Water Discharge Rate Research Articles

Thermal variations of water in the Nam Song stream/Mekong River: II. Experimental data and theoretical predictions

The goals of this study were to use the Nam Song River as a case study for parameters determination and a comparison between the measured data and the mathematical model developed in the first paper of this study. The kinematic wave equation [especially Eq. 16a in Ben-Asher et al. (Sustain Water Resour Manag, 2016. doi: 10.1007/s40899-016-0044-9 )] was expanded to a Taylor series that was used to determine several system parameters including the thermal time constant, the steady state solution, and the daily thermal cycle. Water temperature measured and calculated by the model varied from minimum of 23–24 °C at night to maximum of 27–29 °C at midday. From March 16 to March 25 2004, stream and air temperature were monitored at a point located 4 km downstream from the Nam Song Dam. The average hourly water temperature and its standard deviation were extracted from a family of daily sinusoidal curves. Monitoring downstream data were similar to results assumed by the theoretical model. The effect of water discharge rate on its temperature and on the changing energy input during daytime hours was considered. The analysis indicated that the only controllable system variable is the water flow velocity (V). It can be optimized through a controlled release of water from the dam. The mathematical analysis also identified and quantified the parameters which govern the water environment. The theory as well as the experimental data indicated that for the conditions studied, an increase in water discharge at the dam prevents an increase in water temperature downstream and thus helps to keep the fisheries and domestic water quality of the river in a healthier condition.

Unsteady Groundwater Flow over Sloping Beds: Analytical Quantification of Stream–Aquifer Interaction in Presence of Thin Vertical Clogging Layer

AbstractIn this paper, new analytical solutions are presented to quantify interaction of water between a sloping aquifer and stream of varying heads in presence of a thin vertical sedimentary layer. The initial hydrogeological setting consist of an unconfined sloping aquifer of semi-infinite extent, a fully penetrating stream of varying water level, and a vertical layer of streambank deposits that acts as an interface between stream and aquifer. Unsteady groundwater flow is characterized by a nonlinear Boussinesq equation subject to Robin boundary condition (also referred to as third kind and Cauchy boundary condition). Unlike existing results, which focus only on step changes in stream stage, the current study accounts for gradual rise and decline in stream level. A closed-form analytical solution for water head distribution, discharge rate, and net volumetric exchange of water between stream and aquifer are developed from the solution of a linearized advection-diffusion equation. Performance of the anal...

Discharge rate measurements in a canal using radiotracer methods

Discharge rates of water were measured in a canal using radiotracer methods with an objective to validate the efficacy of Concrete Volute Pumps (CVPs) installed at various pumping stations along the canal. Pulse velocity and dilution methods were applied to measure the discharge rates using Iodine-131 as a radiotracer. The discharge rate measured in one of the sections of the canal using the pulse velocity method was found to be 22.5m3/s, whereas the discharge rates measured using the dilution method in four different sections of the canal varied from 20.27 to 20.62m3/s with single CVP in operation. The standard error in discharge rate measurements using dilution method ranged from ±1.1 to ±1.8%. The experimentally measured values of the discharge rate were in good agreement with the design value of the discharge rate (20m3/s) thus validating the performance of the CVPs used in the canal.

Hydrogeological assessment of the Tabarteh fault zone by physicochemical analysis and multivariate statistical methods

Hydrogeologically, faults may impede, conduit, exert no influence, or may play a combination of these roles on groundwater flow. The object of this paper is to study the hydrogeological role of the Tabarteh fault, which is located on the border of Zagros and Central Iran tectonic zones in an alluvial aquifer. The recorded data of water table levels, chemical parameters, and discharge rate of wells, in addition to geological maps and geophysical results, were collected and evaluated. The outcrop of travertine in limited areas and the emergence of a few small springs within the alluvium show a barrier role of the fault in the groundwater flow. The spatial analysis of chemical components, head time series, and groundwater flow direction assessment demonstrated that the fault acts as both a barrier and a non-barrier in different sections. The multivariate statistical methods of cluster and discriminant analyses also confirm the dual role of the fault.

Water Discharge Rate and Lifting Rate of Treadle Water Wheel

Water Discharge Rate and Lifting Rate of Treadle Water Wheel

Enhanced Particle Swarm Optimization for Short-Term Non-Convex Economic Scheduling of Hydrothermal Energy Systems

This paper presents an Enhanced Particle Swarm Optimization (EPSO) to solve short-term hydrothermal scheduling (STHS) problem with non-convex fuel cost function and a variety of operational constraints related to hydro and thermal units. The operators of the conventional PSO are dynamically controlled using exponential functions for better exploration and exploitation of the search space. The overall methodology efficiently regulates the velocity of particles during their flight and results in substantial improvement in the conventional PSO. The effectiveness of the proposed method has been tested for STHS of two standard test generating systems while considering several operational constraints like system power balance constraints, power generation limit constraints, reservoir storage volume limit constraints, water discharge rate limit constraints, water dynamic balance constraints, initial and end reservoir storage volume limit constraints, valve-point loading effect, etc. The application results show that the proposed EPSO method is capable to solve the hard combinatorial constraint optimization problems very efficiently.

Unsteady seepage flow over sloping beds in response to multiple localized recharge

New generalized solutions of linearized Boussinesq equation are derived to approximate the dynamic behavior of subsurface seepage flow induced by multiple localized time-varying recharges over sloping ditch–drain aquifer system. The mathematical model is based on extended Dupuit–Forchheimer assumption and treats the spatial location of recharge basins as additional parameter. Closed form analytic expressions for spatio-temporal variations in water head distribution and discharge rate into the drains are obtained by solving the governing flow equation using eigenvalue–eigenfunction method. Downward and zero-sloping aquifers are treated as special cases of main results. A numerical example is used for illustration of combined effects of various parameters such as spatial coordinates of the recharge basin, aquifer’s bed slope, and recharge rate on the dynamic profiles of phreatic surface.

Probability-based classifications for spatially characterizing the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region, Taiwan.

Accurately classifying the spatial features of the water temperatures and discharge rates of hot springs is crucial for environmental resources use and management. This study spatially characterized classifications of the water temperatures and discharge rates of hot springs in the Tatun Volcanic Region of Northern Taiwan by using indicator kriging (IK). The water temperatures and discharge rates of the springs were first assigned to high, moderate, and low categories according to the two thresholds of the proposed spring classification criteria. IK was then used to model the occurrence probabilities of the water temperatures and discharge rates of the springs and probabilistically determine their categories. Finally, nine combinations were acquired from the probability-based classifications for the spatial features of the water temperatures and discharge rates of the springs. Moreover, various combinations of spring water features were examined according to seven subzones of spring use in the study region. The research results reveal that probability-based classifications using IK provide practicable insights related to propagating the uncertainty of classifications according to the spatial features of the water temperatures and discharge rates of the springs. The springs in the Beitou (BT), Xingyi Road (XYR), Zhongshanlou (ZSL), and Lengshuikeng (LSK) subzones are suitable for supplying tourism hotels with a sufficient quantity of spring water because they have high or moderate discharge rates. Furthermore, natural hot springs in riverbeds and valleys should be developed in the Dingbeitou (DBT), ZSL, Xiayoukeng (XYK), and Macao (MC) subzones because of low discharge rates and low or moderate water temperatures.

Hydraulic properties of concentrated flow of a bank gully in the dry‐hot valley region of southwest China

AbstractTo quantify spatiotemporal variation in hydraulic properties of bank gully concentrated flow, a series of scour experiments were run under water discharge rates ranging from 30 to 120 l min−1. Concentrated flows were found to be turbulent and supercritical in the upstream catchment area and downstream gully beds. As discharge increased, values of the soil erosion rate, Reynolds number (Re), shear stress, stream power, and flow energy consumption (ΔE) increased while values of the Froude number (Fr) and the Darcy–Weisbach friction factor (resistance f ) did not. With the exception of gully headcut collapse under discharge rates of 60, 90, and 120 l min−1, a declining power function trend (P < 0.05) in the soil erosion rate developed in the upstream catchment area, headcuts, and downstream gully beds. However, increasing trends were observed in temporal variations of hydraulic properties for downstream gully beds and the upstream catchment area. Despite significant differences in temporal variation between the soil erosion rate and hydraulic property values, relative steady state conditions of the soil erosion rate and ΔE were attained following an initial period of adjustment in the upstream catchment area, headcuts, and downstream gully beds under different discharge rates. A logarithmic growth of flow energy consumption per unit soil loss (ΔEu) was observed in bank gullies and the upstream catchment area as the experiment progressed, further illustrating the actual reason behind the discrepancy in temporal variation between soil erosion rates and ΔE. Results demonstrate that ΔE can be used to estimate headcut erosion soil loss, but further quantitative studies are required to quantify coupling effects between hydraulic properties and vertical variation in soil mechanical properties on temporal variation for bank gully soil erosion rates. Copyright © 2015 John Wiley & Sons, Ltd.

Simple Method for Determining the Emitter Discharge Rate in the Reclamation of Coastal Saline Soil Using Drip Irrigation

AbstractA laboratory experiment was carried out to study the relationships of emitter discharge rate (EDR) and distribution of water and salt for two typical coastal saline soils. The objective was to find a simple method to determine a suitable EDR for reclamation of coastal saline soil using drip irrigation. The experiment included five EDR treatments in a coastal saline sandy-loam soil (SAS): 0.23, 0.55, 0.8, 1.5, and 2.9 L·h−1; another five EDR treatments were conducted in a coastal saline silt soil (SIS): 0.23, 0.55, 1.0, 1.5, and 2.0 L·h−1. The water distribution and the low-salinity zone (with electrical conductivity of the saturated soil extract ≤1, ≤2, and ≤4 dS·m−1) were clearly affected by EDR. The relationships of EDR and wetted front, wetted zone volume, and low-salinity zone were difficult to obtain because of the requirements of determining and calculating the vertical wetted front and the volume of wetted, saturated, and low-salinity zones in the field. For this reason, these relationsh...

Seismologically determined bedload flux during the typhoon season.

Continuous seismic records near river channels can be used to quantify the energy induced by river sediment transport. During the 2011 typhoon season, we deployed a seismic array along the Chishan River in the mountain area of southern Taiwan, where there is strong variability in water discharge and high sedimentation rates. We observe hysteresis in the high-frequency (5–15 Hz) seismic noise level relative to the associated hydrological parameters. In addition, our seismic noise analysis reveals an asymmetry and a high coherence in noise cross-correlation functions for several station pairs during the typhoon passage, which corresponds to sediment particles and turbulent flows impacting along the riverbed where the river bends sharply. Based on spectral characteristics of the seismic records, we also detected 20 landslide/debris flow events, which we use to estimate the sediment supply. Comparison of sediment flux between seismologically determined bedload and derived suspended load indicates temporal changes in the sediment flux ratio, which imply a complex transition process from the bedload regime to the suspension regime between typhoon passage and off-typhoon periods. Our study demonstrates the possibility of seismologically monitoring river bedload transport, thus providing valuable additional information for studying fluvial bedrock erosion and mountain landscape evolution.

Short-term hydro-thermal scheduling using CMA-ES with directed target to best perturbation scheme

Covariance matrix adaptation evolution strategy with directed target to best perturbation (CMS-ES_DTBP) scheme is applied for determining the optimal hourly schedule of power generation in a hydro-thermal power system. In the proposed approach, a multi-reservoir cascaded hydro-electric system with a nonlinear relationship between water discharge rate, net head and power generation is considered. Constraints such as power balance, water balance, reservoir volume limits and operation limits of hydro and thermal plants are also considered. The feasibility, and effectiveness of the proposed algorithm is demonstrated through a test system, and the obtained results are compared with the existing conventional and evolutionary algorithms. Simulation results reveal that the proposed CMS-ES_DTBP scheme appears to be best in terms of convergence speed and cost compared with other techniques.

Экстремальный дождевой паводок 2014 года в бассейне Верхней Оби: причины, прогноз и натурные наблюдения

Forecasting of inundations caused by spring high-water periods and rainfall floods is of a great social/economic importance. Methods of short-term forecasting are of special signifi cance for solution of operative tasks connected with protection of population and material values, as well as operation of water-work facilities. Big floods at the rivers of our country are regular over the recent years: disastrous flood in Krymsk in 2012 becase of extreme rainfall flood in the Agadum River basin; flooding of vast territories in the Far East due to the rainfall flood in the Amur River basin in 2013. In 2014 heavy rainfall in the Altay foothills caused a major inundation at the Upper Ob basin rivers in Republic of Altay and Altay Kray. The article discusses the reasons of the extreme rainfall flood formation at Altay in 2014. Calculations of the rainfall flood wave propagation at the range from Fominskoye to the Novosibirsk hydro power station dam have been made on the basis of the computer model of flows in the Upper Ob beds system and operative data concerning levels at hydro observation stations. Measurements of water discharge rate at Barnaul have been made during the flood. Outcomes of the predictive computations of levels and field observations data concerning the maximal water discharge rates are discussed. A good agreement of the predicted and observed values has been obtained in terms of maximal levels at the range of the Barnaul hydro observation station. It has been demonstrated that the obtained computer model for description of the Ob River flows can be used for short-term forecasts of floodplains flooding of the Upper Ob and justification of the discharges regime from the Novosibirsk Reservoir.

Оценка максимальных расходов воды реки Каскелен и её притоков.

Оценка максимальных расходов воды реки Каскелен и её притоков.

Determining and plugging the groundwater recharge channel with comprehensive approach in Siwan coal mine, North China coal basin

In North China coal basin, there is an accident: the water which comes from Ordovician system aquifer (O2) discharges into underground coal mines. The coal mining operations would be seriously threatened by this kind of accident. In order to solve this problem, the characteristics of various exploration methods have been discussed. A comprehensive approach involving hydrogeological analysis, geophysical prospecting, hydrogeological drilling, and hydrogeological field test was proposed to explore the groundwater recharge channel. A typical North China coal mine, Siwan coal mine, was taken as an example. The groundwater recharge channel on F8 fault was precisely explored and plugged. After the curtain grouting, the water discharge rate per unit of drawdown was dropped from 12.0 to 7.0 m3/(h m), and the water yield in coal mine was reduced by 600 m3/h. A much safer condition can be provided for Siwan coal mine, avoiding the waste of water resource.

Alteraciones geomorfológicas recientes en los sistemas fluviales mediterráneos de la Península Ibérica: Síntomas y problemas de incisión en los cauces

This work gives and overview of the recent morphological adjustments to Mediterranean fl uvial systems in Spain caused by human action. First, we discuss the main actions affecting the amount and rate of water and sediment discharge. After analyzing the current conditions of instability and natural imbalance in most of these systems, we studies the important changes observed in the morphodynamics of channels and alluvial plains. We then analyze, in detail, the marked increase in bed incision, particularly over the last decades, which has both environmental and socioeconomic impacts, in relation to the management of the hydrological resources and the different actions undertaken in watersheds and waterways.

Transport dynamics of mass failures along weakly cohesive clinoform foresets

AbstractThis study addresses the initiation mechanisms of mass failures on clinoform foresets. Previous studies have created mass flows by releasing dense water–sediment mixtures into standing water, thus imposing the initial conditions for the mass failures rather than allowing them to form on their own. Para‐meters such as the density, composition and initial momentum of the failures are pre‐determined, precluding observation of the factors that set them initially. This study uses a new experimental method that allows a range of mass failures to self‐generate. Building a clinoform using a cohesive mixture of walnut‐shell sand and kaolinite allows the foreset to build up and fail episodically, generating mass failures. Slopes undergo a series of morphological changes prior to failure, creating a concave shape that becomes exaggerated as deposition continues. This morphology leaves the slope in a metastable state. Once the slope is destabilised, failure is initiated. This study investigates the effect of clinoform progradation rates on failure size and frequency by conducting experiments over a range of water and sediment discharge rates. Neither failure size nor failure frequency changes with discharge rate; instead, increases in sediment supply are taken up by changes in the partitioning of sediment between the steep upper foreset and the more gradual delta‐front apron (toeset) below. Sediment is delivered to the delta‐front apron by a form of semi‐continuous slow creep along the foreset. This slow creep is a failure mode that has not received sufficient attention in the submarine mass‐flow literature. The independence of failure size and frequency from sediment supply rate suggests that the presence of mass‐failure deposits does not provide information on the rate of sediment delivery. If these relations hold at field scales, this would imply that individual mass failures are relatively insensitive to changes in water and sediment supply.

Measurement of discharge rate in a canal using radiotracer dilution technique

Measurement of discharge rates of fluids and solids is an essential requirement in industrial and environmental systems. Radiotracer techniques are widely used for measurement of fluids/solids in situations where conventional techniques cannot be applied. The present paper describes application of radiotracer dilution technique to measure the discharge rate of water in a canal with an objective to validate efficiency of the Concrete Volute Pump used for pumping water in the canal. 131I radioisotope having activity of 55.5 GBq was used as radiotracer. The discharge rate of water was measured to be 20.6 m3/s.

Quantitative study on experimentally observed poroelastic behavior of Berea sandstone in two‐phase fluid system

AbstractCoupled two‐phase fluid flow and poroelastic deformation of Berea sandstone is studied through laboratory experiment and numerical simulation. In the experiment, compressed air was infiltrated from the bottom of a water‐saturated cylindrical Berea sandstone sample under hydrostatic external stress condition. Both axial and circumferential strains at half the height of the sample showed sudden extension and monotonic and gradual extension afterward. Numerical simulation based on thermodynamically consistent constitutive equations was conducted in order to quantitatively analyze the experimental results. In a simulation assuming isotropy of material properties, the volumetric discharge rate of water at the outlet and one of the axial, circumferential, and volumetric strains at half the height of the sample were reproduced well by each parameter set, while the other two strains were not. When introducing transverse isotropy, all the experimental data were reproduced well. In addition, the effect of saturation dependency of Bishop's effective stress coefficient on the deformation behavior of porous media was discussed, and it was found that strains, both axial and circumferential, are sensitive to the coefficient.

Short-term environmental/economic hydrothermal scheduling

This paper proposes a new technique based on lexicographic optimization and ɛ-constraint method to solve the combined economic emission scheduling problem of hydrothermal systems comprising several equality constraints as well as non-equality ones. The hydrothermal scheduling problem is modeled as a multi-objective problem with two objective functions as fuel cost minimization and also pollutant emission minimization. After deriving the Pareto set, the most preferred solution is determined using a fuzzy satisfying method. The thermal plants are considered with valve point effect and emission level function. Besides, this paper has taken into consideration the multi-reservoir cascaded configuration of hydro units, while the relationship considered between water discharge rate and power generated through these hydro units is nonlinear. Also, there is a water transport delay between hydro units. The presented model is implemented on a sample test system comprising four cascaded hydro units and three thermal units to verify the efficiency of the proposed method. Furthermore, the proposed method is implemented on IEEE 118 bus test case. The results obtained from the simulation show the effectiveness of the presented technique in the case of fuel cost and emission output compared to other approaches recently used.