Journal articles on the topic 'Dam regulation'
To see the other types of publications on this topic, follow the link: Dam regulation.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Dam regulation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Robbins-Manke, Jennifer L., Zoran Z. Zdraveski, Martin Marinus, and John M. Essigmann. "Analysis of Global Gene Expression and Double-Strand-Break Formation in DNA Adenine Methyltransferase- and Mismatch Repair-Deficient Escherichia coli." Journal of Bacteriology 187, no. 20 (October 15, 2005): 7027–37. http://dx.doi.org/10.1128/jb.187.20.7027-7037.2005.
Full textAbstract:
ABSTRACT DNA adenine methylation by DNA adenine methyltransferase (Dam) in Escherichia coli plays an important role in processes such as DNA replication initiation, gene expression regulation, and mismatch repair. In addition, E. coli strains deficient in Dam are hypersensitive to DNA-damaging agents. We used genome microarrays to compare the transcriptional profiles of E. coli strains deficient in Dam and mismatch repair (dam, dam mutS, and mutS mutants). Our results show that >200 genes are expressed at a higher level in the dam strain, while an additional mutation in mutS suppresses the induction of many of the same genes. We also show by microarray and semiquantitative real-time reverse transcription-PCR that both dam and dam mutS strains show derepression of LexA-regulated SOS genes as well as the up-regulation of other non-SOS genes involved in DNA repair. To correlate the level of SOS induction and the up-regulation of genes involved in recombinational repair with the level of DNA damage, we used neutral single-cell electrophoresis to determine the number of double-strand breaks per cell in each of the strains. We find that dam mutant E. coli strains have a significantly higher level of double-strand breaks than the other strains. We also observe a broad range in the number of double-strand breaks in dam mutant cells, with a minority of cells showing as many as 10 or more double-strand breaks. We propose that the up-regulation of recombinational repair in dam mutants allows for the efficient repair of double-strand breaks whose formation is dependent on functional mismatch repair.
2
Camacho, Eva M., Ana Serna, Cristina Madrid, Silvia Marqués, Raúl Fernández, Fernando de la Cruz, Antonio Juárez, and Josep Casadesús. "Regulation of finP Transcription by DNA Adenine Methylation in the Virulence Plasmid of Salmonella enterica." Journal of Bacteriology 187, no. 16 (August 15, 2005): 5691–99. http://dx.doi.org/10.1128/jb.187.16.5691-5699.2005.
Full textAbstract:
ABSTRACT DNA adenine methylase (Dam−) mutants of Salmonella enterica serovar Typhimurium contain reduced levels of FinP RNA encoded on the virulence plasmid. Dam methylation appears to regulate finP transcription, rather than FinP RNA stability or turnover. The finP promoter includes canonical −10 and −35 modules and depends on the σ70 factor. Regulation of finP transcription by Dam methylation does not require DNA sequences upstream from the −35 module, indicating that Dam acts at the promoter itself or downstream. Unexpectedly, a GATC site overlapping with the −10 module is likewise dispensable for Dam-mediated regulation. These observations indicate that Dam methylation regulates finP transcription indirectly and suggest the involvement of a host factor(s) responsive to the Dam methylation state of the cell. We provide evidence that one such factor is the nucleoid protein H-NS, which acts as a repressor of finP transcription in a Dam− background. H-NS also restrains transcription of the overlapping traJ gene, albeit in a Dam-independent fashion. Hence, the decreased FinP RNA content found in Dam− hosts of S. enterica appears to result from H-NS-mediated repression of finP transcription.
3
Fälker, Stefan, M. Alexander Schmidt, and Gerhard Heusipp. "DNA methylation in Yersinia enterocolitica: role of the DNA adenine methyltransferase in mismatch repair and regulation of virulence factors." Microbiology 151, no. 7 (July 1, 2005): 2291–99. http://dx.doi.org/10.1099/mic.0.27946-0.
Full textAbstract:
DNA adenine methyltransferase (Dam) plays an important role in physiological processes of Gram-negative bacteria such as mismatch repair and replication. In addition, Dam regulates the expression of virulence genes in various species. The authors cloned the dam gene of Yersinia enterocolitica and showed that Dam is essential for viability. Dam overproduction in Y. enterocolitica resulted in an increased frequency of spontaneous mutation and decreased resistance to 2-aminopurine; however, these effects were only marginal compared to the effect of overproduction of Escherichia coli-derived Dam in Y. enterocolitica, implying different roles or activities of Dam in mismatch repair of the two species. These differences in Dam function are not the cause for the essentiality of Dam in Y. enterocolitica, as Dam of E. coli can complement a dam defect in Y. enterocolitica. Instead, Dam seems to interfere with expression of essential genes. Furthermore, Dam mediates virulence of Y. enterocolitica. Dam overproduction results in increased tissue culture invasion of Y. enterocolitica, while the expression of specifically in vivo-expressed genes is not altered.
4
Rödel, R., and T. Hoffmann. "Quantifying the efficiency of river regulation." Advances in Geosciences 5 (December 16, 2005): 75–82. http://dx.doi.org/10.5194/adgeo-5-75-2005.
Full textAbstract:
Abstract. Dam-affected hydrologic time series give rise to uncertainties when they are used for calibrating large-scale hydrologic models or for analysing runoff records. It is therefore necessary to identify and to quantify the impact of impoundments on runoff time series. Two different approaches were employed. The first, classic approach compares the volume of the dams that are located upstream from a station with the annual discharge. The catchment areas of the stations are calculated and then related to geo-referenced dam attributes. The paper introduces a data set of geo-referenced dams linked with 677 gauging stations in Europe. Second, the intensity of the impoundment impact on runoff times series can be quantified more exactly and directly when long-term runoff records are available. Dams cause a change in the variability of flow regimes. This effect can be measured using the model of linear single storage. The dam-caused storage change ΔS can be assessed through the volume of the emptying process between two flow regimes. As an example, the storage change ΔS is calculated for regulated long-term series of the Luleälven in northern Sweden.
5
Jakomin, Marcello, Daniela Chessa, Andreas J. Bäumler, and Josep Casadesús. "Regulation of the Salmonella enterica std Fimbrial Operon by DNA Adenine Methylation, SeqA, and HdfR." Journal of Bacteriology 190, no. 22 (September 19, 2008): 7406–13. http://dx.doi.org/10.1128/jb.01136-08.
Full textAbstract:
ABSTRACT DNA adenine methylase (dam) mutants of Salmonella enterica serovar Typhimurium grown under laboratory conditions express the std fimbrial operon, which is tightly repressed in the wild type. Here, we show that uncontrolled production of Std fimbriae in S. enterica serovar Typhimurium dam mutants contributes to attenuation in mice, as indicated by the observation that an stdA dam strain is more competitive than a dam strain upon oral infection. Dam methylation appears to regulate std transcription, rather than std mRNA stability or turnover. A genetic screen for std regulators showed that the GATC-binding protein SeqA directly or indirectly represses std expression, while the poorly characterized yifA gene product serves as an std activator. YifA encodes a putative LysR-like protein and has been renamed HdfR, like its Escherichia coli homolog. Activation of std expression by HdfR is observed only in dam and seqA backgrounds. These data suggest that HdfR directly or indirectly activates std transcription. Since SeqA is unable to bind nonmethylated DNA, it is possible that std operon derepression in dam and seqA mutants may result from unconstrained HdfR-mediated activation of std transcription. Derepression of std in dam and seqA mutants of S. enterica occurs in only a fraction of the bacterial population, suggesting the occurrence of either bistable expression or phase variation.
6
Mei, Xuefei, Zhijun Dai, Wen Wei, and Jinjuan Gao. "Dams induced stage–discharge relationship variations in the upper Yangtze River basin." Hydrology Research 47, no. 1 (June 6, 2015): 157–70. http://dx.doi.org/10.2166/nh.2015.010.
Full textAbstract:
Although stage–discharge relationships are crucial for discharge estimations and hydrological analyses, few efforts have been taken to assess their temporal alterations in the context of dam regulation. Here, the upper Yangtze River basin serves as an example to demonstrate the influence of hydraulic structures on stage–discharge relationships evolution. Daily records of water level and river discharge from 1950 to 2013 at Yichang hydrometric station were grouped and analyzed. Back-propagation artificial neural network was used to model the stage–discharge relationships. The obtained curves revealed substantial shifts since the Gezhouba Dam (GD) and Three Gorges Dam (TGD) were put into practice sequentially. In low flow scenarios, the decline of water levels due to GD and TGD regulation were variable with river discharge, whereas in normal flow scenarios, the rating curves indicate equilibrium state with almost the same slopes regardless of GD and TGD influence. In high flow scenarios, the rating curves representing natural condition, GD, and TGD regulation intersect with each other. Moreover, the detected changes in stage–discharge relationship were mainly in response to dam regulation, channel erosion and sand exploitation, while irrelevant to precipitation variability. The contribution of sand mining, GD regulation, and TGD regulation on rating curve variations at Yichang station were 36%, 11%, and 53%, respectively.
7
Fälker, Stefan, M. Alexander Schmidt, and Gerhard Heusipp. "Altered Ca2+ Regulation of Yop Secretion in Yersinia enterocolitica after DNA Adenine Methyltransferase Overproduction Is Mediated by Clp-Dependent Degradation of LcrG." Journal of Bacteriology 188, no. 20 (October 1, 2006): 7072–81. http://dx.doi.org/10.1128/jb.00583-06.
Full textAbstract:
ABSTRACT DNA methylation by the DNA adenine methyltransferase (Dam) interferes with the coordinated expression of virulence functions in an increasing number of pathogens. While analyzing the effect of Dam on the virulence of the human pathogen Yersinia enterocolitica, we observed type III secretion of Yop effector proteins under nonpermissive conditions. Dam alters the Ca2+ regulation of Yop secretion but does not affect the temperature regulation of Yop/Ysc expression. The phenotype is different from that of classical “Ca2+-blind” mutants of Yersinia, as Dam-overproducing (DamOP) strains still translocate Yops polarly into eukaryotic cells. Although transcription of the lcrGV and yopN-tyeA operons is slightly upregulated, LcrG is absent from lysates of DamOP bacteria, while the amounts of YopN and TyeA are not changed. We present evidence that clpXP expression increases after Dam overproduction and that the ClpP protease then degrades LcrG, thereby releasing a block in type III secretion. This is the first example of posttranslational regulation of type III secretion by the Clp protease and adds a new flavor to the complex regulatory mechanisms underlying the controlled release of effector proteins from bacterial cells.
8
Degtyarev, G. V., and D. A. Dats’o. "The seasonal regulation basin dam basis deformation forecast." IOP Conference Series: Materials Science and Engineering 698 (December 18, 2019): 022013. http://dx.doi.org/10.1088/1757-899x/698/2/022013.
Full text
9
Mitina, Natalia, Maxim Vashchenko, and Elena Shumakova. "Modern problems of state regulation of operation of a large hydroelectric plants dams area." E3S Web of Conferences 163 (2020): 03011. http://dx.doi.org/10.1051/e3sconf/202016303011.
Full textAbstract:
The article is devoted to the problem of increasing the risk of accidents at the dam areas of a large power plant (HPP) and the surrounding area over time, and the need to take these risks into account during their operation. The purpose of the research is to introduce the concept of a dam area as an object of state regulation, to reveal the ways of development and legislative solution of the problem of safe operation of hydroelectric power plants and dam territories at the Federal level, and to develop recommendations for their state regulation. The paper shows the necessity and expediency of zoning the dam territory according to the degree of dynamic impact of the HPP on it in order to optimize the administrative and economic consequences of the operation of these objects.
10
Martin, Patricia, Li Sun, Derek W. Hood, and E. Richard Moxon. "Involvement of genes of genome maintenance in the regulation of phase variation frequencies in Neisseria meningitidis." Microbiology 150, no. 9 (September 1, 2004): 3001–12. http://dx.doi.org/10.1099/mic.0.27182-0.
Full textAbstract:
In Neisseria meningitidis, the reversible expression of surface antigens, i.e. phase variation, results from changes within repeated simple sequence motifs located in coding or promoter regions of the genes involved in their biosynthesis. The mutation rates of these simple sequences, which have a major influence on the generation of phenotypic diversity, can affect the fitness of the population. The aim of the present study was to investigate the involvement of genetic factors involved (mutS and dam) and not yet analysed (drg and dinB) in the regulation of phase variation frequencies of genes associated with a variety of repeat tracts. The frequency of frameshifts occurring in the polycytidine (polyC) tracts associated with siaD, spr and lgtG and in the tetranucleotide (TAAA) repeat tract associated with nadA was determined by colony immunoblotting or using the lacZ gene as a reporter. Inactivation of mutS increased the frequency of phase variation of genes presenting homopolymeric tracts of diverse length. Overexpression of dinB enhanced the instability of the homopolymeric tract associated with siaD. Investigation of the dam locus in a population of genetically distinct N. meningitidis strains revealed that 27 % of strains associated with invasive disease contained the dam gene. In all strains where a Dam function was absent, the drg gene had been inserted into the dam locus. Disruption of dam and drg in strains representative of each genotype, i.e. dam +/drg and dam/drg +, did not modify phase variation frequencies. In contrast to the effects of certain genes on homopolymeric tracts, none of the genetic factors investigated affected the stability of tetranucleotide repeat tracts.
11
Zhao, Qinghe, Shengyan Ding, Zihan Geng, Xunling Lu, Zhendong Hong, Yi Liu, and Jinhai Yu. "Concentration, Health Risk, and Hydrological Forcing of Heavy Metals in Surface Water Following Water-Sediment Regulation of the Xiaolangdi Dam in the Yellow River." International Journal of Environmental Research and Public Health 19, no. 9 (May 7, 2022): 5713. http://dx.doi.org/10.3390/ijerph19095713.
Full textAbstract:
Water and sediment regulation aimed at aquatic ecosystems and preserving reservoir capacity to minimize the negative consequences of dams can fundamentally change the distribution of heavy metals (HMs) in the reservoir and downstream reaches. However, the effects of water and sediment regulation on variation in HMs are still poorly understood. In this study, the variations in concentration, contamination, human health risk, potential sources, and influencing factors of the metalloid As and HMs (Cr, Hg, Ni, Pb, and Zn) in surface water in the reservoir and the downstream reach of the Xiaolangdi Dam (XLD) following the operation of the water-sediment regulation scheme (WSRS) were determined. These results indicate that HM concentrations in the two post-WSRS seasons were much lower than the water quality standards, but were significantly increased over time due to the trapping effects of the XLD (p < 0.05, except for Zn). However, As concentration in the reservoir was significantly lower than that observed in downstream reaches, likely due to anthropogenic input from agricultural activities. Meanwhile, HM concentrations varied with distance to the dam, which displayed a distinct accumulation closer to the dam in the post-WSRS II season. The contamination of HMs, the carcinogenic risk of exposure to As, and the noncarcinogenic risks associated with exposure to Hg, Ni, Pb, and Zn via the direct ingestion pathway of drinking water were all within acceptable levels following the WSRS, but increased over time. The carcinogenic risk of Cr in the post-WSRS II season was at an unacceptably high level, particularly at sites near the dam. Hydrological characteristics (water level and flow rate) were the dominant factors in determining the distribution of HMs. These results can provide new insight for a better understanding of the variations in HMs following the water and sediment regulation practices, and guide future management in regulating the trapping effects of dams.
12
Lyu, Jiqiang, Pingping Luo, Shuhong Mo, Meimei Zhou, Bing Shen, Lei Fan, and Daniel Nover. "Towards sustainable water regulation based on a distributed hydrological model for a heavily polluted urban river, northwest China." Hydrology Research 50, no. 3 (March 19, 2019): 961–73. http://dx.doi.org/10.2166/nh.2019.005.
Full textAbstract:
Abstract The Qinling Mountains are located in a transition zone between (semi)-arid regions in north China and humid regions in south China. The water resource and water ecology of regional rivers are strongly affected by climate change and human activity. In this paper, the stochastic simulation of river water regulation was performed and an optimal water regulation scheme of rubber dam projects was developed by establishing a multi-objective stochastic constraint water regulation model of rubber dam projects based on the coupling of a distributed hydrological model and a water balance model. Results show that a ∼40% reduction of water occurred in the lower river channel due to the operation of water supply project in the upper reach and impoundment by rubber dam projects in the lower reaches. This water reduction was associated with decreased water environment self-purification capacity and serious deterioration of water quality for smaller ecological basic flow and mean flow velocity. By establishing a multi-objective stochastic constraint programming model, the average velocity and the ecological basic flow at different adjusting heights of rubber dams are determined. The regulation scheme of rubber dam projects we propose in this paper may optimize the current river water management strategies and help to improve the river water quality environment in urban rivers.
13
Lavallée, Daniel. "Évaluation de la remontée des vagues sur des barrages en milieu forestier créant des retenues modestes." Canadian Journal of Civil Engineering 32, no. 5 (October 1, 2005): 830–38. http://dx.doi.org/10.1139/l05-046.
Full textAbstract:
Safe dam design, especially when the dam is likely to erode when submerged, must take into account wave surge. The lack of data for small structures built in a forest environment is a problem when assessing this surge. This paper proposes an approach to assess wave surge for these structures. The proposed approach is based on relationships developed by Saville et al. (1962) for inland lakes. An example to illustrate the application of this approach is discussed in the framework of the Quebec Dam Safety Regulation (Quebec Government 2002).Key words: dam design, dam safety.[Journal translation]
14
Chen, Ang, Miao Wu, and Michael E. McClain. "Classifying Dams for Environmental Flow Implementation in China." Sustainability 12, no. 1 (December 21, 2019): 107. http://dx.doi.org/10.3390/su12010107.
Full textAbstract:
The implementation of environmental flows is of the utmost importance for ecosystem protection and restoration in dammed rivers. A key challenge in optimizing dam regulation is the uncertainty of the ecohydrology relationship between flow release and ecological response. In the present paper, we develop a framework of dam classification to organize the categories of the ecohydrology relationship for implementing environmental flows. Dams are classified from three major categories that differ in dam properties, hydrological alteration, and downstream hydrobiological diversities based on the relationship of hydrology and ecology. Finally, 773 dams in China are screened and ranked into four classes involving a great diversity of environmental flow components. A classification of dams that utilizes the implementation of environmental flows is presented. (1) Class 1 includes dams with rare and endangered fish species in the downstream. It is the category with the highest priority for environmental flow releases and regulation, requiring continuous flow and flood pulse components for fish spawning and migration. (2) Class 2 includes dams with significant hydrological alteration in the downstream. It is the category with second priority for environmental flow releases and regulation, requiring natural hydrological regimes simulation or complete flow component recovery for optimizing the flow duration curve and mitigating adverse impacts of dam operation. (3) Class 3 includes dams with a high degree of regulation where there is urgency for environmental flow releases and regulation, requiring that minimum flow is guaranteed by cascade reservoir regulation. (4) Class 4 includes dams with a low degree of regulation where there is less urgency for environmental flow releases and regulation. This classification method is important for future research, including environmental flow release regulation and the effectiveness evaluation of environmental flow adaptive management. It will be useful for guiding the implementation of environmental flows.
15
Hu, Liangming, Xu Yang, Qian Li, and Shuyu Li. "Numerical Simulation and Risk Assessment of Cascade Reservoir Dam-Break." Water 12, no. 6 (June 17, 2020): 1730. http://dx.doi.org/10.3390/w12061730.
Full textAbstract:
Despite the fact that cascade reservoirs are built in a large number of river basins nowadays, there is still an absence of studies on sequential embankment dam-break in cascade reservoirs. Therefore, numerical simulations and risk analyses of cascade reservoir dam-break are of practical engineering significance. In this study, by means of contacting the hydraulic features of upstream and downstream reservoirs with flood routing simulation (FRS) and flood-regulating calculation (FRC), a numerical model for the whole process of cascade reservoir breaching simulation (CRBS) is established based on a single-embankment dam-break model (Dam Breach Analysis—China Institute of Water Resources and Hydropower Research (DB-IWHR)). In a case study of a fundamental cascade reservoir system, in the upstream Tangjiashan barrier lake and the downstream reservoir II, the whole process of cascade reservoir dam-break is simulated and predicted under working schemes of different discharge capacities, and the risk of cascading breaching was also evaluated through CRBS. The results show that, in the dam-break of Tangjiashan barrier lake, the calculated values of the peak outflow rate are about 10% more than the recorded data, which are in an acceptable range. In the simulation of flood routing, the dam-break flood arrived at the downstream reservoir after 3 h. According to the predicted results of flood-regulating calculations and the dam-break simulation in the downstream reservoir, the risk of sequential dam-break can be effectively reduced by setting early warnings to decrease reservoir storage in advance and adding a second discharge tunnel to increase the discharge capacity. Alongside the simulation of flood routing and flood regulation, the whole process of cascade dam-break was completely simulated and the results of CRBS tend to be more reasonable; CRBS shows the great value of engineering application in the risk assessment and flood control of cascade reservoirs as an universal numerical prediction model.
16
S. Hassan, Mohamad, Musa, Al-Tamir, and Faiza I. Hassan. "Study of Regulation Lake’s Water Quality of Mosul Dam." Rafidain Journal of Science 16, no. 14 (December 1, 2005): 113–27. http://dx.doi.org/10.33899/rjs.2005.43516.
Full text
17
Tardieu, Henri. "Automatic dam management and river regulation for irrigation purposes." Irrigation and Drainage Systems 2, no. 1 (1988): 53–61. http://dx.doi.org/10.1007/bf01102752.
Full text
18
Balbontín, Roberto, Gary Rowley, M. Graciela Pucciarelli, Javier López-Garrido, Yvette Wormstone, Sacha Lucchini, Francisco García-del Portillo, Jay C. D. Hinton, and Josep Casadesús. "DNA Adenine Methylation Regulates Virulence Gene Expression in Salmonella enterica Serovar Typhimurium." Journal of Bacteriology 188, no. 23 (September 22, 2006): 8160–68. http://dx.doi.org/10.1128/jb.00847-06.
Full textAbstract:
ABSTRACT Transcriptomic analyses during growth in Luria-Bertani medium were performed in strain SL1344 of Salmonella enterica serovar Typhimurium and in two isogenic derivatives lacking Dam methylase. More genes were repressed than were activated by Dam methylation (139 versus 37). Key genes that were differentially regulated by Dam methylation were verified independently. The largest classes of Dam-repressed genes included genes belonging to the SOS regulon, as previously described in Escherichia coli, and genes of the SOS-inducible Salmonella prophages ST64B, Gifsy-1, and Fels-2. Dam-dependent virulence-related genes were also identified. Invasion genes in pathogenicity island SPI-1 were activated by Dam methylation, while the fimbrial operon std was repressed by Dam methylation. Certain flagellar genes were repressed by Dam methylation, and Dam− mutants of S. enterica showed reduced motility. Altered expression patterns in the absence of Dam methylation were also found for the chemotaxis genes cheR (repressed by Dam) and STM3216 (activated by Dam) and for the Braun lipoprotein gene, lppB (activated by Dam). The requirement for DNA adenine methylation in the regulation of specific virulence genes suggests that certain defects of Salmonella Dam− mutants in the mouse model may be caused by altered patterns of gene expression.
19
Ridolfi, Elena, Silvia Di Francesco, Claudia Pandolfo, Nicola Berni, Chiara Biscarini, and Piergiorgio Manciola. "Coping with Extreme Events: Effect of Different Reservoir Operation Strategies on Flood Inundation Maps." Water 11, no. 5 (May 10, 2019): 982. http://dx.doi.org/10.3390/w11050982.
Full textAbstract:
The need of addressing “residual flood risk” associated with structural protection measures, such as levee systems and flood-control reservoirs, has fostered actions aimed at increasing flood risk awareness. Structural measures have lowered risk perception by inducing a false sense of safety. As a result, these structures contribute to an underestimation of the “residual risk”. We analyze the effect of different reservoir operations, such as coping with drought versus coping with flood events, on flood inundation patterns. First, a hydrological model simulates different scenarios, which represent the dam regulation strategies. Each regulation strategy is the combination of an opening of the outlet gate and of the initial water level in the reservoir. Second, the corresponding outputs of the dam in terms of maximum discharge values are estimated. Then, in turn, each output of the dam is used as an upstream boundary condition of a hydraulic model used to simulate the flood propagation and the inundation processes in the river reach. The hydraulic model is thus used to determine the effect, in terms of inundated areas, of each dam regulation scenario. Finally, the ensemble of all flood inundation maps is built to define the areas more prone to be flooded. The test site is the Casanuova dam (Umbria, central Italy) which aims at: (i) mitigating floods occurring at the Chiascio River, one of the main tributaries of Tiber River, while (ii) providing water supply for irrigation. Because of these two competitive interests, the understanding of different scenarios generated by the dam operations offers an unique support to flood mitigation strategies. Results can lead to draw interesting remarks for a wide number of case studies.
20
Kang, Ying Bin, Abdurxt Rjap, and Kun Huang. "The Application of Hydraulic Automatic Flap Gate in the Regulation Project of Duanmijian River." Applied Mechanics and Materials 380-384 (August 2013): 4155–58. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.4155.
Full textAbstract:
Informed by water pressure and gate weight balance principle, the hydraulic automatic flap dam makes use of hydraulic power together with the damping feedback system, which makes it possible to automatically open the discharge when water level at the upper stream is high and to close when the level is low. This helps to ensure that the water level at the upper stream always stays within the normal range and has been widely applied in city water regulation projects and hydropower renovation projects alike. The flap dam in the project reported here is constructed upon the existing levees of Duanmijian river. This paper discusses the design of the flap dam as well as the entire outline and its major features.
21
Xiong, Lihua, Cong Jiang, Shenglian Guo, Shuai Li, Rongrong Li, and Wenbin Li. "Multivariate Dam-Site Flood Frequency Analysis of the Three Gorges Reservoir Considering Future Reservoir Regulation and Precipitation." Water 14, no. 2 (January 6, 2022): 138. http://dx.doi.org/10.3390/w14020138.
Full textAbstract:
Under a changing environment, the current hydrological design values derived from historical flood data for the Three Gorges Reservoir (TGR) might be no longer applicable due to the newly-built reservoirs upstream from the TGR and the changes in climatic conditions. In this study, we perform a multivariate dam-site flood frequency analysis for the TGR considering future reservoir regulation and summer precipitation. The Xinanjiang model and Muskingum routing method are used to reconstruct the dam-site flood variables during the operation period of the TGR. Then the distributions of the dam-site flood peak and flood volumes with durations of 3, 7, 15, and 30 days are built by Pearson type III (PIII) distribution with time-varying parameters, which are expressed as functions of both reservoir index and summer precipitation anomaly (SPA). The multivariate joint distribution of the dam-site flood variables is constructed by a 5-D C-vine copula. Finally, by using the criteria of annual average reliability (AAR) associated with the exceedance probabilities of OR, AND and Kendall, we derive the multivariate dam-site design floods for the TGR from the predicted flood distributions during the future operation period of the reservoir. The results indicate that the mean values of all flood variables are positively linked to SPA and negatively linked to RI. In the future, the flood mean values are predicted to present a dramatic decrease due to the regulation of the reservoirs upstream from the TGR. As the result, the design dam-site floods in the future will be smaller than those derived from historical flood distributions. This finding indicates that the TGR would have smaller flood risk in the future.
22
Amenuvor, Mawusi, Weilun Gao, Dongxue Li, and Dongdong Shao. "Effects of Dam Regulation on the Hydrological Alteration and Morphological Evolution of the Volta River Delta." Water 12, no. 3 (February 28, 2020): 646. http://dx.doi.org/10.3390/w12030646.
Full textAbstract:
The Volta River in West Africa is one of the most regulated rivers influenced by dams in the world, and the regulation has resulted in substantial impacts on the hydrological alteration and morphological evolution of the Volta River Delta. However, comprehensive analyses of the relevant effects are still lacking to date. In this study, inter-annual variations of river discharge and sediment load for pre- and post-Akosombo Dam periods (1936 to 2018) were analyzed through simple regression and Mann–Kendall (MK) trend analysis whereas the intra-annual variations were dictated by the non-uniformity and regulated coefficients. The shoreline changes were further evaluated using Landsat remote sensing images (1972 to 2018) to explore the effects of hydrological alteration on the morphological evolution of the Volta River Delta. Hydrological analyses show that the inter- and intra-annual variations are much higher in the pre-dam period, suggesting the substantial regulation of the Akosombo Dam on the Volta River. The dam regulation has more significant effects on the sediment load delivered to the delta than the river discharge, which decreased by 92.32% and 23.23%, respectively. Morphological analyses show that the progradation-erosion of the Volta River Delta constantly fluctuates within a relatively small range (maximum 0.5%) after the 1970s. The relationship between the variations of the delta area and sediment load implicates that a quasi-equilibrium state may have been established at the Volta River Delta, given the current sediment load. Our findings provide references for the future regulation and restoration of the Volta River Delta.
23
Wu, Rongmei, Janine Cooney, Sumathi Tomes, Ria Rebstock, Sakuntala Karunairetnam, Andrew C. Allan, Richard C. Macknight, and Erika Varkonyi-Gasic. "RNAi-mediated repression of dormancy-related genes results in evergrowing apple trees." Tree Physiology 41, no. 8 (February 10, 2021): 1510–23. http://dx.doi.org/10.1093/treephys/tpab007.
Full textAbstract:
Abstract DORMANCY-ASSOCIATED MADS-box (DAM) and SHORT VEGETATIVE PHASE (SVP) genes have been implicated in the regulation of winter dormancy in perennials. Ectopic expression of apple (Malus × domestica Borkh. ‘Royal Gala’) DAM and SVP genes delays budbreak and constrains lateral shoot outgrowth. In this study, we used RNA interference (RNAi) to simultaneously target all apple DAM and SVP genes in order to study their role and mode of action in the regulation of bud dormancy, budbreak and flowering. A synthetic construct carrying a hairpin fragment assembled from sequences specific to coding regions of three DAM and two SVP genes was used to generate transgenic lines. Reduced expression of DAM/SVP genes resulted in delayed leaf senescence and abscission in autumn, failure to enter bud dormancy in winter and continual growth of new leaves regardless of the season for over 3 years. Precocious flowering but normal flower morphology, fertility and fruit development were observed. The non-dormant phenotype was associated with modified phytohormone composition. The content of gibberellins (GAs) and jasmonates (JAs) was significantly increased in terminal buds of RNAi lines compared with wildtype plants, accompanied by elevated expression of the key GA biosynthesis pathway gene GIBBERELLIN 20 OXIDASE-2 (MdGA20ox-2) along with the FLOWERING LOCUS T gene MdFT2. The key mediator of plasmodesmatal closure, MdCALLOSE SYNTHASE 1 (MdCALS1), was repressed in RNAi lines. This study provides functional evidence for the role of DAM/SVP genes in vegetative phenology of apple and paves the way for production of low-chill varieties suitable for growth in warming climates.
24
Pozdnyakov, A. V. "Self-Freezing of the Ice Dam: The Self-Regulation Algorithm." Geography and Natural Resources 40, no. 2 (April 2019): 180–86. http://dx.doi.org/10.1134/s1875372819020112.
Full text
25
Li, Shuai, Yong You, Xiaoqing Chen, Jinfeng Liu, and Jiangang Chen. "Regulation effectiveness of a window-check dam on debris flows." Engineering Geology 253 (April 2019): 205–13. http://dx.doi.org/10.1016/j.enggeo.2019.03.020.
Full text
26
Ruiz-González, Clara, Lorenzo Proia, Isabel Ferrera, Josep M. Gasol, and Sergi Sabater. "Effects of large river dam regulation on bacterioplankton community structure." FEMS Microbiology Ecology 84, no. 2 (January 14, 2013): 316–31. http://dx.doi.org/10.1111/1574-6941.12063.
Full text
27
Bazarov, Dilshod, Bekhzod Norkulov, Oybek Vokhidov, Fotima Artikbekova, Bobur Shodiev, and Ikboloy Raimova. "Regulation of the flow in the area of the damless water intake." E3S Web of Conferences 263 (2021): 02036. http://dx.doi.org/10.1051/e3sconf/202126302036.
Full textAbstract:
The article discusses the results of numerical studies of the flow of the Amudarya river above the point of the damless water intake to the head structure of the damless water intake to the Karshi Main Canal-KMC. The system of two-dimensional equations of hydrodynamics-Saint-Venant is used as the basis of the mathematical model. In this work, a series of calculations of the field of currents in the river channel during low-water periods is carried out. Below are the main research results and proposals for ensuring the stable operation of the damless water intake in low-water conditions. The applicability of a numerical model composed of the equations of shallow water -the vector equation for the conservation of momentum and the scalar equation for the conservation of mass, has been proved, when describing a flow with the presence of circulation zones, which is typical when the water flow is constrained by blind dams. In this case, the solution pulsates around a certain average value, and the average length of the circulation zone behind the sudden expansion of the open flow is in good agreement with laboratory experiments. Numerical studies have shown that the device of a jet-guiding dam 150 m above the water intake gate in the CMC is more effective than when the dam is located 250 m above. In essence, dam № 2 with a length of 65 m does not affect the conditions at the water intake in the KMC at all, and dam № 2 with a length of 120 m is almost equivalent in its impact on the flow to dam №1 with a length of 50 m. Analysis of the results shows that the placement of an additional threshold in the Amudarya river bed improves the situation by raising the water level at the water intake. The threshold is flooded even at low water levels, which reduces the speed load on its body. At the same time, the threshold is located directly at the beginning of the channel, in part to protect the intake from incoming sediment, and high enough speed water glistening over the threshold in line, ensure the transit of sediment that can reduce enters the intake. Such measures will reduce the turbidity of water entering the channel. This, in turn, reduces the intensity of the silting process.
28
Henegar, Jeffrey R., Dean D. Schwartz, and Joseph S. Janicki. "ANG II-related myocardial damage: role of cardiac sympathetic catecholamines and β-receptor regulation." American Journal of Physiology-Heart and Circulatory Physiology 275, no. 2 (August 1, 1998): H534—H541. http://dx.doi.org/10.1152/ajpheart.1998.275.2.h534.
Full textAbstract:
The objectives of this study were 1) to determine whether ANG II-induced myocardial damage (ANG Dam) is mediated via the β1-adrenergic receptor, 2) to elucidate whether adrenal medulla or cardiac sympathetic neuron catecholamines are responsible for ANG Dam, and 3) to determine whether the lack of damage after 3 days of elevated ANG II levels is due to β1-receptor downregulation. To this end, ANG II was administered to rats 1) that were treated with a β-receptor blocker, 2) after adrenal medullectomy and/or cardiac sympathectomy, and 3) for 3 or 8 days. ANG II caused both myocyte necrosis and coronary vascular damage after adrenal medullectomy but not after cardiac sympathectomy. There was a 38 and 55% decrease in β-receptor density after 3 and 8 days, respectively, of ANG II infusion, and an upregulation to control levels 5 days after a 3-day ANG II infusion was stopped. We conclude that cardiac sympathetic neuron catecholamines are responsible for ANG Dam and that the acute nature of this damage is associated with a downregulation of β1-adrenergic receptors.
29
Bell, Derek C., and Claire G. Cupples. "Very-Short-Patch Repair in Escherichia coli Requires the dam Adenine Methylase." Journal of Bacteriology 183, no. 12 (June 15, 2001): 3631–35. http://dx.doi.org/10.1128/jb.183.12.3631-3635.2001.
Full textAbstract:
ABSTRACT Strains of Escherichia coli which lack thedam-encoded adenine methylase are mutators due to a reduction in the efficiency of postreplication mismatch repair. In this study, we show that Dam− strains are also defective in very-short-patch repair, the system which corrects T/G mismatches arising from the deamination of 5-methylcytosine. This defect is associated with decreased levels of Vsr, the endonuclease which initiates short-patch repair. We also show that production of thedcm-encoded cytosine methylase is unaffected in Dam− strains. Since the dcm andvsr genes are cotranscribed, the regulation of Vsr by Dam is probably posttranscriptional.
30
Nikitina, Oxana I., Valentina G. Dubinina, Mikhail V. Bolgov, Mikhail P. Parilov, and Tatyana A. Parilova. "Environmental Flow Releases for Wetland Biodiversity Conservation in the Amur River Basin." Water 12, no. 10 (October 10, 2020): 2812. http://dx.doi.org/10.3390/w12102812.
Full textAbstract:
Flow regulation by large dams has transformed the freshwater and floodplain ecosystems of the Middle Amur River basin in Northeast Asia, and negatively impacted the biodiversity and fisheries. This study aimed to develop environmental flow recommendations for the Zeya and Bureya rivers based on past flow rate records. The recommended floodplain inundation by environmental flow releases from the Zeya reservoir are currently impracticable due to technical reasons. Therefore, the importance of preserving the free-flowing tributaries of the Zeya River increases. Future technical improvements for implementing environmental flow releases at the Zeya dam would improve dam management regulation during large floods. The recommendations developed for environmental flow releases from reservoirs on the Bureya River should help to preserve the important Ramsar wetlands which provide habitats for endangered bird species while avoiding flooding of settlements. The results emphasize the importance of considering environmental flow during the early stages of dam planning and the need to enhance the role of environmental flow in water management planning.
31
Badie, Golnaz, Douglas M. Heithoff, Robert L. Sinsheimer, and Michael J. Mahan. "Altered Levels of Salmonella DNA Adenine Methylase Are Associated with Defects in Gene Expression, Motility, Flagellar Synthesis, and Bile Resistance in the Pathogenic Strain 14028 but Not in the Laboratory Strain LT2." Journal of Bacteriology 189, no. 5 (December 15, 2006): 1556–64. http://dx.doi.org/10.1128/jb.01580-06.
Full textAbstract:
ABSTRACT Comparative genomic analysis has revealed limited strain diversity between Salmonella pathogenic and nonpathogenic isolates. Thus, some of the relative virulence and host-immune response disparities may be credited to differential gene regulation rather than gross differences in genomic content. Here we show that altered levels of Salmonella DNA adenine methylase (Dam) resulted in acute defects in virulence-associated gene expression, motility, flagellin synthesis, and bile resistance in the Salmonella pathogenic strain 14028 but not in avirulent laboratory strain LT2. The defects in motility exhibited by 14028 in response to altered Dam levels was not dependent on the presence of the regulatory protein, RpoS. The transitioning between flagellar types (phase variation) was also differentially regulated in 14028 versus LT2 in response to dam levels, resulting in distinct differences in flagellin expression states. These data suggest that differential gene regulation may contribute to the relative virulence disparities observed between Salmonella serovars that are closely related at the DNA level.
32
Zheng, Yuexin, Guangxin Zhang, Yanfeng Wu, Y. Jun Xu, and Changlei Dai. "Dam Effects on Downstream Riparian Wetlands: The Nenjiang River, Northeast China." Water 11, no. 10 (September 29, 2019): 2038. http://dx.doi.org/10.3390/w11102038.
Full textAbstract:
Many studies have found that damming a river can change downstream hydrology, sediment transport, channel morphology, and fish habitat. However, little is known about river dam effects on downstream riparian wetland dynamics and their quantitative relationship with hydrological alterations. In this study, hydrological time series and wetland distribution data spanning nearly 40 years (1978–2016) before and after the construction of a large dam in 2005 across the Nenjiang River in Northeast China were used to reveal the impact of dam on the downstream discharge regime and wetland degradation. Hydro-statistical and stepwise multiple regression analyses were performed to quantify the relationship of riparian wetland area with a metrics of 33 hydrological indicators. Dam construction caused decline in peak discharge, flood frequency, and magnitude. Moreover, 150 km riparian wetlands along the downstream of the dam was largely reduced. The count and duration of high flow pulses, 1-day maximum, and date of maximum discharge changed significantly after the dam construction. The hydrological changes have made a significant contribution to the 44% reduction in riparian wetlands following the dam construction. Our results indicated that hydrological alterations caused by dam regulation led to the area reduction of downstream riparian wetlands. The findings provide relevant information for developing best dam operation practices to protect and restore downstream wetland ecosystems.
33
Kumar, Avinash, Vipin Kumar Pal, Vinay Kumar Chaurasiya, and Ajay Singh. "Dams Gate Control Using Programmable Logic Controller and SCADA." International Journal of Advance Research and Innovation 9, no. 3 (2021): 57–63. http://dx.doi.org/10.51976/ijari.932109.
Full textAbstract:
This paper is focused on the automation of gates of dam with using the current smart technologies of Programmable Logic Controller (PLC) and SCADA. A dam is an artificial reservoir made to collect a huge volume of water across a river or water body and use it for the purpose of generation of electricity, irrigation, water conservation and stream regulation. Due to uneven rainfall in India, it is not possible for some areas to get regular supply of water or due to their geographical conditions a huge amount of water runoff. So, water collected in the dam is very essential for these areas. Hence, it is necessary to make dams gates automatic for the wise use of available water resource, and increase efficiency of dams that would result in best commercial, agricultural and social benefits. A large number of dams in the world still uses manual system for the controlling of gates of dam, which employs humans for the desired operation, that may have the chances of human error resulting in improper regulation of the stream and also decreases the overall efficiency. To overcome these problems an Automation system is essential that comprises of PLC and SCADA to control the gates of dam by using a single system operation. The operations of dam gates are based on the feedback signals from the level sensors (Digital Input) and float sensor (Analog Input). The forward and reverse operation of dc motor of gates is achieved with the PLC.Ladder programming is used to implement the wholeoperations of this system. SCADA is used for remote monitoring for a number of dams from a central controlling station.
34
Y.S. Mah, Darrien, and Frederik J. Putuhena. "Modelling of Dam-Weir Operations for Environmental Quality." Journal of Civil Engineering, Science and Technology 5, no. 1 (April 1, 2014): 7–10. http://dx.doi.org/10.33736/jcest.126.2014.
Full textAbstract:
It is the desire of many societies to have clean and safe potable water sources. As manmade structures are built in water supply catchments for the purposes to increase safe yield, then facilities management of these structures should be steered towards environmental quality. Hydraulics over a weir is well studied. However, this paper probes into benchmarking of flows over a Batu Kitang Weir to guide operations of an upstream Bengoh Dam in Sarawak, Malaysia. Flow releases from the dam are tried and routed through Sarawak Kiri River to achieve supercritical states at weir by means of computer modelling. For daily dam-weir operations, the modelling results suggest a condition of 20 m3/s < dam releases < 200 m3/s to meet raw water demand as well as adequate river flow regulation.
35
Majhi, Ipshita, and Daqing Yang. "Streamflow Characteristics and Changes in Kolyma Basin in Siberia." Journal of Hydrometeorology 9, no. 2 (April 1, 2008): 267–79. http://dx.doi.org/10.1175/2007jhm845.1.
Full textAbstract:
Abstract This study documents major changes in streamflow hydrology over the Kolyma watershed due to climatic variations and human impacts. Streamflow seasonal cycles over the basin are characteristic of the northern region, with the lowest runoff in April and peak flow in June. Analyses of monthly flows and trends show that reservoir construction and operation have considerably affected streamflow regimes. Comparisons of mean monthly discharge records between pre- and post-1986 dam periods indicate that the mid–lower basin (downstream of the dam) experienced significant increase in low flows and decrease in peak flows after dam construction. For example, mean monthly flows during the post-dam period at the Ust’-Srednekan station (located 1423 km downstream of the dam) has strongly increased by about 205 m3 s−1 (or 522%–3157%) during December–April, and decreased by 133 m3 s−1 (41%) in June. Long-term monthly discharge data reveal an overall increase in streamflow during low flow seasons; the increase is greater for the stations located downstream of the dam. The Srednekolunsk station (1720 km from dam) shows low flow increase ranging from 130 (43%) to 268 m3 s−1 (454%) during November–April, and high discharge decrease by 2550 to 519 m3 s−1 during June–August in the post-dam era (1986–2000). These changes in flow patterns are mainly caused by reservoir regulation, as reservoirs release water in winter for power generation and store water in summer for flood control. Dam impact on flow regimes and changes are visible along the main river trunk; thus, the cold season discharge increase at the basin outlet is primarily the result of reservoir regulation. Annual discharge records show different changes within the Kolyma basin, with moderate increases in the upper basin and weak decreases in the mid–lower basin. Overall annual discharge near the basin outlet has decreased by 1.5% during 1978–2000. This study emphasizes the importance of human activities (particularly reservoirs) on seasonal and regional hydrology changes and points to the need to further examine natural causes and human impacts over other high-latitude watersheds.
36
Sever, Ö., Ş. Tiğrek, and N. Şarlak. "Balancing energy and environmental concerns: the case of the Kayraktepe dam, Turkey." Hydrology and Earth System Sciences Discussions 9, no. 10 (October 16, 2012): 11769–89. http://dx.doi.org/10.5194/hessd-9-11769-2012.
Full textAbstract:
Abstract. In this study, an alternative solution for a large dam, namely the Kayraktepe Dam in Turkey, is investigated. The dam was planned for flood control, energy generation and flow regulation for a downstream irrigation project more than 30 yr ago, but until now the project has not begun due to it receiving severe criticism about environmental and social considerations. The project formulation was redeveloped several times in the past but the options were not found to be feasible. In this study, a detailed analysis of the available feasibility studies is provided and then a new formulation, consisting of the proposed one medium dam and five run-of-river type hydropower stations instead of a large scale dam, is evaluated. The new formulation is equivalent to the existing project in terms of energy production and flood control. On the other hand, there are some benefits relative to other configurations as solutions to some of the environmental and social problems being addressed.
37
Luino, F., and J. V. De Graff. "The Stava mudflow of 19 July 1985 (Northern Italy): a disaster that effective regulation might have prevented." Natural Hazards and Earth System Sciences 12, no. 4 (April 16, 2012): 1029–44. http://dx.doi.org/10.5194/nhess-12-1029-2012.
Full textAbstract:
Abstract. The disaster occurring in the Eastern Italian Alps in the summer of 1985 was caused by the failure of two tailings dams located just upstream from the village of Stava in the municipality of Tesero (Trento province, Italy). The structure comprised two small storage basins for the deposition of tailings from the separation process of the Prestavel fluorite mine. On their downstream sides, the basins were contained by steep earth embankments, whereas upstream they rested directly on the natural slope. The total height from the base of the lower dam to the crest of the upper dam was over 50 m. On 19 July 1985, the front of the upper dam suddenly burst, triggering a vast mudflow (180 000 m3) that flowed down-channel through Stava, a small village of 20 buildings. The mudflow rapidly traveled over 4.2 km along the Stava Valley and passed through Tesero, before flowing into the Avisio River. The mudflow destroyed many buildings and resulted in 268 fatalities and 20 injuries. From an analysis of the data collected and field observation, several factors may be cited as having contributed to increasing instability, as the upper dam continued to be raised until the disastrous collapse of 19 July. Foremost among these factors is the mistaken assumption that the tailings deposited in the impoundments would consolidate fairly quickly. Indeed, no monitoring system was ever installed to verify the assumed consolidation. Other operational shortcomings and construction errors were contributing factors. Regulations requiring construction standards, operational monitoring, and independent periodic inspection could have prevented this disaster. Comprehensive legislation is required to effectively limit the adverse consequences of tailings dam failures by providing a regulatory environment where the safety and welfare of the local area can be balanced with the economic benefits of mining operations.
38
Katsman, E. A. "Floristic Description of Parts of the Khoper River Upstream and Downstream of the Potlovskaya Dam and Water Quality Assessment by Hydrochemical Indicators." Povolzhskiy Journal of Ecology, no. 4 (February 14, 2020): 524–28. http://dx.doi.org/10.35885/1684-7318-2019-4-524-528.
Full textAbstract:
In the modern world, increasing importance is attached to the formation and preservation of surface water quality, which is recognized as one of the leading factors in maintaining human health and well-being. In the 2000s the water quality in the Khoper river was considered as one of the best in Europe, but now the waters have become more polluted, and flow regulation (even with a low-pressure dam) may cause declension of their condition due to disruption of the water exchange process. The aim of the study was to evaluate the river flow regulation effect on the floristic diversity of vascular aquatic plants and the water quality in the vicinity of the Potlovskaya Dam near the source of the Khoper River (Penza region, Russia). The content of nutrients in water was estimated since their concentration and ratio determine the trophic status, water quality, and the state of aquatic vegetation, which is important in assessing the status of the environment of a particular region. Water chemistry and plants were sampled at two sites, one being upstream of the Dam, the other one being downstream. We have found that flow regulation by this small hydraulic installation causes some changes in the hydrochemical regime but does not affect the floristic diversity.
39
Nikitina, Oxana I., Kirill Y. Bazarov, and Evgeny G. Egidarev. "Application of remote sensing data for measuring freshwater ecosystems changes below the Zeya dam in the Russian Far East." Proceedings of the International Association of Hydrological Sciences 379 (June 5, 2018): 49–53. http://dx.doi.org/10.5194/piahs-379-49-2018.
Full textAbstract:
Abstract. The large Zeya hydropower dam is located on the Zeya River, the largest left-bank tributary of the Amur-Heilong River in Russia. The dam had been constructed by 1980 and its operation has significantly transformed the flow regime of the Zeya River. The flow regulation has reduced the magnitude of periodic flooding of the floodplain areas located downstream from the Zeya dam and disrupted habitats of flora and fauna. An estimation of the transformation of the freshwater ecosystems is required to develop measures necessary either to maintain or restore disrupted ecosystems. Application of remote sensing methods allows measuring characteristics of the ecosystem's components. Two sections of a floodplain below the Zeya dam were considered for analysis in order to detect changes in objects at each site during the comparison of remote data from 1969/1971 and 2016.
40
DEWI, AYU SUKA, MADE ANTARA, and I. DEWA AYU SRI YUDHARI. "Dampak Proses Pembangunan Bendungan Sidan terhadap Sosial Ekonomi Masyarakat dan Lingkungan di Desa Buahan Kaja, Kabupaten Gianyar dan Desa Sidan, Kabupaten Badung." Jurnal Agribisnis dan Agrowisata (Journal of Agribusiness and Agritourism) 11, no. 1 (July 26, 2022): 36. http://dx.doi.org/10.24843/jaa.2022.v11.i01.p04.
Full textAbstract:
Impact of Sidan Dam Construction Process on Socio-Economic Community and Environment in Buahan Kaja Village, Gianyar Regency and Sidan Village, Badung Regency. The construction of Sidan dam is a national strategic project stipulated under Presidential Regulation No. 56 of 2018. The purpose of this study is to identify social impacts, analyze economic impacts and estimate the environmental impact of the Sidan dam construction process. The research methods used in this study use quantitative and qualitative descriptive research. The process of building Sidan dam has no social impact on the community measured from 4 parameters consisting of social activities, land acquisition processes, the emergence of criminality and lifestyle changes. However, the process of building Sidan dam has a social impact on the community, measured from 3 other parameters consisting of communication between farmers, the usefulness of dam construction and payment of compensation. The process of building the Sidan dam has no economic impact on the community, measured from the parameters of increasing the selling price of agricultural commodities. However, the process of building Sidan dam has an economic impact measured from 4 other parameters consisting of income, land prices, property ownership and job additions. The Sidan dam construction process has no environmental impact measured from 3 parameters consisting of water and air pollution, environmental cleanliness and water quality and quantity. However, the Sidan dam construction process has an environmental impact measured from 3 other parameters consisting of loss of agricultural land, noise and road access around the agricultural area.
41
Mahlil, Mahlil, and Teddy Wartono Sudinda. "OPTIMIZATION STUDY OF GATE OPERATION RULE IN CIAWI DAM AS FLOOD CONTROL FUNCTION." Jurnal Teknik Sipil 18, no. 1 (April 1, 2022): 118–39. http://dx.doi.org/10.28932/jts.v18i1.4517.
Full textAbstract:
The purpose of this research is to find out the effectiveness of operating gate on the design of flood routing and provide an alternative outlet operation gate for maximum flood reduction. The location of the research area is the Ciawi Dam watershed with an area of 88.50 km2, a river length of ±16.70 km and an average river slope of 5.60%. This research data is based on climatological data, low discharge data, flood hydrograph, and dam and reservoir engineering data. In addition, there are supporting data to perform calculations and analyzes, such as flood discharge data, elevation curve – reservoir volume and layout of the dam and its complementary buildings, existing operating patterns, and regional socio-economic data studies. The method used is to calculate flood routing of the capital flow curve at the outlet operation gate. The simulation is carried out using a design flood hydrograph so that optimal flood reduction can be determined by the outlet operation gate. Based on the results of the maximum reduction in the design of the reservoir operation dam design without utilizing the conduit gate as a flood control function, the researchers optimized the door operation pattern to increase the flood reduction capacity (optimization) of the Ciawi Dam. The result of the calculation and analysis is that the flood return period (Q25 th) is able to reduce flooding by 54.64%; flood return period (Q50 yr.) is able to reduce flooding by 45.21%; flood return period (Q100 yr.) is able to reduce flooding by 38.06%; flood return period (Q500 yr.) is able to reduce flooding by 38.50%; and the flood return period (Q1000 yr.) was able to reduce flooding by 33.22%. So, it can be concluded that by utilizing the bottom outlet gate as a flood discharge regulation, the benefits obtained are 42.27% (at Q 25 yrs.) from the pattern of dam operation without gate regulation.
42
Bhakta, Dibakar, Wakamban Anand Meetei, Gopinathan Vaisakh, Sanjoy Kumar Das, and Ranjan Kumar Manna. "Impacts of water regulation on Tenualosa ilisha in the Narmada Estuary, Gujarat, India." Journal of Fisheries 6, no. 1 (February 5, 2018): 563. http://dx.doi.org/10.17017/jfish.v6i1.2018.254.
Full textAbstract:
Hilsa, Tenualosa ilisha is a highly prestigious fish for esteemed delicious taste, high market demand and price. It forms an important fishery of funnel-shaped 72 km long Narmada Estuary. Rapid decline in hilsa catch has been recorded in the Narmada Estuary over last few decades. Hilsa catch was recorded 5180 ton in 2006–07 that reduced to only 419 ton in 2014–15. Pre-impoundment of dam showed that T. ilisha contributed to the tune of 977.1 to 3727 ton from 1974–75 to 1982–83 and the highest catch of hilsa was 15319 ton during 1993–94. Sardar Sarovar Dam started functional in the year 1994 which has impacted natural water flow of the river and resulted in a reduction of freshwater availability in the estuary; the development of sand bars at the mouth of the estuary also reduced the tidal ingress into the system; low depth, loss of breeding, nursery and feeding grounds, over fishing may be the most important factors affecting hilsa fishery in Narmada estuary. Catching of juvenile hilsa during winter by ‘Golava’ net (small meshed bag net) also led to a rapid decline in hilsa catch. To maintain the sustainable yield of hilsa, selective fishing and control of juvenile catch are the prerequisites along with maintaining regular flow from the dam.
43
Uday Kumar, A., and K. V. Jayakumar. "Assessment of hydrological alteration and environmental flow requirements for Srisailam dam on Krishna River, India." Water Policy 20, no. 6 (August 16, 2018): 1176–90. http://dx.doi.org/10.2166/wp.2018.203.
Full textAbstract:
Abstract Natural flow plays a vital role in forming biotic diversity by controlling essential environmental conditions within the river channel and floodplain. This paper assesses the changes in streamflow and ecology caused on Krishna River by Srisailam dam. Regulated and unregulated river flow discharge data were collected at Nagarjuna Sagar gauge station which is located downstream of Srisailam dam. Flow Health (FH) software developed by the International Water Centre, Brisbane is used to calculate the hydrological alteration and environmental flow requirements due to Srisailam dam. Results show that impoundment of the dam mainly decreases the high flows by storing flood flow for water supply, irrigation purposes, etc., and enhances low flows due to hydropower operation. Regulation of the dam significantly affected the mean flow in August, September, and October. Mean annual flow (MAF) decreased considerably and seasonal flow shifted. The minimum flow released from the dam to downstream was calculated by two options, namely, low risk and medium risk to the environment. Low risk achieved a score of 0.61 FH and 0.5 FH was achieved by high risk, with a MAF volume of 40% (i.e., 7,225 m3) and 30% (5,847 m3), respectively.
44
Julio, Steven M., Douglas M. Heithoff, Robert L. Sinsheimer, David A. Low, and Michael J. Mahan. "DNA Adenine Methylase Overproduction in Yersinia pseudotuberculosis Alters YopE Expression and Secretion and Host Immune Responses to Infection." Infection and Immunity 70, no. 2 (February 2002): 1006–9. http://dx.doi.org/10.1128/iai.70.2.1006-1009.2002.
Full textAbstract:
ABSTRACT Yersinia pseudotuberculosis mutants that overproduce the DNA adenine methylase (Dam) are highly attenuated, confer fully protective immune responses, and secrete several Yersinia virulence proteins (Yersinia outer proteins [Yops]) under conditions that are nonpermissive for secretion in wild-type strains. We examined here the effects of Dam overproduction on Yersinia virulence determinant expression and secretion, as well as the host immune response to Yersinia antigens. Western blot analysis with convalescent antisera identified several low-calcium-responsive antigens whose synthesis was affected by Dam overproduction. One of these antigens was shown to be the type III secretion effector protein, YopE, a cytotoxin involved in antiphagocytosis. Dam overproduction disrupted both the thermal and calcium regulation of YopE synthesis and relaxed the thermal but not the calcium dependence of YopE secretion. Altered expression and/or secretion of Yersinia proteins in Dam-overproducing strains may contribute to the decreased virulence and heightened immunity observed in vaccinated hosts and may provide a means by which to deliver heterologous antigens and/or immune modulators of the inflammatory response.
45
Muchanga, Manoah, and Bertha Mzyece. "Economic Effects of the Failure of Kandesha Dam on Local Communities in Mumbwa District, Zambia." American Journal of Environmental Economics 1, no. 2 (January 8, 2023): 1–5. http://dx.doi.org/10.54536/ajee.v1i2.945.
Full textAbstract:
Despite of undoubtful economic contribution to the nation, sometimes dam causes sufferings due to uncertain breakage. The study investigated the economic effects of the breakage of Kandesha Dam in the far West of Lusaka Business District. It shows that the magnitude and intensity of the impact of dam breaking is dependent on the anthropogenic activities downstream of the dams. The most notable effects of the breaking of Kandesha dam included loss of income (24%), reduced working capitals among community members (14%), due to disturbed business activities resulting from the rampant flooding (12%). Generally, the findings showed diversity of economic effects following the breaking of the dams. The paper recommends regulation of human activities on the immediate downstream in order to minimize the ultimate impact of the dam breaking. Landscape-based assessment of catchment in order to understand the biophysical processes and human activities before siting and constructing dams would potentially reduce the risk of future breaking of dams and, could further immunize several economic losses on both government and community members part.
46
Kolerski, Tomasz. "Ice cover progression due to flow regulation at the Włocławek dam." Acta Scientiarum Polonorum Formatio Circumiectus 14, no. 1 (2015): 229–40. http://dx.doi.org/10.15576/asp.fc/2015.14.1.229.
Full text
47
Mor, Jordi-René, Albert Ruhí, Elisabet Tornés, Héctor Valcárcel, Isabel Muñoz, and Sergi Sabater. "Dam regulation and riverine food-web structure in a Mediterranean river." Science of The Total Environment 625 (June 2018): 301–10. http://dx.doi.org/10.1016/j.scitotenv.2017.12.296.
Full text
48
Casadesús, Josep, and David Low. "Epigenetic Gene Regulation in the Bacterial World." Microbiology and Molecular Biology Reviews 70, no. 3 (September 2006): 830–56. http://dx.doi.org/10.1128/mmbr.00016-06.
Full textAbstract:
SUMMARY Like many eukaryotes, bacteria make widespread use of postreplicative DNA methylation for the epigenetic control of DNA-protein interactions. Unlike eukaryotes, however, bacteria use DNA adenine methylation (rather than DNA cytosine methylation) as an epigenetic signal. DNA adenine methylation plays roles in the virulence of diverse pathogens of humans and livestock animals, including pathogenic Escherichia coli, Salmonella, Vibrio, Yersinia, Haemophilus, and Brucella. In Alphaproteobacteria, methylation of adenine at GANTC sites by the CcrM methylase regulates the cell cycle and couples gene transcription to DNA replication. In Gammaproteobacteria, adenine methylation at GATC sites by the Dam methylase provides signals for DNA replication, chromosome segregation, mismatch repair, packaging of bacteriophage genomes, transposase activity, and regulation of gene expression. Transcriptional repression by Dam methylation appears to be more common than transcriptional activation. Certain promoters are active only during the hemimethylation interval that follows DNA replication; repression is restored when the newly synthesized DNA strand is methylated. In the E. coli genome, however, methylation of specific GATC sites can be blocked by cognate DNA binding proteins. Blockage of GATC methylation beyond cell division permits transmission of DNA methylation patterns to daughter cells and can give rise to distinct epigenetic states, each propagated by a positive feedback loop. Switching between alternative DNA methylation patterns can split clonal bacterial populations into epigenetic lineages in a manner reminiscent of eukaryotic cell differentiation. Inheritance of self-propagating DNA methylation patterns governs phase variation in the E. coli pap operon, the agn43 gene, and other loci encoding virulence-related cell surface functions.
49
Cai, Zhu, Peng, Wang, and Fan. "Flood Risk Analysis for Cascade Dam Systems: A Case Study in the Dadu River Basin in China." Water 11, no. 7 (June 30, 2019): 1365. http://dx.doi.org/10.3390/w11071365.
Full textAbstract:
To quantify the flood risks in cascade dam systems, it is critical to analyze the risk factors and potential breaking failure paths. In this study, Bayesian networks (BNs) were applied to create a flood risk analysis model for a cascade dam system. Expert experiment, historical data, and computational formulas were employed to estimate the prior probability and original conditional probability tables (CPTs) in the BN model; sensitivity analysis was used to ensure the original continuous breaking failure path in the system. To avoid the possible misperceptions of the probability of a certain event, Dam Breach Analysis Model (DB-IWHR) 2014 software and the flood regulation method were used to simulate the dam breaking progress. The posteriori continuous breaking failure paths were obtained, and then the original CPTs were refined based on the new evidence. The proposed method was applied to the Bala-Busigou-Shuangjiangkou (BL-BSG-SJK), which is located upstream of the Dadu River basin in China. The results show that three continuous breaking failure paths could be identified in the researched cascade dam system. A new BN model was created to determine the failure probability of the cascade dam system under the three continuous breaking failure paths. This analytical method may also be useful for other similar cases.
50
SHIELDS JR, F. DOUGLAS, ANDREW SIMON, and LYLE J. STEFFEN. "Reservoir effects on downstream river channel migration." Environmental Conservation 27, no. 1 (March 2000): 54–66. http://dx.doi.org/10.1017/s0376892900000072.
Full textAbstract:
Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.