Naturalizing the freezeup regimes of regulated rivers and exploring implications to spring ice‐jam flooding

2021 ◽  
Author(s):  
Spyros Beltaos ◽  
Daniel L. Peters
Keyword(s):  
Regulated Rivers ◽  
Ice Jam

3D Visualization of Ice-Jam Based on Multipatch

2009 ◽  
Vol 11 (2) ◽  
pp. 196-201
Author(s):  
Rulin XIAO ◽  
Fenzhen SU ◽  
Qing WAN ◽  
Yunyan DU ◽  
Yeseng LIU ◽  
...  
Keyword(s):  
3D Visualization ◽  
Ice Jam

Finite element modeling of surge propagation and an application to the Hay River, N.W.T.

1992 ◽  
Vol 19 (3) ◽  
pp. 454-462 ◽  
Author(s):  
F. E. Hicks ◽  
P. M. Steffler ◽  
R. Gerard
Keyword(s):  
Finite Element ◽  
Channel Flow ◽  
Open Channel ◽  
Initial Conditions ◽  
Open Channel Flow ◽  
Kinematic Wave ◽  
Finite Element Scheme ◽  
Flow Problems ◽  
Ice Jam

This paper describes the application of the characteristic-dissipative-Galerkin method to steady and unsteady open channel flow problems. The robust performance of this new finite element scheme is demonstrated in modeling the propagation of ice jam release surges over a 500 km reach of the Hay River in Alberta and Northwest Territories. This demonstration includes the automatic determination of steady flow profiles through supercritical–subcritical transitions, establishing the initial conditions for the unsteady flow analyses. The ice jam releases create a dambreak type of problem which begins as a very dynamic situation then develops into an essentially kinematic wave problem as the disturbance propagated downstream. The characteristic-dissipative-Galerkin scheme provided stable solutions not only for the extremes of dynamic and kinematic wave conditions, but also through the transition between the two. Key words: open channel flow, finite element method, dam break, surge propagation.

Measuring the skill of an operational ice jam flood forecasting system

2021 ◽  
Vol 52 ◽  
pp. 102001
Author(s):  
Brandon S. Williams ◽  
Apurba Das ◽  
Peter Johnston ◽  
Bin Luo ◽  
Karl-Erich Lindenschmidt
Keyword(s):  
Flood Forecasting ◽  
Ice Jam ◽  
Forecasting System

scholarly journals Relative Contribution of the Xiaolangdi Dam to Runoff Changes in the Lower Yellow River

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 521
Author(s):  
Qinghe Zhao ◽  
Shengyan Ding ◽  
Xiaoyu Ji ◽  
Zhendong Hong ◽  
Mengwen Lu ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Sustainable Management ◽  
Yellow River ◽  
Dam Construction ◽  
Regulated Rivers ◽  
Flood Season ◽  
Abrupt Changes ◽  
Runoff Changes ◽  
Seasonal Runoff

Human activities are increasingly recognized as having a critical influence on hydrological processes under the warming of the climate, particularly for dam-regulated rivers. To ensure the sustainable management of water resources, it is important to evaluate how dam construction may affect surface runoff. In this study, using Mann–Kendall tests, the double mass curve method, and the Budyko-based elasticity method, the effects of climate change and human activities on annual and seasonal runoff were quantified for the Yellow River basin from 1961–2018; additionally, effects on runoff were assessed after the construction of the Xiaolangdi Dam (XLD, started operation in 2001) on the Yellow River. Both annual and seasonal runoff decreased over time (p < 0.01), due to the combined effects of climate change and human activities. Abrupt changes in annual, flood season, and non-flood season runoff occurred in 1986, 1989, and 1986, respectively. However, no abrupt changes were seen after the construction of the XLD. Human activities accounted for much of the reduction in runoff, approximately 75–72% annually, 81–86% for the flood season, and 86–90% for the non-flood season. Climate change approximately accounted for the remainder: 18–25% (annually), 14–19% (flood season), and 10–14% (non-flood season). The XLD construction mitigated runoff increases induced by heightened precipitation and reduced potential evapotranspiration during the post-dam period; the XLD accounted for approximately 52% of the runoff reduction both annually and in the non-flood season, and accounted for approximately −32% of the runoff increase in the flood season. In conclusion, this study provides a basic understanding of how dam construction contributes to runoff changes in the context of climate change; this information will be beneficial for the sustainable management of water resources in regulated rivers.

FIELD SURVER OF ICE JAM IN MARCH 2020 AND EVALUATION OF ICE JAM OCCURANCE RISK

2020 ◽  
Vol 76 (2) ◽  
pp. I_157-I_162
Author(s):  
Hiroshi YOKOYAMA ◽  
Yasuhiro YOSHIKAWA ◽  
Yu INAMI ◽  
Hiroki YABE
Keyword(s):  
Ice Jam

Emerging mitigation measures and strategies are needed for riverine ecology to ensure sustainable hydropeaking production in Norway 

2021 ◽  
Author(s):  
Jo Halvard Halleraker ◽  
Mahmoud S. R. Kenawi ◽  
Jan Henning L’Abée - Lund ◽  
Anders G. Finstad ◽  
Knut Alfredsen
Keyword(s):  
Biological Indicators ◽  
Ecological Impacts ◽  
Mitigation Strategies ◽  
Mitigation Measures ◽  
National Database ◽  
Political Agenda ◽  
Regulated Rivers ◽  
Hydropower Production ◽  
Multiple Pressures ◽  
Environmental Requirements

&lt;p&gt;&lt;strong&gt;Riverine biodiversity&lt;/strong&gt; is threatened with severe degradation from multiple pressures worldwide. One of the key pressures in European rivers are hydromorphological alterations. Rehabilitation of river habitats is accordingly high on the political agenda at the start of UN decade of ecological restoration (2021-2030).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Water storage&lt;/strong&gt; for hydropower production (HP) has severe impacts on aquatic ecology in Norway, with more than 3000 water bodies designated as heavily modified due to hydropower. Norway is the largest hydropower producer in Europe with a huge amount of high head storage schemes. Ca 86 TWh of this is&amp;#160;storage hydropower, which constitutes more than 50% of the total in Europe. This makes Norway a potentially significant supplier of hydropeaking services. Flexible hydropower operations are crucial for EUs Green Deal in balancing electricity from renewable intermittent power generation such as wind and solar.&amp;#160;&lt;/p&gt;&lt;p&gt;Many Norwegian &lt;strong&gt;HP licenses&lt;/strong&gt; were issued before modern environmental requirements evolved. Few are re-licensed with emerging strategies to mitigate hydropeaking. Still, there seems to be a common understanding of relevant mitigation strategies emerging between many large hydropower producers. For example, flow ramping from hydropower tailrace water with direct outlet into fjords or other lake reservoirs may be less environmentally harmful than outlet into riverine habitat.In this study, we have assessed the Norwegian hydropower portfolio of more than 1600 HP facilities constructing a national database focusing on the knowledge base for assessing potential downstream hydropower ecological impacts. The ecological severity of such flow ramping and the restoration/mitigation potential, may depend on;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;About 51 % of the HPs (ca&lt;strong&gt; 80TWh&lt;/strong&gt;) have tailrace into shorter rivers (&lt;1 km) or directly into fjords or lake/reservoirs. Many of the largest HPs are in this category (e.g 50 HP&gt; 500 MW). Close to 800 HP might have downstream impacts on rivers (&gt; 0.5 km; about 49 % of all HP, in total of ca&lt;strong&gt; 56 TWh&lt;/strong&gt;). Probably &lt;strong&gt;&gt; 3 000 km of regulated rivers&lt;/strong&gt; in Norway therefor might need more ecosystem-based mode of HP operation.&amp;#160;&lt;strong&gt;Flow ramping analysis: &lt;/strong&gt;&amp;#160;Ecosystem-based HP operational rules are established in a selection of sustainably managed Norwegian rivers, still with significant baseload production (0.35-0.76 - TWh annual prod). However, eco-friendly mode of operation seems to be rare as our analysis indicate that flow ramping with potential ecological degradation seems widespread in many rivers. Surprisingly, even in many with operational ramping restriction as required mitigation.Our database may be further improved and updated (with e.g. more flow ramping data and biological indicators) and serve as a basis for a national hydropeaking strategy, and hence make more of the Norwegian hydropower portfolio in line with the EUs sustainability taxonomy.&lt;/p&gt;

scholarly journals Effect of discharge and upstream jam angle on the flow distribution beneath a simulated ice jam

2019 ◽  
Vol 46 (5) ◽  
pp. 413-423 ◽  
Author(s):  
Baafour Nyantekyi-Kwakye ◽  
Tanzim Ahmed ◽  
Shawn P. Clark ◽  
Mark F. Tachie ◽  
Karen Dow
Keyword(s):  
Pressure Gradient ◽  
Power Law ◽  
Reynolds Shear Stress ◽  
Measurement Techniques ◽  
Adverse Pressure Gradient ◽  
Mean Bias Error ◽  
Bias Error ◽  
Particle Image Velocimetry System ◽  
Ice Jam ◽  
Two Parameter

The velocity field beneath simulated rough ice jams under various upstream jam angles and discharge were investigated using a particle image velocimetry system. Three discharges were examined at 2.3 L/s, 3.4 L/s, and 4.0 L/s and two upstream ice jam angles were tested at 4° and 6°. Increasing the discharge resulted in high turbulence production beneath the jam. The adverse pressure gradient exerted on the flow increased the levels of the Reynolds shear stress. The measured velocities beneath the jam were used to assess the performances of three traditional field measurement techniques as well as the validity of the two-parameter power law. The two-point measurement technique performed remarkably well with the least mean bias error of 2.0%. The error associated with the different techniques showed their inability to accurately predict the average velocity under high discharge. The two-parameter power law accurately predicted velocity profiles within the equilibrium section of the jam, but failed within the boundary layers when the flow was subjected to a pressure gradient.

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