scholarly journals Mathematical modeling of flow hydraulics as a result of the development of the NSM channel open pit (on the example of the Tom river)

2021 ◽  
Vol 2131 (3) ◽  
pp. 032070
Author(s):  
T Pilipenko ◽  
T Mikhailova ◽  
D Panov

Abstract Active development of channel pits has begun with the aim of extracting nonmetallic building materials for the construction of cities and towns. When developing open pits, violations and non-fulfillment of compensatory measures in the river bed are possible. As a result of nonfulfillment of these measures, changes in the level regime of the river occur. All these actions lead to disastrous consequences. Therefore, the article considers the section of the Tom River. In its channel it is planned to develop a quarry of nonmetallic building materials. For the section of the quarry, the landing of the water level was determined, through a change in the slope of the free surface and the total drop in the water level. the change in flow rates in the everyday state was analyzed, development of the open pit was taken into account. To visually display the depth of the open pit, a matrix of heights was formed at the site of the Popadeykin deposit of sand and gravel materials. Based on the elevation matrix, a 3-D model of the pit was built, both before and after dredging. According to the data obtained, a possible change in speeds after the development of a quarry was predicted in comparison with domestic ones. The intervals of the velocity of the eroding and non-eroding flow were calculated.

2021 ◽  
Vol 410 ◽  
pp. 778-783
Author(s):  
Pavel V. Matyukhin ◽  
Daler I. Mirzoev

The paper presents the results of ferriferous wastes modification process research carried on the basis of JCS “Leninobad rare metals Plant” located in the Republic of Tajikistan. The wastes for the study were taken from the western tailing. The article presents the justification of the chosen wastes as a filling material in the development of new radiation protective composite building materials. The data on the initial ferriferous chemical composition of the tailing wastes and the chemical composition of the material that passed the enrichment process is presented. The study contains microphotos of ferriferous haematite raw material particles surface before and after completing the modifying process. The paper presents and describes the study of X-ray phase analysis diffractograms of enriched iron-containing wastes before and after the modification process. The current research proves that the enrichment ferriferous wastes particles modification process is possible and as a result it can be used as a filling for the development of new kinds of radioprotective composite materials.


2021 ◽  
pp. 1-8
Author(s):  
Zilca Campos ◽  
Fábio Muniz ◽  
William E. Magnusson ◽  
Guilherme Mourão

Abstract The Belo Monte hydroelectric dam on the Xingu River has the third largest generating capacity of any hydroelectric dam in the world. We conducted surveys of crocodilians (Caiman crocodilus, Paleosuchus trigonatus) by boat in the Xingu River at the site of the dam prior to (2013-2015), and after filling (2016-2017). While the number of C. crocodilus sighted decreased with increasing water level, there was no difference in numbers prior to, and after reservoir filling. The number of P. trigonatus was unaffected by both water level prior to and after reservoir filling. Reservoir filling had little effect on the number of crocodilians using the forest around the Xingu River reservoir. Most crocodilians seen in forest surveys were P. trigonatus, both before and after reservoir filling, but C. crocodilus was recorded occasionally in the forest. It seems that most Amazonian crocodilians are sufficiently generalist to adapt to the new conditions created by the construction of dams, at least in the short-term. However, there may be long-term collateral effects on crocodilian populations from dams, due to as deforestation and improved access for hunters.


2015 ◽  
Vol 19 (6) ◽  
pp. 2663-2672 ◽  
Author(s):  
A.-M. Kurth ◽  
C. Weber ◽  
M. Schirmer

Abstract. In this study, we investigated whether river restoration was successful in re-establishing groundwater–surface water interactions in a degraded urban stream. Restoration measures included morphological changes to the river bed, such as the installation of gravel islands and spur dykes, as well as the planting of site-specific riparian vegetation. Standard distributed temperature sensing (DTS) and novel active and passive DTS approaches were employed to study groundwater–surface water interactions in two reference streams and an experimental reach of an urban stream before and after its restoration. Radon-222 analyses were utilized to validate the losing stream conditions of the urban stream in the experimental reach. Our results indicated that river restoration at the study site was indeed successful in increasing groundwater–surface water interactions. Increased surface water downwelling occurred locally at the tip of a gravel island created during river restoration. Hence, the installation of in-stream structures increased the vertical connectivity and thus groundwater–surface water interactions. With the methods presented in this publication, it would be possible to routinely investigate the success of river restorations in re-establishing vertical connectivity, thereby gaining insight into the effectiveness of specific restoration measures. This, in turn, would enable the optimization of future river restoration projects, rendering them more cost-effective and successful.


Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6110
Author(s):  
Qin Li ◽  
Xiuguo Liu ◽  
Yulong Zhong ◽  
Mengmeng Wang ◽  
Manxing Shi

As the largest hydroelectric project worldwide, previous studies indicate that the Three Gorges Dam (TGD) affects the local climate because of the changes of hydrological cycle caused by the impounding and draining of the TGD. However, previous studies do not analyze the long-term precipitation changes before and after the impoundment, and the variation characteristics of local precipitation remain elusive. In this study, we use precipitation anomaly data derived from the CN05.1 precipitation dataset between 1988 and 2017 to trace the changes of precipitation before and after the construction of the TGD (i.e., 1988–2002 and 2003–2017), in the Three Gorges Reservoir Area (TGRA). Results showed that the annual and dry season precipitation anomaly in the TGRA presented an increasing trend, and the precipitation anomaly showed a slight decrease during the flood season. After the impoundment of TGD, the precipitation concentration degree in the TGRA decreased, indicating that the precipitation became increasingly uniform, and the precipitation concentration period insignificantly increased. A resonance phenomenon between the monthly average water level and precipitation anomaly occurred in the TGRA after 2011 and showed a positive correlation. Our findings revealed the change of local precipitation characteristics before and after the impoundment of TGD and showed strong evidence that this change had a close relationship with the water level.


2017 ◽  
Vol 16 (4) ◽  
pp. 298-303
Author(s):  
E. I. Mikhnevich

Territory protection against flood water inundation and creation of polder systems are carried out with the help of protection dikes. One of the main requirements to the composition of polder systems in flood plains is a location of border dikes beyond meander belt in order to avoid their erosion when meander development occurs. Meander belt width can be determined on the basis of the analysis of multi-year land surveying pertaining top river-bed building and in the case when such data is not available this parameter is calculated in accordance with the Snishchenko formula. While banking-up a river bed a flooded area is decreasing and, consequently, water level in inter-dike space and rate of flood water are significantly increasing. For this reason it is necessary to locate dikes at a such distance from a river bed which will not cause rather high increase in water level and flow velocity in the inter-dike space. Methodology for hydraulic calculation of river regulation has been developed in order to substantiate design parameters for levee systems, creation of favourable hydraulic regime in these systems and provision of sustainability for dikes. Its main elements are calculations of pass-through capacity of the leveed channel and rise of water level in inter-dike space, and distance between dikes and their crest level. Peculiar feature of the proposed calculated formulae is an interaction consideration of channel and inundated flows. Their mass-exchanging process results in slowing-down of the channel flow and acceleration of the inundated flow. This occurrence is taken into account and coefficients of kinematic efficiency are introduced to the elements of water flow rate in the river channel and flood plain, respectively. The adduced dependencies for determination of a dike crest level (consequently their height) take into consideration a rise of water level in inter-dike space for two types of polder systems: non-inundable (winter) dikes with maximum spring flood rate and inundable (summer) dikes with summer-autumn flood rates. The proposed calculated formulae can be recommended for application at design organizations.


2020 ◽  
Vol 8 (12) ◽  
pp. 979
Author(s):  
Wei Huang ◽  
Chunyan Li

In this paper, subtidal responses of Barataria Bay to an atmospheric cold front in 2014 and Hurricane Barry of 2019 are studied. The cold fronts had shorter influencing periods (1 to 3 days), while Hurricane Barry had a much longer influencing period (about 1 week). Wind direction usually changes from southern quadrants to northern quadrants before and after a cold front’s passage. For a hurricane making its landfall at the norther Gulf of Mexico coast, wind variation is dependent on the location relative to the location of landfall. Consequently, water level usually reaches a trough after the maximum cold front wind usually; while after the maximum wind during a hurricane, water level mostly has a surge, especially on the right-hand side of the hurricane. Water level variation induced by Hurricane Barry is about 3 times of that induced by a cold front event. Water volume flux also shows differences under these two weather types: the volume transport during Hurricane Barry was 4 times of that during a cold front. On the other hand, cold front events are much more frequent (30–40 times a year), and they lead to more frequent exchange between Barataria Bay and the coastal ocean.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nils Reidar B. Olsen ◽  
Stefan Haun

AbstractSoil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical model used for the simulation of reservoir flushing that includes the slide movements. The geotechnical failure algorithms start with modelling the groundwater levels at the banks of the reservoir. A limit equilibrium approach is further used to find the location of the slides. The actual movement of the sediments is computed by assuming the soil to be a viscous liquid and by solving the Navier–Stokes equations. The resulting bed elevation changes from the slides are computed in adaptive grids that change as a function of water level, bed erosion and slide movements. The numerical model is tested on the Bodendorf reservoir in Austria, where field measurements are available of the bank elevations before and after a flushing operation. The results from the numerical simulations are compared with these observations. A parameter test shows that the results are very sensitive to the cohesion and less sensitive to the E and G modules of the soil.


2018 ◽  
Vol 38 ◽  
pp. 03042
Author(s):  
Dong Feng Li ◽  
Fu Qing Bai ◽  
Hui Nie

In order to analyze the influence of bridge holes widening on hydrodynamic such as water level, a two-dimensional mathematical model was used to calculate the hydrodynamic factors, river network flow velocity vector distribution is given, water level and difference of bridge widening before and after is calculated and charted, water surface gradient in seven different river sections near the upper reaches of bridges is counted and revealed. The results of hydrodynamic calculation indicate that The Maximum and the minimum deducing numerical value of the water level after bridge widening is 0.028m, and 0.018m respective. the seven sections water surface gradient becomes smaller until it becomes negative, the influence of bridge widening on the upstream is basically over, the range of influence is about 450m from the bridge to the upstream. reach


2007 ◽  
Vol 5 (3) ◽  
pp. 33 ◽  
Author(s):  
Geoffrey H. Donovan, PhD ◽  
Patricia A. Champ, PhD ◽  
David T. Butry, PhD

Drought conditions in much of the West, increased residential development, and elevated fuels from a century of wildfire suppression have increased wildfire risk in the United States. In light of this increased risk, an innovative wildfire risk education program in Colorado Springs was examined, which rated the wildfire risk of 35,000 homes in the city’s wildlandurban interface. Evidence from home sales before and after the program’s implementation suggests that the program was successful at changing homebuyer’s attitudes toward wildfire risk, particularly preferences for flammable building materials.


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