scholarly journals Methods of the Real-time Runoff Account under the Conditions of the Bed Silting (the Matyra River in the village of Krutoye range as a study case)

2017 ◽  
Author(s):  
Keyword(s):  
Real Time ◽  
Discharge Rate ◽  
Water Discharge ◽  
Water Levels ◽  
Accounting Data ◽  
The Real ◽  
Discharge Rates ◽  
Auto Correlation Function ◽  
The Village ◽  
Adequate Reliability

This paper presents the updated method of the real-time runoff calculation in conditions of river channel silting based on the method of optimal extrapolation. The Matyra river used as the example. The results of the analysis of the data obtained by observations of the Matyra River water regime during the period from 1994 to 2013 have been presented. We have analyzed all specific features of the hydrologic regime characteristics alterations under the influence of meteorological factors over the periods of the bed silting. The proposed decisions for real-time runoff account employ basic many-year dependence of the water discharge rates on water levels that have been exactly defined by the latest measurements of the water discharge rate through introduction of corrections that characterize changing of the bed passage ability of the year under consideration. These changes are calculated by the method of optimal extrapolation of the series of relative deviations from many-year water discharge curve calculated over the year under consideration. Assessment of the statistic characteristics of the relative deviation series such as auto-correlation function, dispersion and expectation value has been done to calculate weight coefficients in the optimal extrapolation formulas. Assessment of the proposals effectiveness has been carried out on the basis of the data of realtime and regime runoff accounting over the 2008-2013 period. Root mean square deviations from the regime accounting data were 5–10 %. The obtained results enable to make a conclusion on adequate reliability of the real-time runoff accounting data obtained with the use of the developed methods and to recommend it for real-time accounting of the small and medium-sized considerably silted rivers runoff.

New analytical solution for the study of hydraulic interaction between Alpine tunnels and groundwater

2003 ◽  
Vol 174 (5) ◽  
pp. 441-448 ◽  
Author(s):  
Jean-Christophe Maréchal ◽  
Pierre Perrochet
Keyword(s):  
Analytical Solution ◽  
Surface Waters ◽  
Discharge Rate ◽  
Water Discharge ◽  
Rate Condition ◽  
Type Curves ◽  
Discharge Rates ◽  
The Alps ◽  
Surface Monitoring ◽  
Tunnel Discharge

Abstract The present paper addresses two major problems encountered during tunnel drilling and related to the hydraulic interaction with surrounding groundwater bodies. The first one is the prediction of water discharge into the tunnel, as a function of the geometric and hydrogeological data. The second problem is related to the assessment of the draining effects on surface waters (springs, lakes, wetlands). Surface monitoring campaigns are costly and evaluating their duration is a sensitive question. Both problems are tightly related and depend on aquifer dynamics. It is shown that in a geological context with steeply dipping structures, nearly vertical, inducing series of aquifers and aquicludes such as in the Alps, the drainage of the aquifer by the tunnel can be modelled by the analytical solution of Jacob and Lohman [1952] for artesian wells. First developed for horizontal, confined unsteady flow towards a vertical well with constant drawdown, it is adapted here to a horizontal tunnel by a rotation of π/2. The main difference between this solution and more classical Theis’ solutions is that a constant drawdown condition replaces the constant discharge rate condition. Hence, a relation is obtained for the time-dependent discharge rate Q(t) detected at the tunnel after drilling, as a function of aquifer transmissivity (T), storage coefficient (S), initial drawdown (so) and tunnel radius (ro). This analytical solution is compared to a finite-elements model simulating a draining tunnel in a simplified 2D vertical cross-section. The comparisons show that the decay of the tunnel discharge can be divided into two periods. During the first period, radial drawdown develops around the tunnel and there is excellent match between analytical and numerical results. Tunnel discharge results from the decompression of rock and water (storage effects) as a response to the sudden initial drawdown at the tunnel location. During the second period, the drawdown cone reaches the aquifer limits (lateral and upper) and numerical discharge rates decrease faster than analytical rates because of hydraulic heads decline at the aquifer limits. In the Alps, such trends were observed for the discharge rates into the Simplon and Mont-Blanc tunnels, and the analytical solution of Jacob and Lohman [1952] was applied to the first discharge period to evaluate aquifer transmissivity and storage coefficients. As indicated by the simulations, and corroborated by field observations, the analytical solution is only valid during a first period after tunnel opening, the duration of which scaling with the inverse of the aquifer diffusivity (T/S). In the second part of the paper, dimensionless type-curves are presented to enable rapid evaluation of the time where a given drawdown is observed at a given distance from the tunnel. Accounting for tunnel geometry (radius and depth) and aquifer parametres (T and S), these curves could for instance help in practice to determine when surface waters would start to be affected by a draining tunnel underneath. Although neglecting the boundary effects discussed in the first part of the paper, these type-curves demonstrate the great inertia of mountain aquifers, and could be used to adjust the duration of surface monitoring campaigns according to the specific tunnel/aquifer settings.

A diffusion process model for the optimal operation of a reservoir system

1975 ◽  
Vol 12 (4) ◽  
pp. 859-863 ◽  
Author(s):  
Stanley R. Pliska
Keyword(s):  
Optimal Control ◽  
Diffusion Process ◽  
Process Model ◽  
Discharge Rate ◽  
Water Discharge ◽  
Optimal Operation ◽  
Water Levels ◽  
Control Problems ◽  
Release Rates ◽  
Controlled Diffusion

The water level in a reservoir is modelled as a controlled diffusion process on a compact interval of the real line. The problem is to control the water discharge rate so as to minimise the expected costs, which depend upon the histories of the water levels and release rates. The form of the optimal control is studied for two general classes of reservoir control problems.

scholarly journals Hydrodynamic and Wave Responses During Storm Surges on the Southern Brazilian Coast: A Real-Time Forecast System

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3397
Author(s):  
Arslaan Khalid ◽  
Andre de Souza de Lima ◽  
Felicio Cassalho ◽  
Tyler Miesse ◽  
Celso Ferreira
Keyword(s):  
Water Level ◽  
Real Time ◽  
Extreme Weather ◽  
Coastal Areas ◽  
Water Levels ◽  
Coastal Communities ◽  
Economic Losses ◽  
Forecast System ◽  
The Real ◽  
Daily Weather

Coastal flooding is a global phenomenon that results in severe economic losses, threatens lives, and impacts coastal communities worldwide. While recent developments in real-time flood forecasting systems provide crucial information to support coastal communities during coastal disasters, there remains a challenge to implement such systems in data-poor regions. This study demonstrates an operational real-time coupled surge wave guidance system for the coastal areas of Southern Brazil. This system is based on the recently developed integrated flood (iFLOOD) model, which utilizes the coupled hydrodynamic and phase-averaged ADCIRC–SWAN wave numerical model, driven by astronomical tides and atmospheric forcing from the Global Forecast System (GFS). This numerical modeling framework can simulate water levels and waves with a lead time of 84 h. A version of the coupled ADCIRC–SWAN model calibrated for Brazil, i.e., iFLOOD-Brazil, was operationally implemented (i.e., twice a day) over a period of 4 months (April to September 2020) for normal daily weather validation, as well as during a recent “bomb” cyclone that strongly impacted the southern coast of the country in June 2020. The real-time water levels and waves forecasted by iFLOOD-Brazil showed promising results against observations, with root mean square error (RMSE) values of 0.32 m and 0.68 m, respectively, for normal daily weather. Additionally, the RMSE values were 0.23 m for water levels and 1.55 m for waves during extreme weather, averaged over eight water level and two wave recording stations. In order to improve real-time predictions, a bias correction scheme was introduced and was shown to improve the water level and wave forecasts by removing the known systematic errors resulting from underestimation of astronomical tides and inadequate initial boundary conditions. The bias-corrected forecasts showed significant improvements in forecasted wave heights (0.47 m, 0.35 m) and water levels (0.17 m, 0.28 m) during daily and extreme weather conditions. The real-time iFLOOD-Brazil forecast system is the first step toward developing an accurate prediction model to support effective emergency management actions, storm mitigation, and planning in order to protect these economically valuable and socially vulnerable coastal areas.

scholarly journals KELANGSUNGAN HIDUP BENIH IKAN BETOK (Anabas testudineus, BL) DENGAN DEBIT AIR YANG BERBEDA PADA SISTEM RESIRKULASI

2018 ◽  
Vol 3 (1) ◽  
pp. 12
Author(s):  
Azrianto Azrianto ◽  
Muhammad Sugihartono ◽  
Muarofah Ghofur
Keyword(s):  
Survival Rate ◽  
Discharge Rate ◽  
Water Discharge ◽  
Water Volume ◽  
Anabas Testudineus ◽  
Important Type ◽  
Discharge Rates ◽  
Survival And Growth ◽  
Optimum Water

Fish betok (Anabas testudineus, BL) is a type of fish that live and breed naturally, especially in the swamps of Lebak on the island of Sumatra and Kalimantan. The fish is an important type of fish in public waters. In general, the price of fish cake in Indonesia ranges from Rp 20.000,00 to Rp 40.000,00 per kg for that there needs to be efforts to increase production. The purpose of this research is to know the optimum water discharge rate for survival and growth of fish seeds of betok. This study used four differents water discharge rates, without water discharge, 10 ml / sec, 20 ml / sec and 30 ml / sec. The fish seeds are then stocked into an aquarium with a water volume of 49 liters with a density of 2-tail fish / liter. The results showed that the water discharge rate of 30 ml / sec gave the best survival rate and growth of the best fish seeds.  AbstrakIkan betok (Anabas testudineus, BL) merupakan jenis ikan yang hidup dan berkembang biak secara alami terutama di rawa lebak di Pulau Sumatera dan Kalimantan. Ikan betok merupakan jenis ikan ekonomis penting di perairan umum. Secara umum harga ikan betok di Indonesia berkisar antara Rp 20.000,00 sampai Rp 40.000,00 per kg untuk itu perlu ada upaya penimgkatan produksi. Tujuan penelitian ini untuk mengetahui debit air yang optimal untuk kelangsungan hidup dan pertumbuhan benih ikan betok. Penelitian ini menggunakan 4 perlakuan laju debit air yang berbeda yaitu tanpa debit air, 10 ml/detik, 20 ml/detik dan 30 ml/detik. Benih ikan betok kemudian ditebar ke dalam akuarium dengan volume air sebanyak 49 liter dengan kepadatan benih ikan betok 2 ekor/liter. Hasil penelitian menunjukkan bahwa laju debit air sebanyak 30 ml/detik memberikan tingkat kelangsungan hidup benih ikan betok terbaik.  Kata Kunci : Benih betok, sistem resirkulasi, debit air, kelangsungan hidup, kualitas air

scholarly journals Stochastic modeling of artificial neural networks for real-time hydrological forecasts based on uncertainties in transfer functions and ANN weights

2021 ◽  
Author(s):  
Shiang-Jen Wu ◽  
Chih-Tsung Hsu ◽  
Che-Hao Chang
Keyword(s):  
Real Time ◽  
Transfer Functions ◽  
Prediction Interval ◽  
Forecast Error ◽  
Correction Method ◽  
Study Data ◽  
Water Levels ◽  
Model Verification ◽  
The Real ◽  
Artificial Neural

Abstract This study proposes a stochastic artificial neural network (named ANN_GA-SA_MTF), in which the parameters of the multiple transfer functions considered are calibrated by the modified genetic algorithm (GA-SA), to effectively provide the real-time forecasts of hydrological variates and the associated reliabilities under the observation and predictions given (model inputs); also, the resulting forecasts can be adjusted through the real-time forecast-error correction method (RTEC_TS&KF) based on difference between real-time observations and forecasts. The observed 10-days rainfall depths and water levels (i.e., hydrological estimates) from 2008 to 2018 recorded within the Shangping sub-basin in northern Taiwan are adopted as the study data and their stochastic properties are quantified for simulating 1,000 sets of rainfall and water levels at 36 10-days periods as the training datasets. The results from the model verification indicate that the observed 10-days rainfall depths and water levels are obviously located at the prediction interval (i.e., 95% confidence interval), revealing that the proposed ANN_GA-SA_MTF model can capture the temporal behavior of 10-days rainfall depths and water levels within the study area. In spite of the resulting forecasts with an acceptable difference from the observation, their real-time corrections have evident agreement with the observations, namely, the resulting adjusted forecasts with high accuracy.

A diffusion process model for the optimal operation of a reservoir system

1975 ◽  
Vol 12 (04) ◽  
pp. 859-863
Author(s):  
Stanley R. Pliska
Keyword(s):  
Optimal Control ◽  
Diffusion Process ◽  
Process Model ◽  
Discharge Rate ◽  
Water Discharge ◽  
Optimal Operation ◽  
Water Levels ◽  
Control Problems ◽  
Release Rates ◽  
Controlled Diffusion

The water level in a reservoir is modelled as a controlled diffusion process on a compact interval of the real line. The problem is to control the water discharge rate so as to minimise the expected costs, which depend upon the histories of the water levels and release rates. The form of the optimal control is studied for two general classes of reservoir control problems.

scholarly journals The Real-time Water Discharge Computation in the Conditions of Unsteady Flow (the Yana River in the Verkhoyansk Gaging Section as a Study Case)

2021 ◽  
pp. 51-70
Author(s):  
Keyword(s):  
Unsteady Flow ◽  
Real Time ◽  
Land Surface ◽  
River Flow ◽  
Water Discharge ◽  
Information Support ◽  
The Real ◽  
Reduced Gradient Method ◽  
Daily Monitoring ◽  
Daily Data

The real-time water discharge computation involves practical real-time computation of water discharge values to ensure forecasting and preventing dangerous hydrological phenomena, as well as daily monitoring of river water content and information support for the functioning of water management facilities in river basins. Nowadays the task of the real-time discharge accounting is very relevant. The article presents the outcomes of the study of two methods of computation of the real-time water discharges in the conditions of the unsteady flow that enable to pass to automatic operative accounting of the river flow. The first method is based on using of optimal extrapolation of the relative deviations of the measured water discharges from the reference rating curve obtained from the data of water discharge measurements for previous years. The second method is a new approach based on the Jones formula. The parameters of the Jones formula were obtained from measurements of water discharge over the past years using an optimization tool based on the generalized reduced gradient method. The daily real-time water discharges calculated in two ways were compared with the daily water discharges published in the reference books of the water cadaster «Daily data on the regime and resources of land surface waters». As a result, it was found that both methods can be used for automated real-time water discharge computation in conditions of unsteady flow.

scholarly journals Laboratory modelling of the effects of temporal changes of estuarine-fresh-water discharge rates on the propagation speed of oceanographic coastal currents

2010 ◽  
Vol 664 ◽  
pp. 337-347
Author(s):  
PETER J. THOMAS ◽  
P. F. LINDEN
Keyword(s):  
Discharge Rate ◽  
Water Discharge ◽  
Propagation Speed ◽  
Current Speed ◽  
Discharge Condition ◽  
Kelvin Wave ◽  
Coastal Currents ◽  
Discharge Rates ◽  
The Mean ◽  
Fresh Water Discharge

In this paper, results of laboratory experiments simulating buoyancy-driven coastal currents produced by estuarine discharges into the ocean, are discussed. The responses of the propagation speeds of the currents to increases and decreases of the volumetric discharge rate at the source are investigated. For increasing discharge rate, we find that the mean speed of the current head displays a sharp rise some time after the source discharge condition has changed. In contrast, a decrease of the current speed following a decreasing discharge rate proceeds gradually. The current speed after acceleration or deceleration is found to be equal to the speed that would be expected had the discharge been at the higher or lower rate from the start of the experiment. The relative speed at which the information of the changed discharge condition at the source approaches the advancing current head from upstream, for both increasing and decreasing discharge rates, is found to be approximately one to three times the mean speed of the current. Further, we find that this transmission speed is 0.82±0.20 times the propagation speed of a linear, long interfacial Kelvin wave.

The Real-Time Neural Genesis of a Punchline

2014 ◽  
Author(s):  
Irving Biederman ◽  
Ori Amir
Keyword(s):  
Real Time ◽  
The Real
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