Determination of spatial scale of response unit for the WASSI-C eco-hydrological model—a case study on the upper Zagunao River watershed of China

2013 ◽  
Vol 37 (2) ◽  
pp. 132-141 ◽  
Author(s):  
Ning LIU ◽  
Peng-Sen SUN ◽  
Shi-Rong LIU ◽  
Ge SUN
2020 ◽  
Author(s):  
Felipe Sierra ◽  
Jorge Sanabria ◽  
Gerald Corzo ◽  
Germán Santos

<p>Reservoir operation has been a task that always relate to integrated water resources concepts, the rules of such systems require to adapt to changes in the uses of water or in their prioritization. The storage body of La Copa reservoir, located in the upper Chicamocha river basin in Colombia was originally built with the objective of mitigating the floods over the upper Chicamocha valley. However, an irrigation district was latter established, with the objective of supplying water to farmers. This study presents the analysis and optimization of operational rules to minimize the likelihood of floods and shortages for the irrigation district. This is done by contemplating the uncertainty in the hydrological system.</p><p>A methodology is developed to obtain the optimal management and operation of the reservoir, aiming at reducing droughts and flood, which will end up in a regulated basins. A simulation model of the reservoir using the HEC-ResSim tool was used to aim at an optimal guide curve. The guide curve in this study is the base for operational decisions. A continuous simulation hydrological model using the HEC-HMS tool. The model was calibrated using annual series of daily flows as input into the reservoir model.  A two-dimensional hydrodynamic model using (HEC-RAS 2D) was used to test the results of regulation through the comparison of the simulations of the current and optimal regulation conditions.  Several guide curves were developed for the evaluation of the operation. Four of them among are selected and tested using the HEC-ResSim model through the quantification of the minimum and maximum volumes discharge failures. Finally, the guide curve with the least number of failures was selected as the one that provides the best system operation. The benefits of the selected guide curve were verified by the transit of the regulated hydrographs in the 2D hydraulic model. The simulation was carried out in the most period in terms of flows and maximum rainfall, from April 06 to May 15, 2011. The period between April 15 and 21 has the highest flow through the critical sector. On the other hand, unregulated conditions were evaluated using the flows of the hydrological model. It is found that the channel presents a notable improvement, in the simulation of April 15, through the discharges made in a controlled manner from the La Copa reservoir. The methodology presents a simple and practical way to obtain relative optimal operational rules for a multipurpose storage.</p>


TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.


1999 ◽  
Author(s):  
S.E. Church ◽  
D.L. Fey ◽  
E.M. Brouwers ◽  
C.W. Holmes ◽  
Robert Blair

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.


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