Water Mixing Processes Research Articles

Marmara Sea waters with the Mediterranean origin in the formation of the salinity and dynamics fields in the Black Sea

The peculiarities of the bottom of the central basin of the Black Sea are specified, and four depression zones with maximum depths of 2170, 2210, 2171 and 2140 m were allocated for the first time, as well as the positions of the focuses of maximum salinity in the Black Sea water column in a long-term climatic plan. The presence of three foci of maximum salinity in the water column, which are connected with the bottom depressions in the central Black Sea basin, and two similar foci which are located in the coastal areas of the sea (SW ― the Bosphorus and SE ― the Batumi-Trabzon area), was determined with the field of factual average annual salinity. In the fields of salinity extremes, there are 4 foci of maximum salinity in the central basin of the sea and two ones in the SW and SE sea coastal areas. The nature of their occurrence and permanent existence was explained by the entry of highly salted Marmara Sea waters of Mediterranean origin into the bottom layers of the Black Sea and their further intrusion from the depths to the surface because there are no other sources of high-saline waters. The up-welling vertical movements that occur during the intrusion of water from the depths into the overlying layers are interacted with the Coriolis force and are led to the formation of horizontal cyclonic circulation in high salinity cupolas. This process develops and exists in the entire water column.The differences are established in the vertical distribution of average and extreme salinity. Well-defined disturbances caused by water mixing processes are traced in the curves of salinity extremes: in the field of minimal salinity they are located at horizons from 300 to 1200 m with the formation of even a homogeneous layer of water at depths of 500―600 m; in the field of maximum salinity, a abrupt decrease in the gradient at the horizon of 400―500 m, as well as the formation of a homogeneous layer of water at depths of 800―1000 m.

SCR 시스템의 믹서 및 요소 수용액 분사각도가 유동 혼합에 미치는 영향

For efficient reduction of nitrogen oxides in selective catalytic reduction systems, the injected urea water solution must be converted almost 100% to ammonia for a short time. This paper presented the effects of mixer configuration on the urea water solution evaporation and mixing process in a selective catalytic reduction system, using numerical analysis tool of ANSYS FLUENT R15.0. The results of numerical analysis were compared to experimental results for verifying the numerical reliability. Compared to the case without the mixer, in case of the vane type mixer was installed, the conversion rate of NH₃ increased by 21.4% and uniformity by 48.9%. In addition, when the injection angle of the urea-water-solution was 45° based on the exhaust gas flow direction, the conversion rate of NH3 was highest as 89.0%, and the uniformity was highest as 52.5% at 15°. In this study, proposed a method to convert urea solution rapidly, and it is expected that this results could be used to reduce ammonia slip in SCR systems.

Estimation of apparent water age and mixing process of water in the creek ecosystem of Mumbai Harbour Bay

Short-lived Ra isotopes (224Ra and 223Ra) were used to estimate the apparent water age and mixing process, in the creek ecosystem of Mumbai Harbour Bay. The apparent water age was estimated using the Radium Age Model and the Radium Balance Approach. The apparent water age for three different sampling trips in the creek varies from 3.65 ± 1.22 to 4.51 ± 1.51 days using the Radium age model. Whereas using the Radium Balance Approach in the creek, the apparent water age was estimated to be 6.51 ± 1.67 days. Similar apparent water age from both approaches was found for the creek ecosystem under steady state. The longitudinal variation of the 224Ra and 223Ra activity ratio from the middle of the creek indicated net water mass movement towards the open sea. The flushing rate of the creek water towards the open sea was estimated to be 6.67 ± 0.89 km day−1. The horizontal mixing coefficient (Kh) of the creek water was estimated to be 800 ± 107 m2s−1 indicating rapid dispersion of the tracer.

Mechanism of molasses–water mixing behavior in bioethanol fermenter. Experiments and CFD modeling

Molasses is a first-generation bioethanol feedstock that is a byproduct of sugar production. Molasses is a viscous fluid; consequently, when it serves as a substrate, it needs to be dissolved in water to obtain the appropriate conditions for the yeast. Therefore, the mixing process of molasses and water is an essential factor that significantly affects the efficiency of the fermentation process. This work aims to study the molasses–water mixing behavior in a cylindrical cone-shaped stirred-tank system reviewed by the effect of the molasses–water rheological characteristics. The molasses–water mixing behavior was investigated through a simple visualization method by using a camera and a 650 nm red laser as an observation plane of molasses–water interface height changes. Based on the results of the rheological characterization, it is known that molasses are a non-Newtonian fluid that exhibits shear thinning behavior. A rheological model molasses–water mixture has been developed. The behavior of molasses–water mixture comprises three zone mechanisms. The Eulerian multiphase model is the closest to the experimental results, and the combination of the Eulerian multiphase model and Large Eddy Simulation can be applied to predict the mixing behavior in an industrial scale stirred-tank.

Analysis of the Mixing Processes in a Shallow Subtropical Reservoir and Their Effects on Dissolved Organic Matter

A good understanding of the physical processes of lakes or reservoirs, especially of those providing drinking water to residents, plays a vital role in water management. In this study, the water circulation and mixing processes occurring in the shallow, subtropical Tingalpa Reservoir in Australia have been investigated. Bathymetrical, meteorological, chemical and physical data collected from field measurements, laboratory analysis of water sampling and an in-situ Vertical Profile System (VPS) were analysed. Based on the high-frequency VPS dataset, a 1D model was developed to provide information for vertical transport and mixing processes. The results show that persistent high air temperature and stable reservoir water depth lead to a prolonged thermal stratification. Analysis indicates that heavy rainfalls have a significant impact on water quality when the dam level is low. The peak value of Dissolved Organic Carbon (DOC) concentration occurred in the wet season, while the specific UV absorbance (SUVA) value decreased when solar radiation increased from spring to summer. The study aims to provide a comprehensive approach for understanding and modelling the water mixing processes in similar lakes with high-frequency data from VPS’s or other monitoring systems.

Kelvin-Helmholtz Billows Induced by Shear Instability along the North Passage of the Yangtze River Estuary, China

Kelvin-Helmholtz (K-H) instability plays a significant role in mixing. To investigate the existence of K-H instability along the North Passage of the Yangtze River Estuary, the non-hydrostatic model NHWAVE is utilized to simulate the fresh-salt water mixing process along the North Passage of the Yangtze River Estuary. Using high horizontal resolution, the structure of K-H billows have been successfully captured within the Lower Reach of the North Passage. The K-H instability occurs between the max flood and high-water slack. The duration and length scale of the K-H billows highly depends on the local interaction between fresh-water discharge and tide. The horizontal length scale of the instability is about 60 m, similar to the observations in other estuaries. In the vertical direction, the K-H billows exist within the pycnocline with length scale ranging from 6 to 7 m. The timescale of the billows is approximate 6 min. By analyzing the changes of potential energy during the mixing process, results show that the existence of K-H instability induces intense vertical mixing, which can greatly increase mixing efficiency in the North Passage of the Yangtze River Estuary.

Geo-Dynamics, Salinity Gradient, and Vegetation Interdependence in Chilika Lagoon, a Tropical Wetland in Eastern India

<p>Chilika a shallow brackish lagoon, India, is shrinking for sediment surplus budget. South Mahanadi deltaic branches <em>i.e.</em> Daya and Bhargavi terminate at the southwest swamps of the Lagoon. The annual average salinity of the lake was depleted from 22.31ppt (1957-58) to 8.5 ppt. (1999-2000) as the mixing process of saline and fresh water was influenced from 1995. Trepidation of conversion of Chilika to a atrophied fresh water lake due to blooming population and their hydrologic interventions like Kolleru lake in (India), Aral Lake (Uzbekistan) was apprehended by 1950’s and was alarming by 1999 when the shallow inlet(s) shifted extreme north. The shallow mud flats of lean salinity were reclaimed further for agriculture. The ecology and biodiversity degraded with substantial pecuniary loss to the lagoon dependents. Anthropogenic interventions like, Hirakud dam (1956), dredging of Sipakuda Inlet (2000), Naraj barrage at delta head (2004), Gobardhanpur barrages (1998) and Gabkund cut with weir (2014) were made to the hydraulic system. The deteriorating health, perturbed biodiversity and declined ecosystem of the lagoon has forced to have a comparative study of the various morphologic changes passed over the Chilika with time. The meteorological, hydrologic and the salinity study of the lagoon area for the period 1990 to 2016 have shown changes. Topographic study using GIS is developed by collecting data from Glovis Classic (Google) and the interpretation is done using ERDAS 9.2 software for various geomorphic features (1984 and 2017) before and after the current anthropogenic interventions and compared with previous studies.</p>

The impact of well drawdowns on the mixing process of river water and groundwater and water quality in a riverside well field, Northeast China

AbstractRiverbank filtration (RBF) has been widely used throughout the world as an effective means to regulate surface water and groundwater resources and pretreat raw water for municipal water supply. The quality of the water from a riverside well field and the mixing ratios of surface water and groundwater is primarily impacted by the hydrodynamic processes in the RBF system. The RBF system is largely controlled by the water exploiting system in addition to the natural hydrologic condition of the river–aquifer system. As one of the most important design parameters of the riverside well field, the drawdown of groundwater level greatly determines the water head differences between the river water and groundwater as well as the field flow net, which subsequently impacts the mixing of river water and groundwater and water quality significantly. This study aimed to improve the understanding of the mixing process between the surface water and groundwater and estimate the impact of the RBF on the mixing ratio of surface water–groundwater and water quality quantitatively. A set of field pumping tests with various groundwater level drawdowns were carried out independently and successively at a riverside field with a single pumping well near the Songhua River in Northeast China in August 2017. During these tests, the water levels and hydrochemical parameters of the Songhua River, the adjacent aquifer, and the pumping well were monitored. The dynamic mixing process of the river water and groundwater and water quality under various drawdown conditions were analysed systematically using analytical methods. The results obtained from Dupuit method and the Mirror Image method in conjunction with the Hydrochemical Tracing method showed that the pumping water directly from the river water reached 60% ± 10% after a steady flow net was established. The larger the proportion of the pumping water captured from the river, the better quality of the pumping water was, because the quality of the river water (only limited to some water quality parameters monitored which were minority) was better than that of the groundwater. The results also showed that total Fe, TDS, total hardness, CODMn, and K+ were relatively sensitive to the changes of groundwater drawdown, and their concentrations decreased with an increase in the groundwater drawdown. It can be concluded that both the mixing ratio of the surface water and the groundwater and the water quality of the riverside well field can be regulated through adjusting the designed drawdown of the groundwater level, which is helpful for the design and the optimization of the riverside well water intake engineering.

Experimental study on characteristics of air entrainment and distribution of void fraction in surf zone

The study of breaking wave-induced air bubble flows near the seashore is a great challenge. The process of air entrainment is highly complex and air bubbles evolution takes place over a wide range of spatial and temporal scales. Surf wave breaking can generate strong turbulence and entrain a large amount of air in the water and produce many air bubbles with different lifetimes. It is a typical two-phase flow involving water and air. The evolution and transport of wave-induced air bubbles can significantly affect coastal structures with respect to impact intensity, seawater-air exchange, sediment transport and wave energy dissipation. Studying the characteristics of wave-induced air bubbles in the nearshore wave breaking zone has important theoretical value and scientific significance. A better understanding of this process is also important to improving engineering practice and environmental protection in the nearshore region. Past studies have been focused on the transport law of the wave-induced air bubbles and the related statistics of air bubbles involved in the wave breaking process. Due to the complexity of water and gas mixing processes and the difficulty of the corresponding measurements, the prior research mainly focused on the formation and distribution of wave-induced air bubbles and their relationship with wave energy dissipation. However, quantitative research on how air bubble characteristics vary with different wave parameters still lacks in-depth discussion. This work presents a wave tank experiment to fully understand the void fraction distribution and its relationship with prominent wave parameters during the air entrainment process during surf wave breaking. Spatial and temporal variations of air entrainment and void fraction evolutions are recorded by an air bubble measuring system and high speed camera, respectively. The main factors affecting the distribution of void fraction are determined. The experimental data demonstrates that the distribution of void fraction is closely related to the water depth, prominent wave parameters and distance from the wave breaking location. We discuss the spatial and temporal evolution of the void fraction and derive an empirical formula to predict the void fraction by introducing two factors named C 0 and k 1. The factor k 1 is inversely proportional to wave height and C 0 varies with the wave steepness, relative water depth and dimensionless horizontal position. The empirical formula is used to analyze the relationship between each wave parameter and the distribution of void fraction. Experimental results show that the maximum void faction was close to 20% at the water surface and that the maximum penetration depth of air bubbles was close to 5 cm below the still water surface. As the water depth increased, void faction varied with e-index. Results of this work can be used to analyze and predict the spatiotemporal distribution of the void fraction in wave breaking zone and provide a good reference for further study of air bubble transport during surf wave breaking.

THE EFFECTS OF MIXING UNDERGROUND AND SURFACE WATER IN THE CONDITIONS OF WATER DISCHARGE FROM THE EXCAVATION DRAINAGE – CASE STUDY OF THE POTOK SŁUŻEWIECKI IN WARSAW

The paper presents a typical problem for agglomeration areas, i.e. the discharge of drainage water from the excavation pit to the watercourse. In case of the Potok Służewiecki, the most important problem is a significant difference in the chemical composition of surface and groundwater. An important part of the Potok Służewiecki water originates from polluted water discharged from rainwater sewage collectors. Discharged groundwater is mostly categorized as the quality class II, but significant concentrations of Fe and Mn reduce its categorization to quality class III. In order to determine the extent of changes in the chemical composition of the Potok Służewiecki water due to water mixing process, geochemical modelling in various quantitative ratios was carried out. Obtained results show lowering of the pH and almost complete transition of all Fe speciations into the Fe3+ form, regardless of the mixing ration of ground and surface water. This implies the appearance of coloured water in the Potok Służewiecki. Therefore, assuming the use of additional aeration measures, the oxygen amount needed for complete removal of iron from groundwater before its discharge to the Potok Służewiecki was calculated. Possible impact of the Potok Służewiecki on the rock matrix before and after mixing with discharge water was also presented in the article.

The Remobilization and Removal of Fe in Estuary—A Case Study in the Changjiang Estuary, China

AbstractDissolved iron (dFe) delivered by rivers plays a vital role in supporting primary productivity in coastal ecosystems. River‐borne Fe is generally removed in estuaries due to the salt‐induced flocculation. However, effects of the river mouth bar area on the variations of dFe concentration are frequently overlooked. Here we show the results of quasi‐synchronous observation conducted in three water channels in the mouth bar area of the Changjiang Estuary during both spring and neap tides in July 2014. dFe showed high spatial variation, from 2.63 to 690 nM, with higher values commonly found in the inner study area. An episode of significant Fe remobilization was observed in the inner mouth bar before the removal in the subsequent fresh‐saline water mixing process. Averaged dFe concentration increased from 45.2 ± 22.9 nM at Xuliujing to 188 ± 185 nM in the inner salinity (S) ≤ 1 water, then decreased to 10.3 ± 9.53 nM in the outer S > 1 water. Budget calculations revealed that the Changjiang input was the largest terrestrial source for dFe, while desorption from particles was the main reason for dFe enhancement in the study area. The entire mouth bar area was identified as a net sink for dFe, whereas, its S ≤ 1 and S > 1 zones were a source and a sink, respectively. We suggest that the mouth bar area diversifies the biogeochemical behavior of Fe in the estuary and enhances Fe output flux. Our study offers a new insight for better understanding the behavior of Fe and other particle‐reactive elements in large dynamic estuaries.

Impact of irrigated agriculture on groundwater resources in a temperate humid region

The groundwater irrigation expansion, and its multiple potential impacts on the quantity and quality of water resources, is not just restricted to areas that are water limited. In this study we present the seasonal impacts irrigation practices can have on groundwater resources in a temperate humid region, where the average annual rain/PET ratio is 1.0. In this system the irrigation expansion is solely supported by groundwater pumping, but despite this only 5 boreholes are monitored for hydraulic head data. In this study, we compensate the scarce hydrophysical dataset by incorporating environmental tracers (major ions, δ18O, δ2H and δ13C) and dating tracers (3H, CFC, SF6 and 14C). Results indicate that at 9 of the 15 irrigation sites investigated, groundwater pumping for irrigation has induced the mixing of recent groundwater (up to <1year) with older waters. The origin of the older waters was from either the deeper marl aquifer, or the shallow sand-clay aquifer (SCB) that has a 14C mean residence time (MRT) of up to 9700years. Secondly, although high nitrate loads in infiltrating waters were being diverted via the artificial subsurface drainage system, increases in fertiliser loads have resulted in higher NO3 concentrations in younger groundwater (NO3: 9–45mg/L, MRT <20years), compared with older groundwater (NO3≤9mg/L, MRT>20years). The changes in flow pathways, induced by irrigation, also results in seasonal declines in groundwater NO3 concentrations due to mixing with older waters. In temperate humid areas, such evaluations of the seasonal evolution of water residence time, mixing process, and agrochemical contaminants are an important contribution to real water resources management in irrigated catchments.

Seasonal variability of stable carbon isotopes (δ13CDIC) in the Skagerrak and the Baltic Sea: Distinguishing between mixing and biological productivity

We documented the annual cycle of the carbon isotopic composition of dissolved inorganic carbon (δ13CDIC) in the water columns of the Skagerrak and Baltic Sea to obtain an increased understanding of the processes involved controlling the carbon isotopic distribution in shelf seas. The lowest δ13CDIC values (−4.9‰) were found in the low-oxygen, brackish Baltic bottom water whereas the highest values (+1.8‰) were observed in the surface water of the Skagerrak during late summer. Photosynthesis drove the high δ13CDIC values (between 1.0 and 1.8‰) noted in the surface waters of both the Skagerrak and the Baltic. The δ13CDIC values below the halocline in the Baltic reflect mixing of brackish water and the more saline water from the Skagerrak, and foremost organic matter remineralization processes that release significant amounts of low-δ13C CO2. Similarly, in the stagnant fjord basins, little deep water exchange and the degradation of terrestrial and marine organic matter set the δ13C composition. Deep-water renewal in the fjord basins resulted in rapid increases of the δ13CDIC on the order of 1‰, whereas remineralization processes caused a decrease in δ13CDIC of 0.1–0.3‰ per month depending on location. The combined effects of water mixing and remineralization processes (estimated using apparent oxygen utilization (AOU) values) yielded the expression: δ13CDIC=0.032∗S−0.01∗AOU−0.12 for the Baltic – Skagerrak region at water depths below the halocline.

Simulation of rainfall-induced debris flow considering material entrainment

In order to simulate soil erosion and sedimentation processes of debris flow, a depth-integrated particle method with soil-water mixing model is proposed. In the model, each numerical particle represents a mixture of soil grains and water with a certain soil volume concentration and can exchange the soil mass with the neighboring particles according to the diffusion equation. A unique relationship is also assumed between the soil volume concentration and its critical deposition angle to compute the bottom shear stress acting on the flowing numerical particles. Therefore, the model only contains three major mechanical parameters: the classical Manning coefficient, the critical slope angle for the loose soil deposit at the base of valley, and the diffusion coefficient to control the soil water mixing process. In addition, a two-step simulation method is proposed to evaluate the initial distribution of the loose soil deposit in the valley bottom. The model is initially validated by a laboratory flume experiment taken from the open literature, and adequate values of the mechanical parameters are determined. Next, the model is applied into the case study of the 2010 debris flow event in Zhouqu, and the simulation results are compared with the field investigation, as well as the post-event satellite images. The affected area, the travel distance, and the flow velocity statistics exhibit good agreement.

Radium isotopes assess water mixing processes and its application in the Zhujiang River estuary

Radium (Ra) isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, chlorophyll-a (chl-a), suspended particulate matter (SPM) and Ra isotopes (223Ra, 224Ra and 226Ra) of surface waters of the Zhujiang (Pearl) River estuary (ZRE) were measured. This was done for both winter (December) and summer (July) seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially 224Ra (about 2–5 times higher). The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM (low light penetration). The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.

Contained density currents with high volume of release

AbstractContained density currents with high volume of release reflect against the boundaries of the reception environment commonly leading to oscillatory flow. These flows exist in sediment clarifiers, compromising their operations, and deposited signatures of contained turbidity currents are found as part of the infill of sedimentary basins; for operation of the former and interpretation of the latter it is essential to understand the dynamic processes of these flows. Six lock‐exchange experiments with different initial densities were made in a horizontal flume, where the volume of the saline mixture in the lock was equivalent to the volume of the ambient fluid. A further two tests, with a repeated initial density, were made: one with high volume of release and very long duration; and another with low volume of release. Firstly, the movement of the current is discussed, including the oscillations within the experimental tank involving the density current and an upper layer counter‐current. It is shown that the cyclic behaviour is self‐similar with the reduced gravity of the initial density in the lock. Secondly, entrainment and water mixing processes are characterized. The time evolution of mixing is characterized qualitatively by analysing the background potential energy of the density distributions to show that mixing occurs even in the earlier stages of the current, and mainly within the first cycle of the oscillation. Quantified analysis reveals that, in currents with high volume of release, entrainment discharge is one order of magnitude higher, mainly due to the larger interface between the ambient fluid and the current. A model for the evolution of the mixing process is proposed for density currents with high volume of release. Finally, the dynamics of the head of the current is analysed. The entrainment in the head, when compared to the entrainment in the remainder body of the flows, is less important for the configuration with a larger lock.

Elucidation of mixing process of acidic hot spring water and river water based on Sr and S isotopic ratios and chemical composition of dissolved components in Shibukuro and Tama Rivers, Akita, Japan

Elucidation of mixing process of acidic hot spring water and river water based on Sr and S isotopic ratios and chemical composition of dissolved components in Shibukuro and Tama Rivers, Akita, Japan

Boosting capacitive blue-energy and desalination devices with waste heat.

We show that sustainably harvesting "blue" energy from the spontaneous mixing process of fresh and salty water can be boosted by varying the water temperature during a capacitive mixing process. Our modified Poisson-Boltzmann calculations predict a strong temperature dependence of the electrostatic potential of a charged electrode in contact with an adjacent aqueous 1:1 electrolyte. We propose to exploit this dependence to boost the efficiency of capacitive blue engines, which are based on cyclically charging and discharging nanoporous supercapacitors immersed in salty and fresh water, respectively [D. Brogioli, Phys. Rev. Lett. 103, 058501 (2009)]. We show that the energy output of blue engines can be increased by a factor of order 2 if warm (waste-heated) fresh water is mixed with cold sea water. Moreover, the underlying physics can also be used to optimize the reverse process of capacitive desalination of water.

Evaluation of Temperature and Mixing Process of Water in Deep and Shallow Aquifers in the Southwestern Tunisia: Case of Djerid Region

This study addresses the hydrogeochemistry of thermal and cold waters circulating in the mineralised area of the Djerid basin (South-western of Tunisia) that aimed basically at understanding the mixing processes influencing their chemical compositions. Temperature intervals are 38–75 and 24.5–26.8 °C for thermal water and cold water, respectively. Two distinct hydrogeological systems supply water either for irrigation or for drinking; they are: (1) the Continental Intercalaire geothermal aquifer (CI), and (2) the Complex Terminal aquifer (CT). Geological, geophysical, hydrogeological, hydrochemical methods are applied to reliably analyze and understand the operating model of the aquifer systems, to determine the hydrogeological, the geochemical behaviours, and the possible inter-aquifers water transfer in south western of Tunisia. The reservoir temperature is estimated to be between 60 and 104 °C according to calculations using silica geothermometers and computation of saturation indexes for different solid phases. Based on chemical and thermal data, it is hypothesized that: (1) mixing rate, which occurs between the ascending deep geothermal water and shallow cold water, is estimated from the enthalpy and chloride methods to be about 65 and 73 % respectively, (2) Mixing models can explain the temperature of the geothermal fluid component.

Sediment transport and saltwater intrusion into the weakly stratified estuary of the Delaware R.

Data on the hydrological regime and morphological structure of the estuarine-type mouth area of the Delaware R. are presented. The specific features of fresh and salt water interaction in different parts of the estuary are considered. The attention is focused on water mixing processes and water and sediment dynamics in the estuary under the joint effect of river runoff and tides. The parameter that governs the type of water circulation and stratification in the estuary is evaluated. Correlation between variations in water salinity and turbidity along the estuary is analyzed. Estimates of sediment balance components in the Delaware R. estuary are given.