scholarly journals Evaluation of Non Damaging Flow for a Set of Upstream Sub Basins in a River System

2016 ◽  
Vol 5 (2) ◽  
pp. 58 ◽  
Author(s):  
Parthasarathi Choudhury ◽  
Sangita Deb Barman ◽  
Jotish Nongthombam

<p class="emsd"><span lang="EN-GB">A model for evaluating non damaging flow for a set of sub basins in a river system is presented. Linear Programming technique incorporating multiple inflows routing scheme is employed to evaluate upstream flow conditions necessary for satisfying specified downstream flood flow conditions. Non damaging flow for the sub basins are determined by using river system properties. The model is applied to a river system in India having flows from gauged and ungauged sub basins; flow contributions from the ungauged basins are estimated by using unit hydrograph technique. Peak flow studies involving major and minor sub basins indicate relative importance of the basins in the study area. Results obtained in the study depict variations in the non-damaging flow with the flow in the main channel. Model applications show that for flood with peaks exceeding 7566 m<sup>3</sup>/s regulating intervening basins only may not lead to safe flow at the downstream section(s). The model allows evaluating effectiveness of controlling the intervening basins in a river system; model applications to a real life river system yield results that are useful in adopting flood control measures for the study area.</span></p>

2013 ◽  
Vol 838-841 ◽  
pp. 1709-1714
Author(s):  
Xiu Yong Yi ◽  
Yang Zhang

Considering topography, climate, river system, and existing problems in Taiyuan, the urban flood control planning in Taiyuan boils down to the following points: determine the flood control standard according to the size of city; study the flood alleviating measures in the upstream area; provide adequate water and soil conservation measures in the mountainous areas reduce flash floods; divert flood from mountainous areas to the downstream area instead of to the urban; improve the river channels in the urban area; provide flood detention and retarding area in the downstream area; study non-engineering flood control measures.


1999 ◽  
Vol 1 (1) ◽  
pp. 33-58 ◽  
Author(s):  
Peter Goodwin ◽  
Thomas B. Hardy

River management is a rapidly evolving science and recent major floods have prompted a re-examination of traditional approaches such as channelization, levees, flood walls and dams. These flood control measures are capital intensive, require significant maintenance costs, only protect local regions, and often require a tradeoff with ecological resources. Further, recent analyses have shown that the intended benefits and hydraulic performances are not achieved. A new paradigm in river management is evolving, which requires a broad range of design objectives to be met that include reduction in flood risks, ecological enhancement, recreation and aesthetics, as well as complying with strict environmental protection legislation. These more complex projects require extensive data and simulation tools to assist decision makers and communities in selecting management strategies which offer the maximum benefits, whilst preserving and enhancing the ecological integrity of the river system. A framework for the systematic analysis of the river ecosystem is outlined and illustrated by examples from the Western U S A.


2020 ◽  
Vol 20 (3) ◽  
pp. 325-332
Author(s):  
Le Nhu Da ◽  
Le Thi Phuong Quynh ◽  
Phung Thi Xuan Binh ◽  
Duong Thi Thuy ◽  
Trinh Hoai Thu ◽  
...  

Recently, the Asian rivers have faced the strong reduction of riverine total suspended solids (TSS) flux due to numerous dam/reservoir impoundment. The Red river system is a typical example of the Southeast Asian rivers that has been strongly impacted by reservoir impoundment in both China and Vietnam, especially in the recent period. It is known that the reduction in total suspended solids may lead to the decrease of some associated elements, including nutrients (N, P, Si) which may affect coastal ecosystems. In this paper, we establish the empirical relationship between total suspended solids and total phosphorus concentrations in water environment of the Red river in its downstream section from Hanoi city to the Ba Lat estuary based on the sampling campaigns conducted in the dry and wet seasons in 2017, 2018 and 2019. The results show a clear relationship with significant coefficient between total suspended solids and total phosphorus in the downstream Red river. It is expressed by a simple equation y = 0.0226x0.3867 where x and y stand for total suspended solids and total phosphorus concentrations (mg/l) respectively with the r2 value of 0.757. This equation enables a reasonable prediction of total phosphorus concentrations of the downstream Red river when the observed data of total suspended solids concentrations are available. Thus, this work opens up the way for further studies on the calculation of the total phosphorus over longer timescales using daily available total suspended solids values.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509e-509
Author(s):  
Robert P. Rice

The Cal Poly philosophy of “Learn and Understand by Doing” has been integrated with problem-based learning and the use of the latest technology to produce a class that closely simulates real-life pest control situations. Goals of the class, Disease and Pest Control Systems for Ornamental Plants, are to teach students pest monitoring, control and problem solving techniques, the use of resources including the internet and journals, and the use of the latest pest control equipment and application techniques. Students are shown pest situations and then work in groups to diagnose the problem, investigate management strategies, apply control measures, and monitor results. Weekly class presentations inform the class of the various projects and help to teach the class organization and presentation skills. Student evaluations and test performance have demonstrated that students achieve class objectives substantially better with the problem-based learning approach than with the previous lecture-based approach to the class.


2009 ◽  
Vol 9 (4) ◽  
pp. 1349-1363 ◽  
Author(s):  
D. Nijssen ◽  
A. Schumann ◽  
M. Pahlow ◽  
B. Klein

Abstract. As a result of the severe floods in Europe at the turn of the millennium, the ongoing shift from safety oriented flood control towards flood risk management was accelerated. With regard to technical flood control measures it became evident that the effectiveness of flood control measures depends on many different factors, which cannot be considered with single events used as design floods for planning. The multivariate characteristics of the hydrological loads have to be considered to evaluate complex flood control measures. The effectiveness of spatially distributed flood control systems differs for varying flood events. Event-based characteristics such as the spatial distribution of precipitation, the shape and volume of the resulting flood waves or the interactions of flood waves with the technical elements, e.g. reservoirs and flood polders, result in varying efficiency of these systems. Considering these aspects a flood control system should be evaluated with a broad range of hydrological loads to get a realistic assessment of its performance under different conditions. The consideration of this variety in flood control planning design was one particular aim of this study. Hydrological loads were described by multiple criteria. A statistical characterization of these criteria is difficult, since the data base is often not sufficient to analyze the variety of possible events. Hydrological simulations were used to solve this problem. Here a deterministic-stochastic flood generator was developed and applied to produce a large quantity of flood events which can be used as scenarios of possible hydrological loads. However, these simulations imply many uncertainties. The results will be biased by the basic assumptions of the modeling tools. In flood control planning probabilities are applied to characterize uncertainties. The probabilities of the simulated flood scenarios differ from probabilities which would be derived from long time series. With regard to these known unknowns the bias of the simulations was considered by imprecise probabilities. Probabilities, derived from measured flood data were combined with probabilities which were estimated from long simulated series. To consider imprecise probabilities, fuzzy sets were used to distinguish the results between more or less possible design floods. The need for such a differentiated view on the performance of flood protection systems is demonstrated by a case study.


1997 ◽  
Vol 22 (4) ◽  
pp. 252-258 ◽  
Author(s):  
Tadahiko Nakao ◽  
Koji Tanimoto

Author(s):  
Anuradha Mathrani ◽  
Sanjay Mathrani

Purpose The paper aims to capture the nuances of two client–supplier relationships to offer new insights on the influences of transactional, knowledge and social elements in outsourcing partnerships. Design/methodology/approach The study has used descriptive case studies with narrative storylines. Interviews were conducted with three relationship managers (boundary gatekeepers) to understand preferred governance practices between clients and suppliers in diverse economic markets. Findings Experiences of three real-life cases engaged in offshore outsourcing have helped to identify the market, operational knowledge and social influences in a relational exchange. Findings reveal that offshore partnerships are first constituted with service-level agreements, which set control measures and layout business expectations from both partners. Boundary gatekeepers bring further accountability across firms by designing social networks for capturing and sharing of knowledge, thereby reducing each partner’s perception of risk. As firms evaluate transactional, knowledge and social elements for building a futuristic relational exchange, more disaggregated and dispersed enterprises evolve as new opportunities are explored in foreign markets. Research limitations/implications The retrospective nature of the client–supplier partnership is a limitation in this research study. However, retrospection adds to experience, and to practice perspectives made in hindsight, and therefore has a positive influence in this study. Originality/value This paper shares real-world experiences that can be used by scholars and practitioners to better understand how relational governance practices operate in a global socio-economic setting.


2011 ◽  
Vol 2 (2) ◽  
pp. 53-59
Author(s):  
Yiau S.S. ◽  
F.J. Putuhena

Probable Maximum Precipitation is defined as the greatest depth of precipitation which is possible for a given time and duration over a given size storm area under known meteorological conditions. This concept has been used as design criterion of major flood control measures such as spillways of large dams worldwide. It is essential for the generation of Probable Maximum Flood. This paper represents the results of PMP analysis for Bakun Dam Area which has a catchment area of 14,750 km2. Three sets of results were produced, i.e. by statistical method (with frequency factors from World Meteorological Organization manual and National Hydraulic Research Institute of Malaysia in Technical Research Publication No. 1 (TRP 1)) for duration of 1 hour, 8 hours, 24 hours and daily and by experimental method for production of daily PMP. The results were compared with each other and the one made by Sarawak Electricity Supply Corporation on Bakun Dam construction. The set of PMP values results from substitution of Km developed by NAHRIM was concluded to be the most reliable results as daily PMP (276mm) was consistent with the one (280mm) produced by SESCO. However, 6 days PMP value (950mm) done by SESCO was recommended as the Bakun Dam Area cover huge catchment area which higher duration of PMP value should be applied .


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