scholarly journals Influence of reservoir shape upon the choice of Hydraulic vs. Hydrologic reservoir routing method

2019 ◽  
Vol 85 ◽  
pp. 07001 ◽  
Author(s):  
Cristina Sorana Ionescu ◽  
Daniela Elena Gogoaşe Nistoran
Keyword(s):  
Continuity Equation ◽  
The Other ◽  
Initial Water ◽  
Control Structures ◽  
Backwater Effect ◽  
Hydraulic Method ◽  
Reservoir Routing ◽  
Saint Venant Equations ◽  
Routing Method ◽  
Routing Methods

The objective of the paper is to compare the hydrologic and hydraulic reservoir routing methods in term of assumptions, equations, numerical computation procedures, necessary data and advantages-disadvantages of their use. To test the results provided by the two methods, a set of two reservoirs from Romania was chosen: one long and narrow and the other one roundly shaped. Corresponding inflow hydrographs were chosen, and similar conditions were imposed for the outflow dam control structures, namely the initial water level in the reservoir to be at the Spillway Crest Level (SCL) and no outflow control. For the hydrologic method the Puls procedure was used and a program was written in Scilab to solve the continuity equation in finite differences. For the hydraulic method HEC-RAS software was used to solve the 1D Saint-Venant equations. Outflow and stage hydrographs at the dam were compared together with the stage hydrograph at the reservoir tail for the hydraulic method. Results show that the hydraulic method should be used for the long and narrow reservoirs, as it considers the backwater effect, whereas the hydrologic method can be efficiently used for all other reservoirs where this effect is negligible.

scholarly journals Assessment of Discharge and Sediment Flows in a River Through a Combined Hydraulic and Hydrologic Routing Technique

2021 ◽  
Author(s):  
Abebe Tadesse Bulti
Keyword(s):  
Regression Model ◽  
River Basin ◽  
Swat Model ◽  
Model Performance ◽  
Simulation Models ◽  
Flood Routing ◽  
Recent Approach ◽  
Routing Method ◽  
Routing Techniques ◽  
Routing Methods

Abstract An advancement on flood routing techniques is important for a good perdiction and forecast of the flow discharge in a river basins. Hydraulic and hydrologic routing techniques are widely applied in most simulation models separately. A combined hydrologic and hydraulic routing method is a recent approach that used to improve the modeling effort in hydrological studies. The main drawback of hydrologic routing methods was inaccuracy on downstream areas of the river basin, where the effect of hydraulic structures and the river dynamics processes are dominant. The hydraulic routing approaches are relatively good on a downstream reaches of a river. This research was done on the Awash River basin, at the upstream areas of a Koka dam. A combined hydrologic and hydraulic approach was used to assess the discharge and sediment flow in the river basin. The hydrologic routing method was applied at an upstream part of a river basin through a SWAT model. HEC-RAS model was applied at the middle and downstream areas of the study basin based on hydraulic routing principle. A combined routing method can improve the result from a simulation process and increases an accuracy on a prediction of the peak flow. It can simulate a flow discharges for both short and long-term duration, with good model performance indicators. Besides, sediment modeling was done by comparing a regression model, SWAT model, and combination of HEC-RAS and SWAT model. The result from the sediment modeling indicates that the regression model and combined model show good agreement in predicting the suspended sediment in the river basin. The integrated application of such different type of models can be one of the option for sediment modeling.

On the Mechanism and the Rate of Sub-Ground Erosion in the Loess Material

2011 ◽  
Vol 233-235 ◽  
pp. 2528-2531 ◽  
Author(s):  
Xi An Li ◽  
Qiang Xu ◽  
Hong Zhou Lin ◽  
Wan Jun Ye
Keyword(s):  
Critical Condition ◽  
Theoretical Basis ◽  
Field Survey ◽  
Influential Factors ◽  
The Other ◽  
Initial Water Content ◽  
Key Factors ◽  
Erosion Process ◽  
Initial Water ◽  
The Relationship

Sub-ground erosion often resulted in severe problems in various engineering constructions, most of which is due to the sub-erosion in loess. In this paper, the critical condition of “soil bursting” was analyzed and the formula describing the critical condition of soil bursting was derivated by the analytical method. Furthermore, the velocity of tunnel-erosion in loess and its influential factors were studied. A set of tests are designed to study the relationship between the tunnel-erosion velocity and the key influential factors. The key factors considered in the test include soil density as well as the initial water content. The other purpose is to reveal the characteristics of the tunnel-erosion process. Phenomena observed during the tests together with the data from field survey revealed the mechanism of tunneling in loess very well, and the work in this paper formed a theoretical basis for further study about sub-ground erosion in loess.

scholarly journals Comparison of generalized non-data-driven lake and reservoir routing models for global-scale hydrologic forecasting of reservoir outflow at diurnal time steps

2020 ◽  
Vol 24 (5) ◽  
pp. 2711-2729 ◽  
Author(s):  
Joseph L. Gutenson ◽  
Ahmad A. Tavakoly ◽  
Mark D. Wahl ◽  
Michael L. Follum
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Model Performance ◽  
Global Scale ◽  
Army Corps ◽  
Time Step ◽  
Large Spatial Scale ◽  
Reservoir Routing ◽  
Routing Methods ◽  
Improved Model

Abstract. Large-scale hydrologic forecasts should account for attenuation through lakes and reservoirs when flow regulation is present. Globally generalized methods for approximating outflow are required but must contend with operational complexity and a dearth of information on dam characteristics at global spatial scales. There is currently no consensus on the best approach for approximating reservoir release rates in large spatial scale hydrologic forecasting, particularly at diurnal time steps. This research compares two parsimonious reservoir routing methods at daily steps: Döll et al. (2003) and Hanasaki et al. (2006). These reservoir routing methods have been previously implemented in large-scale hydrologic modeling applications and have been typically evaluated seasonally. These routing methods are compared across 60 reservoirs operated by the U.S. Army Corps of Engineers. The authors vary empirical coefficients for both reservoir routing methods as part of a sensitivity analysis. The method proposed by Döll et al. (2003) outperformed that presented by Hanasaki et al. (2006) at a daily time step and improved model skill over most run-of-the-river conditions. The temporal resolution of the model influences model performances. The optimal model coefficients varied across the reservoirs in this study and model performance fluctuates between wet years and dry years, and for different configurations such as dams in series. Overall, the method proposed by Döll et al. (2003) could enhance large-scale hydrologic forecasting, but can be subject to instability under certain conditions.

scholarly journals Roughness Effect of Submerged Groyne Fields with Varying Length, Groyne Distance, and Groyne Types

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1253 ◽  
Author(s):  
Ronald Möws ◽  
Katinka Koll
Keyword(s):  
Flow Resistance ◽  
Relative Increase ◽  
Design Guidelines ◽  
Water Levels ◽  
Constant Field ◽  
Initial Water ◽  
Mobile Bed ◽  
Wake Interference ◽  
Backwater Effect ◽  
Varying Length

Design guidelines were developed for a number of in-stream structures; however, the knowledge about their morphological and hydraulic function is still incomplete. A variant is submerged groynes, which aim to be applicable for bank protection especially in areas with restricted flood water levels due to their shallow height. Laboratory experiments were conducted to investigate the backwater effect and the flow resistance of submerged groyne fields with varying and constant field length and groyne distance. The effect of the shape of a groyne model was investigated using two types of groynes. The validity of different flow types, from “isolated roughness” to “quasi smooth”, was analyzed in relation to the roughness density of the groyne fields. The results show a higher backwater effect for simplified groynes made of multiplex plates, compared to groynes made of gravel. The relative increase of the upstream water level was lower at high initial water levels, for short length of the groyne field, and for larger distance between the single groynes. The highest roughness of the groyne fields was found at roughness densities, which indicated wake interference flow. Considering a mobile bed, the flow resistance was reduced significantly.

scholarly journals Effect of Salinity Adaptation Technique on Survival and Growth Rate of Patin Catfish, Pangasius sp.

2007 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
K. Nirmala ◽  
D.P. Lesmono ◽  
D. Djokosetiyanto
Keyword(s):  
Growth Rate ◽  
The Other ◽  
Water Salinity ◽  
Salinity Adaptation ◽  
Initial Water ◽  
Growth And Survival ◽  
Survival And Growth

<p>This study was carried out to determine the effect of salinity adaptation techniques on growth and survival of patin catfish <em>Pangasius</em> sp. fry.  Fry of 1.5-2.0 inch in length were reared in the water with different of the initial salinity of 1, 2, 3, 4 and 5 ppt.  Salinity was then daily increased by duplicated the initial water salinity until fish died.  The results of study showed that fry could survive by initial salinity adaptation of 1 ppt and then increasing the salinity by 1 ppt/day to reach 27 ppt.  In the other treatments, all fry died after the salinity reach 18-25 ppt.</p> <p>Keywords: patin catfish, <em>Pangasius</em>, adaptation, salinity</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini bertujuan untuk mengetahui pengaruh teknik adaptasi salinitas terhadap pertumbuhan dan kelangsungan hidup benih ikan patin <em>Pangasius </em>sp.  Benih patin ukuran 1,5-2 inci dipelihara pada salinitas awal berbeda, yaitu 1, 2, 3, 4 dan 5 ppt. Salinitas air pemeliharaan ditingkatkan kelipatan dari salinitas awal setiap hari hingga ikan mati.  Hasil penelitian menunjukkan bahwa adaptasi salinitas awal 1 ppt dan peningkatan sebesar 1ppt/hari menyebabkan ikan dapat bertahan hidup sampai pada salinitas 27 ppt. Pada perlakuan lainnya, benih ikan mengalami kematian masal ketika salinitas mencapai 18-25 ppt.</p> <em>Kata kunci</em>: ikan patin, <em>Pangasius</em>, adaptasi, salinitas

Integration of 3D-Routing for the Design of Molded Interconnect Devices

2010 ◽  
Vol 139-141 ◽  
pp. 1109-1112
Author(s):  
Yong Zhuo
Keyword(s):  
Two Dimensions ◽  
The Other ◽  
Design System ◽  
Circuit Boards ◽  
Grid Graph ◽  
A Algorithm ◽  
Printed Circuit ◽  
Routing Methods ◽  
Effective Product ◽  
Molded Interconnect Devices

One of the fundamental innovations in the field of mechatronics is the direct material integration of mechanical and electronic functions using Molded Interconnect Devices (MID technology). Unlike conventional circuit boards, they are not limited to two dimensions but offer the possibility to arbitrarily lay printed circuit traces on the surfaces of the 3D carrier, traditional 2D routing function in EDA cannot be directly applied in MID design. In this paper, two new 3D automatic routing methods are introduced. One method is based on a grid graph and extends Hadlock’s minimum detour algorithm; the other is gridless and combines the A*-algorithm and an extension of Hightower’s algorithm. The related 3D routing functions, which are not supported by conventional MCAD und ECAD systems, are integrated in the design system MIDCAD. With these 3D routing functions, MIDCAD enables a more effective product design based on the MID technology.

scholarly journals Quasi-online flood forecasting downstream of dams based on rainfall thresholds

2013 ◽  
Vol 45 (4-5) ◽  
pp. 519-528 ◽  
Author(s):  
Bahram Saghafian ◽  
Saeed Golian ◽  
Hossein Khodadadi
Keyword(s):  
Cross Sections ◽  
Flood Control ◽  
Flood Forecasting ◽  
Rainfall Threshold ◽  
Risk Tolerance ◽  
Initial Water ◽  
Reservoir Routing ◽  
Prone Area ◽  
Southwestern Iran ◽  
Water Elevation

Dams are built to supply water to users and often to protect people and properties against floods in downstream areas. Efficiency of dams for flood control is improved substantially if a flood forecasting system is implemented. Rainfall threshold (RT) depths correspond to the occurrence of critical discharge at given cross-sections for given rainfall durations and initial soil moisture conditions of the upstream watershed. Here, we present an RT-based approach for offline flood forecasting downstream of dams. The proposed methodology incorporates rainfall-runoff and reservoir routing models while the spatial distribution of rainfall is probabilistically modeled based on a Monte Carlo approach. The RT curves are derived as a function of initial water elevation in the reservoir. The algorithm is implemented for a flood-prone area downstream of a dam in southwestern Iran. The results showed a clear rise in the RT values compared to the no-dam case, which is mainly due to the reservoir routing effect. The rate of rise in the RT values decreased with higher initial water elevation in the reservoir. The proposed method also provides the operator with the flexibility of adopting one of the various RT curves subject to different probabilities based on risk tolerance.

4 + n-Dimensional Water and Waves on Four and Eleven-Dimensional Manifolds

2018 ◽  
Author(s):  
Alireza Sepehri
Keyword(s):  
Gravitational Waves ◽  
Extra Dimensions ◽  
The Other ◽  
Water Type ◽  
Dimensional Manifold ◽  
Initial Water ◽  
Four Dimensions ◽  
Structure Of Water ◽  
Water Properties

In this paper, we consider the structure of water and waves from viewpoints of two observers, one lives on 4-dimensional manifold and another lives on 11-dimensional manifold. On four dimensional manifold, water emit waves which contain some packages of information about it's structures. If these packages achieve to the second water, produce some structures like the structures of initial water in it. If first water contain molecules of DNA, it's structures change and consequently emit different packages of information. These new packages give their information to second water and produce new structures which are affected by the existence of DNA molecules. By using the PCR and other mechanisms for second water, we can extract exact information about the initial water. Type of packings of DNAs in men is different from women. Consequently, their radiated waves are different and for storing their information, we need to two types of water. However on four dimensional manifold, the structures of water are approximately the same. There is a probability that differences between various types of water could be observed in extra dimensions. On the other hand, waves that interact with water in extra dimensions can play the role of topoisomerases in biology on 11-dimensional manifold. They open packings of DNA, read it's information and transmit it to water. Properties of these topoisomerse-like waves are dierent from electromagnetic and gravitational waves. However,by reducing dimensions from 11 to 4, these waves become similar to known waves in four dimensions. For this reason, we consider the probable structures of water and waves in extra dimensions.

Evaluation of the joint effects of DEM resolution and calculation cell size on discharge simulation performance with two routing methods

2020 ◽  
Author(s):  
Jingjing Li ◽  
Hua Chen ◽  
Chong-Yu Xu ◽  
Haoyuan Zhao ◽  
Lu Li ◽  
...  
Keyword(s):  
Cell Size ◽  
Easy Access ◽  
Runoff Generation ◽  
Hydrological Simulation ◽  
Dem Resolution ◽  
Simulation Performance ◽  
Source To Sink ◽  
Discharge Simulation ◽  
Routing Method ◽  
Routing Methods

&lt;p&gt;Benefit from the easy access to gridded hydrological datasets and global Digital Elevation Model (DEM) datasets, DEM-based routing methods have been widely developed and used. The routing methods can be divided into two categories, i.e., Source-to-Sink and Cell-to-Cell. Limited by the computation capabilities, routing methods are often performed at more coarse resolution of calculation cell rather than the resolution of DEM. Both the DEM resolution and calculation cell-size are factors that affect the discharge simulation performance of routing method. Too little work has been devoted to how these two factors affect routing performance jointly. This study aims to compare the effects of DEM resolution and calculation cell-size on discharge simulation performance with two most popular routing methods, including a Cell-to-Cell routing method, i.e., Liner-reservoir-routing method (LRR) and a Source-to-Sink routing method, i.e., the improved aggregated network-response function routing method (I-NRF). They are compared/evaluated in terms of the changes of simulation performance with calculation cell-size ranging from 5 arc-minutes to 60 arc-minutes and DEM resolutions of 90 m&amp;#215;90 m, 250 m&amp;#215;250 m, 500 m&amp;#215;500 m, 1000 m&amp;#215;1000 m. Besides, two hydrological runoff-generation models and two study basins are used to test the generality of the result. The study finding will help the researchers to choose the appropriate DEM resolution, calculation cell-size and routing method in hydrological simulation.&lt;/p&gt;

scholarly journals Advances in IP Micromobility Management Using a Mobility-Aware Routing Protocol

2007 ◽  
Vol 2007 ◽  
pp. 1-4
Author(s):  
Michael Georgiades ◽  
Kar Ann Chew ◽  
Rahim Tafazolli
Keyword(s):  
Routing Protocol ◽  
Mobility Management ◽  
Mobile Ip ◽  
Ip Address ◽  
Delivery Delay ◽  
Mobility Management Protocols ◽  
Cellular Ip ◽  
Routing Method ◽  
End To End ◽  
Routing Methods

Several micromobility schemes have been proposed to augment Mobile IP and provide a faster and smoother handoff than what is achievable by Mobile IP alone, the majority of which can be categorized into either “network prefix-based” or “host-specific forwarding” mobility management protocols, depending on the routing method used. This letter proposes a mobility-aware routing protocol (MARP) which makes use of both of these routing methods using dynamic IP address allocation. Its performance is evaluated and compared against hierarchical Mobile IP (HMIP) and Cellular IP based on handoff performance, end-to-end delivery delay, and scalability. The results demonstrate that MARP is a more robust, flexible, and scalable micromobility protocol, minimizes session disruption, and offers improvements in handoff performance.

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