Magnitude Of Inflow Research Articles

The Strong Integral Input-to-State Stability Property in Dynamical Flow Networks

Dynamical flow networks serve as macroscopic models for, e.g., transportation networks, queuing networks, and distribution networks. While the flow dynamics in such networks follow the conservation of mass on the links, the outflow from each link is often non-linear due to, e.g., flow capacity constraints and simultaneous service rate constraints. Such non-linear constraints imply a limit on the magnitude of exogenous inflow that is able to be accommodated by the network before it becomes overloaded and its state trajectory diverges. This paper shows how the Strong integral Input-to-State Stability (Strong iISS) property allows for quantifying the effects of the exogenous inflow on the flow dynamics. The Strong iISS property enables a unified stability analysis of classes of dynamical flow networks that were only partly analyzable before, such as networks with cycles, multi-commodity flow networks and networks with non-monotone flow dynamics. We present sufficient conditions on the maximum magnitude of exogenous inflow to guarantee input-to-state stability for a dynamical flow network, and we also present cases when this sufficient condition is necessary. The conditions are exemplified on a few existing dynamical flow network models, specifically, fluid queuing models with time-varying exogenous inflows and multi-commodity flow models.

Modeling seasonal salinity variations in a large West African lagoon (Nokoué, Benin): Major drivers and mechanisms

Nokoué lagoon is a shallow water body connected to the Gulf of Guinea through the long and narrow Cotonou channel. The salinity dynamics in the lagoon is investigated using the 3D SYMPHONIE numerical model. We first validate the model using salinity and water level data. Simulated and observed salinity and water level variations compare well demonstrating that the reference model simulation correctly reproduces the dynamics of the lagoon. By performing several simulations with varying external forcings and freshwater fluxes, the main drivers of salinity variability in the lagoon are identified. We first focus on the salinization phase of the lagoon at the end of the tropical wet season (between November and February), and we investigate the total change in salinity and the salt fluxes involved in these variations. The high frequency salt fluxes associated with the ocean tide import salt from the ocean via the Cotonou channel to the south of the lagoon. Baroclinic fluxes, associated with the influence of salt on density and associated pressure gradient, increase this local salinity input in the south, but also play a major role in the dispersion of salt throughout the lagoon. Two rivers provide a permanent freshwater inflow in the north/ northeast of the lagoon that limits the salinization of the whole lagoon. Finally, wind-generated high frequency recirculation, partially prevents the salinisation of the North-East of the lagoon. During the desalinization period (between May and September), the lagoon salinity variations are highly sensitive to the magnitude of river inflow. At a constant river flux rate, the lagoon attains an equilibrium state in salinity. As this equilibrium is reached, both the overall salinity level and the time needed to achieve it decrease notably with higher fluxes. Beyond 100 m3 s-1, only a small area near the Cotonou channel retains higher salinity, while surpassing 500 m3 s-1 results in complete desalination of the entire Nokoué lagoon.

Effects of a Volcanic-Fluid Cycle System on Water Chemistry of a Deep Caldera Lake: Lake Tazawa, Akita Prefecture, Japan

Lake Tazawa, the deepest lake (423.4 m depth at maximum) in Japan underwent drastically changed water quality in 1940, because volcanic water from two active volcanos was then drawn into the lake for power generation and irrigation. Thereby, the pH of lake water decreased from 6.7 to 4.2, which exterminated a land-locked type of sockeye salmon, Oncorhynchus nerkakawamurae (locally called Kunimasu trout). Additionally, the mean residence time of lake water changed from 195 years to 8.9 years by rapidly increasing the outflow for power generation and irrigation. In this study, long-term chemical fluxes controlling lake water chemistry were obtained, and a groundwater water cycle system between the lake and the volcano was explored by estimating hydrological and chemical budgets of the lake. In the chemical budget estimate, two ionic species, SO42− and Cl−, in volcanic fluids were chosen and each mass conservation equation was yielded. The hydrological budget estimate gave us the net groundwater inflow at −1.36 m3/s on average over three periods in 2020–2021, and then the simultaneous equation coupled with the chemical budget equation allowed us to separate into groundwater inflow and outflow at 6.01 m3/s and 7.37 m3/s, averaged over the three periods, respectively. The evaluated groundwater inflow and outflow were compared with those of the other crater or caldera lakes. The linear relationship between the lake volume and the magnitude of groundwater inflow or outflow suggests that the groundwater cycle scale in such a lake increases with the magnitude of the volcanic eruption to have formed the lake.

The Analysis of Song Putri Reservoir Storage Area on Sedimentation Rate Using Mathematical Model Approach

Song Putri Reservoir is an artificial reservoir with the aim of irrigation channels for rice fields and flood control. This reservoir is located in Eromoko District, Wonogiri Regency Sedimentation modeling in the Song Putri reservoir is needed to analyze the amount of sediment deposition against the Song Putri Reservoir. To analyze the flow patterns and sediment distribution that occurs in reservoirs, SMS (Surface-water Modeling System) 8.0 Softwarse is used. This study aims to determine the flow patterns and effects of sediment distribution on reservoir changes. The data used include Song Putri Reservoir technical data, daily rainfall data for 10 years (2009-2018), sediment data, reservoir inflow data, and bathymetry maps. To analyze the magnitude of inflow and outflow of Song Putri Reservoir, hydrological analysis using empirical methods is used, while sedimentation modeling simulation uses SMS 8.0. Software based on the simulation, result the highest flow velocity in the 50 year return period is 0.097 m / s and the smallest is 0.00 m / s. Based on the simulation results of changes in the reservoirs base for 720 hours (1 month), the values ​​that in the return period of 50 years, 100 years and the highest 1000 years the highest was 5.795 m and the smallest of 0.001 m. Based on the calculation of prediction of sediment growth rates, it obtained the results of sediment growth rates with a percentage for a 50 year return period of 35.68% with a range of percentages between 19% - 21% and a percentage of 29.103% for a 100 year return period with a range of percentages between 22% - 24%, while the percentage growth rate of 1000 year return period sediments is 98 , 20% with a percentage range between 55% - 57%.

Effect of area ratio and Reynolds number on the distribution of discharge in dividing manifold

AbstractThe goal of this study is to determine the role of the area ratio (AR) and the Reynolds number on the distribution of flow and pressure in the dividing manifold. For this purpose, five different models have been used to be analyzed under the test conditions. The first physical model is of 101.6 mm (4 in) in diameter for the master manifold in a regular longitudinal section and five sidelong of 50.8 (2 in) in diameter with a spacing of 220 mm. This model has been utilized to determine the magnitude of maldistribution inflow that usually takes place in such a design. Four other models have employed with different diameters of the header of 101.6, 76.2 and 50.8 mm and lateral of 50.8, 38.1 and 25.4 mm. These models used for the purpose of testing the stream and pressure allocation based on the AR. Three different values of 625, 790 and 950 l/min from of inlet flows examined with the employed models. The outcomes show that the AR parameter has a notable impact on the consistency of the stream from the manifold in which the uniformity of the flow distribution improves by 76% when the AR decreases from 0.48 to 0.13. It is found that the degree of uniformity of the mass discharge from the laterals is unaffected within tested Reynolds numbers of 50,000–200,000.

A description of Florida estuarine gradient complexes and the implications of habitat factor covariation for community habitat analysis

A multi-parameter dataset from 13 Florida estuaries demonstrated complications that multiple gradients (the estuarine gradient complex, EGC) 1 impose when trying to characterize species distributions using regression-based analyses. Variation in the beta diversity of assemblages consisting of 974 taxa in four groups (ichthyoplankton, invertebrate zooplankton, seine nekton, trawl nekton) were assessed using 29 habitat factors. Habitat data were obtained from measurements made during biotic collections, associated characterizations of local habitats, data obtained from the United States Environmental Protection Agency Storage and Retrieval database, and from data that characterized the timing and magnitude of freshwater inflow and turnover. When all habitat factors were used in multivariate regression models (distance-based redundancy analysis, dbRDA) with the objective of explaining variation in beta diversity, the models accounted for as much as 52% of the variation and included factors such as salinity, color, water temperature, distance to the Gulf of Mexico, water depth, presence of mud bottom, and the amount of freshwater input. Habitat factors that contributed to the EGC were identified by performing correlation analyses between each habitat factor and distance to the Gulf of Mexico. This step indicated that, in surface-fed estuaries, submerged aquatic vegetation, mangroves, and warmer temperatures were more common downstream, and lower pH, deeper depths, lower bottom dissolved oxygen, lawn-and-tree shorelines, and manmade bottom substrates were more common upstream. In spring-fed estuaries, oysters and mangroves were more common downstream, and lawn-and-tree shorelines were more common upstream. These correlated factors were used to represent the EGC and were explicitly included in dbRDAs where they explained as much as 78% of the variability in beta diversity. A subsequent partial-dbRDA was performed on the variation that was not explained by EGC habitat factors, and non-EGC factors (freshwater inputs, artificial shorelines, shoreline slope, and the presence of sand bottom) explained as much as an additional 7% of the variability. These results demonstrate the complications inherent in assigning influence to any one habitat factor in estuaries where many habitat factors covary spatially. The substantial amount of beta diversity variation explained by the EGC indicates a goal of estuarine management should be to promote heterogeneity in habitat factors contained in the EGC to maintain overall community diversity.

Interval uncertainty analysis of a confined aquifer

Water inflow forecast is influenced by many factors and yields uncertain results. To more accurately predict the magnitude of water inflow and quantitatively define the corresponding response in the parameter change interval, this study combined a non-probabilistic set theory and uncertainty analysis to derive an equation for the confined water inflow. Using mining area data and comparing the calculation of upper and lower boundary limits obtained by a Monte Carlo method, results of the confined water inflow equation were calculated with relative errors of 5% and 10%. When corresponding to the rate of change of the variable parameter, the results showed that under the same error conditions, the allowable rate of change when calculating the minimum value using Eq. A was greater than when using Eq. B, and the maximum value using Eq. B yielded a greater allowable rate of change than the maximum value calculated by Eq. A. Thus, the obtained rate of change for Eq. A is indicative of the lower limit, and Eq. B is conducive to the calculation of the upper limit of mine water inflow.

A semi-empirical model for water inflow into a tunnel in fractured-rock aquifers considering non-Darcian flow

Water inflow into a tunnel is usually estimated by assuming that the flow follows the linear Darcy’s law. However, fluid flow in fractured-rock aquifers is prone to deviation from Darcy’s law and gives rise to nonlinear flow phenomena due to significant inertial losses. This non-Darcian effect is seldom considered when evaluating water inflow into the tunnel in a fractured-rock aquifer. In this study, we investigated an analytical method for predicting water inflow into a tunnel considering the non-Darcian effect. A series of numerical simulations for water inflow into a tunnel were conducted with different combinations of parameters, where non-Darcian flow was considered and characterized by the Forchheimer’s law. Based on the numerical results and an ingenious parameter integration method, a semi-empirical model was developed to analytically predict water inflow into a tunnel where the flow is under non-Darcian flow regime. The semi-empirical model includes the classic theoretical formula for predicting water inflow and the Forchheimer equation for describing non-Darcian flow. In this context, the non-Darcian effect on water inflow into a tunnel can be quantitatively estimated. This developed model has a concise expression satisfying dimensional consistency with the parameters having sound physical meanings, and it can be successfully reduced to the classic formula under the Darcy flow regime. The validity of this semi-empirical model was confirmed by numerical results, showing a high fidelity in predicting water inflow into a tunnel. By means of this proposed model, the error induced by neglecting non-Darcian effect was estimated for a large number of real engineering cases, which rapidly increased as a power function with the magnitude of water inflow into the tunnel. The necessity of considering the non-Darcian effect when calculating water inflow was thus proven, especially for massive tunnel gushing. The proposed model and the method used in this study can provide guidance for accurately predicting water inflow into a tunnel under a complex non-Darcian flow regime.

Temporal and spatial characteristics of PM2.5 transport fluxes of typical inland and coastal cities in China

Local pollution and the cross-boundary transmission of pollutants between cities have an inevitable impact on the atmosphere. Quantitative assessments of the contribution of transport to pollution in inland and coastal cities are necessary for the implementation of practical, regional, and joint emission control strategies. In this study, the Comprehensive Air Quality Model (CAMx), together with the Weather Research and Forecasting model (WRF), was used to simulate the contributions to pollution of different cities in 2016. The monthly inflow, outflow, and net flux from the ground to the extended layers served as the three main indicators for the analysis of the interactions of PM2.5 transport between adjacent cities. Between inland and coastal cities, the magnitude of inflow and outflow are larger in the former than in the latter. The inflow flux in the inland cities (Beijing and Shijiazhuang) was 10.6 and 10.7 kt/day, respectively, while that in the coastal cities (Tianjin, Shanghai, Hefei, Nanjing, and Hangzhou) was 9.1, 3.3, 5.8, 4.4, and 3.7 kt/day, respectively. In terms of variation over the year, the strongest inflow in the BTH region occurred in April, followed by October, July, and January, while that in the coastal cities in YRD occurred in January, followed by October, April, and July. Therefore, based on the flux intensity calculations and the transport flux pathways, effective joint control measures can be provided with scientific support, and a better understanding of the evolutionary mechanism among inland and coastal cities can be acquired.

Energetic and exergetic investigation of a mixed flow dryer: A case study of maize grain drying

Evolution of energetic and exergetic performance is an important concern for selecting suitable dryer for any drying process. This paper attempts to observe performance evaluation in terms of energy and exergy analysis of a mixed flow dryer for drying of freshly harvested maize grain. Existing models in regard to energy and exergy that were established by investigating the first law and second law of thermodynamics were applied for this study. Grain drying experiments executed for 40–80 °C drying temperature at 3.0 and 6.0 m/s air velocity. Energy utilization ratio decreased with increase of drying temperature at 3.0 m/s air velocity while differing surveillance was noticed for 70 and 80 °C at 6.0 m/s air velocity. Energy efficiency of the research mixed flow dryer vacillated from 26.52 to 71.75% over the temperature range. The magnitude of exergy inflow, exergy outflow and exergy loss varied as increasing trend with the upturn drying temperature. The analysis shows that exergy efficiency and exergetic improvement potential varied between 8.54 and 20.87% and between 0.81 and 11.12 kJ/s, respectively for mixed flow maize drying. Model equations that could aptly illustrate the energetic and exergetic parameters were developed as a function of drying temperature.

Water Inflow Prediction and Grouting Design for Tunnel considering Nonlinear Hydraulic Conductivity

Grouting prevents groundwater leakage into tunnels, based on the exponent model that expresses the nonlinear variation of the hydraulic conductivity of the surrounding rock, the formulas for predicting the magnitude of water inflow and outer water pressure of the lining after grouting are deduced. The parameter analysis shows how the water inflow decreases as the hydraulic conductivity of the grouting circle diminishes and the thickness of the grouting circle increases. When the parameter α (attenuation coefficient), which expresses the decreasing amplitude of the permeability coefficient of the surrounding rock with depth, is greater than 0, the water inflow increases until it reaches a maximum at a certain depth, and then the inflow decreases to 0 if deep enough. After considering the variation in the hydraulic conductivity of the surrounding rock, the thickness and hydraulic conductivity of the grouting circle may be designed to be too large to reduce the magnitude of the water inflow. Meanwhile, to reach the limited drainage criterion of the tunnel groundwater, the grouting circle thickness decreases gradually as α increases after the nonlinear variation of the hydraulic conductivity of the surrounding rock, which can reduce the cost for plugging the groundwater. Thus, it is critical to consider hydraulic conductivity variation during water inflow predicting and grouting when designing tunnels.

The utilization of cold-water zooplankton as prey for chum salmon fry (Oncorhynchus keta) in Yamada Bay, Iwate, Pacific coast of northern Japan

The food availability of chum salmon fry is one of the principal factors affecting survival in their coastal residence period. The aim of this study was to better understand the quality and quantity of available food resources and the feeding habits of salmon fry in nearshore waters. We examined stomach contents of salmon fry and the zooplankton community structure of the water column during salmon fry’s coastal residence period (April and May) over four years in Yamada Bay, a coastal embayment of the Pacific Ocean in northern Japan. The mean water temperatures during study period were low in 2014 and 2013 (6.7 and 8.3 °C, respectively),and high in 2016 and 2015 (11.1 and 9.4 °C, respectively). Neocalanus plumchrus and Themisto japonica, typical cold-water zooplankton dominated the stomach contents of chum fry (except for 2016), however, they were not necessarily the most dominant in the water column, suggesting that chum fry selectively preyed upon these cold-water zooplankters. On the other hand, chum fry preyed primarily on decapod larvae in 2016 the warmest water year. Condition factor of chum fry were higher in cold-water years than those of warm-water years. Because these two cold-water zooplankton species are typically abundant in the Oyashio Current, the magnitude of Oyashio inflow may affect prey availability for chum salmon fry and their nutritional status. The relationship between the food environment at the coastal residence period of chum fry and the adult return rate after three years was also discussed.

Illustrating the value of cross-site comparisons: Habitat use by a large, euryhaline fish differs along a latitudinal gradient

Plasticity in life-history traits and behaviors allows organisms to track spatial environmental variation, such as that resulting from a latitudinal gradient. In estuaries, hydrological patterns can vary greatly with latitude, causing variable habitat use patterns across a species’ range. For Common Snook (Centropomus undecimalis) a large euryhaline fish, seasonal movements between the open estuary and freshwater reaches of rivers have been documented. We hypothesized that the timing of river use by Snook would be driven primarily by the magnitude of freshwater inflow, except at the northern limit of its range where lethal water temperatures may be a stronger influence. Data from electrofishing studies (2012–2016) conducted in rivers associated with four estuaries along a latitudinal gradient in western Florida were compared for seasonal differences in Snook abundance using negative binomial regression. In rivers of southwestern Florida (those in Everglades and Charlotte Harbor), Snook abundances increased three-fold during the time of year when surface waters inundating floodplains recede and force prey into the main stems of rivers. These hydrologically driven processes, and surges in Snook abundance, occurred during spring in the Everglades and fall in rivers of Charlotte Harbor. In Tampa Bay rivers, which have less freshwater inflow than the rivers farther south, Snook abundance differed little between seasons. In spring-fed rivers north of Tampa Bay, Snook abundances in fall and winter were twice those of spring and summer; stable water temperatures were thought to provide thermal refuge at the northernmost range of Snook. This work illustrates how the timing of habitat use by a species, and the underlying reasons, can differ greatly among sites. It also demonstrates the value of cross-site comparisons in providing for a more complete understanding of how a species uses available habitats across its range.

Many-Objective Multi-Scenario Algorithm for Optimal Reservoir Operation Under Future Uncertainties

An increase in greenhouse gases in future can exacerbate the climate change phenomenon and may have negative consequences on different elements of hydrologic system, including rainfall, temperature, and streamflow. Since the reservoir operation is highly dependent on the timing and magnitude of inflow, the impact of potential climate change on inflow sequences should be considered in deriving the system operation rule. Nevertheless, existing algorithms are only able to optimize the operation policy for a single predetermined climate scenario. Thus, the derived operation rule would not work well if the scenario changes. This paper proposes an algorithm which is able to handle simultaneously multiple scenarios in finding optimum system operation rule. Thus, it can overcome drawbacks caused by uncertainties in the occurrence of future scenarios. The proposed algorithm is used to optimize reservoir operation policy considering various climate change scenarios (RCPs). To evaluate the performance of the proposed algorithm, a five-reservoir system within Tehran region with several objectives including municipal, agricultural, environmental, and hydropower demands is employed as the case study. Results show that in all cases the multi-scenario rule derived by the proposed method performs as good as the operation rule derived for any specific scenario using a powerful optimization algorithm when evaluated for that scenario. While, in all other models as the future scenario changes to the one other than that used in deriving the operation rule, the model performance declines as compared to the proposed model.

The relative importance of water temperature and residence time in predicting cyanobacteria abundance in regulated rivers

Despite a growing awareness of the problems associated with cyanobacterial blooms in rivers, and particularly in regulated rivers, the drivers of bloom formation and abundance in rivers are not well understood. We developed a Bayesian hierarchical model to assess the relative importance of predictors of summer cyanobacteria abundance, and to test whether the relative importance of each predictor varies by site, using monitoring data from 16 sites in the four major rivers of South Korea. The results suggested that temperature and residence time, but not nutrient levels, are important predictors of summer cyanobacteria abundance in rivers. Although the two predictors were of similar significance across the sites, the residence time was marginally better in accounting for the variation in cyanobacteria abundance. The model with spatial hierarchy demonstrated that temperature played a consistently significant role at all sites, and showed no effect from site-specific factors. In contrast, the importance of residence time varied significantly from site to site. This variation was shown to depend on the trophic state, indicated by the chlorophyll-a and total phosphorus levels. Our results also suggested that the magnitude of weir inflow is a key factor determining the cyanobacteria abundance under baseline conditions.

Experiments on the effect of inflow and outflow sequences on suspended sediment exchange rates

In laboratory experiments, the influence of inflow and outflow sequences on the behavior of fine sediment was investigated. The experimental set-up consisted of two interconnected rectangular basins, between which water was moved back and forth. Suspended sediment concentration in the main basin as well as the sediment exchange rates were derived from turbidity measurements.The suspended sediment ratio, SSR, and sediment exchange rates (influx sediment rate, ISR, and evacuated sediment rate, ESR) were measured. In twenty test runs, a parametric study on the magnitude and frequency of inflow and outflow cycles, the relative duration between inflow and outflow sequences, the initial sediment concentration, and the intake position was done. An initial test with stagnant water described the settling behavior of fine sediment and served as a reference scenario.The test results show that settling of fine particles near the intake/outlet structure can be considerably reduced by the nature of the inflow and outflow sequences. High cycle magnitude and frequency lead to maximum suspended sediment ratio in the system. For low discharges, the evolution of suspended sediment concentration cannot be directly correlated to the inflow and outflow cycles. However, compared to “no operation” conditions, the suspended sediment ratio could be increased by 10% to 40% locally. For high discharge, the evolution of suspended sediment concentration correlated with discharge cycles and suspended sediment ratios between 50% and 80% higher than for stagnant water could be achieved. Similar ratios could be obtained when the intake is located closer to the bottom or to the free water surface.Meanwhile, the overall sediment balance remained in equilibrium over the test period, indicating that the influx and evacuated sediment rates are not significantly influenced by the inflow and outflow cycles.

Bottleneck effects on the bidirectional crowd dynamics**Project supported jointly by the National Natural Science Foundation of China (Grant Nos. 61322307 and 2016YJS023).

The bottleneck effect on bidirectional crowd dynamics is of great theoretical and practical significance, especially for the designing of corridors in public places, such as subway stations or airports. Based on the famous social force model, this paper investigates the bottleneck effects on the free flow dynamics and breakdown phenomenon under different scenarios, in which different corridor shapes and inflow ratios are considered simultaneously. Numerical simulation finds an interesting self-organization phenomenon in the bidirectional flow, a typical characteristic of such a phenomenon is called lane formation, and the existence of which is independent of the corridor’s shape and inflow rate. However, the pattern of the lane formed by pedestrian flow is related to the corridor’s shape, and the free flow efficiency has close relationship with the inflow rate. Specifically, breakdown phenomenon occurs when inflows from both sides of the corridor are large enough, which mostly originates from the bottleneck and then gradually spreads to the other regions. Simulation results further indicate that the leaving efficiency becomes low as breakdown occurs, and the degree of congestion is proportional to the magnitude of inflow. The findings presented in this paper match well with some of our daily observations, hence it is possible to use them to provide us with theoretical suggestions in design of infrastructures.

Modeling ecosystem processes with variable freshwater inflow to the Caloosahatchee River Estuary, southwest Florida. I. Model development

Variations in freshwater inflow have ecological consequences for estuaries ranging among eutrophication, flushing and transport, and high and low salinity impacts on biota. Predicting the potential effects of the magnitude and composition of inflow on estuaries over a range of spatial and temporal scales requires reliable mathematical models. The goal of this study was to develop and test a model of ecosystem processes with variable freshwater inflow to the sub-tropical Caloosahatchee River Estuary (CRE) in southwest Florida from 2002 to 2009. The modeling framework combined empirically derived inputs of freshwater and materials from the watershed, daily predictions of salinity, a box model for physical transport, and simulation models of biogeochemical and seagrass dynamics. The CRE was split into 3 segments to estimate advective and dispersive transport of water column constituents. Each segment contained a sub-model to simulate changes in the concentrations of organic nitrogen and phosphorus (ON and OP), ammonium (NH4+), nitrate-nitrite (NOx−), ortho-phosphate (PO4−3), phytoplankton chlorophyll a (CHL), and sediment microalgae (SM). The seaward segment also had sub-models for seagrasses (Halodule wrightii and Thalassia testudinum). The model provided realistic predictions of ON in the upper estuary during wet conditions since organic nitrogen is associated with freshwater inflow and low salinity. Although simulated CHL concentrations were variable, the model proved to be a reliable predictor in time and space. While predicted NOx− concentrations were proportional to freshwater inflow, NH4+ was less predictable due to the complexity of internal cycling during times of reduced freshwater inflow. Overall, the model provided a representation of seagrass biomass changes despite the absence of epiphytes, nutrient effects, or sophisticated translocation in the formulation. The model is being used to investigate the relative importance of colored dissolved organic matter (CDOM) vs. CHL in submarine light availability throughout the CRE, assess if reductions in nutrient loads are more feasible by controlling freshwater quantity or N and P concentrations, and explore the role of inflow and flushing on the fates of externally and internally derived dissolved and particulate constituents.

Infrastructure as a Determinant of Foreign Direct Investment in India and China

This study examines the role of infrastructure in attracting FDI inflows into India and China. Infrastructure is the main determinant in attracting sizeable amount of FDI. During the late 1990’s FDI inflows headed towards developing nations including China and India. China attracted huge amounts of FDI due to rapid growth in infrastructure. India attracted lower FDI due to slow phase growth in infrastructure. The infrastructure development is not similar in both the countries; similarly, the magnitude of inflow of FDI is different. The present study empirically examines the inflow of FDI in to India and China in relation to the physical infrastructure development during the period 2000 to 2012. Regression analysis is employed to study the causal relationship between the inflow of FDI and the infrastructure. Total Road Length, Total Rail Length, Air Passengers, Internet Users, Mobile Cellular Subscriptions and Electricity Production are highly positively related with FDI; In India, Air Passengers, Internet Users, Mobile Cellular Subscriptions and Electricity Production are highly positively related with FDI. Among the infrastructure variables, heavy FDI investment is attracted by the Energy Sector (Electricity Production) both in China as well as in India.

The suitability of a simplified isotope-balance approach to quantify transient groundwater–lake interactions over a decade with climatic extremes

Summary Groundwater inflow to a subtropical seepage lake was estimated using a transient isotope-balance approach for a decade (2001–2011) with wet and dry climatic extremes. Lake water δ 18 O ranged from +0.80‰ to +3.48‰, reflecting the 4 m range in stage. The transient δ 18 O analysis discerned large differences in semiannual groundwater inflow, and the overall patterns of low and high groundwater inflow were consistent with an independent water budget. Despite simplifying assumptions that the isotopic composition of precipitation ( δ P ), groundwater inflow, and atmospheric moisture ( δ A ) were constant, groundwater inflow was within the water-budget error for 12 of the 19 semiannual calculation periods. The magnitude of inflow was over or under predicted during periods of climatic extreme. During periods of high net precipitation from tropical cyclones and El Nino conditions, δ P values were considerably more depleted in 18 O than assumed. During an extreme dry period, δ A values were likely more enriched in 18 O than assumed due to the influence of local lake evaporate. Isotope balance results were most sensitive to uncertainties in relative humidity, evaporation, and δ 18 O of lake water, which can limit precise quantification of groundwater inflow. Nonetheless, the consistency between isotope-balance and water-budget results indicates that this is a viable approach for lakes in similar settings, allowing the magnitude of groundwater inflow to be estimated over less-than-annual time periods. Because lake-water δ 18 O is a good indicator of climatic conditions, these data could be useful in ground-truthing paleoclimatic reconstructions using isotopic data from lake cores in similar settings.