influence on hydraulic roughness, and, thereby, on water levels which could affect the navigability of rivers and performance of hydraulic structures. The present study investigated the variation of geometric and topographic characteristics of dune bedforms and flow features as measured in laboratory studies (data sets from laboratory experiments) to estimate the roughness coefficient and characteristics of dune height. The Least Squares Support Vector Machine (LSSVM), which was optimized using Particle Swarm Optimization (PSO), was used as the Meta model approach to predict the values of interest. Developed models were separated into three categories: modeling using flow characteristics, modeling of flow and bedform characteristics, and modeling by using flow and sediment characteristics. It was found that for estimation of the roughness coefficient in open channels with dune bedforms, models developed based on flow and sediment characteristics performed more successfully. The model with input parameters of flow and grain Reynolds numbers (Re and Rb, respectively) and the ratio of the hydraulic radius (R) to the median grain diameter (D50) yields a squared correlation coefficient (R2) of 0.8609, a coefficient of determination (DC) of 0.7361, and a root mean square error (RMSE) of 0.0034 for a test series of Manning's roughness coefficient which was the most accurate model. Results proved the key role of flow Reynolds number (Re) values as an input feature for all models predicting the roughness coefficient. Accordingly, classic approaches led to poor results in comparison. On the other hand, results obtained for estimated values of relative dune height led to moderate prediction quality, which albeit, outperformed classic approaches.

Predicting the effects of sediment based internal nutrient loads on eutrophication in Küçükçekmece Lagoon for rehabilitation planning
Pages 527-554
Cenk Gürevin, Ali Erturk, Meric Albay
Abstract
In deep stratified coastal lagoons, hypoxic waters that result from phytoplankton decomposition in the stratified bottom waters are often associated with eutrophication. Decomposing biomass reaches the bottom sediments and enriches them with nutrients and organic matter. Nutrients trapped in sediments are released with time and promote excessive phytoplankton growth in the surface water. Because eutrophication in lentic ecosystems progresses in a self-fuelling cycle, outflow is the only available process for exporting excess nutrients to recover from eutrophication. Thus, rehabilitation of eutrophic coastal lagoons that have limited seawater interactions is a long term process. The importance of nutrient release from sediments on eutrophication and the delay effect of internal nutrient loading on the rehabilitation of a eutrophic coastal lagoon with limited seawater exchange were analysed in this study. An ecological model that couples the water column and the sediment diagenesis processes, was developed for water quality management purposes. Our findings indicate that the recovery of the Lagoon from eutrophication will be taken decades even in the absence of external nutrient loading. Therefore, we suggest applying rehabilitation strategies that control the nutrient fluxes from sediments for a faster recovery from heavily eutrophic conditions. Land-based nutrient sources must also be controlled because they feed water column and the bottom sediments with nutrients.

Impacts of urban headwater disturbances on downstream sediment loading where streamside management zones for forest harvesting activities are present downstream
Pages 555-563
Ilkim Cavus, Latif Kalin, Ferhat Kara
Abstract
Watershed disturbances caused by land use/land cover (LU/LC) change, intensive forestry practices, and other forms of watershed disturbance are known to negatively affect water quality, if best management practices (BMPs) are not present. Disturbances near or around headwaters where BMPs are absent or are inadequate may impact downstream water quality and stream ecology regardless of the presence of downstream BMPs. In this study, the recovery of two small forest-dominated watersheds (WW and EW) in Auburn, Alabama, USA, was monitored 6-years after a partial clearcut was done. The streamside management zone (SMZ) in WW was also partially harvested shortly after the partial clearcut to improve its sediment trapping effectiveness over the long-term. The hydrology and sediment transport in these watersheds were expected to stabilize over this period, however, new disturbances in the headwaters of both watersheds changed the watershed dynamics. Streamflow and sediment load were examined over a 15-month period from February 2014 to May 2015. The clearcut in WW and EW, and the partially harvested SMZ in WW seemed to have recovered; however, substantial amount of sediment load were measured across all monitoring sites in both watersheds as a result of upstream disturbances. This study emphasizes the necessity of watershed management as a whole, and the importance of BMP applications within the entire watershed. It also highlights the fact that watershed management and BMP implementation is a dynamic process, thus, strategies and techniques need to be continuously adapted in response to environmental changes.

Estimation of bedload discharge in sewer pipes with different boundary conditions using an evolutionary algorithm
Original research article
Kiyoumars Roushangar, Roghayeh Ghasempour
Abstract
Sediment transport is a complex phenomenon due to the nonlinearity and uncertainties of the process. The present study applies Gene Expression Programming (GEP) to develop bedload transport models in sewer pipes. In this regard, two types of bedload were considered: loose bed (deposition state) and rigid bed (limit of deposition state). In order to develop the models, two scenarios with different input combinations were considered: Scenario 1 considers only hydraulic characteristics and Scenario 2 considers both hydraulic and sediment characteristics as inputs for modeling bedload discharge. The results proved the capability of GEP in prediction of sediment transport and it was found that for prediction of bedload transport in sewer pipes Scenario 2 performed more successfully than Scenario 1. According to the outcome of sensitivity analysis, Frm (Modified Froude number) and d50/y (relative particle size) for rigid boundary and Frm for loose boundary had key roles in the modeling. The outcome of the GEP models also was compared with existing empirical equations and it was found the GEP models yielded better results. It was also found that pipe diameter affected the transport capacity of the sewer pipe. Increasing pipe diameter caused an increase in model efficiency. A pipe with a diameter of 305 mm yielded to the best results.

An analysis of shear stress distribution in circular channels with sediment deposition based on Gene Expression Programming
Pages 575-584
Zohreh Sheikh Khozani, Hossein Bonakdari, Isa Ebtehaj
Abstract
Knowledge of the boundary shear stress distribution in channels is important because it is a key factor affecting on erosion and sedimentation rates. The presence of sediment deposits in sewers is often reported during operation, and circular channels are frequently used in sewer networks. Gene expression programming (GEP) is applied in this study to determine an equation for evaluating the shear stress distribution along the wetted perimeter of a circular channel with a flat bed, because of the presence of sediment on the bed. In view of the parameters affecting the shear stress distribution, five dimensionless parameters are applied to develop six GEP models to be used with 905 experimental data. The impact of the shear stress parameters is studied using the six GEP models and by dividing the wetted perimeter into wall and bed sections. Two equations are extracted from the GEP models’ output to estimate wall and bed shear stresses. The best model results are compared with a well-known equation based on the entropy concept. The GEP model predictions of wall and bed shear stresses are very similar to the experimental outcomes, whereas the entropy-based model overestimates the shear stress distribution. The proposed GEP models demonstrate superior performance in estimating the shear stress distribution with a mean absolute percentage error (MAPE) of 3.79% compared to an existing equation with MAPE of 9.52%.

Development and validation of a morphological model for multiple sediment classes
Pages 585-596
Guilherme Franz, Paulo Leitão, Lígia Pinto, Eduardo Jauch, ... Ramiro Neves
Abstract
The complexity of sediment dynamics in aquatic systems can be better understood by applying numerical models. The development of a comprehensive morphological model is presented in this paper. The model aims to predict the sediment transport and bed evolution in natural systems composed of different sediment types. The morphological model was implemented in MOHID, a modelling system that solves the three-dimensional hydrodynamics and advection-diffusion transport of suspended sediments. Multiple sediment classes were taken into account (non-cohesive and cohesive) considering the effects of sediment mixtures and bed consolidation on resistance to erosion. To represent bottom stratigraphy, the bottom column can be divided into several layers. The key points of the simulated processes are discussed in this paper. Model results are assessed in six test cases through comparison with analytic solutions or experimental data. The outcomes demonstrate the model׳s capacity to simulate the transport dynamics of non-cohesive and cohesive sediments. The speed up of morphological changes by an acceleration factor permitted modelling bed evolution for long time periods. Moreover, a test case for the Tagus Estuary demonstrated the model׳s capacity for generating realistic sediment distribution based on the local hydrodynamic conditions. Limitations in the availability of bed composition data can be overcome by considering a warm-up run to provide realistic initial conditions for further predictions of morphological developments.

Geologic framework as a factor controlling coastal morphometry and dynamics. Curonian Spit, Lithuania
Pages 597-603
Darius Jarmalavičius, Gintautas Žilinskas, Donatas Pupienis
Abstract
The geologic framework is an important factor worth consideration when analyzing the development of seacoasts. The different coastal responses to hydrometeorological and anthropogenic factors depend on the composition and amount of original coast-forming sediments. The impact of sediment composition on morphometric parameters is best observed in areas where sand unrepresentative of the adjacent coastal sectors appears on beaches with a relatively uniform lithological composition. These areas are referred to as lithological anomalies. Large amounts of coarse-grained sand, uncharacteristic of the adjacent coastal sectors of the Curonian spit, accumulated in the area of the strait that existed in the Post-Littorina Late Subboreal (3.7–2.5 ka BP) time south of the Juodkrantė settlement. Due to accumulation of coarse sand, the beach in this sector is narrow and has a higher slope, and the ridge is lower and with a smaller volume of sand than in the adjacent coastal sectors. The specific sand composition and morphology of this coastal sector are responsible for different coastal dynamics during storms. During extreme storms, beach erosion in this coastal sector is minimal (sometimes even accretion takes place) compared with other sectors where beach erosion is rather substantial. Meanwhile, during periods of relatively calm weather, i.e. times of expected regeneration of the cross profile, this sector stands out for active erosion processes.

Discussion on “Representative sediment sizes in predicting the bed-material load for nonuniform sediments” by Wan Hanna Melini Wan Mohtar, Junaidi, Suraya Sharil, Muhammad Mukhlisin [Int. J. Sed. Res. 31 (2016) 79–86]
Pages 604-605
Fabian Friedl, Volker Weitbrecht
Abstract
In this discussion, we want to highlight the important findings of the last two decades by Hunziker and Jäggi (2002) and Wong and Parker (2006), among others, who reanalyzed and revised the original data forming the basis of the MPM sediment transport equation. Furthermore, by using an actual adaptation of the original MPM formula, the prediction of the sediment transport rate for the data given in the paper under discussion seems to be acceptable.