Academic literature on the topic 'Water level decline'
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Journal articles on the topic "Water level decline"
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Liu, Xiao Wen, Wen Wan, and Xi Zhong Shen. "The Analysis about Seepage of the Bank Slope under the Cycle Rising and Drawdown of Reservoir Water Level." Applied Mechanics and Materials 353-356 (August 2013): 112–15. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.112.
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Bank slope seepage field is analyzed by saturated-unsaturated seepage theory under the three times cycle conditions of water level rising and drawdown . The pore water pressure distribution laws of the water level rising period, the stabilization period, the period of decline and decline stable period for every cycle are researched. The result shows soil near slope region is saturated easily after many rounds of water level rising and drawdown, and saturation region gradually increases. Soil phreatic line near slope falls fastly in the drawdown period, away from the slope, phreatic line declines slowly.
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Yang, Jun, Hong Lv, Jun Yang, Lemian Liu, Xiaoqing Yu, and Huihuang Chen. "Decline in water level boosts cyanobacteria dominance in subtropical reservoirs." Science of The Total Environment 557-558 (July 2016): 445–52. http://dx.doi.org/10.1016/j.scitotenv.2016.03.094.
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Acreman, M. C., J. R. Meigh, and K. J. Sene. "Modelling the decline in water level of Lake Toba, Indonesia." Advances in Water Resources 16, no. 4 (January 1993): 207–22. http://dx.doi.org/10.1016/0309-1708(93)90039-i.
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Guilin, Yang, and Liu Guodong. "On the water level decline and its tendency in Qinghai Lake." Journal of Lake Sciences 4, no. 3 (1992): 17–24. http://dx.doi.org/10.18307/1992.0303.
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Arkian, Foroozan, Sharon E. Nicholson, and Bahareh Ziaie. "Meteorological factors affecting the sudden decline in Lake Urmia’s water level." Theoretical and Applied Climatology 131, no. 1-2 (November 15, 2016): 641–51. http://dx.doi.org/10.1007/s00704-016-1992-6.
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Wang, Zixiong, Tianxiang Wang, Xiaoli Liu, Suduan Hu, Lingxiao Ma, and Xinguo Sun. "Water Level Decline in a Reservoir: Implications for Water Quality Variation and Pollution Source Identification." International Journal of Environmental Research and Public Health 17, no. 7 (April 1, 2020): 2400. http://dx.doi.org/10.3390/ijerph17072400.
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Continuous water-level decline makes the changes of water quality in reservoirs more complicated. This paper uses trend analyses, wavelet analysis and principal component analysis-multiple linear regression to explore the changes and pollution sources affecting water quality during a period of continuous reservoir water level decline (from 65.37 m to 54.15 m), taking the Biliuhe reservoir as an example. The results showed that the change of water level of Biliuhe reservoir has a significant 13-year periodicity. The unusual water quality changes during the low water level period were as follows: total nitrogen continued to decrease. And iron was lower than its historical level. pH, total phosphorus, and ammonia nitrogen were higher than historical levels and fluctuated seasonally. Permanganate index increased as water level decreased after initial fluctuations. Dissolved oxygen was characterized by high content in winter and relatively low content in summer. The pollutant sources of non-point source pollution (PC1), sediment and groundwater pollution (PC2), atmospheric and production & domestic sewage (PC3), other sources of pollution (PC4) were identified. The main source of DO, pH, TP, TN, NH4-N, Fe and CODMn were respectively PC3 (42.13%), PC1 (47.67%), PC3 (47.62%), PC1 (29.75%), PC2 (47.01%), PC1 (56.97%) and PC2 (50%). It is concluded that the continuous decline of water level has a significant impact on the changes and pollution sources affecting water quality. Detailed experiments focusing on sediment pollution release flux, and biological action will be explored next.
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Guan, Jian-Zhao, Lei Zhang, Chun-Ming Fang, and Jun Feng. "Study on the Causes of the Decline of the Low Water Levels of Poyang Lake, China." E3S Web of Conferences 117 (2019): 00014. http://dx.doi.org/10.1051/e3sconf/201911700014.
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The drastic decline in the water level of Poyang Lake during the dry season has close connection with the water environment and lake ecology. The drastic decline has attracted considerable attention, and has led to intense scientific discussions regarding its cause. However, the importance of the different causes of the low water level decline has not been clearly illustrated. To improve the understanding of the reasons for the decline of low water levels in the Poyang Lake Waterway, this paper investigated the contributions of river channel erosion and sand mining to the water level decline. The results show that sand mining mainly occurred on the beaches of the Waterway, and had a relatively small effect on the change in the shape of the main river channel. It was found that the contribution of sand mining to the decline in the low water level was no more than 30%, while the average contribution by natural erosion was about 85%. This indicates that natural channel erosion of the Waterway has been significant, and plays a dominant role in the declining water levels of the Waterway.
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Zhao, Nenghao, Bin Hu, Qinglin Yi, Wenmin Yao, and Chong Ma. "The Coupling Effect of Rainfall and Reservoir Water Level Decline on the Baijiabao Landslide in the Three Gorges Reservoir Area, China." Geofluids 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/3724867.
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Rainfall and reservoir level fluctuation are two of the main factors contributing to reservoir landslides. However, in China’s Three Gorges Reservoir Area, when the reservoir water level fluctuates significantly, it comes at a time of abundant rainfall, which makes it difficult to distinguish which factor dominates the deformation of the landslide. This study focuses on how rainfall and reservoir water level decline affect the seepage and displacement field of Baijiabao landslide spatially and temporally during drawdown of reservoir water level in the Three Gorges Reservoir Area, thus exploring its movement mechanism. The monitoring data of the landslide in the past 10 years were analyzed, and the correlation between rainfall, reservoir water level decline, and landslide displacement was clarified. By the numerical simulation method, the deformation evolution mechanism of this landslide during drawdown of reservoir water level was revealed, respectively, under three conditions, namely, rainfall, reservoir water level decline, and coupling of the above two conditions. The results showed that the deformation of the Baijiabao landslide was the coupling effect of rainfall and reservoir water level decline, while the latter effect is more pronounced.
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Jasechko, Scott, and Debra Perrone. "Global groundwater wells at risk of running dry." Science 372, no. 6540 (April 22, 2021): 418–21. http://dx.doi.org/10.1126/science.abc2755.
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Groundwater wells supply water to billions of people, but they can run dry when water tables decline. Here, we analyzed construction records for ~39 million globally distributed wells. We show that 6 to 20% of wells are no more than 5 meters deeper than the water table, implying that millions of wells are at risk of running dry if groundwater levels decline by only a few meters. Further, newer wells are not being constructed deeper than older wells in some of the places experiencing significant groundwater level declines, suggesting that newer wells are at least as likely to run dry as older wells if groundwater levels continue to decline. Poor water quality in deep aquifers and the high costs of well construction limit the effectiveness of tapping deep groundwater to stave off the loss of access to water as wells run dry.
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Lihua, Zhou, Chen Guichen, and Peng Min. "Impact of human activities on the decline of water level,Qinghai Lake." Journal of Lake Sciences 4, no. 3 (1992): 32–37. http://dx.doi.org/10.18307/1992.0305.
Full textDissertations / Theses on the topic "Water level decline"
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Wang, Li-Fang, and 王俐方. "Seepage of Embankment Dam under the Rapid Decline Water Level of Reservoir." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/86694912302242758306.
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碩士中原大學
土木工程研究所
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Many reasons can make embankment dam to cause damage, for examples: earthquake, soil liquefaction, rapid take-off and loading water, and the role of wave erosion. This research is about when the rapid decline water level on embankment dam upstream, the seepage and hydraulic pressure distribute in embankment dam. And make an analysis to the change of stability factor. This research will combine the method of seepage and slope stability analysis, and consider under the different speed of decline water level, the seepage change and stabilization in the embankment dam. First, applies the FEMWATER software in simulating the groundwater table, moisture content, and seepage velocity. Next, there are different soil parameters in different moisture content. Then, it applies the mode of WINSTABL software to count each stage the relations between safety factors of slope and time. Last, it changes seepage velocity to hydraulic gradient and analysis if the hydraulic gradient is caused the piping. After the simulation test, we know that the failure will more easy happen when the speed of decline water level more fast. And we know that the hydraulic gradient will bigger when the speed of decline water level more fast. When the speed of decline water level is 53.14m/24hr, the embankment dam can be happened piping.
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Skinner, Dominic. "Sediment resuspension and water quality during declining water levels in a shallow lake : a case study of Lake Alexandrina, South Australia." Thesis, 2012. http://hdl.handle.net/2440/83330.
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Shallow lakes have a tendency to be present in one of two broad alternative states: clear or turbid. Increased demand for water by humans, drought and climatic shifts may reduce water availability and increase the frequency or magnitude of lake water level drawdown. However, there is conflicting evidence as to how shallow lakes respond to water level decline. Many lakes become clearer due to reduced nutrient inputs from inflowing rivers. Alternatively, internal processes, such as the resuspension of sediments, can exacerbate the turbid state as lower water levels attenuate less wind-induced turbulence before it reaches the sediment surface. A better understanding of responses of lake water quality to drawdown will greatly improve the ability of water managers to maximise the ecological benefits of drawdowns, while minimising the adverse consequences. Severe drought in the Murray-Darling Basin, Australia’s largest river system, resulted in extreme water level decline in the two end of system lakes, Lake Alexandrina and Lake Albert (the Lower Lakes). Water depth in Lake Alexandrina dropped from a mean of 2.9 metres in summer 2006/07 to 1.3 metres two years later, where water levels remained until April 2010 when floods refilled the lakes. This provided a unique opportunity to assess the influence of water level decline on lake characteristics. The aims of this work were to firstly elucidate the effects of water level decline on sediment resuspension and redistribution, accompanying nutrient changes and light availability. Secondly, the study sought to understand the interactions between water level decline and sediment resuspension in the context of alternative stable states during periods of drought. As water level fell in the Lower Lakes, the water quality became increasingly brackish as mean salinity rose from 0.6 g L⁻¹ to 3.7 g L⁻¹. The concentration of suspended particulate matter (SPM) and associated nitrogen and phosphorus concentrations increased as water levels declined, whereas soluble phosphorus did not. A mass balance showed that month to month variation in SPM could not be explained by the sum of inputs and outputs, suggesting that sediment resuspension was an important process in Lake Alexandrina at all water levels. Surveys of the size distribution of surface sediments suggested that focusing of fine sediments was more prevalent when water levels were higher. Analysis of gross sedimentation using sediment traps supported the hypothesis that the resuspension and redistribution of sediments had become spatially homogeneous as water levels declined. High-resolution data collected from the centre of Lake Alexandrina suggested that sediment resuspension frequently occurred below even the deepest water. At bed shear stresses greater than 0.031 N m⁻² particles with a nominal diameter of 26 μm were resuspended. Under low water levels, sediment resuspension strongly influenced the depth of light penetration into the water column (euphotic depth ranged between 0.68 and 0.91 metres). However, lower water levels led to an increase in the average irradiance through the water column compared with previous studies at higher water levels. Hydrodynamic modeling was used to quantify the influence of wind speed on sediment resuspension. This showed that wind speeds of 7.7 m s⁻¹ were required to resuspend particles with a nominal diameter of 26 μm when water levels were high. However, at low water levels, the wind speed imparting critical shear velocity at the lake-bed decreased to 2.4 m s⁻¹. The frequency distribution of wind speed suggested that sediments were being resuspended only 27% of the time when water levels were high, but over 87% of the time at the lowest water levels studied. The shallow morphology of Lake Alexandrina, as well as the high wind-induced turbulent energy at the sediment surface due to its large surface area, increased the resuspension and redistribution of fine sediments during water level drawdown. For Lake Alexandrina, the internal process of sediment resuspension overcame the drought-induced reduction in nutrient inputs to result in an increasingly turbid system. These results imply that lake management should centre on the reduction of external nutrients, as well as biomanipulation of the food webs to increase the water clarity of Lake Alexandrina and improve conditions for macrophyte development.Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2012
Books on the topic "Water level decline"
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Winner, M. D. History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina. Raleigh, N.C: U.S. Dept. of the Interior, U.S. Geological Survey, 1986.
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Winner, M. D. History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina. Raleigh, N.C: U.S. Dept. of the Interior, U.S. Geological Survey, 1986.
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Winner, M. D. History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina. Raleigh, N.C: U.S. Dept. of the Interior, U.S. Geological Survey, 1986.
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Winner, M. D. History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina. Raleigh, N.C: U.S. Dept. of the Interior, U.S. Geological Survey, 1986.
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Winner, M. D. History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina. Raleigh, N.C: U.S. Dept. of the Interior, U.S. Geological Survey, 1986.
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Dearborn, Larry L. Water-level declines in wells tapping lower hillside aquifers Anchorage, Alaska (1985). Fairbanks, Alaska: Alaska Division of Geological and Geophysical Surveys, 1987.
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Dearborn, Larry L. Water-level declines in wells tapping lower hillside aquifers Anchorage, Alaska (1985). Fairbanks, Alaska: Alaska Division of Geological and Geophysical Surveys, 1987.
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McAda, Douglas P. Projected water-level declines in the Ogallala aquifer in Lea County, New Mexico. [Albuquerque, N.M.]: U.S. Dept. of the Interior, Geological Survey, 1985.
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McAda, Douglas P. Projected water-level declines in the Ogallala aquifer in Lea County, New Mexico. [Albuquerque, N.M.]: U.S. Dept. of the Interior, Geological Survey, 1985.
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McAda, Douglas P. Projected water-level declines in the Ogallala aquifer in Lea County, New Mexico. [Albuquerque, N.M.]: U.S. Dept. of the Interior, Geological Survey, 1985.
Find full textBook chapters on the topic "Water level decline"
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Nechwatal, Jan, Anna Wielgoss, and Kurt Mendgen. "Flooding events and rising water temperatures increase the significance of the reed pathogen pythium phragmitis das a contributing factor in the decline of phragmites australis." In Ecological Effects of Water-Level Fluctuations in Lakes, 109–15. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-9192-6_11.
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Thomsen, A. R., M. R. Saalmann, N. H. Nicolay, A. L. Grosu, and Peter Vaupel. "Temperature Profiles and Oxygenation Status in Human Skin and Subcutis Upon Thermography-Controlled wIRA-Hyperthermia." In Water-filtered Infrared A (wIRA) Irradiation, 69–80. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92880-3_5.
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AbstractEfficacy of wIRA immediately followed by hypofractionated radiation in the treatment of locally recurrent breast cancer and other superficial tumors is documented. A prerequisite for the additive and synergistic radiosensitizing properties of hyperthermia is the assessment of resulting temperatures of tumors and normal tissues. To assess the role of hyperthermia in reversing tumor hypoxia through its effects on local blood flow, oxygen profiles in skin, subcutis, and superficial tumors have been additionally assessed during mild hyperthermia (39–43 °C).Upon wIRA-exposure, skin surface temperatures increased from 35 to 41.6 °C within 5–12 min. Maximum temperatures of 42 °C were found in subepidermal regions, with a steady decline in deeper layers reaching 40.1 °C at a depth of 20 mm. Heating was accompanied by increases in tissue oxygen tensions. Effective hyperthermia levels (≥ 39 °C) were established in depths up to 25 mm. Following wIRA exposure, tissue temperatures returned to pretreatment levels within a few minutes, with the decay time depending on tissue depths, while pO2 values remained on therapeutical levels for 30–60 min postheat, outlasting the period needed for subsequent radiotherapy. Monitoring in the upper dermis layer of skin and recurrent breast cancers confirmed the improved O2 status during wIRA exposure and outlasted the time needed for subsequent radiotherapy.
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Heckel-Reusser, S. "Whole-Body Hyperthermia (WBH): Historical Aspects, Current Use, and Future Perspectives." In Water-filtered Infrared A (wIRA) Irradiation, 143–54. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92880-3_11.
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AbstractWhole-body hyperthermia (WBH), induced by passive heating, and active fever therapy induced by pyrogenic drugs, have been accepted as therapy of various diseases for many decades. However, the introduction of antibiotics and anti-inflammatory drugs caused the interest in this traditional therapy to decline. The development of modern WBH using infrared irradiation (IR) started in the 1960s.Three levels of hyperthermia differ fundamentally in practical implementation, mechanisms of action, and indications. Mild WBH is stress-free and aims mainly to muscle relaxation and increased perfusion in the locomotor system. Fever-range whole-body hyperthermia (FRWBH) requires a more extensive nursing care due to major thermoregulatory stress. FRWBH is applied for stimulation of anti-tumor immune responses and for anti-inflammatory effects in case of chronic inflammation. Moreover, anti-depressive effects of FRWBH could recently be shown. Extreme WBH needs an intensive care environment and aims to the direct damage of cancer cells or therapy-resistant pathogens. In general, inconsistent effects of WBH on blood perfusion must be taken into account if combined with medication.Two commercially available medical WBH devices both use water-filtered infrared-A (wIRA), but deviate in the practical implementation. Contraindications and the risk of side effects differ essentially between the three levels and must carefully be observed.
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Adero, Nashon Juma, and John Bosco Kyalo Kiema. "Flow-Based Structural Modelling and Dynamic Simulation of Lake Water Levels." In Green Technologies, 798–814. IGI Global, 2011. http://dx.doi.org/10.4018/978-1-60960-472-1.ch413.
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The continuing decline in lake water levels is both a concern and daunting challenge to scientists and policymakers in this era, demanding a rethinking of technological and policy interventions in the context of broader political and socio-economic realities. It is self-evident that diverse factors interact in space and time in complex dynamics to cause these water-level changes. However, the major question demanding sound answers is how these factors interact and by what magnitude they affect lake water balance with time. This chapter uses Lake Victoria’s hydrological system to shed light on the extensive and flexible modelling and simulation capabilities availed by modern computer models to understand the bigger picture of water balance dynamics. The study used the 1950-2000 hydrological data and riparian population growth to develop a dynamic simulation model for the lake’s water level. The intuitive structure of the model provided clear insights into the combined influence of the main drivers of the lake’s water balance. The falling lake water levels appeared to be mainly due to dam outflows at the outlet and reduced rainfall over the lake. The ensuing conclusions stressed the need for checks against over-release of lake water for hydropower production and measures for sustainable land and water management in the entire basin.
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Kirchman, David L. "Dead Zones in the Oceans." In Dead Zones, 138–53. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780197520376.003.0010.
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As this chapter shows, the open oceans are also running out of dissolved oxygen as seen at Station Papa in the subarctic Pacific Ocean, thanks to work done on Canadian weather ships starting in the 1950s. Not only are areas of severe hypoxia, or oxygen minimum zones, expanding, but the level of dissolved oxygen in all oceans is decreasing. The open oceans are losing oxygen because of climate change. The warming of the oceans reduces the solubility of oxygen in water and stimulates oxygen use by respiring organisms. This chapter explores how climate change is also altering circulation and the mixing of oxygen into oxygen-poor waters. Even where oxygen remains above dead-zone levels, its depletion is another sign of how climate change is reshaping the biosphere. The expansion of low-oxygen water has shifted the habitats of fish and invertebrates, such as the giant squid, over thousands of miles, and has disrupted the nitrogen cycle of the entire biosphere. The chapter explains that because of oxygen depletion, biological production of the oceans may decline due to the loss of nitrogen, while release of a potent greenhouse gas (nitrous oxide) may increase.
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"Eels at the Edge: Science, Status, and Conservation Concerns." In Eels at the Edge: Science, Status, and Conservation Concerns, edited by Yves de Lafontaine, Michel Lagacé, Fernand Gingras, Denis Labonté, François Marchand, and Edith Lacroix. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781888569964.ch15.
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<em>Abstract.—</em>Changes in abundance, seasonal occurrence, and mean size of American eels <em>Anguilla rostrata </em>in the lower St. Lawrence River during the past 50 years were examined. Catch per unit effort indices were calculated from daily catch records of eels captured in an experimental trap fishery and from the personal logbooks of a knowledgeable fisher. These two indices indicated a significant declining trend in eel catch rate by more than 50% since the early 1970s. Interannual fluctuations in catch rate were not related to variability in water level or water temperature. The timing of eel occurrence varied significantly between years and was inversely correlated to water level in August and September. It is hypothesized that eel movement is strongly determined by climatic/hydrological conditions in the previous summer. The average weight of eels has increased by 30% over the past eight years. The decline in catch rate and the increase in mean size of migratory silver eels in recent years are interpreted as the most significant symptoms of low recruitment levels and the precursory signal that the eel fishery in the lower St. Lawrence River may not be sustainable in the near future.
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Graham, Wade. "Conclusion." In Braided Waters, 194–98. University of California Press, 2018. http://dx.doi.org/10.1525/california/9780520298590.003.0008.
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This chapter summarizes key themes and presents some final thoughts. It argues that a certain number of patterns are visible in the long history of Molokai and Hawaii, which together add up to a so-called socio-environmental calculus. First, because of the uneven distribution of water in an often marginal environment, the control of water resources is critical to sustaining life and to maintaining control of the political level in a competitive society. Second, the control of natural and human resources tends, where the environmental conditions for bigness (or resource thickness) exist, to become concentrated in a few hands and reinforces the tendencies toward intensification and stratification. The monopoly control of water and land resources exacerbates and drives the feedback loop of environmental degradation; destruction of common resources; and the decline of small, subsistence-based communities, further reinforcing intensification and the control of monopolists.
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"Mitigating Impacts of Natural Hazards on Fishery Ecosystems." In Mitigating Impacts of Natural Hazards on Fishery Ecosystems, edited by Peter B. Moyle. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781934874011.ch28.
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<em>Abstract</em>.—The San Francisco Estuary is the largest estuary on the west coast of North America and one of the most altered. It supports a diverse fish fauna in which key species are in severe decline. The estuary is faced with catastrophic structural and ecological changes, especially in the Sacramento–San Joaquin Delta and Suisun Marsh, as the result of levee failure caused by the combination of earthquakes, land subsidence, sea level rise, and increased high outflows events (from climate change). The resulting flooding of Sacramento–San Joaquin Delta islands and Suisun Marsh is predicted to disrupt California’s water supply system and, consequently, the state’s economy. From a fish perspective, the changes seem likely to create conditions in which key native species and striped bass can persist at least at present low levels, after a period of possible high mortality created by the initial flooding events. Taking actions to regulate ecological changes in the estuary before a disaster occurs could actually improve conditions for desirable fishes while being highly compatible with delivering services the Sacramento–San Joaquin Delta provides, especially water supply. Specific actions include improving habitat for fish in Suisun Marsh, Cache Slough, the Yolo Bypass, and the San Joaquin River, while creating islands in which flooding can be managed. The key is increasing and maintaining habitat heterogeneity. The present situation in the estuary represents an unprecedented opportunity to reverse the impacts of more than 150 years of undesirable ecological change.
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"From Catastrophe to Recovery: Stories of Fishery Management Success." In From Catastrophe to Recovery: Stories of Fishery Management Success, edited by Nukhkadi I. Rabazanov, Alexei M. Orlov, Akhma S. Abdusamadov, Ruslan M. Barkhalov, and Kurban M. Akhemedkhanov. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874554.ch20.
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<i>Abstract.</i>â€â€This chapter provides the history of the Caspian Kutum <i>Rutilus kutum</i> (Kamensky 1901) fishery in the Caspian Sea, analyzes long-term changes of stock condition and the main causes of fluctuations in abundance, and describes conservation measures that allowed resumption of fishing. Caspian Kutum (Cyprinidae family) is an endemic, semi-anadromous, medium-sized fish, reaching 53–67 cm in total length (rarely 71 cm) and weighing up to 4.0 kg (rarely 5.0 kg). Commercially important fisheries occur in Russia, Azerbaijan, Iran, and Turkmenistan. Flesh and roe are enjoyed as food and have a high price in markets. Variability in sea level, construction of hydroelectric power plants on rivers, water irrigation withdrawals, industrial and domestic pollution, overfishing, and illegal fishing resulted in a sharp decline of Caspian Kutum abundance and resulted in a total ban on harvest in Russia between 1995 and 2004. In Iran, fishing for Caspian Kutum continued due to their stocking program. Conservation measures for Caspian Kutum stocks (e.g., listing in federal and local Red Data books, fishing ban, fight against illegal fishing), as well as an increase of artificial propagation in Iran, Azerbaijan, and Dagestan (Russia) during subsequent years, have allowed the recovery of stocks in Russian waters to 1990s levels as well as the resumption of fishing. The follow lessons may be applicable to fishery management programs elsewhere:
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"From Catastrophe to Recovery: Stories of Fishery Management Success." In From Catastrophe to Recovery: Stories of Fishery Management Success, edited by Christopher S. Vandergoot, Matthew D. Faust, James T. Francis, Donald W. Einhouse, Richard Drouin, Charles Murray, and Roger L. Knight. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874554.ch18.
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<i>Abstract.</i>â€â€This chapter describes management actions implemented after a large-scale population decline of the Walleye <i>Sander vitreus</i> population in Lake Erie, one of the Laurentian Great Lakes in North America. Intensive fishery exploitation during the 1950s combined with declining water quality conditions collapsed the Walleye stock during the early 1960s. The fishery persisted at low levels until 1970 when the fishery was closed (1970–1972) due to elevated mercury concentrations in Walleye tissue. Lake Erie fishery managers at the time recognized the need for a coordinated, multi-agency approach to protect this ecologically, economically, and socially important resource. The harvest ban was lifted in 1973 when mercury levels dropped below advisory levels. In 1976, an interagency management framework was established, which relied on a coordinated, science-based management philosophy consisting of estimating safe harvest levels, performing applied research, and conducting annual population assessments. The population rebounded during the 1980s in response to improving environmental conditions, regulated harvest, and a series of strong recruitment events. Declines in harvest and population size were again observed during the late 1990s and mid-2000s, likely due to variation in natural processes controlling recruitment, and fishery managers enacted harvest practices during this period to promote long-term sustainability. Today, Lake Erie Walleyes support one of the largest self-sustaining freshwater fisheries in North America. Throughout the years, Lake Erie managers have iteratively adopted changes to their population assessment model and altered harvest policies to avoid future fishery and population collapses. More than 40 years later, Lake Erie continues to support commercial and recreational fisheries lake wide. Lessons learned from the stock recovery and subsequent coordinated management for fishery sustainability include the importance of conducting routine population assessments, using science-based research to address key uncertainties, adopting modern stock assessment approaches, incorporating stakeholder input into the quota setting process, and addressing environmental concerns collaboratively at the lake level.
Conference papers on the topic "Water level decline"
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Schafer, Jr., John S. "Lake Michigan-Huron Water Level Decline due to Hydraulic Scour of the St. Clair River." In World Environmental and Water Resources Congress 2007. Reston, VA: American Society of Civil Engineers, 2007. http://dx.doi.org/10.1061/40927(243)430.
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Wang, Xiuhong, Jingmin Du, Minxiong Cao, Guozheng Cai, Xinnong Zhang, Dongdong Jia, and Aixing Ma. "Study on water level decline effected on navigation in the reach of Changzhou Hydraulic Complex to Jieshou of Xijiang River." In International Conference on Earth Science and Environmental Protection (ICESEP2013). Southampton, UK: WIT Press, 2013. http://dx.doi.org/10.2495/icesep130291.
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Al Ghafri, Zaaima Sulaiman, Sulaiman Saad Al Mandhari, Ghusun Amur Al Aamri, and Yousuf Salim Al Zaabi. "A Novel Approach for Improving Water Injection Performance in Oil Field by Applying Lean Six Sigma." In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211190-ms.
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Abstract Objectives/Scope Water injection (WI) is very critical in Oil Fields to improve pressure build up; hence maximizing oil recovery and increase volume. In X field in South Sultanate of Oman, Water Injection is a key factor to stabilize Oil production. In 2018, rapid pressure decline has been seen in oil producing wells. Since then, a clear decline is seen in water injector wells which resulted in Oil lost up to 100 m3 of Oil per day. Methods, Procedures, Process To arrest WI decline, a ‘Lean Six-Sigma’ study was carried out using the DMAIC (Define, Measure, Analyze, Improve & Control) approach. The DMAIC approach is a proven improvement approach in global industries successfully utilized outside of Oil and Gas for number of years, but never utilized in this context until now. The application of this approach helped significantly to enhance and reduce the defect, decline and variation, of the injectivity process. The DMAIC approach helped the team to understand the problem, analyze it and identify the root cause of the injection decline, to reach an optimized solution which is replicated across the field. Results, Observations, Conclusions The study showed that, due to the reservoir having low permeability and porosity, even a small amount of TSS (Total Suspended Solids) in the formation can have a significant negative impact on well injectivity. As a result, optimized acid stimulation was recommended for X wells until water is treatment facility is on stream by end 2023. A new acid recipe showed a lower defect, decline and variation in injection rate trend for the piloted WI wells. This had a significant improvement on X field injection and acceptance for the water and hence increase overall production and sustainability of pressure support across the field. The results have proven that, by using this structured approach, the unwanted variation in injectivity and the level of process defects were reduced significantly which resulted in major oil gains. Novel/Additive Information Using this novel Lean Six-Sigma approach to improve injection managed to obtain the following impressive results on increase in Oil gain by 25 m3/day (9.8k/day $) 3.6 Million $ / Year. Along with the impressive oil gain, this study will provide opportunities to many organizations for healthier and enhanced implementation of Lean Six-Sigma projects for Water Injection issues in Oil and Gas Fields. Furthermore, it has opened new era to the way similar problems are tackled.
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Chatterjee, Someshwar, Nasser Riyami, and Ali Ruqaishi. "Journey of Waterflood Excellence in a Matured Field, North of Sultanate of Oman." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2022. http://dx.doi.org/10.2118/200107-ms.
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Abstract Objective/Scope The studied field is located in North Oman asset and developed through waterflood line-drive since 1980s with top quartile recovery factor. In the period between 2010 and 2012, production has declined faster than expected reaching to a peak decline rate of 19% per year resulted to significant associated oil production loss. This abstract summarizes the recovery process for waterflood development supported with lean approach by WRFM team not only to arrest production decline but also to flip the coin to production incline in 2015-2016. Lean Approach The major reasons that led to the ineffective waterflood performance in this field were several surface and subsurface issues related to water distribution, low injection efficiency and low level of integration within the team. The success achieved through focused proactive waterflood management (Asset's WRFM Plan, 2016) and seamless integration with field operations and asset leadership with below key steps: Setting a firm WRFM Waterflood Strategy focusing on waterflood management, field/reservoir operating envelope and pressure maintenance. Goal Deployment value stream metrics aimed to improve reservoir operating envelope compliance by improving water-injectivity compliance that ensures effective and even injection water distribution etc. The pressure maintenance strategies include priorities the injection optimization in the low-pressure blocks and continuous monitoring of reservoir pressure through periodic acquisition of pressure surveys. This resulted in significant improvement of average reservoir pressure. Standardized regular field, pattern/ sector and well reviews (Chatterjee, Someshwar et.al., 2017) resulted in effective sweep monitoring strategy by using latest FDP static and dynamic models calibrated with recent surveillance data (RST, MPLT etc.). This process helps to generate and optimize the WRFM opportunities to maximize the production. Periodic waterflood health checks by external and internal experts mainly focused on accessing waterflood improvements and benchmarked with other fields of the asset during 2014, 2016 and 2018. The waterflood health check score improved with time and field achieved the highest score across all the other matured fields in North Oman. More importantly, the noticeable improvement in integration between different teams i.e. petroleum, operation, and engineering on daily to weekly basis ensures stability of the WI performance, meeting injection target and honest transparent communications to work as ONE TEAM through different session using Leader Standard Work (LSW). Results and Conclusion These efforts by the integrated team resulted in: Arresting the production decline from 19% annual effective to 6% within 3 years Reversing the decline trend of 3% between 2015-2016 Safeguard more than a mln m3 of asset's reserves A gain of average oil rate for reversing the decline trend This project is an excellent example of being innovative with lean structure and simple "Going Back to Basics" principle for water flood management. The projects delivered with commercial mindset to arrest the decline and safeguard reserves; external focus by benchmarking with waterflood assessment and strong integration- displaying highest standard of improved organizational behavior.
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Oughanem, Rezki, Thomas Gumpenberger, Jean Grégoire Boero-Rollo, Scherwan Suleiman, Jalel Ochi, Maria-Magdalena Chiotoroiu, and Abdalla Hannes. "A Core Flood Test-Program Performed with a Pilot-Skid to Quantify the Permeability Decline Induced by Real Treated Produced Waters Also Containing Degraded Polymer or Not." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/207633-ms.
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Abstract A water treatment pilot skid called WaOω has been developed by TotalEnergies to test the efficiency of the centrifugation technology in treating the produced water containing back produced polymer. In case of success, this technology would be implemented on field and the water quality targeted by the technology must allow re-injecting the treated produced water in matrix flow regime for pressure maintain and sweep efficiency. The same interest was expressed by OMV and a partnership project has been built. It was also agreed that OMV builds a second pilot skid called PRT that allows carrying out core flood tests onsite to assess the formation damage and related permeability decline that could be induced by the treated produced water. Both pilot skids have been implemented, connected to each other, and tested during more than one year on the OMV's Matzen oil field nearby Vienna where degraded polymer is already back produced by wells and present in the produced water. More than seventy core flooding tests have been performed in different centrifugation conditions in terms of speed and water qualities, some of them on high permeable sand packs representing the field targeted by TotalEnergies and some others on consolidated sandstone samples of lower permeability representing OMV reservoirs. The effect of adding fresh polymer to the treated produced water for EOR purposes has also been investigated. Some complementary core flood tests have also been performed in TotalEnergies labs using reconstituted sand packs and produced waters with and without polymer to understand the contribution of the degraded polymer alone, the produced water quality alone and both to understand the formation damage and some uncommon results observed with the PRT pilot skid. Core flood tests data often obtained on long injection periods revealed of a high quality, reliable and reproducible. They also showed that even if centrifugation seems to be a good technology, the very clean and transparent water that it delivered induced surprisingly some core permeability declines the origin of which would be discussed in this paper. However, it was clearly established that the presence of degraded polymer has a cleaning effect and limits the formation damage induced by the produced water injected on cores if the Total Suspended Solids in the treated water remains at an acceptable level. Adding fresh polymers limited even more the formation damage because their cleaning effect is more pronounced than with degraded polymer.
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Widyoko, Bhayu, Patria Indrayana, Toto Hutabarat, Andriadi Budiarko, Mitterank Siboro, and Henricus Herwin. "Enhancing Economics of Resources Development of Mature Mahakam Fields Through Innovation, Design Optimization, and Value Engineering." In SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205713-ms.
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Mahakam Contract Area is located in East Kalimantan Province, Indonesia. It covers an operating area of 3,266 km2, and consists of 7 producing fields. Most of Mahakam hydrocarbon accumulations are located below body of water, with wellhead production facilities installed in the estuary of Mahakam river (referred as swamp area, 0 to 5m water depth) and the western part of Makassar Strait (referred as offshore area, 30 to 70 m water depth). Mahakam production history goes as far back as mid 1970s with production of Handil and Bekapai oil fields. Gas production started by the decade of 1990s along with emergence of LNG trading, supplying Bontang LNG plant, through production of 2 giant gas fields: Tunu and Peciko, and smaller Tambora field. In the mid 2000s, Mahakam attained its peak gas production in the level of 2,600 MMscfd and was Indonesia's biggest gas producer. Two remaining gas discoveries, Sisi Nubi and South Mahakam, were put in production respectively in 2007 and 2012. Due to absence of new discoveries and new fields brought into production, Mahakam production has entered decline phase since 2010, and by end of 2020, after 46 years of production, the production is in the level of 600 MMscfd. In 2018, along with the expiration of Mahakam production sharing contract, Pertamina Hulu Mahakam (PHM), a subsidiary of Indonesian national energy company, Pertamina, was awarded operatorship of Mahakam Block. This paper describes the efforts undertaken by PHM to fight production decline and rejuvenate development portfolio, with focus on expanding subsurface development portfolio and reserves renewal by optimizing development concept and cost through fit-for-purpose design, innovation, and full cycle value engineering.
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Senger, R., and J. Ewing. "Investigations of the Possible Separation Distance Between Spent Fuel/High-Level Waste and a Low/Intermediate-Level Waste Repositories due to Gas and Heat Generation." In ASME 2011 14th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2011. http://dx.doi.org/10.1115/icem2011-59220.
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This study is part of a generic investigation for the assessment of the required minimum distance between a Spent Fuel/High-Level Waste/ Intermediate-Level Waste (SF/HWL/ILW) repository and a Low/ Intermediate-Level Waste (L/ILW) repository. For this, a large-scale numerical model was constructed to investigate the two-phase flow behavior for such a repository configuration in a low-permeability claystone formation. The modeling focused on the pressurization mechanisms associated with (a) resaturation of backfilled underground facilities, (b) thermal effects caused by heat generation from the SF/HLW canisters, and (c) gas generation from corrosion and degradation of different wastes in the L/ILW and ILW caverns and in the SF/HLW emplacement tunnels. The model accounts for gas generation from corrosion and degradation of both L/ILW and ILW wastes indicating decreasing rates with time, and from corrosion of the SF/HLW canisters characterized by a constant rate. Heat generation from radioactive decay of radionuclides of MOX/UO2 wastes is described by an exponential decay with time. The preceding operational phases of the different repository components were simulated representing the transient initial conditions for the post-closure phase. The simulated pressure buildup in the L/ILW repository shows a near linear increase between 10 and 4,000 years when the peak pressure of 6.5 MPa is reached for a repository at about 370 m bg. This is followed by a similar decline, recovering to near hydrostatic pressures after 1 million years. The SF/HLW repository (repository level 600 m bg) indicates a pressure rise between 100 and 1,000 years affected by the early thermal effects, followed by a steep increase between 3,000 and 100,000 years when the pressures level off to a maximum of 6.5 MPa after 160,000 years (corresponding to a steel corrosion rate of 1 μm/year). This is the time when all the metal is corroded and the gas generation stops resulting in a sudden decline, and the pressures level off to about 4.5 MPa in the SF/HLW emplacement tunnel after 1 million years. The numerical modeling demonstrates that the main pressurization mechanism is from gas generation in the different repository components. The pressure histories show a distinct separation of the pressure peaks between the L/ILW repository and the SF/HLW/ILW repository. Moreover, the thermal phenomena affect the pressures in the SF/HLW repository at early time only (prior to about 2,000 years). The thermal expansion of the pore water in the nearfield around the SF/HLW tunnels does produce a relatively steep pressure buildup after 100 years, but it dissipates rapidly prior to the main pressure buildup caused by the gas generation and gas accumulation in the SF/HLW repository. The thermally induced pressure buildup is restricted to the vicinity of the SF/HLW emplacement tunnels (decameter range) and thus, significant interference of the thermally induced pressure perturbation around the SF/HLW/ILW repository with the early gas pressure buildup in the L/ILW repository can be excluded.
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Kamal, Hamzah, Prakoso Noke Fajar, Ghozali Farid, Aryanto Agus, Priyantoro Tri Atmojo, Amru Kautsar, and Respati Pradhipta Seno. "Resolving Multiple Formation Damage Mechanism in Carbonate Reservoir Through Systematic Approach Using Combination of Aromatic Solvent and Less Aggressive Acid." In SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205816-ms.
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Abstract There is no well operation that is truly non-damaging. Any invasive operation, even production phase itself, may be damaging to well productivity. An interesting case was found in L-Field which is located in South Sumatra, Indonesia. All four wells are predicted to cease to flow after five-year production and artificial lift have to be installed to prevent steep decline in oil production. Unfortunately, all of wells’ productivity index (PI) decreased post well intervention and therefore, couldn’t achieve target. The PI was continuously decreasing during production phase and aggravated the decline in oil production. Remediation action by systematic approach was applied to solve the problem. Early diagnostic revealed some potential causes through evaluation of both production and well treatment data. Laboratory test such as mineralogy analysis, crude composition and water analysis, solubility and compatibility test have been conducted and clarified the root cause that formation damage occurred in multiple mechanism related to incompatibility of the workover fluid and organic deposition. Then, possible well treatments were listed with pros and cons by considering post water production related to the carbonate reservoir properties. Subsequently, chemical matrix injection was ranked based on less possibility of water breakthrough risk. Diesel fuel and de-emulsifier injection was decided as the first treatment in order to remove formation damage caused by organic deposition. The rate was increased temporary with Water Cut (WC) remained at the same level. The subseqeuent effort was to inject low reaction chelating acid and the result showed temporary improvement and the production did achieve significant gain. Finally, the third attempt indicated promising results with the injection of aromatic solvent followed by chelating acid. The well productivity was increased to more than 20 times of the pre treatment levels. The method can be replicated to other affected wells with similar damage mechanism. High vertical permeability over horizontal permeability becomes a real threat in carbonate strong water driver reservoir in L-field. Thus, matrix acidizing treatment has to be carefully applied to prevent unwanted water production. Non-aggressive and slow reaction acid were chosen to prevent face dissolution reaction that leads to water breakthrough.
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Ting, Yang, Li Guang Sheng, Li Zeng Fen, Peng Yue, and Hu Jian. "Study on Effects of Environment Conditions on Essential Service Water System of Nuclear Power Station." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66189.
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For nuclear power stations, the main function of Essential Service Water System (ESWS) is to discharge the waste heat from reactor core and spent fuel pool to the environment controllably, which is directly related to the safety and economy of nuclear power stations. Usually ESWS use open water from sea, rivers, lakes, reservoirs, as heat transfer medium. Extremely harsh environmental conditions may disable system functions and even lead to ESWS failure, directly reduce the safety and economy of nuclear power stations, and cause serious nuclear accidents. Failure of ESWS is one of the main reasons that lead to the Fukushima nuclear accident because of the loss of electricity after the earthquake and tsunami. Based on the typical ESWS configuration and conditions of serving nuclear power stations in China, the influence of environmental conditions on the function of water system is studied, and the corresponding measures are analyzed. These conditions can be divided into three categories: temperatures, water levels, and physical and chemical characteristics. Temperatures affect cooling characteristic of ESWS mainly. Nuclear power stations in tropical areas need to focus on cooling capacity might be reduced by high temperature. Those in cold region need attention to excessive cooling and freezing problems caused by low temperature. The influence of water levels is mainly fluid transport capacity and selection of equipment to ESWS. When the range of natural water level is too wide, designers shall consider measures to narrow it, such as the construction of highly reliable reservoir. Inland nuclear power stations shall try to ensure the reliability of ESWS; prevent water level changes beyond the scope of design caused by drought and flood disasters. The effects of physical and chemical properties are derived from the open water characteristics, including high salinity, high chloride ion concentration, carrying solid particles, suspended solids, and aquatics, and so on. These characteristics will cause the equipment and pipeline eroded or even damaged, aqueducts of intake and output jammed, heat exchangers of the final heat sink weakened and other negative effects, resulting in ESWS performance decline. Some of these factors are the characteristics of station site natural environment, some others are changes caused by human activities. Some factors are sustained, long-term; some others may be sudden, temporary. Influence on these factors need to be taken measures from many aspects, including structure, biological disinfection, special materials and equipment, environmental protection measures around the nuclear power station, and so on. On the whole, the environmental factors that affect ESWS in the nuclear power stations are wide, and the influence mechanism is more complex. These factors ultimately act on ESWS, but most of them cannot be banished inside of ESWS or the final heat sink system. Against the negative effects from environmental conditions, it has to be considered from all steps in the engineering of nuclear power stations, including design, construction and operation. All the measures shall be suitable to local conditions, in order to ensure the safety and economy of nuclear power stations.
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Chen, Xuyi, Xiaoying Zhang, Junying Xu, Biao Wang, Dekui Zhan, and Huiyong Zhang. "Transient Simulation on Reactor Core Melt and Lower Support Plate Ablation in In-Vessel Retention." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66172.
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To precisely understand the accident process of reactor core melt in In-vessel retention (IVR) condition, 3-dimensional transient thermal conduction analysis with moving boundary is performed on quarter reactor core model. The decline of decay power and water level in reactor pressure vessel (RPV), and the radial distribution of assemblies of different material is considered. Convective heat transfer on rod surface and coolant interface is computed with empirical correlation of natural convection of saturated steam vapor / water. Radiation heat transfer with 16 neighboring rod is considered. Also, a dynamic ablation model is developed to simulate the ablation of lower support plate (LSP) caused by continuously accumulation of molten corium. The impingement heat transfer of the falling corium and the molten pool formed in LSP ablation cavity is taken into account. The simulation gives the ablation process on the surface of LSP as well as temperature history and molten proportion of the reactor core, which shows agreement with reference. Simulation shows: the melt process of reactor core accelerated in the accident process of 2600s, when coolant in RPV dry up. 65% of the core mass has molten at 8000 second. LSP is completely penetrated in 6000s, the ablation of LSP is mainly focused on an annular region of radius 700mm.
Reports on the topic "Water level decline"
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Wurstner, S. K., and M. D. Freshley. Predicted impacts of future water level decline on monitoring wells using a ground-water model of the Hanford Site. Office of Scientific and Technical Information (OSTI), December 1994. http://dx.doi.org/10.2172/10105769.
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Kirby, Stefan M., J. Lucy Jordan, Janae Wallace, Nathan Payne, and Christian Hardwick. Hydrogeology and Water Budget for Goshen Valley, Utah County, Utah. Utah Geological Survey, November 2022. http://dx.doi.org/10.34191/ss-171.
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Goshen Valley contains extensive areas of agriculture, significant wetlands, and several small municipalities, all of which rely on both groundwater and surface water. The objective of this study is to characterize the hydrogeology and groundwater conditions in Goshen Valley and calculate a water budget for the groundwater system. Based on the geologic and hydrologic data presented in this paper, we delineate three conceptual groundwater zones. Zones are delineated based on areas of shared hydrogeologic, geochemical, and potentiometric characteristics within the larger Goshen Valley. Groundwater in Goshen Valley resides primarily in the upper basin fill aquifer unit (UBFAU) and lower carbonate aquifer unit (LCAU) hydrostratigraphic units. Most wells in Goshen Valley are completed in the UBFAU, which covers much of the valley floor. The UBFAU is the upper part of the basin fill, which is generally less than 1500 feet thick in Goshen Valley. Important spring discharge at Goshen Warm Springs issues from the LCAU. Relatively impermeable volcanic rocks (VU) occur along much of the upland parts of the southern part of Goshen Valley. Large sections of the southwest part of the Goshen Valley basin boundary have limited potential for interbasin flow. Interbasin groundwater flow is likely at several locations including the Mosida Hills and northern parts of Long Ridge and Goshen Gap in areas underlain by LCAU. Depth to groundwater in Goshen Valley ranges from at or just below the land surface to greater than 400 feet. Groundwater is within 30 feet of the land surface near and north of Goshen, in areas of irrigated pastures and wetlands that extend east toward Long Ridge and Goshen Warm Springs, and to the north towards Genola. Groundwater movement is from upland parts of the study area toward the valley floor and Utah Lake. Long-term water-level change is evident across much of Goshen Valley, with the most significant decline present in conceptual zone 2 and the southern part of conceptual zone 1. The area of maximum groundwater-level decline—over 50 feet—is centered a few miles south of Elberta in conceptual zone 2. Groundwater in Goshen Valley spans a range of chemistries that include locally high total dissolved solids and elevated nitrate and arsenic concentrations and varies from calcium-bicarbonate to sodium-chloride-type waters. Overlap in chemistry exists in surface water samples from Currant Creek, the Highline Canal, and groundwater. Stable isotopes indicate that groundwater recharges from various locations that may include local recharge, from the East Tintic Mountains, or far-traveled groundwater recharged either in Cedar Valley or east of the study area along the Wasatch Range. Dissolved gas recharge temperatures support localized recharge outside of Goshen. Most groundwater samples in Goshen Valley are old, with limited evidence of recent groundwater recharge. An annual water budget based on components of recharge and discharge yields total recharge of 32,805 acre-ft/yr and total discharge of 35,750 acre-ft/yr. Most recharge is likely from interbasin flow and lesser amounts from precipitation and infiltration of surface water. Most discharge is from well water withdrawal with minor spring discharge and groundwater evapotranspiration. Water-budget components show discharge is greater than recharge by less than 3000 acreft/yr. This deficit or change in storage is manifested as longterm water-level decline in conceptual zone 2, and to a lesser degree, in conceptual zone 1. The primary driver of discharge in conceptual zone 2 is well withdrawal. Conceptual zone 3 is broadly in balance across the various sources of recharge and discharge, and up to 1830 acre-ft/yr of water may discharge from conceptual zone 3 into Utah Lake. Minimal groundwater likely flows to Utah Lake from zones 1 or 2.
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Raymond, Kara, Laura Palacios, Cheryl McIntyre, and Evan Gwilliam. Status of climate and water resources at Saguaro National Park: Water year 2019. Edited by Alice Wondrak Biel. National Park Service, December 2021. http://dx.doi.org/10.36967/nrr-2288717.
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Climate and hydrology are major drivers of ecosystems. They dramatically shape ecosystem structure and function, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and water quality and quantity is central to assessing the condition of park biota and key cultural resources. The Sonoran Desert Network collects data on climate, groundwater, and surface water at 11 National Park Service units in south-ern Arizona and New Mexico. This report provides an integrated look at climate, groundwater, and springs conditions at Saguaro National Park (NP) during water year 2019 (October 2018–September 2019). Annual rainfall in the Rincon Mountain District was 27.36" (69.49 cm) at the Mica Mountain RAWS station and 12.89" (32.74 cm) at the Desert Research Learning Center Davis station. February was the wettest month, accounting for nearly one-quarter of the annual rainfall at both stations. Each station recorded extreme precipitation events (>1") on three days. Mean monthly maximum and minimum air temperatures were 25.6°F (-3.6°C) and 78.1°F (25.6°C), respectively, at the Mica Mountain station, and 37.7°F (3.2°C) and 102.3°F (39.1°C), respectively, at the Desert Research Learning Center station. Overall temperatures in WY2019 were cooler than the mean for the entire record. The reconnaissance drought index for the Mica Mountain station indicated wetter conditions than average in WY2019. Both of the park’s NOAA COOP stations (one in each district) had large data gaps, partially due to the 35-day federal government shutdown in December and January. For this reason, climate conditions for the Tucson Mountain District are not reported. The mean groundwater level at well WSW-1 in WY2019 was higher than the mean for WY2018. The water level has generally been increasing since 2005, reflecting the continued aquifer recovery since the Central Avra Valley Storage and Recovery Project came online, recharging Central Arizona Project water. Water levels at the Red Hills well generally de-clined starting in fall WY2019, continuing through spring. Monsoon storms led to rapid water level increases. Peak water level occurred on September 18. The Madrona Pack Base well water level in WY2019 remained above 10 feet (3.05 m) below measuring point (bmp) in the fall and winter, followed by a steep decline starting in May and continuing until the end of September, when the water level rebounded following a three-day rain event. The high-est water level was recorded on February 15. Median water levels in the wells in the middle reach of Rincon Creek in WY2019 were higher than the medians for WY2018 (+0.18–0.68 ft/0.05–0.21 m), but still generally lower than 6.6 feet (2 m) bgs, the mean depth-to-water required to sustain juvenile cottonwood and willow trees. RC-7 was dry in June–September, and RC-4 was dry in only September. RC-5, RC-6 and Well 633106 did not go dry, and varied approximately 3–4 feet (1 m). Eleven springs were monitored in the Rincon Mountain District in WY2019. Most springs had relatively few indications of anthropogenic or natural disturbance. Anthropogenic disturbance included spring boxes or other modifications to flow. Examples of natural disturbance included game trails and scat. In addition, several sites exhibited slight disturbance from fires (e.g., burned woody debris and adjacent fire-scarred trees) and evidence of high-flow events. Crews observed 1–7 taxa of facultative/obligate wetland plants and 0–3 invasive non-native species at each spring. Across the springs, crews observed four non-native plant species: rose natal grass (Melinis repens), Kentucky bluegrass (Poa pratensis), crimson fountaingrass (Cenchrus setaceus), and red brome (Bromus rubens). Baseline data on water quality and chemistry were collected at all springs. It is likely that that all springs had surface water for at least some part of WY2019. However, temperature sensors to estimate surface water persistence failed...
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Munter, J. A. Water-level declines in wells in south Anchorage, Alaska. Alaska Division of Geological & Geophysical Surveys, 1985. http://dx.doi.org/10.14509/1128.
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Dearborn, L. L., and J. A. Munter. Water-level declines in wells tapping lower hillside aquifers, Anchorage, Alaska. Alaska Division of Geological & Geophysical Surveys, 1985. http://dx.doi.org/10.14509/1094.
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Dearborn, L. L., and J. A. Munter. Water-level declines in wells tapping lower hillside aquifers, Anchorage, Alaska (1985). Alaska Division of Geological & Geophysical Surveys, 1987. http://dx.doi.org/10.14509/2435.
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Munter, J. A. Water-level declines in wells in south Anchorage, Alaska: a presentation to the Alaska water board, September 12, 1985. Alaska Division of Geological & Geophysical Surveys, 1987. http://dx.doi.org/10.14509/2438.
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Munter, J. A. A preliminary evaluation of static water level declines in wells in the Maddux Park Subdivision, Anchorage, Alaska. Alaska Division of Geological & Geophysical Surveys, 1989. http://dx.doi.org/10.14509/1424.
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Czarnecki, J. B. Simulated water-level declines caused by withdrawals from wells J-13 and J-12 near Yucca Mountain, Nevada. Office of Scientific and Technical Information (OSTI), December 1992. http://dx.doi.org/10.2172/138884.
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Raymond, Kara, Laura Palacios, Cheryl McIntyre, and Evan Gwilliam. Status of climate and water resources at Chiricahua National Monument, Coronado National Memorial, and Fort Bowie National Historic Site: Water year 2019. National Park Service, May 2022. http://dx.doi.org/10.36967/nrr-2293370.
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Climate and hydrology are major drivers of ecosystems. They dramatically shape ecosystem structure and function, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and water quality and quantity is central to assessing the condition of park biota and key cultural resources. The Sonoran Desert Network collects data on climate, groundwater, and surface water at 11 National Park Service units in southern Arizona and New Mexico. This report provides an integrated look at climate, groundwater, and springs conditions at Chiricahua National Monument (NM), Coronado National Memorial (NMem), and Fort Bowie National Historic Site (NHS) during water year (WY) 2019 (October 2018–September 2019). Overall annual precipitation at Chiricahua NM and Coronado NMem in WY2019 was approximately the same as the normals for 1981–2010. (The weather station at Fort Bowie NHS had missing values on 275 days, so data were not presented for that park.) Fall and winter rains were greater than normal. The monsoon season was generally weaker than normal, but storm events related to Hurricane Lorena led to increased late-season rain in September. Mean monthly maximum temperatures were generally cooler than normal at Chiricahua, whereas mean monthly minimum temperatures were warmer than normal. Temperatures at Coronado were more variable relative to normal. The reconnaissance drought index (RDI) indicated that Chiricahua NM was slightly wetter than normal. (The WY2019 RDI could not be calculated for Coronado NMem due to missing data.) The five-year moving mean of annual precipitation showed both park units were experiencing a minor multi-year precipitation deficit relative to the 39-year average. Mean groundwater levels in WY2019 increased at Fort Bowie NHS, and at two of three wells monitored at Chiricahua NM, compared to WY2018. Levels in the third well at Chiricahua slightly decreased. By contrast, water levels declined in five of six wells at Coronado NMem over the same period, with the sixth well showing a slight increase over WY2018. Over the monitoring record (2007–present), groundwater levels at Chiricahua have been fairly stable, with seasonal variability likely caused by transpiration losses and recharge from runoff events in Bonita Creek. At Fort Bowie’s WSW-2, mean groundwater level was also relatively stable from 2004 to 2019, excluding temporary drops due to routine pumping. At Coronado, four of the six wells demonstrated increases (+0.30 to 11.65 ft) in water level compared to the earliest available measurements. Only WSW-2 and Baumkirchner #3 have shown net declines (-17.31 and -3.80 feet, respectively) at that park. Springs were monitored at nine sites in WY2019 (four sites at Chiricahua NM; three at Coronado NMem, and two at Fort Bowie NHS). Most springs had relatively few indications of anthropogenic or natural disturbance. Anthropogenic disturbance included modifications to flow, such as dams, berms, or spring boxes. Examples of natural disturbance included game trails, scat, or evidence of flooding. Crews observed 0–6 facultative/obligate wetland plant taxa and 0–3 invasive non-native species at each spring. Across the springs, crews observed six non-native plant species: common mullein (Verbascum thapsus), spiny sowthistle (Sonchus asper), common sowthistle (Sonchus oleraceus), Lehmann lovegrass (Eragrostis lehmanniana), rabbitsfoot grass (Polypogon monspeliensis), and red brome (Bromus rubens). Baseline data on water quality and water chemistry were collected at all nine sites. It is likely that that all nine springs had surface water for at least some part of WY2019, though temperature sensors failed at two sites. The seven sites with continuous sensor data had water present for most of the year. Discharge was measured at eight sites and ranged from < 1 L/minute to 16.5 L/minute.