Vertical Sediment Research Articles

Fiddler crab bioturbation determines consistent changes in bacterial communities across contrasting environmental conditions

Ecosystem functions are regulated by compositional and functional traits of bacterial communities, shaped by stochastic and deterministic processes. Biogeographical studies have revealed microbial community taxonomy in a given ecosystem to change alongside varying environmental characteristics. Considering that stable functional traits are essential for community stability, we hypothesize that contrasting environmental conditions affect microbial taxonomy rather than function in a model system, testing this in three geographically distinct mangrove forests subjected to intense animal bioturbation (a shared deterministic force). Using a metabarcoding approach combined with sediment microprofiling and biochemistry, we examined vertical and radial sediment profiles of burrows belonging to the pantropical fiddler crab (subfamily Gelasiminae) in three contrasting mangrove environments across a broad latitudinal range (total samples = 432). Each mangrove was environmentally distinct, reflected in taxonomically different bacterial communities, but communities consistently displayed the same spatial stratification (a halo effect) around the burrow which invariably determined the retention of similar inferred functional community traits independent of the local environment.

Holocene Evolution of Patos Lagoon, Brazil: The Role of Antecedent Topography

Bortolin, E.; Weschenfelder, J., and Cooper, A., 2019. Holocene evolution of Patos Lagoon, Brazil: The role of antecedent topography. Journal of Coastal Research, 35(2), 357–368. Coconut Creek (Florida), ISSN 0749-0208.The Patos Lagoon in Rio Grande do Sul, Brazil, is part of the largest barrier lagoon system in the world. It is enclosed by a 400-km-long composite late Pleistocene/Holocene sandy barrier and has a single tidal inlet. The modern lagoon is shallow (average < 5 m) and is dominated by silt deposition. More than 1000 km of shallow seismic data (3.5 kHz) indicate that the lagoon is underlain by several shore-normal incised valleys separated by interfluves. Each incised valley existed as an individual estuary since its first flooding during the mid-Holocene. The infill of these valleys contains a basal fluvial unit, a central estuarine mud unit, and locally developed tidal sand bodies associated with former tidal inlets. The contemporary lagoonal sediments form a blanketing upper unit. Ultimately, the interfluves were drowned and the contemporary lagoon was formed by the coalescence of the incised valley estuarine systems in the late Holocene. This expansion of accommodation space coincided with a dramatic reduction in vertical sedimentation rates. Seismic profiling reveals the contemporary sandy spits, and their subaqueous extensions coincide with the location of former interfluves, indicating that inherited topography exerts major control over the location and development of lagoon-marginal spits.

Laboratory study of suspended sediment dynamics over a mildly sloping sandy seabed

Summary This paper presents the results of laboratory measurements of suspended sediment movement induced by regular non-linear water waves propagating over a mildly sloping sandy seabed covered with ripples. The measurements conducted in a water flume were carried out by applying the technique of particle image velocimetry (PIV). The aim of those experiments was to investigate near-bed velocities of sediment particles under controlled surface wave conditions. In particular, horizontal and vertical profiles of sand grain velocities were measured, and some comparisons between the measured and theoretically-predicted quantities were carried out. A number of selected wave cases were examined, for which the Ursell number ranged from 18 to 39, and the sediment grain mobility numbers varied between 12 and 26. For these flow conditions, the near-bed layer of intense sediment grain movements had a thickness of about 2–3 ripple heights. The maximum horizontal sediment velocities measured over ripple crests were about twice as large as those over ripple troughs. Vertical sediment velocities above ripple crests and troughs were similar, amounting to about 1/4 to 1/3 of horizontal velocities over ripple crests. The detailed quantitative results obtained in the flume can help validate other experimental techniques and can be useful in testing numerical models for simulating surface wave-induced sediment dynamics.

СКОРОСТИ ОСАДКОНАКОПЛЕНИЯ, ВЕРТИКАЛЬНЫЕ ПОТОКИ ВЕЩЕСТВА И АБСОЛЮТНЫЕ МАССЫ ОСАДКОВ В ШЕЛЬФОВОЙ ОБЛАСТИ РОССИЙСКОЙ АРКТИКИ

A new approach has been applied in the study of marine sedimentation using the scattered sedimentary material of the water column obtained by means of sediment traps (vertical sediment fluxes), in comparison with the surface layer of bottom sediments (absolute masses). This opens the possibility in situ (through sediment fluxes in the water column) to study modern sedimentation in the surface layers of sediments, and at the current technological level understand the relationship of sedimentary processes with the natural environment and climate. Opportunity to solve the inverse problem - on the velocities (or absolute masses) of precipitation is restored to restore the fluxes of matter and chemical elements in the seas of the geological past.

Constitutive simulation of a Kaolin clay with vertical and horizontal sedimentation axes

Experimental observations indicate that the mechanical behavior of clays is not only dependent on the stress and void ratio, but on its inherent anisotropy. The latter is the one arising from the material sedimentation process. In this work, the inherent anisotropy of a Kaolin clay is studied. For this purpose, soil samples are prepared with a proposed method producing samples with horizontal and vertical sedimentation axes. The samples go thru permeability tests, unconfined compression tests, oedometric compression tests and direct shear tests and the results carefully analyzed from the constitutive modeling point of view using the hypoplastic model for clays by [1]. Later, identify parameters depending on the inherent anisotropy; then perform some simulations to evaluate the model performance upon different samples with vertical and horizontal sedimentation angles. At the end, some concluding remarks are given.

Sediment Dynamics in Wind Wave‐Dominated Shallow‐Water Environments

AbstractSediment dynamics driven by waves and currents in shallow‐water estuarine environments impacts many physical and biological processes and is important to the estuary‐wide sediment budget. Observational restrictions have limited our ability to understand the physics governing sediment entrainment and mixing in these environments. To this end, we use direct numerical simulation to simulate sediment transport processes in shallow, combined wave‐ and current‐driven flows. Simulations are run with depth‐averaged currents ranging from 0 to 9 cm/s, while wave conditions are held constant with a bottom orbital velocity and period of 10 cm/s and 3 s, respectively. Our results indicated that for wave‐dominated conditions, waves reduce vertical momentum fluxes and the associated bottom drag, thereby accelerating mean currents. Conversely, currents do not significantly affect the wave velocity field. However, they increase the bed shear stress and change the timing and duration of sediment entrainment throughout the wave cycle. Counterintuitively, these effects lead to lower suspended sediment concentrations near the bed for a portion of the wave cycle. By analyzing sediment fluxes, waves are shown to drive near‐bed sediment dynamics while currents control vertical mixing above the buffer layer, where downward settling is predominantly balanced by the current‐generated vertical turbulent sediment flux. In the absence of currents, sediment concentrations are negligible above the wave boundary layer because mixing is weak. We show that the time‐ and phase‐averaged sediment concentration profiles for wave and current conditions resemble the theoretical Rouse profile derived for equilibrium conditions in statistically steady, unidirectional turbulent channel flow.

Comparative EEG characteristics in patients with neurotic and neurosis-like disorders

In the study, we describe the sedimentary dynamics in a shallow-water seagrass meadow. We examined the dynamics of vertical sedimentation flux over a Posidonia oceanica meadow during the course of a one-year investigation. Total sedimentary flux was monitored off the northern Latium coast (Italy) in the central Tyrrhenian Sea using sediment traps from October 2015 to December 2016 at three stations established on bare sand, in the P. oceanica meadow, and on a sand patch within the meadow. The traps were deployed during 11 surveys planned on the basis of the weather conditions and seagrass growth phase. The trap content was analysed for the amount of mass trapped and particle grain size, useful for describing sedimentary processes during storms. The meteorological data, P. oceanica leaf biometry, and sand patch evolution during the year were analysed to determine their relation to the vertical sedimentation flux. The resuspension process dominated the shallow-water dynamics, but P. oceanica buffers the resuspension, especially during calm sea conditions. The sedimentological tracers showed that when high energy-flow regimes were present, the vegetation near the bottom enhanced the deposition of particles transported from adjacent unvegetated areas. During late summer, leaf litter deposited on the unvegetated seafloor buffered the seabed sediment particles, preventing resuspension. We also detected the active transport of material from the sand patch to the meadow that was dependent on the energy flow regime, showing that the vegetation plays two roles: preventing resuspension and promoting deposition.

A conceptual model for groundwater discharge to a coastal brackish lagoon based on seepage measurements (Ringkøbing Fjord, Denmark)

AbstractGroundwater discharge to a brackish lagoon (Ringkøbing Fjord) was quantified with seepage meters along four transects perpendicular to the shore during four seasons in 1 year. The objectives were to develop a conceptual model of the spatiotemporal variability of seepage and how landscape characteristics and saltwater intrusion affect seepage fluxes. The electrical conductivity of the groundwater was measured in vertical sediment profiles up to 3 m below the lagoon bed to assess the effects of the freshwater–saltwater interface location on flux distribution. The main differences compared with existing theoretical models are a lower discharge near the shore line (0–5 m) and two discharge peaks more offshore (15–20 and &gt;25 m), which allowed the development of a conceptual model that is different from the classical concepts introduced for marine or lake environments and which can be representative of other similar areas. These differences are explained by the vegetation and organic material deposition in the near‐shore environment reducing discharge, the presence of the saline wedge leading to upward flow, and the increase of recirculation of brackish water due to wave pumping in areas offshore most exposed to the wind. The seasonal variability in discharge is smaller than the spatial variability between and within transects along the shoreline. Based on the conceptual model, fresh water discharge in a 20‐m‐wide fringe was calculated to be between 66 and 388 L·day−1·m−1 shore line, corresponding to a difference of a factor of six due to the variations in coast morphology and local characteristics of the area. The seasonal changes were responsible for changes of only 8% to 75% depending on the location.

Horizontal migration process of Pb in bottom waters in Jiaozhou Bay 1989

This paper quantified the horizontal migration processes of Plumbum (Pb) in Jiaozhou Bay in 1989. Results showed that Pb contents in bottom waters in April and July 1989 were 8.15-10.10 μg L-1 and 3.39-7.15 μg L-1, respectively. The pollution level of Pb in bottom waters in April and July 1989 could be considered as heavy and moderate, respectively. In April 1989, Pb contents in bottom waters from the bay center to the bay mouth were decreasing from 10.10 μg L-1 to 8.15 μg L-1, indicating that the sedimentation rate was high in the bay center, yet was low in the bay mouth. In July 1989, Pb contents in bottom waters from the bay center to the bay mouth were decreasing from 7.15 μg L-1 to 3.39 μg L-1, also indicating that the sedimentation rate was high in the bay center, yet was low in the bay mouth. By means of source input and the vertical water’s effect, the sedimentation rate in the bay center was high via the rapid vertical sedimentation process. The major source of Pb were river runoff and atmosphere deposition, the sedimentation rate in the bay mouth was low due to the water exchange. By means of the vertical water’s effect and the water exchange process, Pb contents in marine bay were changing continuously.

Vertical Sediment Concentration Distribution in High-Concentrated Flows: An Analytical Solution Using Homotopy Analysis Method

Transport of suspended sediment in open channel flow has an enormous impact on real life situations, viz. control and management of reservoir sedimentation, geomorphic evolution such as dunes, rivers, and coastlines etc. Transport entails advection and diffusion. Turbulent diffusion is governed by the concept of Fick’s law, which is based on the molecular diffusion theory, and the equation that represents the distribution of sediment concentration is the advection-diffusion equation. The study uses the existing governing equation which considers different phases for solid and fluid, and then couples the two phases. To deal with high-concentrated flow, sediment and turbulent diffusion coefficients are taken to be different from each other. The effect of hindered settling on sediment particles is incorporated in the governing equation, which makes the equation highly non-linear. This study derives an explicit closed-form analytical solution to the generalized one-dimensional diffusion equation representing the vertical sediment concentration distribution with an arbitrary turbulent diffusion coefficient profile. The solution is obtained by Homotopy Analysis Method, which does not rely on the small parameters present in the equation. Finally, the solution is validated by comparing it with the implicit solution and the numerical solution. A relevant set of laboratory data is selected to check the applicability of the model, and a close agreement shows the potential of the model in the context of application to high-concentrated sediment-laden open channel flow.

Turbulent bursting and sediment resuspension in hyper-eutrophic Lake Taihu, China

Turbulent bursting plays a crucial role in sediment resuspension and transportation in many shallow lakes. This study analyzed the relationships between coherent structures and sediment resuspension in regions with and without intense wind waves in Lake Taihu. Acoustic Doppler Velocimetry (ADV) and Optical Backscatter Sensor (OBS) were used to measure field data sets including flow velocities and intense wind waves respectively. The results showed that the intermittent bursting events contributed significantly to the processes of momentum and sediment exchanges. Turbulent bursting effectively controlled the three patterns of sediment suspension during the 512 s observation period. In the windy region, the bursting motions, i.e. “ejection” and “sweep” events mainly accounted for the Reynolds stress generation and made major contribution to sediment resuspension. While in the current-dominant region, turbulent mixing from inward and outward interactions overwhelmed other processes. The vertical sediment fluxes reduced by an order of magnitude due to the less effect of wind waves and the lack of upwelling currents. It is therefore important to study turbulent coherent structures and sediment resuspension to understand the spatio-temporal and frequency characteristics of bursting events.

Geochemistry and distribution of sediments in the East Indian shelf, SW Bay of Bengal: implications on weathering, transport and depositional environment

Forty-two substrate sediment samples and three cores procured from the shelf region between Chennai and Cuddalore were analyzed to understand the spatial and vertical sediment distribution. Samples subjected to grain size, bulk and clay mineralogical analyses, REE and trace element geochemistry yielded interesting results about the sediment characteristics with respect to the modern day environment. The present study revealed that the study area is characterized by high energy environment marked by predominant composition of medium sand. Results confirmed the evidence of more illite than kaolinite, smectite, and chlorite in the clay mineral assemblage indicating a terrigenous source. Geochemical data also revealed that the enrichment of light rare earth elements (LREE) in the sediments is due to continental source of Precambrian times. High feldspar content in the sediments which is emphasized by bulk mineralogical data displayed positive Eu anomaly. By using the paleoredox index, the area of interest is considered to have undergone no major changes in its depositional settings.

Vertical sediment migrations of dominant midge species in subtropical lakes with implications for bioassessment

Propsilocerus akamusi (Diptera: Chironomidae) is a dominant species in numerous eutrophic lakes and they could burrow into deep sediments (>30 cm) during summer months. However, common-used grab samplers are efficient in collecting surface-dwelling species (<20 cm), thus vertical migrations of dominant species may interfere bioassessment. Here, we monthly investigated the vertical sediment positioning of P. akamusi larvae and its influence on bioassessment. Our results indicated that, from late-April to October, most individuals aestivated at the sediment below 30 cm depth which maybe an adaptation to the thermal stress. As to other periods, the larvae were generally found in the depth of 10–30 cm. Moreover, Peterson grab samples collected only 0% and 12.6% of total P. akamusi individuals in summer and late-autumn, respectively, resulting in serious underestimation of the actual pollution status. This implied that vertical movements of dominant macroinvertebrates should be taken into account when designing of bioassessment protocols. For P. akamusi, Core-sampling for calibration were strongly encouraged, and the low-temperature period for Grab-sampling is also proposed.

Sediment dynamics and resuspension processes in a shallow-water Posidonia oceanica meadow

In the study, we describe the sedimentary dynamics in a shallow-water seagrass meadow. We examined the dynamics of vertical sedimentation flux over a Posidonia oceanica meadow during the course of a one-year investigation. Total sedimentary flux was monitored off the northern Latium coast (Italy) in the central Tyrrhenian Sea using sediment traps from October 2015 to December 2016 at three stations established on bare sand, in the P. oceanica meadow, and on a sand patch within the meadow. The traps were deployed during 11 surveys planned on the basis of the weather conditions and seagrass growth phase. The trap content was analysed for the amount of mass trapped and particle grain size, useful for describing sedimentary processes during storms. The meteorological data, P. oceanica leaf biometry, and sand patch evolution during the year were analysed to determine their relation to the vertical sedimentation flux. The resuspension process dominated the shallow-water dynamics, but P. oceanica buffers the resuspension, especially during calm sea conditions. The sedimentological tracers showed that when high energy-flow regimes were present, the vegetation near the bottom enhanced the deposition of particles transported from adjacent unvegetated areas. During late summer, leaf litter deposited on the unvegetated seafloor buffered the seabed sediment particles, preventing resuspension. We also detected the active transport of material from the sand patch to the meadow that was dependent on the energy flow regime, showing that the vegetation plays two roles: preventing resuspension and promoting deposition.

Modeling of sediment transport in a saltwater lake with supplemental sandy freshwater.

Considering the highly complex flow structure of saltwater lakes during freshwater supplementation, a three-dimensional numerical model was developed to simulate suspended sediment transport in saltwater lakes. The model was validated using measurements of the salinity and sediment concentration during a pumping test at Yamdrok Lake. The simulation results were in quantitative agreement with the measured data. The observed and simulated results also indicated that the wind stress and vertical salinity gradient have a significant influence on salinity and sediment transport in a saltwater lake. The validated model was then used to predict and analyze the contributions of wind, the supplement flow rate and salinity stratification to the sediment transport process in Yamdrok Lake during continuous river water supplementation. The simulation results showed that after the sandy river water was continuously discharged into the saltwater lake, the lateral diffusion trends of the sediment exhibited three stages: linear growth in the inflow direction, logarithmic growth in the wind direction, and stabilization. Furthermore, wind was the dominant factor in driving the lake flow pattern and sediment transport. Specifically, wind can effectively reduce the area of the sediment diffusion zone by increasing the lateral sediment carrying and dilution capacities. The effect of inflow on the lake current is negligible, but the extent of the sediment turbidity zone mainly depends on the inflow. Reducing the inflow discharge can decrease the area of the sediment turbidity zone to proportions that far exceed the proportions of inflow discharge reductions. In addition, the high-salinity lake water can support the supplemented freshwater via buoyancy forces, which weaken vertical mixing and sediment settlement and increase lake currents and sediment diffusion near the surface.

Progress in the Study of Coastal Storm Deposits

Numerous studies have been carried out to identify storm deposits and decipher storm-induced sedimentary processes in coastal and shallow-marine areas. This study aims to provide an in-depth review on the study of coastal storm deposits from the following five aspects. 1) The formation of storm deposits is a function of hydrodynamic and sedimentary processes under the constraints of local geological and ecological factors. Many questions remain to demonstrate the genetic links between storm-related processes and a variety of resulting deposits such as overwash deposits, underwater deposits and hummocky cross-stratification (HCS). Future research into the formation of storm deposits should combine flume experiments, field observations and numerical simulations, and make full use of sediment source tracing methods. 2) Recently there has been rapid growth in the number of studies utilizing sediment provenance analysis to investigate the source of storm deposits. The development of source tracing techniques, such as mineral composition, magnetic susceptibility, microfossil and geochemical property, has allowed for better understanding of the depositional processes and environmental changes associated with coastal storms. 3) The role of extreme storms in the sedimentation of low-lying coastal wetlands with diverse ecosystem services has also drawn a great deal of attention. Many investigations have attempted to quantify widespread land loss, vertical marsh sediment accumulation and wetland elevation change induced by major hurricanes. 4) Paleostorm reconstructions based on storm sedimentary proxies have shown many advantages over the instrumental records and historic documents as they allow for the reconstruction of storm activities on millennial or longer time scales. Storm deposits having been used to establish proxies mainly include beach ridges and shelly cheniers, coral reefs, estuary-deltaic storm sequences and overwash deposits. Particularly over the past few decades, the proxies developed from overwash deposits have successfully retrieved many records of storm activities during the mid to late Holocene worldwide. 5) Distinguishing sediments deposited by storms and tsunamis is one of the most difficult issues among the many aspects of storm deposit studies. Comparative studies have investigated numerous diagnostic evidences including hydrodynamic condition, landward extent, grain property, texture and grading, thickness, microfossil assemblage and landscape conformity. Perhaps integrating physical, biological and geochemical evidences will, in the future, allow unambiguous identification of tsunami deposits and storm deposits.

The effects of intensive aquaculture on nutrient residence time and transport in a coastal embayment

Aquaculture in many countries around the world has become the biggest source of seafood for human consumption. While it alleviates the pressure on wild capture fisheries, the long-term impacts of large-scale, intensive aquaculture on natural coastal systems need to be better understood. In particular, aquaculture may alter habitat and exceed the carrying capacity of coastal marine ecosystems. In this paper, we develop a high-resolution numerical model for Sanggou Bay, one of the largest kelp and shellfish aquaculture sites in Northern China, to investigate the effects of aquaculture on nutrient transport and residence time in the bay. Drag from aquaculture is parameterized for surface infrastructure, kelp canopies, and bivalve cages. A model for dissolved inorganic nitrogen (DIN) includes transport, vertical turbulent mixing, sediment and bivalve sources, and a sink due to kelp uptake. Test cases show that, due to drag from the dense aquaculture and thus a reduction of horizontal transport, kelp production is limited because DIN from the Yellow Sea is consumed before reaching the interior of the kelp farms. Aquaculture drag also causes an increase in the nutrient residence time from an average of 5 to 10 days in the middle of Sanggou Bay, and from 25 to 40 days in the shallow inner bay. Low exchange rates and a lack of DIN uptake by kelp make these regions more susceptible to phytoplankton blooms due to high nutrient retention. The risk is further increased when DIN concentrations rise due to river inflows.

Measurement of Sediment Concentration of the Oscillatory Flow in the Surf- and Swash-zone

Wang, J.; Qu, Z.; Xu, Z.; Shim, J.S.; Liang, B., and Lee, D.Y., 2018. Measurement of Sediment Concentration of the Oscillatory Flow in the Surf- and Swash-zone.. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1231–1235. Coconut Creek (Florida), ISSN 0749-0208.The sediment transports near the bed need to be accurately observed to validate the existing models that are based on the empirical formula for the sediment flux and to develop more realistic morphology prediction model. One of the essential tasks for the evaluating the existing models and developing new one is the precise measurement of the sediment transport at swash zone without disturbing flow. Different methods in estimating the sediment transport rates at the surf-zone and swash-zone such as measuring the time evolution of the bed profile, sand ripple volume and migration speed are investigated and evaluated. To develop more reliable estimation of the sediment flux by measuring the vertical profiles of sediment concentration and velocity without disturbing the flow conditions, method of estimation of the vertical sediment concentration profile by detecting the backscattered light intensity using high quality camera was tested and evaluated. The problems of different methods in estimating the sediment flux are identified and discussed.

Aeolian sediment transport on a recovering storm‐eroded foredune with sand fences

AbstractStudies of sediment transport on developed coasts provide perspective on how human adjustments alter natural processes. Deployment of sand‐trapping fences is a common adjustment that changes the characteristics of the dune ramp and its role in linking sediment transfers from the backshore to the foredune. Fence effects were evaluated in the field using anemometer arrays and vertical sediment traps placed across a beach and dune at Seaside Park, New Jersey, USA during onshore and longshore winds. The foredune is 18 m wide and 4.5 m above the backshore. The mean speed of onshore winds at 0.5 m elevation decreased by 17% from the berm crest to the upper ramp and 36% in the lee of a fence there. Sediment transport during mean wind speeds up to 8.0 m s−1 at 0.5 m elevation was &lt; 0.06 kg m−1 h−1 on the berm crest and backshore where fetch distances were &lt; 45 m and surface sediment was relatively coarse (0.74–0.85 mm) but increased to 5.63 kg m−1 h−1 on the upper ramp aided by the longer fetch distances (up to 82 m) and finer grain size of the source sediment there (0.52 mm). Sediment transport along the berm crest and backshore during longshore winds, where fetch distances were &gt; 200 m, was up to 58.69 kg m−1 h−1, about three orders of magnitude greater than during the onshore winds. Fences can displace the toe of the ramp farther seaward than would occur under natural conditions. They can create a gentler slope and change the shape of the ramp to a more convex form. A fence on the ramp can cut off a portion of sediment supply to the upper slope. Decisions about fence placement thus should consider these morphologic changes in addition to the effects on dune volume. Copyright © 2017 John Wiley &amp; Sons, Ltd.

A Study of Nutrient Distribution in Sediment Layer at Sembrong Dam

Reservoir is one of the key sources of water supply as it provides hydroelectric power, domestic usage, agriculture, farming, recreation and provides flood protection. Sedimentation in the reservoir makes the storage of water loss and the sediment sink contain a source of nutrients. Sediment deposition creates habitats for aquatic life but if too much sediment, it can destroy their habitats and even physically alter a waterway. The use of nutrients such as Total Phosphorus (TP) is key to growing plants and animals thus to feed growing populations. An excess of nutrients in the reservoir such as from agricultural activity makes algae growth rapidly and it can affected the water quality in the reservoir. This research was conducted at the Sembrong dam as this dam is a major water source for people in Kluang and parts Batu Pahat and the water quality become decreased because of algae bloom. The main objective of this study is to determine the distribution of nutrient in different location and to determine the nutrient distribution in vertical sediment layer. The study were conducted by taking sediments samples throughout the reservoir by using sediment corer and the sediment have been sliced every 5 cm. The samples were digested using USEPA Method 3050B which is acid digestion for sediments, sludge and soil for TP. The laboratory testing on these nutrients was conducted by following Standard Method for the Examination of Water and Wastewater (APHA, 1999) using spectrophotometer. The highest value of TP obtain is at outlet of the reservoir which is 30.72 mg/l. The results obtained shows that the top of sediment has high number of TP and it decreasing by depth. However, continuous and periodic monitoring should be done to avoid the increasing of the concentration of TP in the sediment to ensure the life of Sembrong dam can be extending for future.