Does iodine supplementation of the prepartum dairy cow diet affect serum immunoglobulin G concentration, iodine, and health status of the calf?

PubMed

Conneely, M; Berry, D P; Sayers, R; Murphy, J P; Doherty, M L; Lorenz, I; Kennedy, E

2014-01-01

Absorption of adequate IgG from colostrum is critical to provide the newborn calf with adequate immunological protection and resistance to disease. Excessive iodine supplementation of the prepartum ewe reduces IgG absorption of her offspring; it is possible that excessive iodine supplementation of the prepartum dairy cow may similarly impair the ability of the calf to acquire immunological protection. The objectives of this study were to determine whether the iodine status, health status, and ability of calves to absorb IgG from colostrum were affected by prepartum iodine supplementation strategies of their dams. Dairy cows (n=127) received one of the following levels of iodine supplementation precalving: 15mg of iodine/kg of dietary dry matter (DM) (HI); no additional iodine supplementation (MI); 5mg/kg of dietary DM (SI); and 15mg of iodine/kg of DM for the first 3.5wk of the precalving period and no additional supplementation for the second 3.5wk (HMI). Calves were assigned to 1 of 6 experimental treatments, based on the prepartum iodine supplementation treatment of their dam and the precalving treatment group of the cows from which the colostrum fed was obtained: (1) HI_HI: born to HI dams, fed HI colostrum (i.e., colostrum produced by cows in the HI group); (2) MI_MI: born to MI dams, fed MI colostrum; (3) SI_SI: born to SI dams, fed SI colostrum; (4) HI_MI: born to HI dams, fed MI colostrum; (5) MI_HI: born to MI dams, fed HI colostrum; and (6) HMI_HMI: born to HMI dams, fed HMI colostrum. Concentration of calf serum IgG and plasma inorganic iodine (PII) was measured at 0 and 24h of age. Apparent efficiency of absorption for IgG was determined. Health scores were assigned to calves twice weekly and all episodes of disease were recorded. Cow experimental treatment group affected calf PII at 0h of age; the PII of calves born to HI dams (987.2µg/L) was greater than that of calves born to MI dams (510.1µg/L), SI (585.2µg/L), and HMI dams (692.9µg/L). Calf experimental treatment group affected calf PII at 24h of age; the PII of HI_HI (1,259.2µg/L) and HI_MI (1,177.8µg/L) calves was greater than MI_MI (240.7µg/L), SI_SI (302.2µg/L), HMI_HMI (320.7µg/L), and MI_HI (216.3µg/L) calves. No effect of experimental treatment was observed on the concentration of IgG measured in calf serum at 24h of age, or on apparent efficiency of absorption. Experimental treatment had no effect on the likelihood of a calf being assigned a worse nasal, eye and ear, cough, or fecal score within the study period, nor did it affect the probability of a calf receiving treatment for a disease a greater number of times. Prepartum iodine supplementation of cows at 15mg/kg of DM increased the iodine levels in their calves at birth and 24h of age, but did not affect their ability to absorb IgG from colostrum. Supplementation with iodine above the minimum requirements established by the National Research Council was unnecessary to ensure appropriate iodine levels in calves at birth. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Nitrate-nitrogen levels in rural drinking water: Is there an association with age-related macular degeneration?

PubMed

Klein, Barbara E K; McElroy, Jane A; Klein, Ronald; Howard, Kerri P; Lee, Kristine E

2013-01-01

We examined the association of nitrate-nitrogen exposure from rural private drinking water and incidence of age-related macular degeneration (AMD). All participants in the Beaver Dam Eye Study (53916 improvement plan code) completed a questionnaire and had an ocular examination including standardized, graded fundus photographs at five examinations. Only information from rural residents in that study are included in this report. Data from an environmental monitoring study with probabilistic-based agro-chemical sampling, including nitrate-nitrogen, of rural private drinking water were available. Incidence of early AMD was associated with elevated nitrate-nitrogen levels in rural private drinking water supply (10.0% for low, 19.2% for medium, and 26.1% for high nitrate-nitrogen level in the right eye). The odds ratios (ORs) were 1.77 (95% confidence interval [CI]: 1.12-2.78) for medium and 2.88 (95% CI: 1.59-5.23) for high nitrate-nitrogen level. Incidence of late AMD was increased for those with medium or high levels of nitrate-nitrogen compared to low levels (2.3% for low and 5.1% for the medium or high nitrate-nitrogen level, for the right eye). The OR for medium or high nitrate-nitrogen groups was 2.80 (95% CI: 1.07-7.31) compared to the low nitrate-nitrogen group.

Analysis of High Resolution Satellite imagery to acsees Glacier Mass Balance and Lake Hazards in Sikkim Himalayas

NASA Astrophysics Data System (ADS)

Bhushan, S.; Shean, D. E.; Haritashya, U. K.; Arendt, A. A.; Syed, T. H.; Setiawan, L.

2017-12-01

Glacial lake outburst floods can impact downstream communities due to the sudden outflux of huge quantities of stored water. In this study, we develop a hazard assessment of the moraine dammed glacial lakes in Sikkim Himalayas by analyzing the morphometry of proglacial features, and the surface velocity and mass balance of glaciers. We generated high-resolution digital elevation models (DEMs) using the open-source NASA Ames Stereo Pipeline (ASP) and use other open-source tools to calculate surface velocity and patterns of glacier downwasting over time. Geodetic glacier mass balance is obtained for three periods using high-resolution WorldView/GeoEye stereo DEMs (8 m posting, 2014-2016), Cartosat-1 stereo DEMs (10 m, 2006-2008) and SRTM (30 m, 2000). Initial results reveal a region-wide mass balance of -0.31±0.13 m w.eq.a-1 for the 2007-2015 period, with some debris covered glaciers showing a very low mass loss rate. Additionally, 12 annual glacier velocity fields spanning from 1991 to 2017.derived from Landsat imagery are used to explore the relationship between glacier dynamics and changes in proglacial lakes. Multi-temporal glacial lake mapping is conducted using Landsat and Cartosat imagery. Avalanche and rockfall modeling are combined with morphometric analysis of the proglacial lake area to assess the likelihood of glacial lake dam failure. The above parameters are integrated into a decision tree approach enabling categorization of moraine-dammed lakes according to their potential for outburst events.

Magnetic resonance safety and compatibility of tantalum markers used in proton beam therapy for intraocular tumors: A 7.0 Tesla study.

PubMed

Oberacker, Eva; Paul, Katharina; Huelnhagen, Till; Oezerdem, Celal; Winter, Lukas; Pohlmann, Andreas; Boehmert, Laura; Stachs, Oliver; Heufelder, Jens; Weber, Andreas; Rehak, Matus; Seibel, Ira; Niendorf, Thoralf

2017-10-01

Proton radiation therapy (PRT) is a standard treatment of uveal melanoma. PRT patients undergo implantation of ocular tantalum markers (OTMs) for treatment planning. Ultra-high-field MRI is a promising technique for 3D tumor visualization and PRT planning. This work examines MR safety and compatibility of OTMs at 7.0 Tesla. MR safety assessment included deflection angle measurements (DAMs), electromagnetic field (EMF) simulations for specific absorption rate (SAR) estimation, and temperature simulations for examining radiofrequency heating using a bow-tie dipole antenna for transmission. MR compatibility was assessed by susceptibility artifacts in agarose, ex vivo pig eyes, and in an ex vivo tumor eye using gradient echo and fast spin-echo imaging. DAM (α < 1 °) demonstrated no risk attributed to magnetically induced OTM deflection. EMF simulations showed that an OTM can be approximated by a disk, demonstrated the need for averaging masses of m ave  = 0.01 g to accommodate the OTM, and provided SAR 0.01g,maximum  = 2.64 W/kg (P in  = 1W) in OTM presence. A transfer function was derived, enabling SAR 0.01g estimation for individual patient scenarios without the OTM being integrated. Thermal simulations revealed minor OTM-related temperature increase (δT < 15 mK). Susceptibility artifact size (<8 mm) and location suggest no restrictions for MRI of the nervus opticus. OTMs are not a per se contraindication for MRI. Magn Reson Med 78:1533-1546, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Military Hydrology. Report 12. Case Study Evaluation of Alternative Dam-Breach Flood Wave Methods. Volume 1. Main Report.

DTIC Science & Technology

1986-11-01

Report Organization. .................... 7 *PART 11: CASE STUDIES .......................... 9 Teton Dam Failure Flood. ...................... 9...channel, (3) Laurel Run Dam , and (4) Stillhouse Hollow Dam . The Laurel Run and Teton case studies involved field data sets from actual dam failures. The...hypothetical prismatic channel case study used the Teton reservoir and dam data but replaced the complex Teton Valley geometry with a prismatic channel

Dams and transnational advocacy: Political opportunities in transnational collective action

NASA Astrophysics Data System (ADS)

Fu, Teng

Possible arguments to explain the gradual decline in big dam development and its site transferring from developed to developing countries include technical, economic, and political factors. This study focuses on the political argument---the rise of transnational anti-dam advocacy and its impact on state policy-making. Under what conditions does transnational anti-dam advocacy matter? Under what conditions does transnational advocacy change state dam policies (delay, scale down, or cancel)? It examines the role of transnational anti-dam actors in big dam building in a comparative context in Asia. Applying the social movement theory of political opportunity structure (POS) and using the qualitative case-study method, the study provides both within-case and cross-case analyses. Within-case analysis is utilized to explain the changing dynamics of big dam building in China (Three Gorges Dam and proposed Nu/Salween River dam projects), and to a lesser extent, Sardar Sarovar Project in India and Nam Theun 2 Dam in Laos. Different domestic and international POS (DPOS and IPOS) impact the strategies and outcomes of anti-dam advocacies in these countries. The degree of openness of the POS directly affects the capacity of transnational efforts in influencing state dam policies. The degree of openness or closure is measured by specific laws, institutions, discourse, or elite allies (or the absence of these) for the participation of non-state actors on big dam issues at a particular moment. This degree of openness is relative, varying over time, across countries and regions. This study finds that the impact of transnational anti-dam activism is most effective when both DPOS and IPOS are relatively open. Transnational anti-dam advocacy is least effective in influencing state dam policies when both DPOS and IPOS are relatively closed. Under a relatively open DPOS and closed IPOS, transnational anti-dam advocacy is more likely to successfully change state dam policies and even facilitate the opening of relatively closed IPOS. In contrast, under a relatively closed DPOS and open IPOS, transnational anti-dam advocacy can hardly exist. Without the domestic anti-dam pressure from below, international anti-dam efforts from above are less likely to affect state dam policies or open up closed DPOS.

Dam removal: Listening in

Treesearch

M. M. Foley; J. R. Bellmore; J. E. O' Connor; J. J. Duda; A. E. East; G. E. Grant; C. W. Anderson; J. A. Bountry; M. J. Collins; P. J. Connolly; L. S. Craig; J. E. Evans; S. L. Greene; F. J. Magilligan; C. S. Magirl; J. J. Major; G. R. Pess; T. J. Randle; P. B. Shafroth; C. E. Torgersen; D. Tullos; A. C. Wilcox

2017-01-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings....

A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

NASA Astrophysics Data System (ADS)

Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

2017-12-01

Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (<10) of dams. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

Hungry Horse Dam Fisheries Mitigation, 1992-1993 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

DosSantos, Joe; Vashro, Jim; Lockard, Larry

1994-06-01

In February of 1900, over forty agency representatives and interested citizens began development of the 1991 Mitigation Plan. This effort culminated in the 1993 Implementation Plan for mitigation of fish losses attributable to the construction and operation of Hungry Horse Dam. The primary purpose of this biennial report is to inform the public of the status of ongoing mitigation activities resulting from those planning efforts. A habitat improvement project is underway to benefit bull trout in Big Creek in the North Fork drainage of the Flathead River and work is planned in Hay Creek, another North Fork tributary. Bull troutmore » redd counts have been expanded and experimental programs involving genetic evaluation, outmigrant monitoring, and hatchery studies have been initiated, Cutthroat mitigation efforts have focused on habitat improvements in Elliott Creek and Taylor`s Outflow and improvements have been followed by imprint plants of hatchery fish and/or eyed eggs in those streams. Rogers Lake west of Kalispell and Lion Lake, near Hungry Horse, were chemically rehabilitated. Cool and warm water fish habitat has been improved in Halfmoon Lake and Echo Lake. Public education and public interest is important to the future success of mitigation activities. As part of the mitigation team`s public awareness responsibility we have worked with numerous volunteer groups, public agencies, and private landowners to stimulate interest and awareness of mitigation activities and the aquatic ecosystem. The purpose of this biennial report is to foster public awareness of, and support for, mitigation activities as we move forward in implementing the Hungry Horse Dam Fisheries Mitigation Implementation Plan.« less

Devopmental toxicity of perfluorooctane Sulfonate (PFOS) is ...

EPA Pesticide Factsheets

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are members of a family of perfluorinated compounds. Both are environmentally persistent and found in the serum of wildlife and humans. PFOS and PFOA are developmentally toxic in laboratory rodents. Exposure to these chemicals in utero delays development and reduces postnatal survival and growth. Exposure to PFOS on the last 4 days of gestation in the rat is sufficient to reduce neonatal survival. PFOS and PFOA are weak agonists of PPARα. The reduced postnatal survival of neonatal mice exposed to PFOA was recently shown to depend on expression of PPARα. This study used PPARα knockout (KO) and 129S1/SvlmJ wild type (WT) mice to determine if PPARα expression is required for the developmental toxicity of PFOS. After mating overnight, the next day was designated gestation day (GD) 0. WT females were weighed and dosed orally from GD15-18 with 0.5% Tween-20, 4.5, 6.5, 8.5, or 10.5 mg PFOS/kg/day. KO females were dosed with water, 8.5 or 10.5 mg PFOS/kg/day. Dams and pups were observed daily and pups were weighed on postnatal day (PND) 1 and PND15. Eye opening was recorded from PND12-15. Dams and pups were killed on PND15, body and liver weights recorded, and serum collected. PFOS did not affect maternal weight gain or body or liver weights of the dams on PND15. Neonatal survival (PND1-15) was significantly reduced by PFOS in both WT and KO litters at all doses. WT and KO pup birth weight and wei

Linkage Analysis of Quantitative Refraction and Refractive Errors in the Beaver Dam Eye Study

PubMed Central

Duggal, Priya; Lee, Kristine E.; Cheng, Ching-Yu; Klein, Ronald; Bailey-Wilson, Joan E.; Klein, Barbara E. K.

2011-01-01

Purpose. Refraction, as measured by spherical equivalent, is the need for an external lens to focus images on the retina. While genetic factors play an important role in the development of refractive errors, few susceptibility genes have been identified. However, several regions of linkage have been reported for myopia (2q, 4q, 7q, 12q, 17q, 18p, 22q, and Xq) and for quantitative refraction (1p, 3q, 4q, 7p, 8p, and 11p). To replicate previously identified linkage peaks and to identify novel loci that influence quantitative refraction and refractive errors, linkage analysis of spherical equivalent, myopia, and hyperopia in the Beaver Dam Eye Study was performed. Methods. Nonparametric, sibling-pair, genome-wide linkage analyses of refraction (spherical equivalent adjusted for age, education, and nuclear sclerosis), myopia and hyperopia in 834 sibling pairs within 486 extended pedigrees were performed. Results. Suggestive evidence of linkage was found for hyperopia on chromosome 3, region q26 (empiric P = 5.34 × 10−4), a region that had shown significant genome-wide evidence of linkage to refraction and some evidence of linkage to hyperopia. In addition, the analysis replicated previously reported genome-wide significant linkages to 22q11 of adjusted refraction and myopia (empiric P = 4.43 × 10−3 and 1.48 × 10−3, respectively) and to 7p15 of refraction (empiric P = 9.43 × 10−4). Evidence was also found of linkage to refraction on 7q36 (empiric P = 2.32 × 10−3), a region previously linked to high myopia. Conclusions. The findings provide further evidence that genes controlling refractive errors are located on 3q26, 7p15, 7p36, and 22q11. PMID:21571680

Experimental research on the dam-break mechanisms of the Jiadanwan landslide dam triggered by the Wenchuan earthquake in China.

PubMed

Xu, Fu-gang; Yang, Xing-guo; Zhou, Jia-wen; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation.

Experimental Research on the Dam-Break Mechanisms of the Jiadanwan Landslide Dam Triggered by the Wenchuan Earthquake in China

PubMed Central

Xu, Fu-gang; Yang, Xing-guo; Hao, Ming-hui

2013-01-01

Dam breaks of landslide dams are always accompanied by large numbers of casualties, a large loss of property, and negative influences on the downstream ecology and environment. This study uses the Jiadanwan landslide dam, created by the Wenchuan earthquake, as a case study example. Several laboratory experiments are carried out to analyse the dam-break mechanism of the landslide dam. The different factors that impact the dam-break process include upstream flow, the boulder effect, dam size, and channel discharge. The development of the discharge channel and the failure of the landslide dam are monitored by digital video and still cameras. Experimental results show that the upstream inflow and the dam size are the main factors that impact the dam-break process. An excavated discharge channel, especially a trapezoidal discharge channel, has a positive effect on reducing peak flow. The depth of the discharge channel also has a significant impact on the dam-break process. The experimental results are significant for landslide dam management and flood disaster prevention and mitigation. PMID:23844387

Dam removal: Listening in

NASA Astrophysics Data System (ADS)

Foley, M. M.; Bellmore, J. R.; O'Connor, J. E.; Duda, J. J.; East, A. E.; Grant, G. E.; Anderson, C. W.; Bountry, J. A.; Collins, M. J.; Connolly, P. J.; Craig, L. S.; Evans, J. E.; Greene, S. L.; Magilligan, F. J.; Magirl, C. S.; Major, J. J.; Pess, G. R.; Randle, T. J.; Shafroth, P. B.; Torgersen, C. E.; Tullos, D.; Wilcox, A. C.

2017-07-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Dam removal: Listening in

USGS Publications Warehouse

Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian E.; Tullos, Desiree D.; Wilcox, Andrew C.

2017-01-01

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals and their findings. Based on dam removals thus far, some general conclusions have emerged: (1) physical responses are typically fast, with the rate of sediment erosion largely dependent on sediment characteristics and dam-removal strategy; (2) ecological responses to dam removal differ among the affected upstream, downstream, and reservoir reaches; (3) dam removal tends to quickly reestablish connectivity, restoring the movement of material and organisms between upstream and downstream river reaches; (4) geographic context, river history, and land use significantly influence river restoration trajectories and recovery potential because they control broader physical and ecological processes and conditions; and (5) quantitative modeling capability is improving, particularly for physical and broad-scale ecological effects, and gives managers information needed to understand and predict long-term effects of dam removal on riverine ecosystems. Although these studies collectively enhance our understanding of how riverine ecosystems respond to dam removal, knowledge gaps remain because most studies have been short (< 5 years) and do not adequately represent the diversity of dam types, watershed conditions, and dam-removal methods in the U.S.

Five-year progression of unilateral age-related macular degeneration to bilateral involvement: the Three Continent AMD Consortium report

PubMed Central

Joachim, Nichole; Colijn, Johanna Maria; Kifley, Annette; Lee, Kristine E; Buitendijk, Gabriëlle H S; Klein, Barbara E K; Myers, Chelsea E; Meuer, Stacy M; Tan, Ava G; Holliday, Elizabeth G; Attia, John; Liew, Gerald; Iyengar, Sudha K; de Jong, Paulus T V M; Hofman, Albert; Vingerling, Johannes R; Mitchell, Paul; Klaver, Caroline C W; Klein, Ronald; Wang, Jie Jin

2018-01-01

Purpose To assess the 5-year progression from unilateral to bilateral age-related macular degeneration (AMD) and associated risk factors. Design Pooled data analyses of three prospective population-based cohorts, the Blue Mountains Eye Study, Beaver Dam Eye Study and Rotterdam Study. Methods Retinal photography and interview with comprehensive questionnaires were conducted at each visit of three studies. AMD was assessed following the modified Wisconsin AMD grading protocol. Progression to bilateral any (early and late) or late AMD was assessed among participants with unilateral involvement only. Factors associated with the progression were assessed using logistic regression models while simultaneously adjusting for other significant risk factors. Results In any 5-year duration, 19–28% of unilateral any AMD cases became bilateral and 27–68% of unilateral late AMD became bilateral. Factors associated with the progression to bilateral involvement of any AMD were age (per year increase, adjusted OR 1.07), carrying risk alleles of the complement factor H and age-related maculopathy susceptibility 2 genes (compared with none, OR 1.76 for 1 risk allele and OR 3.34 for 2+ risk alleles), smoking (compared with non-smokers, OR 1.64 for past and OR 1.67 for current smokers), and the presence of large drusen area or retinal pigmentary abnormalities in the first eye. Conclusion One in four to one in five unilateral any AMD cases, and up to one in two unilateral late AMD cases, progressed to bilateral in 5 years. Known AMD risk factors, including smoking, are significantly associated with the progression to bilateral involvement. PMID:28108569

Variable-intercept panel model for deformation zoning of a super-high arch dam.

PubMed

Shi, Zhongwen; Gu, Chongshi; Qin, Dong

2016-01-01

This study determines dam deformation similarity indexes based on an analysis of deformation zoning features and panel data clustering theory, with comprehensive consideration to the actual deformation law of super-high arch dams and the spatial-temporal features of dam deformation. Measurement methods of these indexes are studied. Based on the established deformation similarity criteria, the principle used to determine the number of dam deformation zones is constructed through entropy weight method. This study proposes the deformation zoning method for super-high arch dams and the implementation steps, analyzes the effect of special influencing factors of different dam zones on the deformation, introduces dummy variables that represent the special effect of dam deformation, and establishes a variable-intercept panel model for deformation zoning of super-high arch dams. Based on different patterns of the special effect in the variable-intercept panel model, two panel analysis models were established to monitor fixed and random effects of dam deformation. Hausman test method of model selection and model effectiveness assessment method are discussed. Finally, the effectiveness of established models is verified through a case study.

Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease.

PubMed

Kaukonen, Maria; Woods, Sean; Ahonen, Saija; Lemberg, Seppo; Hellman, Maarit; Hytönen, Marjo K; Permi, Perttu; Glaser, Tom; Lohi, Hannes

2018-05-29

Maternally skewed transmission of traits has been associated with genomic imprinting and oocyte-derived mRNA. We report canine congenital eye malformations, caused by an amino acid deletion (K12del) near the N terminus of retinol-binding protein (RBP4). The disease is only expressed when both dam and offspring are deletion homozygotes. RBP carries vitamin A (retinol) from hepatic stores to peripheral tissues, including the placenta and developing eye, where it is required to synthesize retinoic acid. Gestational vitamin A deficiency is a known risk factor for ocular birth defects. The K12del mutation disrupts RBP folding in vivo, decreasing its secretion from hepatocytes to serum. The maternal penetrance effect arises from an impairment in the sequential transfer of retinol across the placenta, via RBP encoded by maternal and fetal genomes. Our results demonstrate a mode of recessive maternal inheritance, with a physiological basis, and they extend previous observations on dominant-negative RBP4 alleles in humans. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Landscape context and the biophysical response of rivers to dam removal in the United States

PubMed Central

Magilligan, Francis J.; Torgersen, Christian E.; Major, Jon J.; Anderson, Chauncey W.; Connolly, Patrick J.; Wieferich, Daniel; Shafroth, Patrick B.; Evans, James E.; Infante, Dana; Craig, Laura S.

2017-01-01

Dams have been a fundamental part of the U.S. national agenda over the past two hundred years. Recently, however, dam removal has emerged as a strategy for addressing aging, obsolete infrastructure and more than 1,100 dams have been removed since the 1970s. However, only 130 of these removals had any ecological or geomorphic assessments, and fewer than half of those included before- and after-removal (BAR) studies. In addition, this growing, but limited collection of dam-removal studies is limited to distinct landscape settings. We conducted a meta-analysis to compare the landscape context of existing and removed dams and assessed the biophysical responses to dam removal for 63 BAR studies. The highest concentration of removed dams was in the Northeast and Upper Midwest, and most have been removed from 3rd and 4th order streams, in low-elevation (< 500 m) and low-slope (< 5%) watersheds that have small to moderate upstream watershed areas (10–1000 km2) with a low risk of habitat degradation. Many of the BAR-studied removals also have these characteristics, suggesting that our understanding of responses to dam removals is based on a limited range of landscape settings, which limits predictive capacity in other environmental settings. Biophysical responses to dam removal varied by landscape cluster, indicating that landscape features are likely to affect biophysical responses to dam removal. However, biophysical data were not equally distributed across variables or clusters, making it difficult to determine which landscape features have the strongest effect on dam-removal response. To address the inconsistencies across dam-removal studies, we provide suggestions for prioritizing and standardizing data collection associated with dam removal activities. PMID:28692693

Landscape context and the biophysical response of rivers to dam removal in the United States

USGS Publications Warehouse

Foley, Melissa M.; Magilligan, Francis J.; Torgersen, Christian E.; Major, Jon J.; Anderson, Chauncey; Connolly, Patrick J.; Wieferich, Daniel; Shafroth, Patrick B.; Evans, James E.; Infante, Dana M.; Craig, Laura

2017-01-01

Dams have been a fundamental part of the U.S. national agenda over the past two hundred years. Recently, however, dam removal has emerged as a strategy for addressing aging, obsolete infrastructure and more than 1,100 dams have been removed since the 1970s. However, only 130 of these removals had any ecological or geomorphic assessments, and fewer than half of those included before- and after-removal (BAR) studies. In addition, this growing, but limited collection of dam-removal studies is limited to distinct landscape settings. We conducted a meta-analysis to compare the landscape context of existing and removed dams and assessed the biophysical responses to dam removal for 63 BAR studies. The highest concentration of removed dams was in the Northeast and Upper Midwest, and most have been removed from 3rd and 4th order streams, in low-elevation (< 500 m) and low-slope (< 5%) watersheds that have small to moderate upstream watershed areas (10–1000 km2) with a low risk of habitat degradation. Many of the BAR-studied removals also have these characteristics, suggesting that our understanding of responses to dam removals is based on a limited range of landscape settings, which limits predictive capacity in other environmental settings. Biophysical responses to dam removal varied by landscape cluster, indicating that landscape features are likely to affect biophysical responses to dam removal. However, biophysical data were not equally distributed across variables or clusters, making it difficult to determine which landscape features have the strongest effect on dam-removal response. To address the inconsistencies across dam-removal studies, we provide suggestions for prioritizing and standardizing data collection associated with dam removal activities.

An Evaluation of the Success Rate of Sermo Dam Management in Daerah Istimewa Yogyakarta

NASA Astrophysics Data System (ADS)

Andriawan, A.; Sobriyah; Ikhsan, C.

2017-11-01

In dam operating and maintaining activities, there are some activities becoming the main function: the assessment of dam condition to keep monitoring and safeguarding the condition of dam as the main building. To achieve the maximum service, the maximal dam management is required as well and it should be followed with management evaluation. This case study was taken place in Sermo Dam of Daerah Istimewa Yogyakarta during 2015 - 2017. The method applied in this study was descriptive quantitative one, conducting a research using primary and secondary data. In this research, the assessment of dam condition was viewed from 1 (one) component, dam body, so that the component weight was 100%. The value of dam body condition was obtained from data of Sermo Dam monitoring in 2015-2016 and from the result of field survey in 2017. The result of research showed that the condition values of Sermo Dam with dam body component were 92.66% in 2015, 92.99% in 2016, and 93.99% in 2017. The result also showed that the value of dam body condition tended to increase during 2015-2017. To maintain the condition, the maximal operation and maintenance of dam was recommended.

The Dams and Monitoring Systems and Case Study: Ataturk and Karakaya Dams

NASA Astrophysics Data System (ADS)

Kalkan, Y.; Bilgi, S.; Gülnerman, A. G.

2017-12-01

Dams are among the most important engineering structures used for flood controls, agricultural purposes as well as drinking and hydroelectric power. Especially after the Second World War, developments on the construction technology, increase the construction of larger capacity dams. There are more than 150.000 dams in the world and almost 1000 dams in Turkey, according to international criteria. Although dams provide benefits to humans, they possess structural risks too. To determine the performance of dams on structural safety, assessing the spatial data is very important. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some general information on dams and their different monitoring systems by taking into account two different dams and their structural specifications with the required information. The case study in this paper depends on a comparison of the monitoring surveys on Atatürk Dam and Karakaya Dam, which are constructed on Firat River with two different structural type in Turkey. In addition, brief information is given about these dams and the methods of geodetic and non-geodetic monitoring measurements applied by various disciplines. The last part of the study focuses on the inference of the geodetic monitoring methods, which depend on a seven years of geodetic monitoring.

Harmonizing the Classification of Age-related Macular Degeneration in the Three Continent AMD Consortium

PubMed Central

Klein, Ronald; Meuer, Stacy M.; Myers, Chelsea E.; Buitendijk, Gabriëlle H. S.; Rochtchina, Elena; Choudhury, Farzana; de Jong, Paulus T. V. M.; McKean-Cowdin, Roberta; Iyengar, Sudha K.; Gao, Xiaoyi; Lee, Kristine E.; Vingerling, Johannes R.; Mitchell, Paul; Klaver, Caroline C. W.; Wang, Jie Jin; Klein, Barbara E. K.

2014-01-01

Purpose To describe methods to harmonize the classification of age-related macular degeneration (AMD) phenotypes across four population-based cohort studies: the Beaver Dam Eye Study (BDES), Blue Mountains Eye Study (BMES), Los Angeles Latino Eye Study (LALES), and Rotterdam Study (RS). Methods AMD grading protocols, definitions of categories, and grading forms from each study were compared to determine whether there were systematic differences in AMD severity definitions and lesion categorization among the three grading centers. Each center graded the same set of 60 images using their respective systems to determine presence and severity of AMD lesions. A common five-step AMD severity scale and definitions of lesion measurement cutpoints and early and late AMD were developed from this exercise. Results Applying this severity scale changed the age-sex adjusted prevalence of early AMD from 18.7% to 20.3% in BDES, from 4.7% to 14.4% in BMES, from 14.1% to 15.8% in LALES, and from 7.5% to 17.1% in RS. Age-sex adjusted prevalences of late AMD remained unchanged. Comparison of each center’s grades of the 60 images converted to the consortium scale showed that exact agreement of AMD severity among centers varied from 61.0% to 81.4%, and one-step agreement varied from 84.7% to 98.3%. Conclusion Harmonization of AMD classification reduced categorical differences in phenotypic definitions across the studies, resulted in a new 5-step AMD severity scale, and enhanced similarity of AMD prevalence among four cohorts. Despite harmonization it may still be difficult to remove systematic differences in grading, if present. PMID:24467558

Status and trends of dam removal research in the United States

USGS Publications Warehouse

Bellmore, James; Duda, Jeff; Craig, Laura; Greene, Samantha L.; Torgersen, Christian E.; Collins, Mathias J.; Vittum, Katherine

2017-01-01

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies will increasingly be called upon to inform decisions about whether, and how best, to bring down dams. This raises a critical question: what is the current state of dam-removal science in the United States? To explore the status, trends, and characteristics of dam-removal research in the U.S., we searched the scientific literature and extracted basic information from studies on dam removal. Our literature review illustrates that although over 1200 dams have been removed in the U.S., fewer than 10% have been scientifically evaluated, and most of these studies were short in duration ( < 4 years) and had limited (1–2 years) or no pre-removal monitoring. The majority of studies focused on hydrologic and geomorphic responses to removal rather than biological and water-quality responses, and few studies were published on linkages between physical and ecological components. Our review illustrates the need for long-term, multidisciplinary case studies, with robust study designs, in order to anticipate the effects of dam removal and inform future decision making.

Socioeconomic and Institutional Dimensions of Dam Removals: The Wisconsin Experience

PubMed

Born; Genskow; Filbert; Hernandez-Mora; Keefer; White

1998-05-01

/ There are tens of thousands of small dams in the United States; many of these aging structures are deteriorating. Governments and dam owners face decisions regarding repair or removal of these structures. Along with the many benefits society derives from dams and their impoundments, numerous recent ecological studies are revealing the extensive alteration and degradation of river ecosystems by dams. Dam removal-a principal restoration strategy-is an infrequent event. The major reasons for removal have been public safety and the high costs associated with repair; the goal of river ecosystem restoration now warrants greater attention. Substantial study is being given to the environmental aspects of dams and dam removals, but very little attention has been given to the socioeconomic and institutional dimensions associated with the removal of dams, although these factors play a significant role in the removal decision-making process. Based on a case study of dam removals in Wisconsin-where more than 30 of the state's 3600 small dams have been removed in the past few decades-legal, financial, and socioeconomic issues associated with dam removal are documented and assessed. Dam removal has been complex and contentious, with limited community-based support for removal and loss of the impounded waters. In cases examined here, the estimated costs of repairing a dam averaged more than three times the cost of removal. The availability of governmental financing has been a key determinant in removal decisions. Watershed-scale ecological considerations are not major factors for most local interests. As watershed management and restoration increasingly include dam removal options as part of an integrated strategy, more attention will need to be focused on socioeconomic factors and stakeholder perspectives-variables that strongly influence the viability of this management alternative.KEY WORDS: Dam removal; River restoration; Institutions; Stakeholders

Dam Removal Information Portal (DRIP)—A map-based resource linking scientific studies and associated geospatial information about dam removals

USGS Publications Warehouse

Duda, Jeffrey J.; Wieferich, Daniel J.; Bristol, R. Sky; Bellmore, J. Ryan; Hutchison, Vivian B.; Vittum, Katherine M.; Craig, Laura; Warrick, Jonathan A.

2016-08-18

The removal of dams has recently increased over historical levels due to aging infrastructure, changing societal needs, and modern safety standards rendering some dams obsolete. Where possibilities for river restoration, or improved safety, exceed the benefits of retaining a dam, removal is more often being considered as a viable option. Yet, as this is a relatively new development in the history of river management, science is just beginning to guide our understanding of the physical and ecological implications of dam removal. Ultimately, the “lessons learned” from previous scientific studies on the outcomes dam removal could inform future scientific understanding of ecosystem outcomes, as well as aid in decision-making by stakeholders. We created a database visualization tool, the Dam Removal Information Portal (DRIP), to display map-based, interactive information about the scientific studies associated with dam removals. Serving both as a bibliographic source as well as a link to other existing databases like the National Hydrography Dataset, the derived National Dam Removal Science Database serves as the foundation for a Web-based application that synthesizes the existing scientific studies associated with dam removals. Thus, using the DRIP application, users can explore information about completed dam removal projects (for example, their location, height, and date removed), as well as discover sources and details of associated of scientific studies. As such, DRIP is intended to be a dynamic collection of scientific information related to dams that have been removed in the United States and elsewhere. This report describes the architecture and concepts of this “metaknowledge” database and the DRIP visualization tool.

GC51D-0831: A Study of the Impact of Dams on Sediment Retention in the Mekong River Basin

NASA Technical Reports Server (NTRS)

Munroe, Thailynn; Griffin, Robert; Anderson, Eric; Markert, Kel

2017-01-01

Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), developed at Texas A & M, a rainfall-runoff hydrologic model to determine change in sedimentation in the Mekong Basin after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu & Varis (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

Geo-environmental Study to Identify the Affecting Factors on Dohuk's Dam and the city (Northren Iraq) by Use Remote Sensing Techniques

NASA Astrophysics Data System (ADS)

Hamdon, Alaa

2010-05-01

The Dohuk's dam is one of the most important Aggregated dams in Iraq, located about 1 km from Dohuk city in northern Iraq, So; this vital project provides Dohuk city by water while the city formerly dependent on wells water prior to the establishing of the dam, and this is one of the main reasons for land-use expansion in Dohuk city and its vicinity,which is meant that the Dohuk's dam safety factor ,it is the key of the city safety factor .This dam has initiated the establishment of the dam in 1980 and was established in 1988, and it's capacity is 47.5 million cubic meters. This study aims to analyze the morphometric or geometric properties and the environmental factors at drainage systems and drainage network for Dohuk area's drainage basins (which recharges water of Dohuk Dam's Lake and it is accumulated by rainfall and spring water) scientifically and geometrically. Study of the geology of construction area of the dam Structuraly and tectonically. Satellite image, topographic maps and aerial photographs used in this study for merging its results together and preparing a drainage basin's maps and a geologic interpretation map for the study area to recognize the important geologic impact on the river which comes out from dam lake, also some of the field work investigation has been depended in this study. As a final result from morphometric analysis of drainage basins, tectonic analysis and geological investigations for study area, found as the following: 1 - Determining the amount of the accumulated sediments on the dam body, which has been carried by the collected rain-full water from the drainage basins, snow and spring water (the resources of Dam Lake). Study of the impact of these deposits on dam stability and evaluate the risk of these deposits on dam body and on its safety. 2 - Identification of geological features, which are that threaten the safety of the river of city which concern the only resource for the city and stability of dam body and its related to other geological phenomena (such as earthquakes and floods ... etc.). 3 - Suggestions some of the proposals for the maintenance of the dam lake to preserve the stability of the dam body and to protect the river properties. 4- Prepare some scientific criteria to avoid a disaster affecting human activity or agricultural or industrial, which are located in the city of Dohuk.

DAM Safety and Deformation Monitoring in Dams

NASA Astrophysics Data System (ADS)

Kalkan, Y.; Bilgi, S.; Potts, L.; Miiama, J.; Mahgoub, M.; Rahman, S.

2013-12-01

Water is the life and necessity to water is increasing day by day with respect to the World population, rising of living standards and destruction of nature. Thus, the importance of water and water structures have been increasing gradually. Dams are among the most important engineering structures used for water supplies, flood controls, agricultural purposes as well as drinking and hydroelectric power. There are about 150.000 large size dams in the World. Especially after the Second World War, higher and larger capacity dams have been constructed. Dams create certain risks like the other manmade structures. No one knows precisely how many dam failures have occurred in the World, whereas hundreds of dam failures have occurred throughout the U.S. history. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. These physical data are measured and monitored by the instruments and equipment. Dams and their surroundings have to be monitored by using essential methods at periodic time intervals in order to determine the possible changes that may occur over the time. Monitoring programs typically consist of; surveillance or visual observation. These programs on dams provide information for evaluating the dam's performance related to the design intent and expected changes that could affect the safety performance of the dam. Additionally, these programs are used for investigating and evaluating the abnormal or degrading performance where any remedial action is necessary. Geodetic and non-geodetic methods are used for monitoring. Monitoring the performance of the dams is critical for producing and maintaining the safe dams. This study provides some information, safety and the techniques about the deformation monitoring of the dams. Therefore, this study gives essential information about the dam safety and related analysis. Monitoring of dams is crucial since deformation might have occurred as a result of erosion, water load, hydraulic gradients, and water saturation. The case study is the deformation measurements of Ataturk Dam. This dam was constructed on Firat River and it has importance for providing drinking water, hydroelectric power and especially irrigation. In addition, brief information is given about this dam and the methods of geodetic and non-geodetic monitoring measurements applied by various disciplines. Geodetic monitoring methods are emphasized in this study. Some results have been obtained from this method for nearly seven years are presented in this work. In addition, some deformation predictions have been made especially for the cross sections where the maximum deformations took place.

Risk Analysis of Earth-Rock Dam Failures Based on Fuzzy Event Tree Method

PubMed Central

Fu, Xiao; Gu, Chong-Shi; Su, Huai-Zhi; Qin, Xiang-Nan

2018-01-01

Earth-rock dams make up a large proportion of the dams in China, and their failures can induce great risks. In this paper, the risks associated with earth-rock dam failure are analyzed from two aspects: the probability of a dam failure and the resulting life loss. An event tree analysis method based on fuzzy set theory is proposed to calculate the dam failure probability. The life loss associated with dam failure is summarized and refined to be suitable for Chinese dams from previous studies. The proposed method and model are applied to one reservoir dam in Jiangxi province. Both engineering and non-engineering measures are proposed to reduce the risk. The risk analysis of the dam failure has essential significance for reducing dam failure probability and improving dam risk management level. PMID:29710824

Introduction of an Emergency Response Plan for flood loading of Sultan Abu Bakar Dam in Malaysia

NASA Astrophysics Data System (ADS)

Said, N. F. Md; Sidek, L. M.; Basri, H.; Muda, R. S.; Razad, A. Z. Abdul

2016-03-01

Sultan Abu Bakar Dam Emergency Response Plan (ERP) is designed to assist employees for identifying, monitoring, responding and mitigation dam safety emergencies. This paper is outlined to identification of an organization chart, responsibility for emergency management team and triggering level in Sultan Abu Bakar Dam ERP. ERP is a plan that guides responsibilities for proper operation of Sultan Abu Bakar Dam in respond to emergency incidents affecting the dam. Based on this study four major responsibilities are needed for Abu Bakar Dam owing to protect any probable risk for downstream which they can be Incident Commander, Deputy Incident Commander, On-Scene Commander, Civil Engineer. In conclusion, having organization charts based on ERP studies can be helpful for decreasing the probable risks in any projects such as Abu Bakar Dam and it is a way to identify and suspected and actual dam safety emergencies.

Deformation Monitoring and Bathymetry Analyses in Rock-Fill Dams, a Case Study at Ataturk Dam

NASA Astrophysics Data System (ADS)

Kalkan, Y.; Bilgi, S.

2014-12-01

Turkey has 595 dams constructed between 1936 and 2013 for the purposes of irrigation, flood control, hydroelectric energy and drinking water. A major portion of the dam basins in Turkey are deprived of vegetation and have slope topography on near surrounding area. However, landscaping covered with forest around the dam basin is desirable for erosion control. In fact; the dams, have basins deprived of vegetation, fill up quickly due to sediment transport. Erosion control and forestation are important factors, reducing the sediment, to protect the water basins of the dams and increase the functioning life of the dams. The functioning life of dams is as important as the investment and construction. Nevertheless, in order to provide safety of human life living around, well planned monitoring is essential for dams. Dams are very large and critical structures and they demand the use or application of precise measuring systems. Some basic physical data are very important for assessing the safety and performance of dams. These are movement, water pressure, seepage, reservoir and tail-water elevations, local seismic activities, total pressure, stress and strain, internal concrete temperature, ambient temperature and precipitation. Monitoring is an essential component of the dam after construction and during operation and must en­able the timely detection of any behavior that could deteriorate the dam, potentially result in its shutdown or failure. Considering the time and labor consumed by long-term measurements, processing and analysis of measured data, importance of the small structural motions at regular intervals could be comprehended. This study provides some information, safety and the techniques about the deformation monitoring of the dams, dam safety and related analysis. The case study is the deformation measurements of Atatürk Dam in Turkey which is the 6th largest dam of world considering the filling volume of embankment. Brief information is given about the dam and the methods of monitoring techniques applied by various disciplines. Some results have been obtained from this method for nearly eight years are presented in this work. In addition, the results of bathymetric surveys between 2005 and 2010 will be compared using the cross sections where the maximum changes occurred on the dam bottom of the reservoir area.

Seismic hazard and risk assessment for large Romanian dams situated in the Moldavian Platform

NASA Astrophysics Data System (ADS)

Moldovan, Iren-Adelina; Popescu, Emilia; Otilia Placinta, Anica; Petruta Constantin, Angela; Toma Danila, Dragos; Borleanu, Felix; Emilian Toader, Victorin; Moldoveanu, Traian

2016-04-01

Besides periodical technical inspections, the monitoring and the surveillance of dams' related structures and infrastructures, there are some more seismic specific requirements towards dams' safety. The most important one is the seismic risk assessment that can be accomplished by rating the dams into seismic risk classes using the theory of Bureau and Ballentine (2002), and Bureau (2003), taking into account the maximum expected peak ground motions at the dams site - values obtained using probabilistic hazard assessment approaches (Moldovan et al., 2008), the structures vulnerability and the downstream risk characteristics (human, economical, historic and cultural heritage, etc) in the areas that might be flooded in the case of a dam failure. Probabilistic seismic hazard (PSH), vulnerability and risk studies for dams situated in the Moldavian Platform, starting from Izvorul Muntelui Dam, down on Bistrita and following on Siret River and theirs affluent will be realized. The most vulnerable dams will be studied in detail and flooding maps will be drawn to find the most exposed downstream localities both for risk assessment studies and warnings. GIS maps that clearly indicate areas that are potentially flooded are enough for these studies, thus giving information on the number of inhabitants and goods that may be destroyed. Geospatial servers included topography is sufficient to achieve them, all other further studies are not necessary for downstream risk assessment. The results will consist of local and regional seismic information, dams specific characteristics and locations, seismic hazard maps and risk classes, for all dams sites (for more than 30 dams), inundation maps (for the most vulnerable dams from the region) and possible affected localities. The studies realized in this paper have as final goal to provide the local emergency services with warnings of a potential dam failure and ensuing flood as a result of an large earthquake occurrence, allowing further public training for evacuation. The work is supported from PNII/PCCA 2013 Project DARING 69/2014, financed by UEFISCDI, Romania. Bureau GJ (2003) "Dams and appurtenant facilities" Earthquake Engineering Handbook, CRS Press, WF Chen, and C Scawthorn (eds.), Boca Raton, pp. 26.1-26.47. Bureau GJ and Ballentine GD (2002) "A comprehensive seismic vulnerability and loss assessment of the State of Carolina using HAZUS. Part IV: Dam inventory and vulnerability assessment methodology", 7th National Conference on Earthquake Engineering, July 21-25, Boston, Earthquake Engineering Research Institute, Oakland, CA. Moldovan IA, Popescu E, Constantin A (2008), "Probabilistic seismic hazard assessment in Romania: application for crustal seismic active zones", Romanian Journal of Physics, Vol.53, Nos. 3-4

Mapping the social impacts of small dams: The case of Thailand's Ing River basin.

PubMed

Fung, Zali; Pomun, Teerapong; Charles, Katrina J; Kirchherr, Julian

2018-05-24

The social impacts of large dams have been studied extensively. However, small dams' social impacts have been largely neglected by the academic community. Our paper addresses this gap. We examine the social impacts of multiple small dams in one upstream and one downstream village in Thailand's Ing River basin. Our research is based on semi-structured interviews with beneficiaries, government and NGOs. We argue that small dams' social impacts are multi-faceted and unequal. The dams were perceived to reduce fish abundance and provide flood mitigation benefits. Furthermore, the dams enabled increased access to irrigation water for upstream farmers, who re-appropriated water via the dams at the expense of those downstream. The small dams thus engendered water allocation conflicts. Many scholars, practitioners and environmentalists argue that small dams are a benign alternative to large dams. However, the results of our research mandate caution regarding this claim.

The effect of maternal diabetes on the Wnt-PCP pathway during embryogenesis as reflected in the developing mouse eye

PubMed Central

López-Escobar, Beatriz; Cano, David A.; Rojas, Anabel; de Felipe, Beatriz; Palma, Francisco; Sánchez-Alcázar, José A.; Henderson, Deborah; Ybot-González, Patricia

2015-01-01

Embryopathies that develop as a consequence of maternal diabetes have been studied intensely in both experimental and clinical scenarios. Accordingly, hyperglycaemia has been shown to downregulate the expression of elements in the non-canonical Wnt-PCP pathway, such as the Dishevelled-associated activator of morphogenesis 1 (Daam1) and Vangl2. Daam1 is a formin that is essential for actin polymerization and for cytoskeletal reorganization, and it is expressed strongly in certain organs during mouse development, including the eye, neural tube and heart. Daam1gt/gt and Daam1gt/+ embryos develop ocular defects (anophthalmia or microphthalmia) that are similar to those detected as a result of hyperglycaemia. Indeed, studying the effects of maternal diabetes on the Wnt-PCP pathway demonstrated that there was strong association with the Daam1 genotype, whereby the embryopathy observed in Daam1gt/+ mutant embryos of diabetic dams was more severe. There was evidence that embryonic exposure to glucose in vitro diminishes the expression of genes in the Wnt-PCP pathway, leading to altered cytoskeletal organization, cell shape and cell polarity in the optic vesicle. Hence, the Wnt-PCP pathway appears to influence cell morphology and cell polarity, events that drive the cellular movements required for optic vesicle formation and that, in turn, are required to maintain the fate determination. Here, we demonstrate that the Wnt-PCP pathway is involved in the early stages of mouse eye development and that it is altered by diabetes, provoking the ocular phenotype observed in the affected embryos. PMID:25540130

Compliance Monitoring of Subyearling Chinook Salmon Smolt Survival and Passage at Bonneville Dam, Summer 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

2013-05-01

The purpose of this compliance study was to estimate dam passage survival of subyearling Chinook salmon at Bonneville Dam during summer 2012, as required by the 2008 Federal Columbia River Power System Biological Opinion. The study also estimated smolt passage survival from the forebay 2 km upstream of the dam to the tailrace 1 km below the dam, as well as forebay residence time, tailrace egress, and spill passage efficiency, as required in the 2008 Columbia Basin Fish Accords.

Baseline studies in the Elwha River ecosystem prior to dam removal: Introduction to the special issue

USGS Publications Warehouse

Duda, Jeffrey J.; Freilich, Jerry; Schreiner, Edward G.

2008-01-01

The planned removal of two dams that have been in place for over 95 years on the Elwha River provides a unique opportunity to study dam removal effects. Among the largest dams ever considered for removal, this project is compelling because 83% of the watershed lies undisturbed in Olympic National Park. Eighteen million cubic meters of sediment have accumulated in and will be released from the reservoirs, and there is potential for rehabilitating depressed Pacific salmon runs. Researchers from academia, non-profit organizations, federal and state governments, and the Lower Elwha Klallam Tribe are currently assessing baseline ecological conditions of the Elwha River as part of dam removal studies. We introduce dam removal topics, provide a brief history of the dams, and summarize the ecology of the Elwha River basin as an introduction to a special issue devoted to research in the watershed.

Quantifying and Generalizing Hydrologic Responses to Dam Regulation using a Statistical Modeling Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

McManamay, Ryan A

2014-01-01

Despite the ubiquitous existence of dams within riverscapes, much of our knowledge about dams and their environmental effects remains context-specific. Hydrology, more than any other environmental variable, has been studied in great detail with regard to dam regulation. While much progress has been made in generalizing the hydrologic effects of regulation by large dams, many aspects of hydrology show site-specific fidelity to dam operations, small dams (including diversions), and regional hydrologic regimes. A statistical modeling framework is presented to quantify and generalize hydrologic responses to varying degrees of dam regulation. Specifically, the objectives were to 1) compare the effects ofmore » local versus cumulative dam regulation, 2) determine the importance of different regional hydrologic regimes in influencing hydrologic responses to dams, and 3) evaluate how different regulation contexts lead to error in predicting hydrologic responses to dams. Overall, model performance was poor in quantifying the magnitude of hydrologic responses, but performance was sufficient in classifying hydrologic responses as negative or positive. Responses of some hydrologic indices to dam regulation were highly dependent upon hydrologic class membership and the purpose of the dam. The opposing coefficients between local and cumulative-dam predictors suggested that hydrologic responses to cumulative dam regulation are complex, and predicting the hydrology downstream of individual dams, as opposed to multiple dams, may be more easy accomplished using statistical approaches. Results also suggested that particular contexts, including multipurpose dams, high cumulative regulation by multiple dams, diversions, close proximity to dams, and certain hydrologic classes are all sources of increased error when predicting hydrologic responses to dams. Statistical models, such as the ones presented herein, show promise in their ability to model the effects of dam regulation effects at large spatial scales as to generalize the directionality of hydrologic responses.« less

Status and trends of dam removal research in the United States

Treesearch

J. Ryan Bellmore; Jeffrey J. Duda; Laura S. Craig; Samantha L. Greene; Christian E. Torgersen; Mathias J. Collins; Katherine Vittum

2016-01-01

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies...

Will river erosion below the Three Gorges Dam stop in the middle Yangtze?

NASA Astrophysics Data System (ADS)

Lai, X.; Yin, D.; Finlayson, B. L.; Wei, T.; Li, M.; Yuan, W.; Yang, S.; Dai, Z.; Gao, S.; Chen, Z.

2017-11-01

The environmental impact of the Three Gorges Dam has been a subject of vigorous academic, political and social debate since its inception. This includes the key issue of post-dam river channel erosion, which was predicted by the feasibility study to extend to the river mouth. In this paper we examine the geomorphic response of the channel of the middle Yangtze for 660 km downstream of the dam. Using data on channel characteristics, bed material and sediment transport, we show that in the decade following the dam closure, pre-dam seasonal erosion has been replaced by year-round erosion, a pattern most marked at the upstream end of the study area. The sediment carrying capacity of the river channel has been largely reduced below the dam. The locus of bed scour has moved progressively downstream, ceasing as the bed material became too coarse to be transported (e.g. D50: 0.29 mm pre-dam coarsened to 20 mm below the dam by 2008). About 400 km below the dam there is a reduction in channel slope that changes the sediment carrying capacity from 0.25 kg m-3 to only about 0.05 kg m-3, which is insufficient to move bed sediment. The new long-term hydro-morphological equilibrium that will be established in this section of the middle Yangtze will prevent the further incision downstream initiated by the Three Gorges Dam. The results suggest that the full extent of adverse environmental impact predicted by the pre-dam studies will not eventuate.

Sediment Transport Over Run-of-River Dams

NASA Astrophysics Data System (ADS)

O'Brien, M.; Magilligan, F. J.; Renshaw, C. E.

2016-12-01

Dams have numerous documented effects that can degrade river habitat downstream. One significant effect of large dams is their ability to trap sediment delivered from upstream. This trapping can alter sediment transport and grain size downstream - effects that often motivate dam removal decisions. However, recent indirect observations and modeling studies indicate that small, run-of-river (ROR) dams, which do not impede discharge, may actually leak sediment downstream. However, there are no direct measurements of sediment flux over ROR dams. This study investigates flow and sediment transport over four to six different New England ROR dams over a summer-fall field season. Sediment flux was measured using turbidity meters and tracer (RFID) cobbles. Sediment transport was also monitored through an undammed control site and through a river where two ROR dams were recently removed. These data were used to predict the conditions that contribute to sediment transport and trapping. Year 1 data show that tracer rocks of up to 61 mm were transported over a 3 m ROR dam in peak flows of 84% of bankfull stage. These tracer rocks were transported over and 10 m beyond the dam and continue to move downstream. During the same event, comparable suspended sediment fluxes of up to 81 g/s were recorded both upstream and downstream of the dam at near-synchronous timestamps. These results demonstrate the potential for sediment transport through dammed rivers, even in discharge events that do not exceed bankfull. This research elucidates the effects of ROR dams and the controls on sediment transport and trapping, contributions that may aid in dam management decisions.

Groundwater-Surface Water Interaction: A Case Study of Embankment Dam Safety Assessment in Sweden.

NASA Astrophysics Data System (ADS)

Ferdos, F.; Dargahi, B.

2015-12-01

Seepage, when excessive and unimpeded, can cause embankment dam failure. Such failures are often initiated by internal erosion and piping. Modelling these phenomena in embankment dams, accounting for the groundwater-surface water interactions, is crucial when performing dam safety assessments. The aim of this study was to evaluate the applicability of modelling seepage flows in multi-region dams using a finite element based multi-physics model. The model was applied to the Trängslet dam, the largest dam in Sweden. The objectives were to analyze the characteristics of both the flow and the surface-ground water interactions occurring in the dam, including: i) the saturated and unsaturated laminar flow regimes within the dam body, ii) the non-linear through-flow in the dam shoulders' coarse material, iii) the influence of the surface waves in the reservoir on the seepage flow by coupling the physics to a hydrodynamic interface, and iv) the influence of a conceptual "erosion tunnel" on the seepage flow and its interaction with the surface water flow by coupling the physics to a CFD interface. The focus of the study was on the influence of the transient water head boundary condition, surface waves and the internal erosion tunnel on the location of the phreatic line and the seepage flow rate. The simulated seepage flow of the dam in its original condition tallied with the monitoring measurements (40-70 l/s). The main feature found was the relatively high position of the phreatic line, which could compromise the stability of the dam. The combination of the seepage model with the reservoir hydrodynamics indicated a negligible influence of the surface waves on seepage flow. Results from the combination of the seepage model with fluid dynamics indicated that a conceptual "erosion tunnel" placed within the dam, even as high as in the unsaturated zone, significantly affects the phreatic line's position. This also causes the seepage flow to increase by several orders of magnitude, resulting in non-linear turbulent flow regimes in the downstream shoulder of the dam and, ultimately, dam failure. While the modelling was limited by a lack of reliable geometrical and geotechnical data, the results of the study do highlight the importance of including groundwater-surface water interactions in dam safety assessments.

Role of the check dam in land development on the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Xu, Xiang-Zhou; Zhang, Luo-Hao; Zhu, Tongxin; Dang, Tian-Min; Zhang, Hong-Wu; Xu, Shi-Guo

2017-04-01

Check dam is one of the most effective measures to reduce flow connectivity, which can retain soil and water, and increase land productivity. More than 100,000 check dams have been built on the Loess Plateau since 1950s. However, quantifying the effect of check dams on water resources and water environments remains a challenge. In this study, an in-depth field investigation together with a credible statistical analysis was carried out in two representative catchments on the Loess Plateau, Nanxiaohegou Catchment and Jiuyuangou Catchment, to assess the effectiveness of check dams in soil, water and nutrients conservation. The results show: (1) Check dam plays an important role in conserving water, soil, and nutrients on the Loess Plateau. About half of the total transported water and more than 80 % of the total transported soil and nutrients, had been locally retained in the selected catchments. Hence check dams had a significant benefit to improve soil fertility in the small watersheds, and reducing water pollution downstream of dams. (2) Compared to terrace farmlands, forest lands and grasslands, check-dam lands were much more important in conserving water, soil and nutrients in the catchments. Nearly 50% of the reduced water and more than 70% of the stored soil and nutrients in the study catchments were solely retained by the check dams, whereas the area of the dam lands was less than 7% of the total conservation land area. (3) Check dams are still effective in large storms even if dams were damaged by floods. It is often assumed that check dams could only retain sediment in small flood events whereas most of the stored soil may be washed out as the dams may be destroyed in a disastrous flood. Furthermore, if a major check dam, namely the key project dam, was built in the gully outlet, the flood could be controlled, and thereupon the dam-break can be also avoided. We suggest that a compensation and incentive policy be implemented on dam building to realize the sustainable development of local economy and ecological environment.

Carcase weight and dressing percentage are increased using Australian Sheep Breeding Values for increased weight and muscling and reduced fat depth.

PubMed

Gardner, G E; Williams, A; Ball, A J; Jacob, R H; Refshauge, G; Hocking Edwards, J; Behrendt, R; Pethick, D W

2015-01-01

Pre-slaughter live weight, dressing percentage, and hot standard carcase weight (HCWT) from the 2007, 2008, 2009 and 2010 birth-years of the Information Nucleus Flock Lambs (n=7325) were analysed using linear mixed effects models. Increasing the sire breeding value for post-weaning weight (PWWT), and c-site eye muscle depth (PEMD), and reducing the sire breeding value for fat depth (PFAT) all had positive impacts on HCWT. The magnitude of the PWWT effect was greater in pure bred Merinos compared to Maternal and Terminal sired progeny. The improved HCWT resulting from increased PEMD was entirely due to its impact on improving dressing percentage, given that it had no impact on pre-slaughter live weight. There were marked differences between sire types and dam breeds, with pure-bred Merinos having lower pre-slaughter weight, reduced dressing percentage, and lower HCWT than progeny from Terminal and Maternal sired lambs or progeny from Maternal (1st cross) dams. Copyright © 2014 Elsevier Ltd. All rights reserved.

Downstream passage and impact of turbine shutdowns on survival of silver American Eels at five hydroelectric dams on the Shenandoah River

USGS Publications Warehouse

Eyler, Sheila; Welsh, Stuart A.; Smith, David R.; Rockey, Mary

2016-01-01

Hydroelectric dams impact the downstream migrations of silver American Eels Anguilla rostrata via migratory delays and turbine mortality. A radiotelemetry study of American Eels was conducted to determine the impacts of five run-of-the-river hydroelectric dams located over a 195-km stretch of the Shenandoah River, Virginia–West Virginia, during fall 2007–summer 2010. Overall, 96 radio-tagged individuals (mean TL = 85.4 cm) migrated downstream past at least one dam during the study. Most American Eels passed dams relatively quickly; over half (57.9%) of the dam passage events occurred within 1 h of reaching a dam, and most (81.3%) occurred within 24 h of reaching the dam. Two-thirds of the dam passage events occurred via spill, and the remaining passage events were through turbines. Migratory delays at dams were shorter and American Eels were more likely to pass via spill over the dam during periods of high river discharge than during low river discharge. The extent of delay in migration did not differ between the passage routes (spill versus turbine). Twenty-eight American Eels suffered turbine-related mortality, which occurred at all five dams. Mortality rates for eels passing through turbines ranged from 15.8% to 40.7% at individual dams. Overall project-specific mortality rates (with all passage routes combined) ranged from 3.0% to 14.3%. To protect downstream-migrating American Eels, nighttime turbine shutdowns (1800–0600 hours) were implemented during September 15–December 15. Fifty percent of all downstream passage events in the study occurred during the turbine shutdown period. Implementation of the seasonal turbine shutdown period reduced cumulative mortality from 63.3% to 37.3% for American Eels passing all five dams. Modifying the turbine shutdown period to encompass more dates in the spring and linking the shutdowns to environmental conditions could provide greater protection to downstream-migrating American Eels.

Effect of Seepage on Change in Stress Distribution Scenario in Static and Seismic Behaviour of Earthen Dams

NASA Astrophysics Data System (ADS)

Nandi, N.; Chowdhury, Roy; Dutta, S. C.

2018-02-01

The present study makes an effort to understand the damage of earthen dams under static and seismic loading condition. To make the investigation more realistic, behaviour of earthen dams considering the occurrence of a phreatic line indicating the submerged zone due to seepage within the dam body is considered. In case of earthen dams, homogeneous or nonhomogeneous, the consideration of the occurrence of a phreatic line or seepage line through the dam body is an important part of the earthen dam design methodology. The impervious material properties in the submerged zone below the phreatic line due to seepage may differ a lot in magnitudes as compared to the value of the same materials lying above this line. Hence, to have the exact stress distribution scenarios within the earthen dam, the different material properties above and below the phreatic line are considered in this present study. The study is first carried out by two-dimensional as well as three-dimensional finite element analysis under static loading condition. The work is further extended to observe the effect of seepage due to the consideration of the phreatic line on dynamic characteristics of earthen dams. Free vibration analysis and seismic analysis based on the Complete Quadratic Combination (CQC) method by considering twodimensional and three-dimensional modeling are carried out to present the frequencies, mode shapes and the stress distribution pattern of the earthen dam.

The socio-economics dynamics of Dam on Rural Communities: A case study of Oyan Dam, Nigeria

NASA Astrophysics Data System (ADS)

Ayeni, Amidu; Ojifo, Lawrence

2018-06-01

Dams construction and operations have many benefits, nevertheless, they have also led to lots of negative social, health and human impacts. It is based on this that this study assesses the potential and socio-economics dynamics of Oyan dam between 1980 and 2016. The data used for this study include water level and discharge records of the dam between 2007 and 2016, Landsat imageries of 1984 and 2016 and socio-economic datasets for the period. Analysis of the dam potentials (water supply, agriculture and hydropower) and socio-economic impacts of the dam were carried out using basic statistical tools, land use change anaysis and field survey using questionnaire, structured interview with major stakeholders and personal observation. The results revealed that the water level and storage of the Oyan dam had a relative reduction of about 2 % as well as non-stationarity pattern of water abstraction and production for the period. The landuse classes show all classes decreased in extent except the cultivated landuse that acrued an increased of 19.9 % between 1984 and 2016. Furthermore, commercial water supply varied significantly between 2010 and 2016 while irrigation scheme is grossly under-utilized from the inception in 1983 to 2016. Finally, the result of socio-economic impacts revealed that majority of the selected communities' members are actually not benefiting from the dam and their livelihoods are not from the dam.

Assessment of check-dam groundwater recharge with water-balance calculations

NASA Astrophysics Data System (ADS)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

2017-04-01

Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without check-dam was estimated to be 1 million m3. Upper and lower limits of prediction intervals were computed to assess the uncertainties of the results. The model was rerun with these values and resulted in recharge values of 0.4 m3 as lower and 38 million m3 as upper limit. The sediment survey in the check-dam reservoir area showed that the reservoir area was filled with 2,000 to 3,000 tons of sediment after one rainfall season. This amount of sediment corresponds to 0.2 to 2 t h-1 y-1 sediment yield at the watershed level and reduces the check-dam storage capacity by approximately 10%. Results indicate that check-dams are valuable structures for increasing groundwater resources, but special attention should be given to soil erosion occurring in the upstream area and the resulting sediment built-up in the check-dam reservoir area. This study has received funding from the EU FP7 RECARE Project (GA 603498)

Beaver dams and channel sediment dynamics on Odell Creek, Centennial Valley, Montana, USA

NASA Astrophysics Data System (ADS)

Levine, Rebekah; Meyer, Grant A.

2014-01-01

Beaver dams in streams are generally considered to increase bed elevation through in-channel sediment storage, thus, reintroductions of beaver are increasingly employed as a restoration tool to repair incised stream channels. Here we consider hydrologic and geomorphic characteristics of the study stream in relation to in-channel sediment storage promoted by beaver dams. We also document the persistence of sediment in the channel following breaching of dams. Nine reaches, containing 46 cross-sections, were investigated on Odell Creek at Red Rock Lakes National Wildlife Refuge, Centennial Valley, Montana. Odell Creek has a snowmelt-dominated hydrograph and peak flows between 2 and 10 m3 s- 1. Odell Creek flows down a fluvial fan with a decreasing gradient (0.018-0.004), but is confined between terraces along most of its length, and displays a mostly single-thread, variably sinuous channel. The study reaches represent the overall downstream decrease in gradient and sediment size, and include three stages of beaver damming: (1) active; (2) built and breached in the last decade; and (3) undammed. In-channel sediment characteristics and storage were investigated using pebble counts, fine-sediment depth measurements, sediment mapping and surveys of dam breaches. Upstream of dams, deposition of fine (≤ 2 mm) sediment is promoted by reduced water surface slope, shear stress and velocity, with volumes ranging from 48 to 182 m3. High flows, however, can readily transport suspended sediment over active dams. Variations in bed-sediment texture and channel morphology associated with active dams create substantial discontinuities in downstream trends and add to overall channel heterogeneity. Observations of abandoned dam sites and dam breaches revealed that most sediment stored above beaver dams is quickly evacuated following a breach. Nonetheless, dam remnants trap some sediment, promote meandering and facilitate floodplain development. Persistence of beaver dam sediment within the main channel on Odell Creek is limited by frequent breaching (< 1-5 years), so in-channel sediment storage because of damming has not caused measurable channel aggradation over the study period. Enhanced overbank flow by dams, however, likely increases fine-grained floodplain sedimentation and riparian habitat. Contrasts between beaver-damming impacts on Odell Creek and other stream systems of different scales suggest a high sensitivity to hydrologic, geomorphic, and environmental controls, complicating predictions of the longer-term effects of beaver restoration.

Analyzing the Impacts of Dams on Riparian Ecosystems: A Review of Research Strategies and Their Relevance to the Snake River Through Hells Canyon

PubMed Central

Braatne, Jeffrey H.; Goater, Lori A.; Blair, Charles L.

2007-01-01

River damming provides a dominant human impact on river environments worldwide, and while local impacts of reservoir flooding are immediate, subsequent ecological impacts downstream can be extensive. In this article, we assess seven research strategies for analyzing the impacts of dams and river flow regulation on riparian ecosystems. These include spatial comparisons of (1) upstream versus downstream reaches, (2) progressive downstream patterns, or (3) the dammed river versus an adjacent free-flowing or differently regulated river(s). Temporal comparisons consider (4) pre- versus post-dam, or (5) sequential post-dam conditions. However, spatial comparisons are complicated by the fact that dams are not randomly located, and temporal comparisons are commonly limited by sparse historic information. As a result, comparative approaches are often correlative and vulnerable to confounding factors. To complement these analyses, (6) flow or sediment modifications can be implemented to test causal associations. Finally, (7) process-based modeling represents a predictive approach incorporating hydrogeomorphic processes and their biological consequences. In a case study of Hells Canyon, the upstream versus downstream comparison is confounded by a dramatic geomorphic transition. Comparison of the multiple reaches below the dams should be useful, and the comparison of Snake River with the adjacent free-flowing Salmon River may provide the strongest spatial comparison. A pre- versus post-dam comparison would provide the most direct study approach, but pre-dam information is limited to historic reports and archival photographs. We conclude that multiple study approaches are essential to provide confident interpretations of ecological impacts downstream from dams, and propose a comprehensive study for Hells Canyon that integrates multiple research strategies. PMID:18043964

Influence of maternal hyperthyroidism in the rat on the expression of neuronal and astrocytic cytoskeletal proteins in fetal brain.

PubMed

Evans, I M; Pickard, M R; Sinha, A K; Leonard, A J; Sampson, D C; Ekins, R P

2002-12-01

Maternal hypothyroidism during pregnancy impairs brain function in human and rat offspring, but little is known regarding the influence of maternal hyperthyroidism on neurodevelopment. We have previously shown that the expression of neuronal and glial differentiation markers in fetal brain is compromised in hypothyroid rat dam pregnancies and have now therefore extended this investigation to hyperthyroid rat dams. Study groups comprised partially thyroidectomised dams, implanted with osmotic pumps infusing either vehicle (TX dams) or a supraphysiological dose of thyroxine (T4) (HYPER dams), and euthyroid dams infused with vehicle (N dams). Cytoskeletal protein abundance was determined in fetal brain at 21 days of gestation by immunoblot analysis. Relative to N dams, circulating total T4 levels were reduced to around one-third in TX dams but were doubled in HYPER dams. Fetal brain weight was increased in HYPER dams, whereas litter size and fetal body weight were reduced in TX dams. Glial fibrillary acidic protein expression was similar in HYPER and TX dams, being reduced in both cases relative to N dams. alpha-Internexin (INX) abundance was reduced in HYPER dams and increased in TX dams, whereas neurofilament 68 (NF68) exhibited increased abundance in HYPER dams. Furthermore, INX was inversely related to - and NF68 directly related to - maternal serum total T4 levels, independently of fetal brain weight. In conclusion, maternal hyperthyroidism compromises the expression of neuronal cytoskeletal proteins in late fetal brain, suggestive of a pattern of accelerated neuronal differentiation.

Study on seepage characteristics of inclined wall dam after heavy drought

NASA Astrophysics Data System (ADS)

Wei, YE; Fuheng, MA

2018-05-01

For seepage of the dam slope with cracks after drought, there are two methods to study including the physical model test and numerical calculation. However, the physical model test can not visualize the seepage field in the dam body intuitively, and the mathematical model is not accurate because of the precision of the parameter. So in this paper, combined physical model with mathematical model, the surface crack development on the dam slope and the changes of pore water pressure were studied through the physical model test, and then numerical calculation was carried out to analyze the internal seepage of the dam body. The results showed that cracks were more likely to develop at middle of the upstream dam slope and dam heel, and cracks for different degrees appeared at different parts of the dam slope after drought. The development of cracks provided a preferential permeable channel which caused that the area near the crack was easily to become saturated. The saturated zone kept expanding leading the infiltration line to be close to the transition layer and the infiltration line was no longer a smooth curve. There were seepage damages and landslide hazards existing with such seepage characteristics, which would threaten the safety of the dam.

Perinatal thiamine deficiency-induced spontaneous abortion and pup-killing responses in rat dams.

PubMed

Bâ, Abdoulaye

2013-03-01

The current study attempts to determine whether thiamine (B1 vitamin) deficiency and chronic alcohol-related thiamine-deficient (TD) status, disturb maternal behavior towards pups. During gestation and lactation, Wistar rat dams were exposed to the following treatments: (i) prenatal TD dams; (ii) perinatal TD dams; (iii) postnatal TD dams; (iv) 12% alcohol/water drinking mothers; (v) ad libitum control dams. Pair-feeding treatments controlled malnutrition related to thiamine deficiency; (vi) prenatal pair-fed (PF) dams; (vii) perinatal PF dams; (viii) postnatal PF dams and included also the control of alcohol consummation: (ix) PF saccharose dams. Dams were observed for gestation outcome and for apparent disorders of the maternal behavior related to the pups at parturition. From the nine experimental groups studied, only pre- and perinatal TD dams exhibited spontaneous abortion (33.36 and 41.66%, respectively) followed by pups-killing responses where, respectively, 4 dams/7 (57.14%) and 5 dams/7 (71.43%) showed disruption of maternal behavior and appearance of cannibalism towards pups which all were killed within 48 hours after parturition. Spontaneous abortion and pup-killing responses were not observed in the dams of any other experimental group, suggesting that perinatal disturbances of hormonal factors underlay these maternal disorders. Previous studies reported that thiamine deficiency-induced degeneration of dopamine neurons may be related to mouse-killing aggression in rats. The present study suggests that perinatal thiamine deficiency-induced alteration of dopaminergic neurons in maternal brain could be a trigger factor of pup-killing responses. Central dopamine and oxytocin have been strongly associated with both the onset and maintenance of maternal behavior and the regulation of maternal aggressiveness as well. Our studies suggest that estrogen control oxytocin levels in brain structures of pregnancy-terminated rats via dopamine transmission. Thiamine may modulate cAMP/Ca2+ -dependent estradiol-triggered responses which in turn control dopamine synthesis. Consequently, thiamine deficiency induced perinatally triggers pup-killing responses in pregnancy-terminated rats by the following toxic effects: (i) disturbances of estrogen production and/or release affecting dopamine synthesis; (ii) alterations of dopamine inhibition on central oxytocinergic system-related maternal aggressiveness. Likewise, our results indicate also that perinatal thiamine deficiency alone induces spontaneous abortion, reduces litter size, and lowers birth weight, which together suggest changing in the fetoplacental estrogen receptor alpha/progesterone receptor A ratio during gestation, via autocrine/paracrine regulation disturbances. Those hypotheses should be confirmed by further investigations.

Compliance Monitoring of Subyearling Chinook Salmon Survival and Passage at The Dalles Dam, Summer 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

2013-05-01

The purpose of this compliance study was to estimate dam passage survival of subyearling Chinook salmon at The Dalles Dam during summer 2012. Under the 2008 Federal Columbia River Power System Biological Opinion, dam passage survival is required to be greater than or equal to 0.93 and estimated with a standard error (SE) less than or equal to 0.015. The study also estimated survival from the forebay 2 km upstream of the dam and through the tailrace to 2 km downstream of the dam, forebay residence time, tailrace egress time, spill passage efficiency (SPE), and fish passage efficiency (FPE), asmore » required by the 2008 Columbia Basin Fish Accords.« less

Recent sediment studies refute Glen Canyon Dam hypothesis

USGS Publications Warehouse

Rubin, David M.; Topping, David J.; Schmidt, John C.; Hazel, Joe; Kaplinski, Matt; Melis, Theodore S.

2002-01-01

Recent studies of sedimentology hydrology, and geomorphology indicate that releases from Glen Canyon Dam are continuing to erode sandbars and beaches in the Colorado River in Grand Canyon National Park, despite attempts to restore these resources. The current strategy for dam operations is based on the hypothesis that sand supplied by tributaries of the Colorado River downstream from the dam will accumulate in the channel during normal dam operations and remain available for restoration floods. Recent work has shown that this hypothesis is false, and that tributary sand inputs are exported downstream rapidly typically within weeks or months under the current flow regime.

Impact of beaver dams on abundance and distribution of anadromous salmonids in two lowland streams in Lithuania.

PubMed

Virbickas, Tomas; Stakėnas, Saulius; Steponėnas, Andrius

2015-01-01

European beaver dams impeded movements of anadromous salmonids as it was established by fishing survey, fish tagging and redd counts in two lowland streams in Lithuania. Significant differences in abundancies of other litophilic fish species and evenness of representation by species in the community were detected upstream and downstream of the beaver dams. Sea trout parr marked with RFID tags passed through several successive beaver dams in upstream direction, but no tagged fish were detected above the uppermost dam. Increase in abundances of salmonid parr in the stream between the beaver dams and decrease below the dams were recorded in November, at the time of spawning of Atlantic salmon and sea trout, but no significant changes were detected in the sections upstream of the dams. After construction of several additional beaver dams in the downstream sections of the studied streams, abundance of Atlantic salmon parr downstream of the dams decreased considerably in comparison with that estimated before construction.

Effect of beaver dams on the hydrology of small mountain streams: Example from the Chevral in the Ourthe Orientale basin, Ardennes, Belgium

NASA Astrophysics Data System (ADS)

Nyssen, J.; Pontzeele, J.; Billi, P.

2011-05-01

SummaryThe European beaver ( Castor fiber) was recently reintroduced to Belgium, after an absence of more than 150 years; around 120 beaver dam systems have been established. In Europe, few studies consider the hydrological effects of those dams, and the spatial scale larger than that of one beaver pond system has not been addressed at all. This research focuses on the hydrological effects of a series of six beaver dams on the Chevral R., a second order tributary of the Ourthe Orientale R. in a forested area of the Ardennes. Thereby, also the Ourthe Orientale sub-basin itself was taken into account, being the area with probably the highest density of beaver dams in Belgium. The main research questions regarded: (1) the extent to which discharge peaks are reduced at the very location and well downstream of beaver dams and (2) the impact of the beaver dams on low flows. The first approach consisted of a temporal analysis of the Ourthe Orientale discharge and precipitation data for the periods 1978-2003 (before) and 2004-2009 (after the establishment of beaver dams in the sub-basin). The second study determined the in situ impact of the beaver dams: discharges were measured (September 2009-March 2010) upstream as well as downstream of the 0.52 ha beaver dam system on the Chevral river, and changes in water level within the system of six dams were monitored. Our findings indicate that there is a significant lowering of discharge peaks in the downstream river reaches due to the effect of the beaver dams. The temporal analysis of the Ourthe Orientale sub-basin shows an increase in the recurrence interval for major floods; for instance, the recurrence interval of a reference flood of 60 m 3 s -1 increased from 3.4 years to 5.6 years since the establishment of the beaver dams. At the scale of the Chevral beaver dams' site, we measured that the dams top off the peak flows, in addition delaying them by approximately 1 day. There are also increased low flows: Q355 (i.e. the discharge exceeded 355 days in a year) of the Ourthe Orientale was 0.6 (±0.15) m 3 s -1 before beaver dam installation and 0.88 (±0.52) m 3 s -1 thereafter. These findings agree with studies that suggest natural measures for flood control at the level of small mountain streams instead or in complement of building large anthropogenic constructions. Nevertheless, more studies are needed to assess the effectiveness of beaver dams in flood mitigation at the scale of sub-basins.

How far downstream do dams impact streamflow?

NASA Astrophysics Data System (ADS)

Troy, T.

2017-12-01

Water infrastructure can be a double-edged sword. For example, dams can provide significant flood protection and stable water supplies, but they negatively impact river ecosystems. As the United States enters an era of dam decommissioning instead of dam building, it raises the question of how far downstream dams provide protection against flood peaks and sustaining environmental flows. This study uses USGS streamflow observations, the National Inventory of Dams, and VIC-modeled streamflow as a proxy for naturalized streamflow to evaluate the scale at which dams impact a variety of hydrologic signatures such as flood return period flows, streamflow variability, and low flows. Results over the Delaware River show that the impact of dams quickly dissipates as one moves downstream, but this is due to the basin's characteristics. This analysis is performed over the contiguous United States, quantifying the length scale of impact as a function of dam capacity, position on the river network, and the hydroclimatology.

Characterization of a dam Mutant of Serratia marcescens and Nucleotide Sequence of the dam Region

PubMed Central

Ostendorf, Tammo; Cherepanov, Peter; de Vries, Johann; Wackernagel, Wilfried

1999-01-01

The DNA of Serratia marcescens has N6-adenine methylation in GATC sequences. Among 2-aminopurine-sensitive mutants isolated from S. marcescens Sr41, one was identified which lacked GATC methylation. The mutant showed up to 30-fold increased spontaneous mutability and enhanced mutability after treatment with 2-aminopurine, ethyl methanesulfonate, or UV light. The gene (dam) coding for the adenine methyltransferase (Dam enzyme) of S. marcescens was identified on a gene bank plasmid which alleviated the 2-aminopurine sensitivity and the higher mutability of a dam-13::Tn9 mutant of Escherichia coli. Nucleotide sequencing revealed that the deduced amino acid sequence of Dam (270 amino acids; molecular mass, 31.3 kDa) has 72% identity to the Dam enzyme of E. coli. The dam gene is located between flanking genes which are similar to those found to the sides of the E. coli dam gene. The results of complementation studies indicated that like Dam of E. coli and unlike Dam of Vibrio cholerae, the Dam enzyme of S. marcescens plays an important role in mutation avoidance by allowing the mismatch repair enzymes to discriminate between the parental and newly synthesized strands during correction of replication errors. PMID:10383952

Assessing the potential for change in the middle Yangtze River channel following impoundment of the Three Gorges Dam

NASA Astrophysics Data System (ADS)

Yuan, Wenhao; Yin, Daowei; Finlayson, Brian; Chen, Zhongyuan

2012-04-01

The geomorphic impacts of dams on downstream river channels are complex, not readily predictable for specific cases, but widely reported in the literature. For the Three Gorges Dam on the Yangtze (Changjiang) River in China, no studies of the impact of the changed flow and sediment conditions below the dam on the behaviour of the channel were included in the pre-dam feasibility report. We have assembled a database of flow and sediment data for the middle Yangtze River from Yichang to Hankou and used this to analyse changes following the closure of the dam. While total flow is little affected, the operating strategy for the dam that provides for storage of part of the summer high flows to maintain hydroelectric power generation in winter (the low flow season) is reflected in changes to the seasonal distribution of flow below the dam. We calculated potential sediment carrying capacity and compared it with measured sediment concentrations for both pre- and post-dam conditions. While channel sedimentation is indicated along the middle Yangtze for pre-dam conditions, scour is indicated for post-dam conditions, highest at Yichang immediately below the dam and decreasing downstream.

Computational hydraulics of a cascade of experimental-scale landside dam failures

NASA Astrophysics Data System (ADS)

Wright, N.; Guan, M.

2015-12-01

Abstract: Landslide dams typically comprise unconsolidated and poorly sorted material, and are vulnerable to rapid failure and breaching, particularly in mountainous areas during high intense rainfalls. A large flash flood with high-concentrated sediment can be formed in a short period, and the magnitude is likely to be amplified along the flow direction due to the inclusion of a large amount of sediment. This can result in significant and sudden flood risk downstream for human life and property. Numerous field evidence has indicated the various risks of landslide dam failures. In general, cascading landslide dams can be formed along the sloping channel due to the randomness and unpredictability of landslides, which complexes the hydraulics of landslide dam failures. The failure process of a single dam and subsequent floods has attracted attention in multidisciplinary studies. However, the dynamic failure process of cascading landslide dams has been poorly understood. From a viewpoint of simulation, this study evaluates the formation and development of rapid sediment-charged floods due to cascading failure of landslide dams through detailed hydro-morphodynamic modelling. The model used is based on shallow water theory and it has been successful in predicting the flow and morphological process during sudden dam-break, as well as full and partial dyke-breach. Various experimental-scale scenarios are modelled, including: (1) failure of a single full dam in a sloping channel, (2) failure of two dams in a sloping channel, (3) failure of multiple landslide dams (four) in a sloping channel. For each scenario, different failure modes (sudden/gradual) and bed boundary (fixed /mobile) are assumed and simulated. The study systematically explores the tempo-spatial evolution of landslide-induced floods (discharge, flow velocity, and flow concentration) and geomorphic properties along the sloping channel. The effects of in-channel erosion and flow-driven sediment from dams on the development of flood process are investigated. The results improve the understanding of the formation and development mechanism of flash floods due to cascading landslide dam failures. The findings are beneficial for downstream flood risk assessment and developing control strategies for landslide-induced floods.

Compliance Monitoring of Yearling and Subyearling Chinook Salmon and Juvenile Steelhead Survival and Passage at John Day Dam, 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

The purpose of this compliance study was to estimate dam passage survival of yearling and subyearling Chinook salmon and steelhead smolts at John Day Dam during the spring and summer outmigrations in 2012. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 for spring migrants and greater than or equal to 0.93 for summer migrants, estimated with a standard error (SE) less than or equal to 0.015. The study also estimated smolt passage survival from the forebay 2 km upstream of the dam to the tailracemore » 3 km downstream of the dam, as well as the forebay residence time, tailrace egress time, spill passage efficiency (SPE), and fish passage efficiency (FPE), as required in the Columbia Basin Fish Accords (Fish Accords). A virtual/paired-release design was used to estimate dam passage survival at John Day Dam. The approach included releases of smolts, tagged with acoustic micro-transmitters, above John Day Dam that contributed to the formation of a virtual release at the face of John Day Dam. A survival estimate from this release was adjusted by a paired release below John Day Dam. A total of 3376 yearling Chinook salmon, 5726 subyearling Chinook salmon, and 3239 steelhead smolts were used in the virtual releases. Sample sizes for the below-dam paired releases (R2 and R3, respectively) were 997 and 995 for yearling Chinook salmon smolts, 986 and 983 for subyearling Chinook salmon smolts, and 1000 and 1000 for steelhead smolts. The Juvenile Salmon Acoustic Telemetry System (JSATS) tags were manufactured by Advanced Telemetry Systems. Model SS300 tags, weighing 0.304 g in air, were surgically implanted in yearling and subyearling Chinook salmon, and Model SS130 tag, weighing 0.438 g in air, were surgically implanted in juvenile steelhead for this investigation. The intent of the spring study was to estimate dam passage survival during both 30% and 40% spill conditions. The two spill conditions were to be systematically performed in alternating 2-day test intervals over the course of the spring outmigration. High flow conditions in 2012 interrupted the spill study. Dam passage survival was therefore estimated season-wide regardless of spill conditions.« less

Experimental Study on Impact Load on a Dam Due to Debris Flow

Treesearch

lwao Miyoshi

1991-01-01

When a dam is struck by mud or debris flow, it is put under a great impact load and sometimes is destroyed. To prevent such destruction, it is important to perform basic research about the impact load on a dam due to debris flow. Thus, we have made an experimental study and tried to establish a method to estimate such a impact load on the dam. The experiment was...

Geomorphic and Ecological Disturbance and Recovery from Two Small Dams and Their Removal

PubMed Central

Tullos, Desirée D.; Finn, Debra S.; Walter, Cara

2014-01-01

Dams are known to impact river channels and ecosystems, both during their lifetime and in their decommissioning. In this study, we applied a before-after-control-impact design associated with two small dam removals to investigate abiotic and biotic recovery trajectories from both the elimination of the press disturbance associated with the presence of dams and the introduction of a pulse disturbance associated with removal of dams. The two case studies represent different geomorphic and ecological conditions that we expected to represent low and high sensitivities to the pulse disturbance of dam removal: the 4 m tall, gravel-filled Brownsville Dam on the wadeable Calapooia River and the 12.5 m tall, sand and gravel-filled Savage Rapids Dam on the largely non-wadeable Rogue River. We evaluated both geomorphic and ecological responses annually for two years post removal, and asked if functional traits of the macroinvertebrate assemblages provided more persistent signals of ecological disturbance than taxonomically defined assemblages over the period of study. Results indicate that: 1) the presence of the dams constituted a strong ecological press disturbance to the near-downstream reaches on both rivers, despite the fact that both rivers passed unregulated flow and sediment during the high flow season; 2) ecological recovery from this press disturbance occurred within the year following the restoration action of dam removal, whereas signals of geomorphic disturbance from the pulse of released sediment persisted two years post-removal, and 3) the strength of the press disturbance and the rapid ecological recovery were detected regardless of whether recovery was assessed by taxonomic or functional assemblages and for both case studies, in spite of their different geomorphic settings. PMID:25233231

Compliance Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at The Dalles Dam, Spring 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, Thomas J.; Skalski, John R.

2010-10-01

The purpose of this compliance study was to estimate dam passage survival of yearling Chinook salmon and steelhead smolts at The Dalles Dam during spring 2010. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 and estimated with a standard error (SE) less than or equal 0.015. The study also estimated smolt passage survival from the forebay boat-restricted zone (BRZ) to the tailrace BRZ at The Dalles Dam, as well as the forebay residence time, tailrace egress, and spill passage efficiency (SPE), as required in themore » Columbia Basin Fish Accords. A virtual/paired-release design was used to estimate dam passage survival at The Dalles Dam. The approach included releases of acoustic-tagged smolts above John Day Dam that contributed to the formation of a virtual release at the face of The Dalles Dam. A survival estimate from this release was adjusted by a paired release below The Dalles Dam. A total of 4,298 yearling Chinook salmon and 4,309 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation. The dam passage survival results are summarized as follows: Yearling Chinook Salmon 0.9641 (SE = 0.0096) and Steelhead 0.9535 (SE = 0.0097).« less

A pre-dam-removal assessment of sediment transport for four dams on the Kalamazoo River between Plainwell and Allegan, Michigan

USGS Publications Warehouse

Syed, Atiq U.; Bennett, James P.; Rachol, Cynthia M.

2005-01-01

Four dams on the Kalamazoo River between the cities of Plainwell and Allegan, Mich., are in varying states of disrepair. The Michigan Department of Environmental Quality (MDEQ) and U.S. Environmental Protection Agency (USEPA) are considering removing these dams to restore the river channels to pre-dam conditions. This study was initiated to identify sediment characteristics, monitor sediment transport, and predict sediment resuspension and deposition under varying hydraulic conditions. The mathematical model SEDMOD was used to simulate streamflow and sediment transport using three modeling scenarios: (1) sediment transport simulations for 730 days (Jan. 2001 to Dec. 2002), with existing dam structures, (2) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with existing dam structures, and (3) sediment transport simulations based on flows from the 1947 flood at the Kalamazoo River with dams removed. Sediment transport simulations based on the 1947 flood hydrograph provide an estimate of sediment transport rates under maximum flow conditions. These scenarios can be used as an assessment of the sediment load that may erode from the study reach at this flow magnitude during a dam failure. The model was calibrated using suspended sediment as a calibration parameter and root mean squared error (RMSE) as an objective function. Analyses of the calibrated model show a slight bias in the model results at flows higher than 75 m3/s; this means that the model-simulated suspended-sediment transport rates are higher than the observed rates; however, the overall calibrated model results show close agreement between simulated and measured values of suspended sediment. Simulation results show that the Kalamazoo River sediment transport mechanism is in a dynamic equilibrium state. Model results during the 730-day simulations indicate significant sediment erosion from the study reach at flow rates higher than 55 m3/s. Similarly, significant sediment deposition occurs during low to average flows (monthly mean flows between 25.49 m3/s and 50.97 m3/s) after a high-flow event. If the flow continues to stay in the low to average range the system shifts towards equilibrium, resulting in a balancing effect between sediment deposition and erosion rates. The 1947 flood-flow simulations show approximately 30,000 m3 more instream sediments erosion for the first 21 days of the dams removed scenario than for the existing-dams scenario, with the same initial conditions for both scenarios. Application of a locally weighted regression smoothing (LOWESS) function to simulation results of the dams removed scenario indicates a steep downtrend with high sediment transport rates during the first 21 days. In comparison, the LOWESS curve for the existing-dams scenario shows a smooth transition of sediment transport rates in response to the change in streamflow. The high erosion rates during the dams-removed scenario are due to the absence of the dams; in contrast, the presence of dams in the existing-dams scenario helps reduce sediment erosion to some extent. The overall results of 60-day simulations for the 1947 flood show no significant difference in total volume of eroded sediment between the two scenarios, because the dams in the study reach have low heads and no control gates. It is important to note that the existing-dams and dams-removed scenarios simulations are run for only 60 days; therefore, the simulations take into account the changes in sediment erosion and deposition rates only during that time period. Over an extended period, more erosion of instream sediments would be expected to occur if the dams are not properly removed than under the existing conditions. On the basis of model simulations, removal of dams would further lower the head in all the channels. This lowering of head could produce higher flow velocities in the study reach, which ultimately would result in accelerated erosion rates.

Effects of dams in river networks on fish assemblages in non-impoundment sections of rivers in Michigan and Wisconsin, USA

USGS Publications Warehouse

Stewart, Jana S.; Lizhu Wang,; Infante, Dana M.; Lyons, John D.; Arthur Cooper,

2011-01-01

Regional assessment of cumulative impacts of dams on riverine fish assemblages provides resource managers essential information for dam operation, potential dam removal, river health assessment and overall ecosystem management. Such an assessment is challenging because characteristics of fish assemblages are not only affected by dams, but also influenced by natural variation and human-induced modification (in addition to dams) in thermal and flow regimes, physicochemical habitats and biological assemblages. This study evaluated the impacts of dams on river fish assemblages in the non-impoundment sections of rivers in the states of Michigan and Wisconsin using multiple fish assemblage indicators and multiple approaches to distinguish the influences of dams from those of other natural and human-induced factors. We found that environmental factors that influence fish assemblages in addition to dams should be incorporated when evaluating regional effects of dams on fish assemblages. Without considering such co-influential factors, the evaluation is inadequate and potentially misleading. The role of dams alone in determining fish assemblages at a regional spatial scale is relatively small (explained less than 20% of variance) compared with the other environmental factors, such as river size, flow and thermal regimes and land uses jointly. However, our results do demonstrate that downstream and upstream dams can substantially modify fish assemblages in the non-impoundment sections of rivers. After excluding river size and land-use influences, our results clearly demonstrate that dams have significant impacts on fish biotic-integrity and habitat-and-social-preference indicators. The influences of the upstream dams, downstream dams, distance to dams, and dam density differ among the fish indicators, which have different implications for maintaining river biotic integrity, protecting biodiversity and managing fisheries.

Effects of dams in river networks on fish assemblages in non-impoundment sections of rivers in Michigan and Wisconsin, USA

USGS Publications Warehouse

Wang, L.; Infante, D.; Lyons, J.; Stewart, J.; Cooper, A.

2011-01-01

Regional assessment of cumulative impacts of dams on riverine fish assemblages provides resource managers essential information for dam operation, potential dam removal, river health assessment and overall ecosystem management. Such an assessment is challenging because characteristics of fish assemblages are not only affected by dams, but also influenced by natural variation and human-induced modification (in addition to dams) in thermal and flow regimes, physicochemical habitats and biological assemblages. This study evaluated the impacts of dams on river fish assemblages in the non-impoundment sections of rivers in the states of Michigan and Wisconsin using multiple fish assemblage indicators and multiple approaches to distinguish the influences of dams from those of other natural and human-induced factors. We found that environmental factors that influence fish assemblages in addition to dams should be incorporated when evaluating regional effects of dams on fish assemblages. Without considering such co-influential factors, the evaluation is inadequate and potentially misleading. The role of dams alone in determining fish assemblages at a regional spatial scale is relatively small (explained less than 20% of variance) compared with the other environmental factors, such as river size, flow and thermal regimes and land uses jointly. However, our results do demonstrate that downstream and upstream dams can substantially modify fish assemblages in the non-impoundment sections of rivers. After excluding river size and land-use influences, our results clearly demonstrate that dams have significant impacts on fish biotic-integrity and habitat-and-social-preference indicators. The influences of the upstream dams, downstream dams, distance to dams, and dam density differ among the fish indicators, which have different implications for maintaining river biotic integrity, protecting biodiversity and managing fisheries. ?? 2010 John Wiley & Sons, Ltd.

76 FR 57731 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-16

... Competing Applications; McKay Dam Hydropower, LLC On May 31, 2011, McKay Dam Hydropower, LLC filed an... study the feasibility of the McKay Dam Hydroelectric Project (project) to be located at the McKay dam near Pendleton in Umatilla County, [[Page 57732

Why dentists don't use rubber dam during endodontics and how to promote its usage?

PubMed

Madarati, Ahmad A

2016-02-25

This survey study aimed at investigating the frequency of rubber dam use during root canal treatment, identifying influencing factors for not using it by Saudi general dental practitioners (GDPs) and endodontists. It also aimed at identifying measures that increase rubber dam usage. After obtaining an ethical approval, two pilot studies were conducted on staff members at Taibah University College of Dentistry and a group of GDPs. A final online survey was constructed comprising 17 close-ended questions divided into six categories: demographics, endodontic practice, rubber dam use, alternative isolation methods, reasons for not using rubber dam, and measures and policies that increase its usage. The survey was emailed to 375 GDPs randomly selected from the dental register and all endodontists (n = 53) working in the western province, Saudi Arabia. Data were analyzed using the Chi-square and Linear-by-Linear association tests at p ≤ 0.05. The proportion of endodontists who used rubber dam (84.8 %) was significantly greater than that of GDPs (21.6 %) (p < 0.001). Significantly the highest proportion (40.5 %) did not use rubber dam because of unavailability at working place. Most rubber dam none-users (69.25 %) used a combination of other isolation means. The highest proportion of those who used rubber dam were working in the governmental sector (54.3 %). Among rubber dam users, the greatest proportion graduated from Saudi Arabia (57.8 %) compared to those graduated from Egypt (34.3 %) and Syria (22.4 %). There was a significant correlation between the patterns of rubber dam use during undergraduate training and its usage after graduation (p = 0.001). The highest proportion of participants (48.1 %) reported better undergraduate education as the most important factor that would increase rubber dam use in dental practice. Using of rubber dam was not common in Saudi general dental practice. Dentists must follow the recommended standards of care. Place of work and patterns of using rubber dam during undergraduate study were the most influencing factors. Better undergraduate education was the most important proposed measure to increase its usage. The combination of cotton rolls and saliva high-volume ejector or gauze was the most common alternative to rubber dam isolation.

The effect of maternal diabetes on the Wnt-PCP pathway during embryogenesis as reflected in the developing mouse eye.

PubMed

López-Escobar, Beatriz; Cano, David A; Rojas, Anabel; de Felipe, Beatriz; Palma, Francisco; Sánchez-Alcázar, José A; Henderson, Deborah; Ybot-González, Patricia

2015-02-01

Embryopathies that develop as a consequence of maternal diabetes have been studied intensely in both experimental and clinical scenarios. Accordingly, hyperglycaemia has been shown to downregulate the expression of elements in the non-canonical Wnt-PCP pathway, such as the Dishevelled-associated activator of morphogenesis 1 (Daam1) and Vangl2. Daam1 is a formin that is essential for actin polymerization and for cytoskeletal reorganization, and it is expressed strongly in certain organs during mouse development, including the eye, neural tube and heart. Daam1(gt/gt) and Daam1(gt/+) embryos develop ocular defects (anophthalmia or microphthalmia) that are similar to those detected as a result of hyperglycaemia. Indeed, studying the effects of maternal diabetes on the Wnt-PCP pathway demonstrated that there was strong association with the Daam1 genotype, whereby the embryopathy observed in Daam1(gt/+) mutant embryos of diabetic dams was more severe. There was evidence that embryonic exposure to glucose in vitro diminishes the expression of genes in the Wnt-PCP pathway, leading to altered cytoskeletal organization, cell shape and cell polarity in the optic vesicle. Hence, the Wnt-PCP pathway appears to influence cell morphology and cell polarity, events that drive the cellular movements required for optic vesicle formation and that, in turn, are required to maintain the fate determination. Here, we demonstrate that the Wnt-PCP pathway is involved in the early stages of mouse eye development and that it is altered by diabetes, provoking the ocular phenotype observed in the affected embryos. © 2015. Published by The Company of Biologists Ltd.

Examining the economic impacts of hydropower dams on property values using GIS.

PubMed

Bohlen, Curtis; Lewis, Lynne Y

2009-07-01

While the era of dam building is largely over in the United States, globally dams are still being proposed and constructed. The articles in this special issue consider many aspects and impacts of dams around the world. This paper examines dam removal and the measurement of the impacts of dams on local community property values. Valuable lessons may be found. In the United States, hundreds of small hydropower dams will come up for relicensing in the coming decade. Whether or not the licenses are renewed and what happens to the dams if the licenses expires is a subject of great debate. Dams are beginning to be removed for river restoration and fisheries restoration and these "end-of-life" decisions may offer lessons for countries proposing or currently building small (and large) hydropower dams. What can these restoration stories tell us? In this paper, we examine the effects of dams along the Penobscot River in Maine (USA) on residential property values. We compare the results to findings from a similar (but ex post dam removal) data set for properties along the Kennebec river in Maine, where the Edwards Dam was removed in 1999. The Penobscot River Restoration Project, an ambitious basin-wide restoration effort, includes plans to remove two dams and decommission a third along the Penobscot River. Dam removal has significant effects on the local environment, and it is reasonable to anticipate that environmental changes will themselves be reflected in changes in property values. Here we examine historical real estate transaction data to examine whether landowners pay a premium or penalty to live near the Penobscot River or near a hydropower generating dam. We find that waterfront landowners on the Penobscot or other water bodies in our study area pay approximately a 16% premium for the privilege of living on the water. Nevertheless, landowners pay LESS to live near the Penobscot River than they do to live further away, contrary to the expectation that bodies of water function as real estate amenities and boost local property values. Results with respect to the effect of proximity to hydropower generating plants are equivocal. Homeowners pay a small premium for houses close to hydropower dams in our region, but the statistical significance of that result depends on the specific model form used to estimate the effect. Consideration of the social and economic impacts of dam removal-based river restoration can complement studies of the ecological impacts of the practice. Such studies help us understand the extent to which human society's subjective perception of value of aquatic ecosystems relates to objective measures of ecosystem health. The paper also illustrates how geographic information systems (GIS) can help inform these analyses.

Reductions in fish-community contamination following lowhead dam removal linked more to shifts in food-web structure than sediment pollution.

PubMed

Davis, Robert P; Sullivan, S Mažeika P; Stefanik, Kay C

2017-12-01

Recent increases in dam removals have prompted research on ecological and geomorphic river responses, yet contaminant dynamics following dam removals are poorly understood. We investigated changes in sediment concentrations and fish-community body burdens of mercury (Hg), selenium (Se), polychlorinated biphenyls (PCB), and chlorinated pesticides before and after two lowhead dam removals in the Scioto and Olentangy Rivers (Columbus, Ohio). These changes were then related to documented shifts in fish food-web structure. Seven study reaches were surveyed from 2011 to 2015, including controls, upstream and downstream of the previous dams, and upstream restored vs. unrestored. For most contaminants, fish-community body burdens declined following dam removal and converged across study reaches by the last year of the study in both rivers. Aldrin and dieldrin body burdens in the Olentangy River declined more rapidly in the upstream-restored vs. the upstream-unrestored reach, but were indistinguishable by year three post dam removal. No upstream-downstream differences were observed in body burdens in the Olentangy River, but aldrin and dieldrin body burdens were 138 and 148% higher, respectively, in downstream reaches than in upstream reaches of the Scioto River following dam removal. The strongest relationships between trophic position and body burdens were observed with PCBs and Se in the Scioto River, and with dieldrin in the Olentangy River. Food-chain length - a key measure of trophic structure - was only weakly related to aldrin body burdens, and unrelated to other contaminants. Overall, we demonstrate that lowhead dam removal may effectively reduce ecosystem contamination, largely via shifts in fish food-web dynamics versus sediment contaminant concentrations. This study presents some of the first findings documenting ecosystem contamination following dam removal and will be useful in informing future dam removals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Delayed effects of flood control on a flood-dependent riparian forest

USGS Publications Warehouse

Katz, Gabrielle L.; Friedman, Jonathan M.; Beatty, Susan W.

2005-01-01

The downstream effects of dams on riparian forests are strongly mediated by the character and magnitude of adjustment of the fluvial–geomorphic system. To examine the effects of flow regulation on sand-bed streams in eastern Colorado, we studied the riparian forest on three river segments, the dam-regulated South Fork Republican River downstream of Bonny Dam, the unregulated South Fork Republican River upstream of Bonny Dam, and the unregulated Arikaree River. Although Bonny Dam significantly reduced peak and mean discharge downstream since 1951, there was little difference in forest structure between the regulated and unregulated segments. On all river segments, the riparian forest was dominated by the native pioneer tree, Populus deltoides, which became established during a period of channel narrowing beginning after the 1935 flood of record and ending by 1965. The nonnative Elaeagnus angustifolia was present on all river segments, with recruitment ongoing. The lack of contrast in forest structure between regulated and unregulated reaches resulted primarily from the fact that no large floods occurred on any of the study segments since dam construction. Most of the riparian forest in the study area was located on the broad narrowing terrace, which was rarely inundated on the unregulated segments, resulting in little contrast with the regulated segment. A minor dam effect occurred on the small modern floodplain, which was actively disturbed on the unregulated segments, but not on the regulated segments. Although Bonny Dam had the potential to significantly influence downstream riparian ecosystems, this influence had not been expressed, and may never be if a large flood does not occur within the lifetime of the dam. Minor dam effects to riparian systems can be expected downstream of large dams in some settings, including the present example in which there was insufficient time for the dam effects to by fully expressed.

Vulnerability of Karangkates dams area by means of zero crossing analysis of data magnetic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sunaryo,, E-mail: sunaryo@ub.ac.id, E-mail: sunaryo.geofis.ub@gmail.com; Susilo, Adi

2015-04-24

Study with entitled Vulnerability Karangkates Dam Area By Means of Zero Crossing Analysis of Data Magnetic has been done. The study was aimed to obtain information on the vulnerability of two parts area of Karangkates dams, i.e. Lahor dam which was inaugurated in 1977 and Sutami dam inaugurated in 1981. Three important things reasons for this study are: 1). The dam age was 36 years old for Lahor dam and 32 years old for Sutami dam, 2). Geologically, the location of the dams are closed together to the Pohgajih local shear fault, Selorejo local fault, and Selorejo limestone-andesite rocks contactmore » plane, and 3). Karangkates dams is one of the important Hydro Power Plant PLTA with the generating power of about 400 million KWH per year from a total of about 29.373MW installed in Indonesia. Geographically, the magnetic data acquisition was conducted at coordinates (112.4149oE;-8.2028oS) to (112.4839oE;-8.0989oS) by using Proton Precession Magnetometer G-856. Magnetic Data acquisition was conducted in the radial direction from the dams with diameter of about 10 km and the distance between the measurements about 500m. The magnetic data acquisition obtained the distribution of total magnetic field value in the range of 45800 nT to 44450 nT. Residual anomalies obtained by doing some corrections, including diurnal correction, International Geomagnetic Reference Field (IGRF) correction, and reductions so carried out the distribution of the total magnetic field value in the range of -650 nT to 700 nT. Based on the residual anomalies, indicate the presence of 2 zones of closed closures dipole pairs at located in the west of the Sutami dam and the northwest of the Lahor dam from 5 total zones. Overlapping on the local geological map indicated the lineament of zero crossing patterns in the contour of residual anomaly contour with the Pohgajih shear fault where located at about 4 km to the west of the Sutami dam approximately and andesite-limestone rocks contact where located at about 6 km to the west of the Lahor dam approximately. These shown a possible of vulnerability on geohazards at the west zone of the Karangkates (Lahor-Sutami) dams area if there are triggers by the vibration (earthquake) on the Pohgajih shear fault, andesite-limestone contact plane, and instability rocks on two zones of closed closure dipole pairs area. Reality, on the location of the study shown some local landslide at the several locations and the main road that need considering for disaster mitigation.« less

Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data

USGS Publications Warehouse

Velpuri, Naga Manohar; Senay, Gabriel B.

2012-01-01

Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998–2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8–10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternate dam-filling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.

National Program for Inspection of Non-Federal Dams. Miller Pond Dam (CT 00154), Thames River Basin, Waterford, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-08-01

Phase I Investigation; however, the investigation is intended to identify any need for such studies . In reviewing this report, it should be realized that...need for more detailed hydrologic and hydraulic studies , considering the size of the dam, its general condition and the downstream damage potential. The...and/or further study . 1-1 I 1.2 DESCRIPTION OF PROJECT a. Location - The dam is located on Hunt’s Brook in a rural area of the Town of Waterford

Survival of migrating Atlantic salmon smolts through the Penobscot River, Maine: A pre-restoration assessment

USGS Publications Warehouse

Zydlewski, Joseph D.; Kinnison, Michael T.; Holbrook, Christopher M.

2011-01-01

Survival, distribution, and behavior of hatchery (n = 493) and naturally reared (n = 133) smolts of Atlantic salmon Salmo salar migrating through the Penobscot River and estuary in Maine were evaluated with acoustic telemetry in 2005 and 2006. Survival and use of a secondary migration path (the Stillwater Branch) were estimated with a multistate mark–recapture model. Higher rates of mortality per kilometer (range = 0.01–0.22) were observed near release sites and within reaches that contained three particular dams: Howland, West Enfield, and Milford dams. Estimated total survival of tagged hatchery smolts through entire individual reaches containing those dams ranged from 0.52 ( 0.18) to 0.94 ( 0.09), whereas survival through most of the reaches without dams exceeded 0.95. Of those smolts that survived to the Penobscot River–Stillwater Branch split at Marsh Island, most (≥74%) remained in the main stem around Marsh Island, where they experienced lower survival than fish that used the Stillwater Branch. Movement rates of hatchery-reared smolts were significantly lower through reaches containing dams than through reaches that lacked dams. Smolts arriving at dams during the day experienced longer delays than smolts arriving at night. Planned removal of two dams in this system is expected to enhance the passage of smolts through the main-stem corridor. However, the dams currently scheduled for removal (Great Works and Veazie dams) had less influence on smolt survival than some of the dams that will remain. This case study shows that by examining prerestoration migration dynamics throughout entire river systems rather than just in the vicinity of particular dams, tracking studies can help prioritize restoration efforts or predict the costs and benefits of future hydrosystem changes.

Key Impact Factors on Dam Break Fatalities

NASA Astrophysics Data System (ADS)

Huang, D.; Yu, Z.; Song, Y.; Han, D.; Li, Y.

2016-12-01

Dam failures can lead to catastrophes on human society. However, there is a lack of research about dam break fatalities, especially on the key factors that affect fatalities. Based on the analysis of historical dam break cases, most studies have used the regression analysis to explore the correlation between those factors and fatalities, but without implementing optimization to find the dominating factors. In order to understand and reduce the risk of fatalities, this study has proposed a new method to select the impact factors on the fatality. It employs an improved ANN (Artificial Neural Network) combined with LOOCV (Leave-one-out cross-validation) and SFS (Stepwise Forward Selection) approach to explore the nonlinear relationship between impact factors and life losses. It not only considers the factors that have been widely used in the literature but also introduces new factors closely involved with fatalities. Dam break cases occurred in China from 1954 to 2013 are summarized, within which twenty-five cases are selected with a comprehensive coverage of geographic position and temporal variation. Twelve impact factors are taken into account as the inputs, i.e., severity of dam break flood (SF), population at risk (PR), public understanding of dam break (UB), warning time (TW), evacuation condition (EC), weather condition during dam break (WB), dam break mode (MB), water storage (SW), building vulnerability (VB), dam break time (TB), average distance from the affected area to the dam (DD) and preventive measures by government (PG).From those, three key factors of SF, MB and TB are chosen. The proposed method is able to extract the key factors, and the derived fatality model performs well in various types of dam break conditions.

Sediment budget as affected by construction of a sequence of dams in the lower Red River, Viet Nam

NASA Astrophysics Data System (ADS)

Lu, Xi Xi; Oeurng, Chantha; Le, Thi Phuong Quynh; Thuy, Duong Thi

2015-11-01

Dam construction is one of the main factors resulting in riverine sediment changes, which in turn cause river degradation or aggradation downstream. The main objective of this work is to examine the sediment budget affected by a sequence of dams constructed upstream in the lower reach of the Red River. The study is based on the longer-term annual data (1960-2010) with a complementary daily water and sediment data set (2008-2010). The results showed that the stretch of the river changed from sediment surplus (suggesting possible deposition processes) into sediment deficit (possible erosion processes) after the first dam (Thac Ba Dam) was constructed in 1972 and changed back to deposition after the second dam (Hoa Binh Dam) was constructed in 1985. The annual sediment deposition varied between 1.9 Mt/y and 46.7 Mt/y with an annual mean value of 22.9 Mt/y (1985-2010). The sediment deposition at the lower reach of the Red River would accelerate river aggradation which would change river channel capacity in the downstream of the Red River. The depositional processes could be sustained or changed back to erosional processes after more dams (the amount of sediment deposit was much less after the latest two dams Tuyen Quang Dam in 2009 and Sonla Dam in 2010) are constructed, depending on the water and sediment dynamics. This study revealed that the erosional and depositional processes could be shifted for the same stretch of river as affected by a sequence of dams and provides useful insights in river management in order to reduce flood frequency along the lower reach of the Red River.

State-discharge relations at dams on the Illinois and Des Plaines rivers in Illinois

USGS Publications Warehouse

Mades, Dean M.

1981-01-01

Stage-discharge relations were developed for the Brandon Road Dam on the Des Plainse River and the Dresden Island, Marseilles, Starved Rock, Peoria, and La Grange Dams on the Illinois River. At Brandon Road Dam, streamflow is regulated by the operation of tainter gates and headgates. Tainter gates are operated to regulate streamflow at the Dresden Island, Marseilles, and Starved Rock Dams. Peoria Dam and La Grange Dam comprise timber Chanoine wickets which are lowered to a horizontal position on the streambed when used for streamflow regulation. Both dams have concrete abutments housing butterfly valves that are also used for regulation. A total of 50 discharge measurements ranging from 49.0 to 2,450 cubic meter per second were used to determine discharge coefficients in equations expressing discharge as a function of headwater depth, tailwater depth, and gate opening. A stage-discharge relation for Chanoine wicket dams developed from a U.S. Army Corps of Engineers hydraulic model study in 1937 and 1938 was verified with discharge measurements made downstream from the Peoria and La Grange Dams. (USGS)

76 FR 57731 - Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-16

... Competing Applications; Kachess Dam Hydropower, LLC On May 31, 2011, Kachess Dam Hydropower, LLC filed an... study the feasibility of the Kachess Dam Hydroelectric Project (project) to be located at Kachess Reservoir dam, owned and operated by the U.S. Bureau of Reclamation near Cle Elum and Roslyn in Kittitas...

Modelling the impact of dam removal on geomorphic channel response and sediment delivery: an Austrian case study

NASA Astrophysics Data System (ADS)

Pöppl, Ronald; Coulthard, Tom; Keesstra, Saskia; Keiler, Margreth

2015-04-01

Dams are often considered to have the most significant impact on rivers as dam construction generally reduces downstream sediment fluxes which further involves geomorphic changes in the affected river reaches. Since many dams no longer fulfill their intended purpose (e.g. due to siltation), are dangerous (e.g. catastrophic dam failures) and/or are ecologically damaging (e.g. habitat destruction), within the last two decades several dams have been removed and many more are already proposed for removal. Unfortunately, there is still only little empirical knowledge about the geomorphic consequences of dam removals and the related sediment release which represents a big challenge for river management. Modelling is one way to approach this problem. In the presented study we modelled the impacts of dam removal on geomorphic channel processes, channel morphology and sediment delivery further considering the role of channel engineering measures and reservoir excavation within a river reach impacted by a series of dams using the landscape evolution model CAESAR-Lisflood. The model was run with data from a small catchment located in Lower Austria. Modelled geomorphic channel changes and sediment fluxes were spatio-temporally analyzed, related to real-world data and are discussed in the context of river management issues.

Temporal effects of post-fire check dam construction on soil functionality in SE Spain.

PubMed

González-Romero, J; Lucas-Borja, M E; Plaza-Álvarez, P A; Sagra, J; Moya, D; De Las Heras, J

2018-06-09

Wildfire has historically been an alteration factor in Mediterranean basins. Despite Mediterranean ecosystems' high resilience, wildfire accelerates erosion and degradation processes, and also affects soil functionality by affecting nutrient cycles and soil structure. In semi-arid Mediterranean basins, check dams are usually built in gullies and channels after fire as a measure against soil erosion. Although check dams have proven efficient action to reduce erosion rates, studies about how they affect soil functionality are lacking. Our approach focuses on how soil functionality, defined as a combination of physico-chemical and biological indicators, is locally affected by check dam construction and the evolution of this effect over time. Soils were sampled in eight check dams in two semi-arid areas at SE Spain, which were affected by wildfire in 2012 and 2016. The study findings reveal that by altering sediments cycle and transport, check dams influence soil's main physico-chemical and biochemical characteristics. Significant differences were found between check dam-affected zones and the control ones for many indicators such as organic matter content, electrical conductivity or enzymatic activity. According to the ANOVA results, interaction between check dams influence and time after fire, was a crucial factor. PCA results clearly showed check-dams influence on soil functionality. Copyright © 2018. Published by Elsevier B.V.

Seismic performance of arch dams on non-homogeneous and discontinuous foundations (a case study: Karun 4 Dam)

NASA Astrophysics Data System (ADS)

Ferdousi, A.

2017-06-01

The present study set out to investigate the nonlinear seismic response of the dam-reservoir-rock foundation system, taking into consideration the effects of change in the material properties of discontinuous foundation. To this end, it is important to provide the proper modeling of truncated boundary conditions at the far-end of rock foundation and reservoir fluid domain and to correctly apply the in situ stresses for rock foundation. The nonlinear seismic response of an arch dam mainly depends on the opening and sliding of the dam body's contraction joints and foundation discontinuities, failure of the jointed rock and concrete materials, etc. In this paper, a time domain dynamic analysis of the 3D dam-reservoir-foundation interaction problem was performed by developing a nonlinear Finite Element program. The results of the analysis of Karun-4 Dam revealed the essential role of modeling discontinuities and boundary conditions of rock foundation under seismic excitation.

Research on the water resources regulation ability model of dams in the Huai He River Basin considering ecological and management factors

NASA Astrophysics Data System (ADS)

Shui, Y.; Liu, H. C.; Li, L. H.; Yu, G. G.; Liu, J.

2016-08-01

Research that assesses the scheduling ability of dams gamers a great deal of attention due to the global water resource crisis. These studies can provide useful and practical suggestions for scheduling the water resources of dams to solve problems, such as addressing ecological water needs and so on. Recent studies have primarily evaluated the schedule ability of dams according to their quantifiable attributes, such as water quantity, flow velocity, etc. However, the ecological and management status can directly determine the possibility and efficiency of a dam's water resource scheduling. This paper presents an evaluation model to assess the scheduling capacity of dams that takes into consideration ecological and management factors. In the experiment stage, this paper takes the Sha Ying river of the Huai He River Basin as an example to evaluate the scheduling ability of its dams. The results indicate that the proposed evaluation model can provide more precise and practical suggestions.

Compliance Monitoring of Juvenile Subyearling Chinook Salmon Survival and Passage at The Dalles Dam, Summer 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Carlson, Thomas J.; Skalski, John R.

2010-12-21

The purpose of this compliance study was to estimate dam passage survival of subyearling Chinook salmon smolts at The Dalles Dam during summer 2010. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.93 and estimated with a standard error (SE) less than or equal 0.015. The study also estimated smolt passage survival from the forebay 2 km upstream of the dam to the tailrace 2 km below the dam The forebay-to-tailrace survival estimate satisfies the “BRZ-to-BRZ” survival estimate called for in the Fish Accords. , asmore » well as the forebay residence time, tailrace egress time, and spill passage efficiency, as required in the Columbia Basin Fish Accords. The estimate of dam survival for subyearling Chinook salmon at The Dalles in 2010 was 0.9404 with an associated standard error of 0.0091.« less

Compliance of Saudi dental students with infection control guidelines.

PubMed

Ahmad, Ibrahim Ali; Rehan, Elaf Ali; Pani, Sharat Chandra

2013-08-01

The aim of this study was to investigate compliance of dental students in a Saudi dental school with recommended infection control protocols. A pilot-tested questionnaire concerning various aspects of infection control practices was distributed to 330 dental students. The response rate was 93.9% (n = 311). About 99% of students recorded the medical history of their patients and 80% were vaccinated against hepatitis B. The highest compliance (100%) with recommended guidelines was reported for wearing gloves and use of a new saliva ejector for each patient. Over 90% of the respondents changed gloves between patients, wore face masks, changed hand instruments, burs and handpieces between patients, used a rubber dam in restorative procedures and discarded sharp objects in special containers. A lower usage rate was reported for changing face masks between patients (81%), disinfecting impression materials (87%) and dental prosthesis (74%) and wearing gowns (57%). Eye glasses and face shield were used by less than one-third of the sample. The majority of students were found to be in compliance with most of the investigated infection control measures. Nevertheless, further education is needed to improve some infection control measures including vaccination for Hepatitis B virus (HBV), wearing eye glasses, gowns and face shields and disinfecting impression materials and dental prostheses. © 2013 FDI World Dental Federation.

Alteration of stream temperature by natural and artificial beaver dams.

PubMed

Weber, Nicholas; Bouwes, Nicolaas; Pollock, Michael M; Volk, Carol; Wheaton, Joseph M; Wathen, Gus; Wirtz, Jacob; Jordan, Chris E

2017-01-01

Beaver are an integral component of hydrologic, geomorphic, and biotic processes within North American stream systems, and their propensity to build dams alters stream and riparian structure and function to the benefit of many aquatic and terrestrial species. Recognizing this, beaver relocation efforts and/or application of structures designed to mimic the function of beaver dams are increasingly being utilized as effective and cost-efficient stream and riparian restoration approaches. Despite these verities, the notion that beaver dams negatively impact stream habitat remains common, specifically the assumption that beaver dams increase stream temperatures during summer to the detriment of sensitive biota such as salmonids. In this study, we tracked beaver dam distributions and monitored water temperature throughout 34 km of stream for an eight-year period between 2007 and 2014. During this time the number of natural beaver dams within the study area increased by an order of magnitude, and an additional 4 km of stream were subject to a restoration manipulation that included installing a high-density of Beaver Dam Analog (BDA) structures designed to mimic the function of natural beaver dams. Our observations reveal several mechanisms by which beaver dam development may influence stream temperature regimes; including longitudinal buffering of diel summer temperature extrema at the reach scale due to increased surface water storage, and creation of cool-water channel scale temperature refugia through enhanced groundwater-surface water connectivity. Our results suggest that creation of natural and/or artificial beaver dams could be used to mitigate the impact of human induced thermal degradation that may threaten sensitive species.

Alteration of stream temperature by natural and artificial beaver dams

PubMed Central

Bouwes, Nicolaas; Pollock, Michael M.; Volk, Carol; Wheaton, Joseph M.; Wathen, Gus; Wirtz, Jacob; Jordan, Chris E.

2017-01-01

Beaver are an integral component of hydrologic, geomorphic, and biotic processes within North American stream systems, and their propensity to build dams alters stream and riparian structure and function to the benefit of many aquatic and terrestrial species. Recognizing this, beaver relocation efforts and/or application of structures designed to mimic the function of beaver dams are increasingly being utilized as effective and cost-efficient stream and riparian restoration approaches. Despite these verities, the notion that beaver dams negatively impact stream habitat remains common, specifically the assumption that beaver dams increase stream temperatures during summer to the detriment of sensitive biota such as salmonids. In this study, we tracked beaver dam distributions and monitored water temperature throughout 34 km of stream for an eight-year period between 2007 and 2014. During this time the number of natural beaver dams within the study area increased by an order of magnitude, and an additional 4 km of stream were subject to a restoration manipulation that included installing a high-density of Beaver Dam Analog (BDA) structures designed to mimic the function of natural beaver dams. Our observations reveal several mechanisms by which beaver dam development may influence stream temperature regimes; including longitudinal buffering of diel summer temperature extrema at the reach scale due to increased surface water storage, and creation of cool—water channel scale temperature refugia through enhanced groundwater—surface water connectivity. Our results suggest that creation of natural and/or artificial beaver dams could be used to mitigate the impact of human induced thermal degradation that may threaten sensitive species. PMID:28520714

Toward improved design of check dam systems: A case study in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Pal, Debasish; Galelli, Stefano; Tang, Honglei; Ran, Qihua

2018-04-01

Check dams are one of the most common strategies for controlling sediment transport in erosion prone areas, along with soil and water conservation measures. However, existing mathematical models that simulate sediment production and delivery are often unable to simulate how the storage capacity of check dams varies with time. To explicitly account for this process-and to support the design of check dam systems-we developed a modelling framework consisting of two components, namely (1) the spatially distributed Soil Erosion and Sediment Delivery Model (WaTEM/SEDEM), and (2) a network-based model of check dam storage dynamics. The two models are run sequentially, with the second model receiving the initial sediment input to check dams from WaTEM/SEDEM. The framework is first applied to Shejiagou catchment, a 4.26 km2 area located in the Loess Plateau, China, where we study the effect of the existing check dam system on sediment dynamics. Results show that the deployment of check dams altered significantly the sediment delivery ratio of the catchment. Furthermore, the network-based model reveals a large variability in the life expectancy of check dams and abrupt changes in their filling rates. The application of the framework to six alternative check dam deployment scenarios is then used to illustrate its usefulness for planning purposes, and to derive some insights on the effect of key decision variables, such as the number, size, and site location of check dams. Simulation results suggest that better performance-in terms of life expectancy and sediment delivery ratio-could have been achieved with an alternative deployment strategy.

Particle-bound metal transport after removal of a small dam in ...

EPA Pesticide Factsheets

The Pawtuxet River in Rhode Island, USA, has a long history of industrial activity and pollutant discharges. Metal contamination of the river sediments is well documented and historically exceeded toxicity thresholds for a variety of organisms. The Pawtuxet River dam, a low-head dam at the mouth of the river, was removed in August 2011. The removal of the dam was part of an effort to restore the riverine ecosystem after centuries of anthropogenic impact. Sediment traps were deployed below the dam to assess changes in metal concentrations and fluxes (Ag, Cd, Cr, Cu, Ni, Pb, and Zn) from the river system into Pawtuxet Cove. Sediment traps were deployed for an average duration of 24 days each, and deployments continued for 15 months after the dam was removed. Metal concentrations in the trapped suspended particulate matter dropped after dam removal (e.g., 460 to 276 mg/kg for Zn) and remained below preremoval levels for most of the study. However, particle-bound metal fluxes increased immediately after dam removal (e.g., 1206 to 4248 g/day for Zn). Changes in flux rates during the study period indicated that river volumetric flow rates acted as the primary mechanism controlling the flux of metals into Pawtuxet Cove and ultimately upper Narragansett Bay. Even though suspended particulate matter metal concentrations initially dropped after removal of the dam, no discernable effect on the concentration or flux of the study metals exiting the river could be associa

Cycloplegic refraction is the gold standard for epidemiological studies.

PubMed

Morgan, Ian G; Iribarren, Rafael; Fotouhi, Akbar; Grzybowski, Andrzej

2015-09-01

Many studies on children have shown that lack of cycloplegia is associated with slight overestimation of myopia and marked errors in estimates of the prevalence of emmetropia and hyperopia. Non-cycloplegic refraction is particularly problematic for studies of associations with risk factors. The consensus around the importance of cycloplegia in children left undefined at what age, if any, cycloplegia became unnecessary. It was often implicitly assumed that cycloplegia is not necessary beyond childhood or early adulthood, and thus, the protocol for the classical studies of refraction in older adults did not include cycloplegia. Now that population studies of refractive error are beginning to fill the gap between schoolchildren and older adults, whether cycloplegia is required for measuring refractive error in this age range, needs to be defined. Data from the Tehran Eye Study show that, without cycloplegia, there are errors in the estimation of myopia, emmetropia and hyperopia in the age range 20-50, just as in children. Similar results have been reported in an analysis of data from the Beaver Dam Offspring Eye Study. If the only important outcome measure of a particular study is the prevalence of myopia, then cycloplegia may not be crucial in some cases. But, without cycloplegia, measurements of other refractive categories as well as spherical equivalent are unreliable. In summary, the current evidence suggests that cycloplegic refraction should be considered as the gold standard for epidemiological studies of refraction, not only in children, but in adults up to the age of 50. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

78 FR 49735 - Intent To Prepare a Draft Environmental Impact Statement for Dam Safety Study, Lake Lewisville...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-15

... determine appropriate permanent methods for correcting potential problems, interim risk reduction measures... Environmental Impact Statement for Dam Safety Study, Lake Lewisville Dam, Elm Fork Trinity River, Denton County... primary purposes of the project are flood risk management, [[Page 49736

Plugs or flood-makers? The unstable landslide dams of eastern Oregon

NASA Astrophysics Data System (ADS)

Safran, E. B.; O'Connor, J. E.; Ely, L. L.; House, P. K.; Grant, G.; Harrity, K.; Croall, K.; Jones, E.

2015-11-01

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4-33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40-70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide data sets successfully separate dam sites in eastern Oregon that failed catastrophically from those that did not. Accumulated sediments upstream of about 50% of the dam sites indicate at least short-term persistence of landslide dams prior to eventual failure. Nevertheless, only three landslide dam remnants and one extant dam significantly elevate the modern river profile. We conclude that eastern Oregon's landslide dams are indeed floodmakers, but we lack clear evidence that they form lasting plugs.

Plugs or flood-makers? the unstable landslide dams of eastern Oregon

USGS Publications Warehouse

Safran, Elizabeth B.; O'Connor, Jim E.; Ely, Lisa L.; House, P. Kyle; Grant, Gordon E.; Harrity, Kelsey; Croall, Kelsey; Jones, Emily

2015-01-01

Landslides into valley bottoms can affect longitudinal profiles of rivers, thereby influencing landscape evolution through base-level changes. Large landslides can hinder river incision by temporarily damming rivers, but catastrophic failure of landslide dams may generate large floods that could promote incision. Dam stability therefore strongly modulates the effects of landslide dams and might be expected to vary among geologic settings. Here, we investigate the morphometry, stability, and effects on adjacent channel profiles of 17 former and current landslide dams in eastern Oregon. Data on landslide dam dimensions, former impoundment size, and longitudinal profile form were obtained from digital elevation data constrained by field observations and aerial imagery; while evidence for catastrophic dam breaching was assessed in the field. The dry, primarily extensional terrain of low-gradient volcanic tablelands and basins contrasts with the tectonically active, mountainous landscapes more commonly associated with large landslides. All but one of the eastern Oregon landslide dams are ancient (likely of order 103 to 104 years old), and all but one has been breached. The portions of the Oregon landslide dams blocking channels are small relative to the area of their source landslide complexes (0.4–33.6 km2). The multipronged landslides in eastern Oregon produce marginally smaller volume dams but affect much larger channels and impound more water than do landslide dams in mountainous settings. As a result, at least 14 of the 17 (82%) large landslide dams in our study area appear to have failed cataclysmically, producing large downstream floods now marked by boulder outwash, compared to a 40–70% failure rate for landslide dams in steep mountain environments. Morphometric indices of landslide dam stability calibrated in other environments were applied to the Oregon dams. Threshold values of the Blockage and Dimensionless Blockage Indices calibrated to worldwide data sets successfully separate dam sites in eastern Oregon that failed catastrophically from those that did not. Accumulated sediments upstream of about 50% of the dam sites indicate at least short-term persistence of landslide dams prior to eventual failure. Nevertheless, only three landslide dam remnants and one extant dam significantly elevate the modern river profile. We conclude that eastern Oregon's landslide dams are indeed floodmakers, but we lack clear evidence that they form lasting plugs.

Two-generation reproductive toxicity study of tributyltin chloride in female rats.

PubMed

Ogata, R; Omura, M; Shimasaki, Y; Kubo, K; Oshima, Y; Aou, S; Inoue, N

2001-05-25

A two-generation reproductive toxicity study of the effects of tributyltin chloride (TBTCl) was conducted in female rats using dietary concentrations of 5, 25, and 125 ppm TBTCl. Reproductive outcomes of dams (number and body weight of pups and the percentage of live pups) and the growth of female pups (the day of eye opening and body weight gain) were significantly decreased in the 125 ppm TBTCl group. A delay in vaginal opening and impaired estrous cyclicity were also observed in the 125 ppm TBTCl group. However, an increase in anogenital distance was found in all TBTCl groups on postnatal d 1. A dose-effect relationship was observed in TBTCl-induced changes in anogenital distance. These results indicate that the whole-life exposure to TBTCl affects the sexual development and reproductive function of female rats. In addition, the TBTCl-induced increase in anogenital distance seems to suggest it may exert a masculinizing effect on female neonates. However, the concentrations of TBTCl used in this study are not environmentally relevant.

Soil erosion and sediment yield, a double barrel problem in South Africa's only large river network without a dam

NASA Astrophysics Data System (ADS)

Le Roux, Jay

2016-04-01

Soil erosion not only involves the loss of fertile topsoil but is also coupled with sedimentation of dams, a double barrel problem in semi-arid regions where water scarcity is frequent. Due to increasing water requirements in South Africa, the Department of Water and Sanitation is planning water resource development in the Mzimvubu River Catchment, which is the only large river network in the country without a dam. Two dams are planned including a large irrigation dam and a hydropower dam. However, previous soil erosion studies indicate that large parts of the catchment is severely eroded. Previous studies, nonetheless, used mapping and modelling techniques that represent only a selection of erosion processes and provide insufficient information about the sediment yield. This study maps and models the sediment yield comprehensively by means of two approaches over a five-year timeframe between 2007 and 2012. Sediment yield contribution from sheet-rill erosion was modelled with ArcSWAT (a graphical user interface for SWAT in a GIS), whereas gully erosion contributions were estimated using time-series mapping with SPOT 5 imagery followed by gully-derived sediment yield modelling in a GIS. Integration of the sheet-rill and gully results produced a total sediment yield map, with an average of 5 300 t km-2 y-1. Importantly, the annual average sediment yield of the areas where the irrigation dam and hydropower dam will be built is around 20 000 t km-2 y-1. Without catchment rehabilitation, the life expectancy of the irrigation dam and hydropower dam could be 50 and 40 years respectively.

The remains of the dam: what have we learned from 15 years of US dam removals?

Treesearch

Gordon E. Grant; Sarah L. Lewis

2015-01-01

Important goals for studying dam removal are to learn how rivers respond to large and rapid introductions of sediment, and to develop predictive models to guide future dam removals. Achieving these goals requires organizing case histories systematically so that underlying physical mechanisms determining rates and styles of sediment erosion, transport, and deposition...

Route-Specific Passage Proportions and Survival Rates for Fish Passing through John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ploskey, Gene R.; Weiland, Mark A.; Carlson, Thomas J.

This report fulfills a request of the U.S. Army Engineer District, Portland, Oregon, to produce an interim report of estimates of route-specific fish passage proportions and survival rates for lower Columbia River dams in 2010 and 2011. The estimates are needed to update the Compass Model for the Columbia River Treaty and the new Biological Opinion before detail technical reports are published in late 2012. This report tabulates route-specific fish-passage proportions and survival rates for steelhead and Chinook salmon smolts passing through various sampled routes at John Day Dam, The Dalles Dam, and Bonneville Dam in 2010 and 2011. Resultsmore » were compiled from analyses of data acquired in spring 2010 and 2011 studies that were specifically designed to estimate dam-passage and forebay-to-tailrace survival rates, travel time metrics, and spill passage efficiency, as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the Columbia Basin Fish Accords. The study designs allowed for estimation of route-specific fish passage proportions and survival rates as well as estimation of forebay-passage survival, all of which are summarized herein.« less

Evidence-based dentistry: analysis of dental anxiety scales for children.

PubMed

Al-Namankany, A; de Souza, M; Ashley, P

2012-03-09

To review paediatric dental anxiety measures (DAMs) and assess the statistical methods used for validation and their clinical implications. A search of four computerised databases between 1960 and January 2011 associated with DAMs, using pre-specified search terms, to assess the method of validation including the reliability as intra-observer agreement 'repeatability or stability' and inter-observer agreement 'reproducibility' and all types of validity. Fourteen paediatric DAMs were predominantly validated in schools and not in the clinical setting while five of the DAMs were not validated at all. The DAMs that were validated were done so against other paediatric DAMs which may not have been validated previously. Reliability was not assessed in four of the DAMs. However, all of the validated studies assessed reliability which was usually 'good' or 'acceptable'. None of the current DAMs used a formal sample size technique. Diversity was seen between the studies ranging from a few simple pictograms to lists of questions reported by either the individual or an observer. To date there is no scale that can be considered as a gold standard, and there is a need to further develop an anxiety scale with a cognitive component for children and adolescents.

Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at Bonneville Dam, Spring 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ploskey, Gene R.; Faber, Derrek M.; Weiland, Mark A.

2011-02-01

The purpose of this study was to estimate the survival for yearling Chinook salmon and steelhead smolts during spring 2010 in a portion of the Columbia River that includes Bonneville Dam. The study estimated smolt survival from a virtual release at Bonneville Dam to a survival array 81 km downstream of Bonneville Dam. We also estimated median forebay residence time, median tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fish Accords. A single release design was used to estimate survival from Bonneville Dam to a primary array located 81 km downstream of Bonneville. Themore » approach did not include a reference tailrace release. Releases of acoustic-tagged smolts above John Day Dam to Hood River contributed to the formation of virtual releases at a Bonneville Dam forebay entrance array and at the face of the dam. A total of 3,880 yearling Chinook salmon and 3,885 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation.« less

Quantitative and Qualitative Geospatial Analysis of a Probable Catastrophic Dam Failure

NASA Astrophysics Data System (ADS)

Oduor, P. G.; Stenehjem, J.

2011-12-01

Geospatial techniques were used in assessing inundation extents that would occur in the event of a catastrophic failure of Fort Peck dam. Fort Peck dam, located in Montana, USA has a spillway design which under dam failure the crest is expected to reach Williston a major economic hub in North Dakota in 1.4 days with a peak elevation of 1891 ft (576.377 m) msl (mean sea level). In this study, we address flooding extents and impacts on establishments with respect to a peak elevation of 1891 ft. From this study, we can unequivocally state that the City of Williston will be significantly impacted if Fort Peck dam fails with almost all critical needs, for example, gasoline stations, emergency facilities and grocery stores completely inundated. A secondary catastrophic event may be tied to the primary economic activity in Williston, that is, oil rigs of which most lie on the pathway of an inadvertent flood crest. We also applied a Discrete Fourier Transformation (DFT), and Lomb-Scargle normalized periodogram analyses and fitting of Fort Peck dam reservoir level fluctuations to gauge (a) likelihood of the dam overtopping, and (b) anatomic life span. Whereas we found that inasmuch as the dam could be considered stable by directly analyzing other dams that have failed, there is still a lower likelihood of it to fail at a 99-232 years range from construction. There was lack of concomitancy between overtopping and dam failure rates.

Hydrologic data on channel adjustments, 1970 to 1975, on the Rio Grande downstream from Cochiti Dam, New Mexico before and after closure

USGS Publications Warehouse

Dewey, Jack D.; Roybal, F.E.; Funderburg, D.E.

1979-01-01

Cross-section channel profiles, sediment transport and hydrologic data have been observed and computed for a series of pre-dam and post-dam investigations from 1970 to 1975 at 37 cross sections established along a 59-mile study reach from Cochiti Dam to Isleta Diversion Dam, New Mexico. Cochiti Dam began impounding water in November 1973. Because the dam will trap virtually all of the sediment load originating upstream and water discharge will be controlled, it is expected that equilibrium values of channel width, depth, slope and sediment-transport capability in the existing main stem of the Rio Grande will change. Changes in cross sections with time and space and changes in size distribution of sediments are documented. (Woodard-USGS).

Approach, passage, and survival of juvenile salmonids at Little Goose Dam, Washington: Post-construction evaluation of a temporary spillway weir, 2009

USGS Publications Warehouse

Beeman, J.W.; Braatz, A.C.; Hansel, H.C.; Fielding, S.D.; Haner, P.V.; Hansen, G.S.; Shurtleff, D.J.; Sprando, J.M.; Rondorf, D.W.

2010-01-01

This report describes a study of dam passage and survival of radio-tagged juvenile salmonids after installation of a temporary spillway weir (TSW) at Little Goose Dam, Washington, in 2009. The purpose of the study was to document fish passage and survival when the dam was operated with the TSW in place. Spillway weirs are one of several methods used to improve downstream passage of juvenile salmonids. Each spillway weir design is based on the concept of providing an overflow weir with a depth more similar to the natural migration depth of juvenile salmonids than conventional spill bays. Little Goose Dam was the last of the four lower Snake River dams to have a spillway weir installed. This was the first year that some form of surface passage device was operating at all Snake River and Columbia River dams between Lewiston, Idaho, and the Columbia River estuary. The study design stipulated that a total of 30 percent of the river discharge would continuously be passed over the TSW and the conventional spill bays, and this percentage was achieved. The TSW also was to be operated at the 'low crest' elevation during the spring and the 'high crest' elevation during the summer, but the TSW was only operated at the low crest elevation during this study. Behavior, passage, and survival of spring and summer juvenile salmonid migrants passing through Little Goose Dam were examined using radio telemetry. Survival was estimated using the Route Specific Survival Model (RSSM) by releasing tagged fish near Central Ferry State Park 21 kilometers upstream of the dam and in the tailrace approximately 0.5 kilometer downstream of the dam. From April 18 to May 21, 2009, 1,520 yearling Chinook salmon (Oncorhynchus tshawytscha) and 1,517 juvenile steelhead (O. mykiss) were radio tagged and released. From June 6 to July 5, 2009, 4,251 subyearling Chinook salmon (O. tshawytscha) were radio tagged and released. Release dates of subyearling Chinook salmon were selected to avoid 'reservoir-type' fish that cease to migrate around July. Detection sites were installed in the forebay 2 kilometers upstream of the dam, on the dam, and at several sites downstream. Detection equipment was operated from April 18 to June 5, 2009, and from June 6 to July 6, 2009, hereinafter referred to as the study periods. We describe passage behaviors through the forebay, main passage routes, and tailrace, survival probabilities through the pool (release to the forebay) and forebay and passage and survival probabilities through the main passage routes (TSW, conventional spill bays, turbines, juvenile bypass), and survival passing the concrete (the dam itself) and the dam (concrete plus the forebay).

Monitoring of Juvenile Subyearling Chinook Salmon Survival and Passage at John Day Dam, Summer 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.

The purpose of this study was to evaluate dam passage survival of subyearling Chinook salmon (Oncorhynchus tshawytscha; CH0) at John Day Dam (JDA) during summer 2010. This study was conducted by researchers from the Pacific Northwest National Laboratory (PNNL) in collaboration with the Pacific States Marine Fisheries Commission (PSMFC) and the University of Washington (UW). The study was designed to estimate the effects of 30% and 40% spill treatment levels on single release survival rates of CH0 passing through two reaches: (1) the dam, and 40 km of tailwater, (2) the forebay, dam, and 40 km of tailwater. The studymore » also estimated additional passage performance measures which are stipulated in the Columbia Basin Fish Accords.« less

Potential effects of ongoing and proposed hydropower development on terrestrial biological diversity in the Indian Himalaya.

PubMed

Pandit, Maharaj K; Grumbine, R Edward

2012-12-01

Indian Himalayan basins are earmarked for widespread dam building, but aggregate effects of these dams on terrestrial ecosystems are unknown. We mapped distribution of 292 dams (under construction and proposed) and projected effects of these dams on terrestrial ecosystems under different scenarios of land-cover loss. We analyzed land-cover data of the Himalayan valleys, where dams are located. We estimated dam density on fifth- through seventh-order rivers and compared these estimates with current global figures. We used a species-area relation model (SAR) to predict short- and long-term species extinctions driven by deforestation. We used scatter plots and correlation studies to analyze distribution patterns of species and dams and to reveal potential overlap between species-rich areas and dam sites. We investigated effects of disturbance on community structure of undisturbed forests. Nearly 90% of Indian Himalayan valleys would be affected by dam building and 27% of these dams would affect dense forests. Our model projected that 54,117 ha of forests would be submerged and 114,361 ha would be damaged by dam-related activities. A dam density of 0.3247/1000 km(2) would be nearly 62 times greater than current average global figures; the average of 1 dam for every 32 km of river channel would be 1.5 times higher than figures reported for U.S. rivers. Our results show that most dams would be located in species-rich areas of the Himalaya. The SAR model projected that by 2025, deforestation due to dam building would likely result in extinction of 22 angiosperm and 7 vertebrate taxa. Disturbance due to dam building would likely reduce tree species richness by 35%, tree density by 42%, and tree basal cover by 30% in dense forests. These results, combined with relatively weak national environmental impact assessment and implementation, point toward significant loss of species if all proposed dams in the Indian Himalaya are constructed. ©2012 Society for Conservation Biology.

The blind men meet the elephant at the dam: Alternative spatial and taxonomic components reveal different insights about how low-head dams impact fish biodiversity

USGS Publications Warehouse

Fencl, Jane S.; Mather, Martha E.; Smith, Joseph M.; Hitchman, Sean M.

2017-01-01

Dams are ubiquitous environmental impacts that threaten aquatic ecosystems. The ability to compare across research studies is essential to conserve the native biodiversity that is impacted by the millions of low‐head dams that currently fragment streams and rivers. Here, we identify a previously unaddressed obstacle that impedes this generalization. Specifically, divergent spatial and taxonomic approaches that result from different conceptualizations of the dam‐biodiversity problem can produce conflicting science‐based conclusions about the same dam impact. In this research, using the same dammed and undammed sites, we evaluated the scientific generality of different conceptualizations of the dam‐biodiversity problem. We compared two different but commonly used spatial approaches—(1) above dam–below dam vs. (2) undammed–dammed comparisons—and 11 different, commonly used taxonomic approaches (three assemblage summaries, eight guilds). Sites above the dam structure had less diverse fish assemblages than sites below dams, whereas sites below the dam structure were similar to undammed sites. Thus, spatial approach 1 detected a large dam effect and spatial approach 2 detected a small dam effect. Similarly, some taxonomic responses (species richness, diversity, abundance, and number of guilds) detected large dam effects; other responses detected small (riffle specialist guild) or no dam effects (pool generalists). In summary, our results showed that how the problem was framed altered scientific conclusions and created different dam realities. The metaphor of how individual blind men disagree about the structure of an elephant, based on examinations of different body parts, reinforces the need for a coordinated, holistic perspective on dam research. Although no single approach is adequate for all problems, identifying the form, consequences of, and relationships among different research conceptualizations will set the stage for future syntheses of dam‐biodiversity research to advance science‐based conservation.

Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River

USGS Publications Warehouse

Skalak, Katherine; Benthem, Adam J.; Schenk, Edward R.; Hupp, Cliff R.; Galloway, Joel M.; Nustad, Rochelle A.; Wiche, Gregg J.

2013-01-01

The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries, and habitat. Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Though the effects of dams and reservoirs are well-documented, their impacts have been studied individually, with relatively little attention paid to their interaction along a river corridor. We examine the morphological and sedimentological changes in the Upper Missouri River between the Garrison Dam in ND (operational in 1953) and Oahe Dam in SD (operational in 1959). Through historical aerial photography, stream gage data, and cross sectional surveys, we demonstrate that the influence of the upstream dam is still a major control of river dynamics when the backwater effects of the downstream reservoir begin. In the “Anthropocene”, dams are ubiquitous on large rivers and often occur in series, similar to the Garrison Dam Segment. We propose a conceptual model of how interacting dams might affect river geomorphology, resulting in distinct and recognizable morphologic sequences that we term “Inter-Dam sequence” characteristic of major rivers in the US.

Geophysical Investigations at Hidden Dam, Raymond, California Flow Simulations

USGS Publications Warehouse

Minsley, Burke J.; Ikard, Scott

2010-01-01

Numerical flow modeling and analysis of observation-well data at Hidden Dam are carried out to supplement recent geophysical field investigations at the site (Minsley and others, 2010). This work also is complementary to earlier seepage-related studies at Hidden Dam documented by Cedergren (1980a, b). Known seepage areas on the northwest right abutment area of the downstream side of the dam was documented by Cedergren (1980a, b). Subsequent to the 1980 seepage study, a drainage blanket with a sub-drain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren (1980a, b) suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain in the downstream portion of the dam. The current modeling study is aimed at quantifying how variability in dam and foundation hydrologic properties influences seepage as a function of reservoir stage. Flow modeling is implemented using the COMSOL Multiphysics software package, which solves the partially saturated flow equations in a two-dimensional (2D) cross-section of Hidden Dam that also incorporates true downstream topography. Use of the COMSOL software package provides a more quantitative approach than the flow net analysis by Cedergren (1980a, b), and allows for rapid evaluation of the influence of various parameters such as reservoir level, dam structure and geometry, and hydrogeologic properties of the dam and foundation materials. Historical observation-well data are used to help validate the flow simulations by comparing observed and predicted water levels for a range of reservoir elevations. The flow models are guided by, and discussed in the context of, the geophysical work (Minsley and others, 2010) where appropriate.

Earthshots: Satellite images of environmental change – Lake Turkana, Kenya and Ethiopia

USGS Publications Warehouse

,

2013-01-01

Ethiopia is constructing a series of dams on the Omo River. The Gibe I and Gibe II dams are completed, and the Gibe III dam began filling its reservoir in 2015. Studies are ongoing to understand the interactions between regulated flows as a result of the dams and rainfall on the water levels of Lake Turkana. Scientists use many years’ worth of data to get a better understanding of the lake’s natural variability and how that variability might be affected by dams, irrigation, and rainfall.

Classification of the alterations of beaver dams to headwater streams in northeastern Connecticut, U.S.A.

NASA Astrophysics Data System (ADS)

Burchsted, Denise; Daniels, Melinda D.

2014-01-01

Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the impact of beaver dams at larger scales, this study examines channel shape and sediment distribution in thirty river reaches in northeastern Connecticut, U.S.A. The study reaches fall within the broader categories of impounded and free-flowing segments, leaving a third segment class of beaver meadows requiring additional study. Each of the study reaches were classified at the reach scale as free-flowing, valley-wide beaver pond, in-channel beaver pond, and downstream of beaver dam. The bankfull channel width to depth ratios and channel widths normalized by watershed area vary significantly across the study reach classes. Additionally, reaches modified by beaver dams have finer sediment distributions. This paper provides the first quantitative geomorphic descriptions of the in-channel beaver pond and reaches downstream of beaver dams. Given the different channel shapes and sediment distributions, we infer that geomorphic processes are longitudinally decoupled by these frequent barriers that control local base level. These barriers generate heterogeneity within a river network by greatly increasing the range of channel morphology and by generating patches controlled by different processes. Therefore, in spite of the small size of individual beaver dams, the cumulative effect of multiple dams has the potential to modify processes at larger spatial scales. To improve assessment of the larger-scale impacts, we propose a hierarchical classification scheme based on discontinuities, place the reach classes of this study within that scheme, and suggest that further research should continue investigation of discontinuity at the network scale and quantification of the cumulative impacts.

Effects of disturbed liver growth and oxidative stress of high-fat diet-fed dams on cholesterol metabolism in offspring mice.

PubMed

Kim, Juyoung; Kim, Juhae; Kwon, Young Hye

2016-08-01

Changes in nutritional status during gestation and lactation have detrimental effects on offspring metabolism. Several animal studies have shown that maternal high-fat diet (HFD) can predispose the offspring to development of obesity and metabolic diseases, however the mechanisms underlying these transgenerational effects are poorly understood. Therefore, we examined the effect of maternal HFD consumption on metabolic phenotype and hepatic expression of involved genes in dams to determine whether any of these parameters were associated with the metabolic outcomes in the offspring. Female C57BL/6 mice were fed a low-fat diet (LFD: 10% calories from fat) or a high-fat diet (HFD: 45% calories from fat) for three weeks before mating, and during pregnancy and lactation. Dams and their male offspring were studied at weaning. Dams fed an HFD had significantly higher body and adipose tissue weights and higher serum triglyceride and cholesterol levels than dams fed an LFD. Hepatic lipid levels and mRNA levels of genes involved in lipid metabolism, including LXRα, SREBP-2, FXR, LDLR, and ABCG8 were significantly changed by maternal HFD intake. Significantly lower total liver DNA and protein contents were observed in dams fed an HFD, implicating the disturbed liver adaptation in the pregnancy-related metabolic demand. HFD feeding also induced significant oxidative stress in serum and liver of dams. Offspring of dams fed an HFD had significantly higher serum cholesterol levels, which were negatively correlated with liver weights of dams and positively correlated with hepatic lipid peroxide levels in dams. Maternal HFD consumption induced metabolic dysfunction, including altered liver growth and oxidative stress in dams, which may contribute to the disturbed cholesterol homeostasis in the early life of male mice offspring.

Passage and survival probabilities of juvenile Chinook salmon at Cougar Dam, Oregon, 2012

USGS Publications Warehouse

Beeman, John W.; Evans, Scott D.; Haner, Philip V.; Hansel, Hal C.; Hansen, Amy C.; Smith, Collin D.; Sprando, Jamie M.

2014-01-01

This report describes studies of juvenile-salmon dam passage and apparent survival at Cougar Dam, Oregon, during two operating conditions in 2012. Cougar Dam is a 158-meter tall rock-fill dam used primarily for flood control, and passes water through a temperature control tower to either a powerhouse penstock or to a regulating outlet (RO). The temperature control tower has moveable weir gates to enable water of different elevations and temperatures to be drawn through the dam to control water temperatures downstream. A series of studies of downstream dam passage of juvenile salmonids were begun after the National Oceanic and Atmospheric Administration determined that Cougar Dam was impacting the viability of anadromous fish stocks. The primary objectives of the studies described in this report were to estimate the route-specific fish passage probabilities at the dam and to estimate the survival probabilities of fish passing through the RO. The first set of dam operating conditions, studied in November, consisted of (1) a mean reservoir elevation of 1,589 feet, (2) water entering the temperature control tower through the weir gates, (3) most water routed through the turbines during the day and through the RO during the night, and (4) mean RO gate openings of 1.2 feet during the day and 3.2 feet during the night. The second set of dam operating conditions, studied in December, consisted of (1) a mean reservoir elevation of 1,507 ft, (2) water entering the temperature control tower through the RO bypass, (3) all water passing through the RO, and (4) mean RO gate openings of 7.3 feet during the day and 7.5 feet during the night. The studies were based on juvenile Chinook salmon (Oncorhynchus tshawytscha) surgically implanted with radio transmitters and passive integrated transponder (PIT) tags. Inferences about general dam passage percentage and timing of volitional migrants were based on surface-acclimated fish released in the reservoir. Dam passage and apparent survival probabilities were estimated using the Route-Specific-Survival Model with data from surface-acclimated fish released near the water surface directly upstream of the temperature control tower (treatment group) and slightly downstream of the dam (control group). In this study, apparent survival is the joint probability of surviving and migrating through the study area during the life of the transmitters. Two rearing groups were used to enable sufficient sample sizes for the studies. The groups differed in feed type, and for the December study only, the rearing location. Fish from each group were divided nearly equally among all combinations of release sites, release times, and surgeons. The sizes, travel times, and survivals of the two rearing groups were similar. There were statistical differences in fish lengths and travel times of the two groups, but they were small and likely were not biologically meaningful. There also was evidence of a difference in single-release estimates of survival between the rearing groups during the December study, but the differences had little effect on the relative survival estimates so the analyses of passage and survival were based on data from the rearing groups pooled. Conditions during the December study were more conducive to passing volitionally migrating fish than conditions during the November study. The passage percentage of the fish released in the reservoir was similar between studies (about 70 percent), but the passage occurred in a median of 1.0 day during the December study and a median of 9.3 days during the November study. More than 93 percent of the dam passage of volitionally migrating fish occurred at night during each study. This finding corroborates results of previous studies at Cougar Dam and suggests that the operating conditions at night are most important to volitionally migrating fish, given the current configuration of the dam. Most fish released near the temperature control tower passed through the RO. A total of 92.2 percent of the treatment group passed through the RO during the November study and the RO was the only route open during the December study. The assumptions of the survival model were either met or adjusted for during each study. There was little evidence that tagger skill or premature failure of radio transmitters had an effect on survival estimates. There were statistically significant differences in travel times between treatment and control groups through several of the river reaches they had in common, but the differences were typically only a few hours, and the two groups likely experienced the same in-river conditions. There was direct evidence of bias due to detection of euthanized fish with live transmitters released as part of the study design. The bias was ameliorated by adjusting the survival estimates for the probability of detecting dead fish with live transmitters, which reduced the estimated survival probabilities by about 0.02. The data and models indicated that the treatment effect was not fully expressed until the study reach terminating with Marshall Island Park on the Willamette River, a distance of 105.8 kilometers downstream of Cougar Dam. This was the first reach in which the 95-percent confidence interval of the estimated reach-specific relative survival overlapped 1.0, indicating similar survival of treatment and control groups. The median travel time of the treatment group from release to Marshall Island Park was 1.64 days during the November study and 1.36 days during the December study. The survival probability of fish that passed into the RO was greater during the December study than during the November study. The relative survival probability of fish passing through the RO was 0.4594 (standard error [SE] 0.0543) during the November study and 0.7389 (SE 0.1160) during the December study. These estimates represent relative survival probabilities from release near Cougar Dam to the Marshall Island site. The estimated survival probability of RO passage was lower than previous studies based on balloon and PIT tags, but higher than a similar study based on radio transmitters. We suggest that, apart from dam operations, the differences in survival primarily are due to the release location. We hypothesize that the balloon- and PIT-tagged fish released through a hose at a point near the RO gate opening experienced more benign conditions than the radio-tagged fish passing the RO volitionally. This hypothesis could be tested with further study. An alternative hypothesis is that some live fish remained within the study area beyond the life of their radio transmitter. The results from these and previous studies indicate that entrainment and survival of juvenile salmonids passing Cougar Dam varies with dam operating conditions. The condition most conducive to dam passage has been the discharge and low pool elevation condition tested during December 2012. That condition included large RO gate openings and was the condition with the highest dam passage survival.

Monitoring Strategies of Earth Dams by Ground-Based Radar Interferometry: How to Extract Useful Information for Seismic Risk Assessment.

PubMed

Di Pasquale, Andrea; Nico, Giovanni; Pitullo, Alfredo; Prezioso, Giuseppina

2018-01-16

The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of earth dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of earth dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of earth dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of earth dams.

Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colotelo, Alison HA; Harnish, Ryan A.; Jones, Bryan W.

Steelhead (Oncorhynchus mykiss) populations have declined throughout their range in the last century and many populations, including those of the Snake River Basin are listed under the Endangered Species Act of 1973. The reasons for their decline are many and complex, but include habitat loss and degradation, overharvesting, and dam construction. The 2008 Biological Opinion calls for an increase in the abundance of female steelhead through an increase in iteroparity (i.e., repeat spawning) and this can be realized through a combination of reconditioning and in-river survival of migrating kelts. The goal of this study is to provide the data necessarymore » to inform fisheries managers and dam operators of Snake River kelt migration patterns, survival, and routes of dam passage. Steelhead kelts (n = 487) were captured and implanted with acoustic transmitters and passive integrated transponder (PIT)-tags at the Lower Granite Dam (LGR) Juvenile Fish Facility and at weirs located in tributaries of the Snake and Clearwater rivers upstream of LGR. Kelts were monitored as they moved downstream through the Federal Columbia River Power System (FCRPS) by 15 autonomous and 3 cabled acoustic receiver arrays. Cabled receiver arrays deployed on the dam faces allowed for three-dimensional tracking of fish as they approached the dam face and were used to determine the route of dam passage. Overall, 27.3% of the kelts tagged in this study successfully migrated to Martin Bluff (rkm 126, as measured from the mouth of the Columbia River), which is located downstream of all FCRPS dams. Within individual river reaches, survival per kilometer estimates ranged from 0.958 to 0.999; the lowest estimates were observed in the immediate forebay of FCRPS dams. Steelhead kelts tagged in this study passed over the spillway routes (spillway weirs, traditional spill bays) in greater proportions and survived at higher rates compared to the few fish passed through powerhouse routes (turbines and juvenile bypass systems). The results of this study provide information about the route of passage and subsequent survival of steelhead kelts that migrated through the Snake and Columbia rivers from LGR to Bonneville Dam in 2013. These data may be used by fisheries managers and dam operators to identify potential ways to increase the survival of kelts during their seaward migrations.« less

Passage Distribution and Federal Columbia River Power System Survival for Steelhead Kelts Tagged Above and at Lower Granite Dam, Year 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colotelo, Alison H.A.; Harnish, Ryan A.; Jones, Bryan W.

2014-12-15

Steelhead (Oncorhynchus mykiss) populations have declined throughout their range in the last century and many populations, including those of the Snake River Basin are listed under the Endangered Species Act of 1973. The reasons for their decline are many and complex, but include habitat loss and degradation, overharvesting, and dam construction. The 2008 Biological Opinion calls for an increase in the abundance of female steelhead through an increase in iteroparity (i.e., repeat spawning) and this can be realized through a combination of reconditioning and in-river survival of migrating kelts. The goal of this study is to provide the data necessarymore » to inform fisheries managers and dam operators of Snake River kelt migration patterns, survival, and routes of dam passage. Steelhead kelts (n = 487) were captured and implanted with acoustic transmitters and passive integrated transponder (PIT)-tags at the Lower Granite Dam (LGR) Juvenile Fish Facility and at weirs located in tributaries of the Snake and Clearwater rivers upstream of LGR. Kelts were monitored as they moved downstream through the Federal Columbia River Power System (FCRPS) by 15 autonomous and 3 cabled acoustic receiver arrays. Cabled receiver arrays deployed on the dam faces allowed for three-dimensional tracking of fish as they approached the dam face and were used to determine the route of dam passage. Overall, 27.3% of the kelts tagged in this study successfully migrated to Martin Bluff (rkm 126, as measured from the mouth of the Columbia River), which is located downstream of all FCRPS dams. Within individual river reaches, survival per kilometer estimates ranged from 0.958 to 0.999; the lowest estimates were observed in the immediate forebay of FCRPS dams. Steelhead kelts tagged in this study passed over the spillway routes (spillway weirs, traditional spill bays) in greater proportions and survived at higher rates compared to the few fish passed through powerhouse routes (turbines and juvenile bypass systems). The results of this study provide information about the route of passage and subsequent survival of steelhead kelts that migrated through the Snake and Columbia rivers from LGR to Bonneville Dam in 2013. These data may be used by fisheries managers and dam operators to identify potential ways to increase the survival of kelts during their seaward migrations.« less

1000 dams down and counting

USGS Publications Warehouse

O'Connor, James E.; Duda, Jeff J.; Grant, Gordon E.

2015-01-01

Forty years ago, the demolition of large dams was mostly fiction, notably plotted in Edward Abbey's novel The Monkey Wrench Gang. Its 1975 publication roughly coincided with the end of large-dam construction in the United States. Since then, dams have been taken down in increasing numbers as they have filled with sediment, become unsafe or inefficient, or otherwise outlived their usefulness (1) (see the figure, panel A). Last year's removals of the 64-m-high Glines Canyon Dam and the 32-m-high Elwha Dam in northwestern Washington State were among the largest yet, releasing over 10 million cubic meters of stored sediment. Published studies conducted in conjunction with about 100 U.S. dam removals and at least 26 removals outside the United States are now providing detailed insights into how rivers respond (2, 3).

Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams)

PubMed Central

Othman, Faridah; Taghieh, Mahmood

2016-01-01

Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam’s location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands. PMID:27248152

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ploskey, Gene R.; Faber, Derrek M.; Weiland, Mark A.

The purpose of this study was to estimate the survival for yearling Chinook salmon and steelhead smolts during spring 2010 in a portion of the Columbia River that includes Bonneville Dam. The study estimated smolt survival from a virtual release at Bonneville Dam to a survival array 81 km downstream of Bonneville Dam. We also estimated median forebay residence time, median tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fish Accords. A single release design was used to estimate survival from Bonneville Dam to a primary array located 81 km downstream of Bonneville. Themore » approach did not include a reference tailrace release. Releases of acoustic-tagged smolts above John Day Dam to Hood River contributed to the formation of virtual releases at a Bonneville Dam forebay entrance array and at the face of the dam. A total of 3,880 yearling Chinook salmon and 3,885 steelhead smolts were tagged and released in the investigation. The Juvenile Salmon Acoustic Telemetry System (JSATS) tag model number ATS-156dB, weighing 0.438 g in air, was used in this investigation.« less

Interaction of Dams and Landslides--Case Studies and Mitigation

USGS Publications Warehouse

Schuster, Robert L.

2006-01-01

In the first half of the 20th century, engineering geology and geotechnical engineering were in their infancy, and dams were often built where landslides provided valley constrictions, often without expert site investigation. Only the most important projects were subjected to careful geologic examination. Thus, dams were often built without complete understanding of the possible geotechnical problems occurring in foundations or abutments. Most of these dams still exist, although many have undergone costly repairs because of stability or leakage problems. Today, however, every effort is made in the selection of damsites, including those sited on landslides, to provide foundations and abutments that are generally impervious and capable of withstanding the stresses imposed by the proposed dam and reservoir, and possible landslides. By means of a literature search, technical interviews, and field inventory, I have located 254 large (at least 10 m high) dams worldwide that directly interact with landslides; that is, they have been built on pre-existing landslides or have been subjected to landslide activity during or after construction. A table (Appendix table A) summarizes dam characteristics, landslide conditions, and remedial measures at each of the dams. Of the 254 dams, 164 are earthfill, 23 are rockfill, and 18 are earthfill-rockfill; these are flexible dam types that generally perform better on the possibly unstable foundations provided by landslides than do more rigid concrete dams. Any pre-existing landslides that might impinge on the foundation or abutments of a dam should be carefully investigated. If a landslide is recognized in a dam foundation or abutment, the landslide deposits commonly are avoided in siting the dam or are removed during stripping of the dam foundation and abutment contacts. Contrarily, it has often been found to be technically feasible and economically desirable to site and construct dams on known landslides or on the remnants of these features. In these cases, proven preventive and remedial measures have been used to ensure the stability of the foundations and abutments, and to reduce seepage to acceptable levels.

Toxicity assessment of sediments collected upstream and downstream from the White Dam in Clarke County, Georgia

USGS Publications Warehouse

Lasier, Peter J.

2018-06-06

The White Dam in Clarke County, Georgia, has been proposed for breaching. Efforts to determine potential risks to downstream biota included assessments of sediment collected in the vicinity of the dam. Sediments collected from sites upstream and downstream from the dam were evaluated for toxicity in 42-day exposures using the freshwater amphipod Hyalella azteca. Endpoints of the study were survival, growth, and reproduction of H. azteca. Results indicated no significant differences between the collected sediments and the water-only treatment used for comparison of the test endpoints. Therefore, based on the laboratory experiments in this study, sediment migration downstream from a breach of the Dam may not pose a toxicity risk to downstream biota.

Quantifying the extent of river fragmentation by hydropower dams in the Sarapiquí River Basin, Costa Rica

USGS Publications Warehouse

Anderson, Elizabeth P.; Pringle, Catherine M.; Freeman, Mary C.

2008-01-01

Costa Rica has recently experienced a rapid proliferation of dams for hydropower on rivers draining its northern Caribbean slope. In the Sarapiquí River Basin, eight hydropower plants were built between 1990 and 1999 and more projects are either under construction or proposed. The majority of these dams are small (<15 m tall) and operate as water diversion projects.While the potential environmental effects of individual projects are evaluated prior to dam construction, there is a need for consideration of the basin-scale ecological consequences of hydropower development. This study was a first attempt to quantify the extent of river fragmentation by dams in the Sarapiquí River Basin.Using simple spatial analyses, the length of river upstream from dams and the length of de-watered reaches downstream from dams was measured. Results indicated that there are currently 306.8 km of river (9.4% of the network) upstream from eight existing dams in the Sarapiquí River Basin and 30.6 km of rivers (0.9% of the network) with significantly reduced flow downstream from dams. Rivers upstream from dams primarily drain two life zones: Premontane Rain Forest (107.9 km) and Lower Montane Rain Forest (168.2 km).Simple spatial analyses can be used as a predictive or planning tool for considering the effects of future dams in a basin-scale context. In the Sarapiquí River Basin, we recommend that future dam projects be constructed on already dammed rivers to minimize additional river fragmentation and to protect remaining riverine connectivity.

Turbid releases from Glen Canyon Dam, Arizona, following rainfall-runoff events of September 2013

USGS Publications Warehouse

Wildman, Richard A.; Vernieu, William

2017-01-01

Glen Canyon Dam is a large dam on the Colorado River in Arizona. In September 2013, it released turbid water following intense thunderstorms in the surrounding area. Turbidity was >15 nephelometric turbidity units (NTU) for multiple days and >30 NTU at its peak. These unprecedented turbid releases impaired downstream fishing activity and motivated a rapid-response field excursion. At 5 locations upstream from the dam, temperature, specific conductance, dissolved oxygen, chlorophyll a, and turbidity were measured in vertical profiles. Local streamflow and rainfall records were retrieved, and turbidity and specific conductance data in dam releases were evaluated. Profiling was conducted to determine possible sources of turbidity from 3 tributaries nearest the dam, Navajo, Antelope, and Wahweap creeks, which entered Lake Powell as interflows during this study. We discuss 4 key conditions that must have been met for tributaries to influence turbidity of dam releases: tributary flows must have reached the dam, tributary flows must have been laden with sediment, inflow currents must have been near the depth of dam withdrawals, and the settling velocity of particles must have been slow. We isolate 2 key uncertainties that reservoir managers should resolve in future similar studies: the reach of tributary water into the reservoir thalweg and the distribution of particle size of suspended sediment. These uncertainties leave the source of the turbidity ambiguous, although an important role for Wahweap Creek is possible. The unique combination of limnological factors we describe implies that turbid releases at Glen Canyon Dam will continue to be rare.

Dam methylation is required for efficient biofilm production in Salmonella enterica serovar Enteritidis.

PubMed

Aya Castañeda, María del Rosario; Sarnacki, Sebastián Hernán; Noto Llana, Mariángeles; López Guerra, Adriana Gabriela; Giacomodonato, Mónica Nancy; Cerquetti, María Cristina

2015-01-16

The ecological success of Salmonella enterica to survive in different environments is due, in part, to the ability to form biofilms, something which is especially important for food industry. The aim of the current study was to evaluate the involvement of Dam methylation in biofilm production in S. Enteritidis strains. The ability to generate biofilms was analyzed in wild type and dam mutant strains. In S. Enteritidis, the absence of Dam affected the capacity to develop pellicles at the air-liquid interface and reduced the ability to form biofilm on polystyrene surfaces. Curli and cellulose production, determined by Congo red and calcofluor assays, were affected in dam mutant strains. Relative quantitative real-time PCR experiments showed that the expression of csgD and csgA genes is reduced in mutants lacking dam gene with respect to the wild type strains, whereas transcript levels of bcsA are not affected in the absence of Dam. To our knowledge, this is the first report on the participation of Dam methylation on biofilm production in Enteritidis or any other serovar of S. enterica. Results presented here suggest that changes in gene expression required for biofilm production are finely regulated by Dam methylation. Thus, Dam methylation could modulate csgD expression and upregulate the expression of factors related with biofilm production, including curli and cellulose. This study contributes to the understanding of biofilm regulation in Salmonella spp. and to the design of new strategies to prevent food contamination and humans and animals infections. Copyright © 2014. Published by Elsevier B.V.

Synthesis of juvenile lamprey migration and passage research and monitoring at Columbia and Snake River Dams

USGS Publications Warehouse

Mesa, Matthew G.; Weiland, Lisa K.; Christiansen, Helena E.

2016-01-01

We compiled and summarized previous sources of data and research results related to the presence, numbers, and migration timing characteristics of juvenile (eyed macropthalmia) and larval (ammocoetes) Pacific lamprey Entosphenus tridentatus, in the Columbia River basin (CRB). Included were data from various screw trap collections, data from historic fyke net studies, catch records of lampreys at JBS facilities, turbine cooling water strainer collections, and information on the occurrence of lampreys in the diets of avian and piscine predators. We identified key data gaps and uncertainties that should be addressed in a juvenile lamprey passage research program. The goal of this work was to summarize information from disparate sources so that managers can use it to prioritize and guide future research and monitoring efforts related to the downstream migration of juvenile Pacific lamprey within the CRB. A common finding in all datasets was the high level of variation observed for CRB lamprey in numbers present, timing and spatial distribution. This will make developing monitoring programs to accurately characterize lamprey migrations and passage more challenging. Primary data gaps centered around our uncertainty on the numbers of juvenile and larval present in the system which affects the ability to assign risk to passage conditions and prioritize management actions. Recommendations include developing standardized monitoring methods, such as at juvenile bypass systems (JBS’s), to better document numbers and timing of lamprey migrations at dams, and use biotelemetry tracking techniques to estimate survival potentials for different migration histories.

Thermal effects of dams in the Willamette River basin, Oregon

USGS Publications Warehouse

Rounds, Stewart A.

2010-01-01

Methods were developed to assess the effects of dams on streamflow and water temperature in the Willamette River and its major tributaries. These methods were used to estimate the flows and temperatures that would occur at 14 dam sites in the absence of upstream dams, and river models were applied to simulate downstream flows and temperatures under a no-dams scenario. The dams selected for this study include 13 dams built and operated by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Project, and 1 dam on the Clackamas River owned and operated by Portland General Electric (PGE). Streamflows in the absence of upstream dams for 2001-02 were estimated for USACE sites on the basis of measured releases, changes in reservoir storage, a correction for evaporative losses, and an accounting of flow effects from upstream dams. For the PGE dam, no-project streamflows were derived from a previous modeling effort that was part of a dam-relicensing process. Without-dam streamflows were characterized by higher peak flows in winter and spring and much lower flows in late summer, as compared to with-dam measured flows. Without-dam water temperatures were estimated from measured temperatures upstream of the reservoirs (the USACE sites) or derived from no-project model results (the PGE site). When using upstream data to estimate without-dam temperatures at dam sites, a typical downstream warming rate based on historical data and downstream river models was applied over the distance from the measurement point to the dam site, but only for conditions when the temperature data indicated that warming might be expected. Regressions with measured temperatures from nearby or similar sites were used to extend the without-dam temperature estimates to the entire 2001-02 time period. Without-dam temperature estimates were characterized by a more natural seasonal pattern, with a maximum in July or August, in contrast to the measured patterns at many of the tall dam sites where the annual maximum temperature typically occurred in September or October. Without-dam temperatures also tended to have more daily variation than with-dam temperatures. Examination of the without-dam temperature estimates indicated that dam sites could be grouped according to the amount of streamflow derived from high-elevation, spring-fed, and snowmelt-driven areas high in the Cascade Mountains (Cougar, Big Cliff/Detroit, River Mill, and Hills Creek Dams: Group A), as opposed to flow primarily derived from lower-elevation rainfall-driven drainages (Group B). Annual maximum temperatures for Group A ranged from 15 to 20 degree(s)C, expressed as the 7-day average of the daily maximum (7dADM), whereas annual maximum 7dADM temperatures for Group B ranged from 21 to 25 degrees C. Because summertime stream temperature is at least somewhat dependent on the upstream water source, it was important when estimating without-dam temperatures to use correlations to sites with similar upstream characteristics. For that reason, it also is important to maintain long-term, year-round temperature measurement stations at representative sites in each of the Willamette River basin's physiographic regions. Streamflow and temperature estimates downstream of the major dam sites and throughout the Willamette River were generated using existing CE-QUAL-W2 flow and temperature models. These models, originally developed for the Willamette River water-temperature Total Maximum Daily Load process, required only a few modifications to allow them to run under the greatly reduced without-dam flow conditions. Model scenarios both with and without upstream dams were run. Results showed that Willamette River streamflow without upstream dams was reduced to levels much closer to historical pre-dam conditions, with annual minimum streamflows approximately one-half or less of dam-augmented levels. Thermal effects of the dams varied according to the time of year, from cooling in mid-summer to warm

Cleaning up the big muddy: A meta-synthesis of the research on the social impact of dams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirchherr, Julian, E-mail: julian.kirchherr@sant.ox.ac.uk; Pohlner, Huw, E-mail: huw.pohlner@oxfordalumni.org; Charles, Katrina J., E-mail: katrina.charles@ouce.ox.ac.uk

Scholars have been exploring the social impacts of dams for over 50 years, but a lack of systematic approaches has resulted in many research gaps remaining. This paper presents the first systematic review of the literature on the social impacts of dams. For this purpose, we built a sample of 217 articles published in the past 25 years via key word searches, expert consultations and bibliography reviews. All articles were assessed against an aggregate matrix framework on the social impact of dams, which combines 27 existing frameworks. We find that existing literature is highly biased with regard to: perspective (45%more » negative versus 5% positive); dam size (large dams are overrepresented); spatial focus (on the resettlement area); and temporal focus (5–10 years ex-post resettlement). Additionally, there is bias in terms of whose views are included, with those of dam developers rarely examined by scholars. These gaps need to be addressed in future research to advance our knowledge on the social impact of dams to support more transparency in the trade-offs being made in dam development decisions. - Highlights: • Very first systematic review of the research on dams' social impact • Biases in the literature identified, e. g. large dams over-studied, too much focus solely on resettlement area impacts • Implications of these biases for understanding of the topic are discussed.« less

Dam removal increases American eel abundance in distant headwater streams

USGS Publications Warehouse

Hitt, Nathaniel P.; Eyler, Sheila; Wofford, John E.B.

2012-01-01

American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with decreasing minimum eel lengths in headwater streams, suggesting that the dam previously impeded migration of many small-bodied individuals (<300 mm TL). We hypothesize that restoring connectivity to headwater streams could increase eel population growth rates by increasing female eel numbers and fecundity. This study demonstrated that dams may influence eel abundances in headwater streams up to 150 river kilometers distant, and that dam removal may provide benefits for eel management and conservation at the landscape scale.

Assessing survival of Mid-Columbia River released juvenile salmonids at McNary Dam, Washington, 2008-09

USGS Publications Warehouse

Evans, Scott D.; Walker, Christopher E.; Brewer, Scott J.; Adams, Noah S.

2010-01-01

Few studies have evaluated survival of juvenile salmon over long river reaches in the Columbia River and information regarding the survival of sockeye salmon at lower Columbia River dams is lacking. To address these information gaps, the U.S. Geological Survey was contracted by the U.S. Army Corps of Engineers to evaluate the possibility of using tagged fish released in the Mid-Columbia River to assess passage and survival at and downstream of McNary Dam. Using the acoustic telemetry systems already in place for a passage and survival study at McNary Dam, fish released from the tailraces of Wells, Rocky Reach, Rock Island, Wanapum, and Priest Rapids Dams were detected at McNary Dam and at the subsequent downstream arrays. These data were used to generate route-specific survival probabilities using single-release models from fish released in the Mid-Columbia River. We document trends in passage and survival probabilities at McNary Dam for yearling Chinook and sockeye salmon and juvenile steelhead released during studies in the Mid-Columbia River. Trends in the survival and passage of these juvenile salmonid species are presented and discussed. However, comparisons made across years and between study groups are not possible because of differences in the source of the test fish, the type of acoustic tags used, the absence of the use of passive integrated transponder tags in some of the release groups, differences in tagging and release protocols, annual differences in dam operations and configurations, differences in how the survival models were constructed (that is, number of routes that could be estimated given the number of fish detected), and the number and length of reaches included in the analysis (downstream reach length and arrays). Despite these differences, the data we present offer a unique opportunity to examine the migration behavior and survival of a group of fish that otherwise would not be studied. This is particularly true for sockeye salmon because little information is available about their survival as they pass hydroelectric dams in the lower Columbia River. Collecting information on fish released in the Mid-Columbia River, as well as on fish released 8 kilometers upstream of McNary Dam, allowed us to evaluate similarities and differences in passage and survival probabilities. In general, juvenile salmonids released in the Mid-Columbia River and detected at and downstream of McNary Dam showed trends in passage and survival probabilities that were similar to fish released 8 kilometers upstream of McNary Dam. This suggests that increased migration time or length of migration had little effect on behavior and survival of Mid-Columbia River released juvenile salmonids detected at McNary Dam.

Interim results from a study of the behavior of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March--August 2011

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.

2012-01-01

The movements and dam passage of yearling juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. A total of 411 hatchery fish and 26 wild fish were tagged and released between March 7 and May 21, 2011. A series of 16 autonomous hydrophones placed throughout the reservoir were used to determine general fish movements over the life of the acoustic transmitter, which was expected to be 91 days. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back. The dam passage rate was 11.2 percent (95-percent confidence interval 7.8–14.6 percent) for hatchery fish and 15.4 percent (95-percent confidence interval -1.0–31.8 percent) for wild fish within 91 days from release. Most fish passage occurred at night. The median time from release to dam passage was 34.5 days for hatchery fish and 34.2 days for wild fish. A system of hydrophones near the dam outlet, a temperature control tower, was used to estimate positions of fish in three dimensions to enable detailed analyses of fish behavior near the tower. Analyses of these data indicate that hourly averaged depths of fish within a distance of 74 m from the upstream face of the tower ranged from 0.6 to 9.6 meters, with a median depth of 3.6 meters for hatchery fish and 3.4 meters for wild fish. Dam discharge rates and the diurnal period affected the rates of dam passage. Rates of dam passage were similar when the dam discharge rate was less than 1,200 cubic feet per second, but increased sharply at higher discharges. The rate of dam passage at night was 4.4–7.8 times greater than during the day, depending on the distance of fish from the dam. This report is an interim summary of data collected as of August 3, 2011, for planning purposes.

River-damming, late-Quaternary rockslides in the Ötz Valley region (Tyrol, Austria)

NASA Astrophysics Data System (ADS)

Dufresne, A.; Ostermann, M.; Preusser, F.

2018-06-01

The Ötz Valley and adjacent regions in Tyrol (Austria) have been repeatedly affected by large rockslope failures following deglaciation. Six rockslides, each over 107 m3 in volume, were emplaced into the Ötz and Inn valleys, five of which formed persistent rockslide dams. Even though catastrophic rockslope failures are short-lived events (commonly minutes) they can have long-lasting impacts on the landscape. For example, large fans have built in the Ötz Valley and knickpoints persist at the former dam sites even though the Ötz River has eroded through the deposits during the past thousands of years; exact age-constraints of rockslide dam failure, however, are still scarce. Empirical, geomorphic stability indices from the literature successfully identified the least and the most stable dams of this group, whereas the rest remain inconclusive with some indices variably placing the dams in the stable, unstable, and uncertain categories. This shows (a) that further index calibrations and (b) better age constraints on dam formation and failure are needed, and (c) that the exact processes of dam failure are not always trivial to pinpoint for ancient (partially) breached dams. This study is a contribution towards better constraining the nature and landscape impact of dam formation following large rockslope failures.

Rat gestation during space flight: outcomes for dams and their offspring born after return to Earth.

PubMed

Wong, A M; DeSantis, M

1997-01-01

Sprague-Dawley rats were studied to learn whether gestation in the near-zero gravity, high radiation environment of space impacts selected mammalian postnatal events. Ten rats spent days nine to twenty of pregnancy aboard the space shuttle orbiter Atlantis (STS-66). Their movement was studied shortly after return to Earth; subsequently, several of their offspring were cross-fostered and examined through postnatal day 81 (P81) for whole body growth and somatic motor development. Values for the flight animals were compared to ground-based control groups. Relative to controls, the pregnant flight rats showed a marked paucity of locomotion during the first few hours after returning to Earth. There was greater likelihood of perinatal morbidity for the offspring of flight dams when compared to the control groups. Whole body weight of surviving offspring, averaged for each group separately, showed typical sigmoidal growth curves when plotted against postnatal age. The flight group for our study had a larger ratio of female to male pups, and that was sufficient to account for the lower average daily weight gained by the flight animals when compared to the control groups. Walking was universally achieved by P13 and preceded eye opening, which was complete in all pups by P17. Thus, both of these developmental horizons were attained on schedule in the flight as well as the control rats. Characteristic changes were observed in hind limb step length and gait width as the pups grew. These patterns occurred at the same time in each group of rats. Therefore, prenatal space flight from days nine to twenty of gestation did not interfere with the establishment of normal patterns for hind paw placement during walking.

Rat Gestation During Space Flight: Outcomes for Dams and Their Offspring Born After Return to Earth

NASA Technical Reports Server (NTRS)

Wong, Andre M.; DeSantis, Mark

1997-01-01

Sprague-Dawley rats were studied to learn whether gestation in the near-zero gravity, high radiation environment of space impacts selected mammalian postnatal events. Ten rats spent days nine to twenty of pregnancy aboard the space shuttle orbiter Atlantis (STS-66). Their movement was studied shortly after return to Earth; subsequently, several of their offspring were cross-fostered and examined through postnatal day 81 (P81) for whole body growth and somatic motor development. Values for the flight animals were compared to ground-based control groups. Relative to controls, the pregnant flight rats showed a marked paucity of locomotion during the first few hours after returning to Earth. There was greater likelihood of perinatal morbidity for the offspring of flight dams when compared to the control groups. Whole body weight of surviving offspring, averaged for each group separately, showed typical sigmoidal growth curves when plotted against postnatal age. The flight group for our study had a larger ratio of female to male pups, and that was sufficient to account for the lower average daily weight gained by the flight animals when compared to the control groups. Walking was universally achieved by P13 and preceded eye opening, which was complete in all pups by P17. Thus, both of these developmental horizons were attained on schedule in the flight as well as the control rats. Characteristic changes were observed in hind limb step length and gait width as the pups grew. These patterns occurred at the same time in each group of rats. Therefore, prenatal space flight from days nine to twenty of gestation did not interfere with the establishment of normal patterns for hind paw placement during walking.

Sediment Budgeting in Dam-Affected Rivers: Assessing the Influence of Damming, Tributaries, and Alluvial Valley Sediment Storage on Sediment Regimes

NASA Astrophysics Data System (ADS)

Wilcox, A. C.; Dekker, F. J.; Riebe, C. S.

2014-12-01

Although sediment supply is recognized as a fundamental driver of fluvial processes, measuring how dams affect sediment regimes and incorporating such knowledge into management strategies remains challenging. To determine the influences of damming, tributary supply, and valley morphology and sediment storage on downstream sediment supply in a dryland river, the Bill Williams River (BWR) in western Arizona, we measured basin erosion rates using cosmogenic nuclide analysis of beryllium-10 (10Be) at sites upstream and downstream of a dam along the BWR, as well as from tributaries downstream of the dam. Riverbed sediment mixing calculations were used to test if the dam, which blocks sediment supply from the upper 85% of the basin's drainage area, increases the proportion of tributary sediment to residual upstream sediment in mainstem samples downstream of the dam. Erosion rates in the BWR watershed are more than twice as large in the upper catchment (136 t km-2 yr-1) than in tributaries downstream of Alamo Dam (61 t km-2 yr-1). Tributaries downstream of the dam have little influence on mainstem sediment dynamics. The effect of the dam on reducing sediment supply is limited, however, because of the presence of large alluvial valleys along the mainstem BWR downstream of the dam that store substantial sediment and mitigate supply reductions from the upper watershed. These inferences, from our 10Be derived erosion rates and mixing calculations, are consistent with field observations of downstream changes in bed material size, which suggest that sediment-deficit conditions are restricted to a 10 km reach downstream of the dam, and limited reservoir bathymetry data. Many studies have suggested that tributary sediment inputs downstream of dams play a key role in mitigating dam-induced sediment deficits, but here we show that in a dryland river with ephemeral tributaries, sediment stored in alluvial valleys can also play a key role and in some cases trumps the role of tributaries.

Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams

USGS Publications Warehouse

Hitchman, Sean M.; Mather, Martha E.; Smith, Joseph M.; Fencl, Jane S.

2018-01-01

Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness. As we show here, mosaic habitat sampling and path analysis can help conservation practitioners improve science-based management plans for disturbed aquatic systems worldwide.

Habitat mosaics and path analysis can improve biological conservation of aquatic biodiversity in ecosystems with low-head dams.

PubMed

Hitchman, Sean M; Mather, Martha E; Smith, Joseph M; Fencl, Jane S

2018-04-01

Conserving native biodiversity depends on restoring functional habitats in the face of human-induced disturbances. Low-head dams are a ubiquitous human impact that degrades aquatic ecosystems worldwide. To improve our understanding of how low-head dams impact habitat and associated biodiversity, our research examined complex interactions among three spheres of the total environment. i.e., how low-head dams (anthroposphere) affect aquatic habitat (hydrosphere), and native biodiversity (biosphere) in streams and rivers. Creation of lake-like habitats upstream of low-head dams is a well-documented major impact of dams. Alterations downstream of low head dams also have important consequences, but these downstream dam effects are more challenging to detect. In a multidisciplinary field study at five dammed and five undammed sites within the Neosho River basin, KS, we tested hypotheses about two types of habitat sampling (transect and mosaic) and two types of statistical analyses (analysis of covariance and path analysis). We used fish as our example of biodiversity alteration. Our research provided three insights that can aid environmental professionals who seek to conserve and restore fish biodiversity in aquatic ecosystems threatened by human modifications. First, a mosaic approach identified habitat alterations below low-head dams (e.g. increased proportion of riffles) that were not detected using the more commonly-used transect sampling approach. Second, the habitat mosaic approach illustrated how low-head dams reduced natural variation in stream habitat. Third, path analysis, a statistical approach that tests indirect effects, showed how dams, habitat, and fish biodiversity interact. Specifically, path analysis revealed that low-head dams increased the proportion of riffle habitat below dams, and, as a result, indirectly increased fish species richness. Furthermore, the pool habitat that was created above low-head dams dramatically decreased fish species richness. As we show here, mosaic habitat sampling and path analysis can help conservation practitioners improve science-based management plans for disturbed aquatic systems worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.

Monitoring and Evaluation of Yearling Fall Chinook Salmon Released from Acclimation Facilities Upstream of Lower Granite Dam; 1998 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocklage, Stephen J.

The Nez Perce Tribe, in cooperation with the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife, conducted monitoring and evaluation studies on Lyons Ferry Hatchery (Snake River stock) yearling fall chinook salmon that were acclimated and released at three Fall Chinook Acclimation Project sites upstream of Lower Granite Dam along with yearlings released on-station from Lyons Ferry Hatchery in 1998. The three fall chinook acclimation facilities are operated by the Nez Perce Tribe and located at Pittsburg Landing and Captain John Rapids on the Snake River and at Big Canyon Creek on the Clearwater River. Yearlingsmore » at the Big Canyon facility consisted of two size classes that are referred to in this report as 9.5 fish per pound (fpp) and 30 fpp. The Big Canyon 9.5 fpp were comparable to the yearlings at Pittsburg Landing, Captain John Rapids and Lyons Ferry Hatchery. A total of 9,942 yearlings were PIT tagged and released at Pittsburg Landing. PIT tagged yearlings had a mean fork length of 159.9 mm and mean condition factor of 1.19. Of the 9,942 PIT tagged fish released, a total of 6,836 unique tags were detected at mainstem Snake and Columbia River dams (Lower Granite, Little Goose, Lower Monumental and McNary). A total of 4,926 9.5 fpp and 2,532 30 fpp yearlings were PIT tagged and released at Big Canyon. PIT tagged 9.5 fpp yearlings had a mean fork length of 156.9 mm and mean condition factor of 1.13. PIT tagged 30 fpp yearlings had a mean fork length of 113.1 mm and mean condition factor of 1.18. Of the 4,926 PIT tagged 9.5 fpp yearlings released, a total of 3,042 unique tags were detected at mainstem Snake and Columbia River dams. Of the 2,532 PIT tagged 30 fpp yearlings released, a total of 1,130 unique tags were detected at mainstem Snake and Columbia River dams. A total of 1,253 yearlings were PIT tagged and released at Captain John Rapids. PIT tagged yearlings had a mean fork length of 147.5 mm and mean condition factor of 1.09. Of the 1,253 PIT tagged fish released, a total of 719 unique tags were detected at mainstem Snake and Columbia River dams. A total of 2,420 yearlings were PIT tagged and released at Lyons Ferry Hatchery. PIT tagged yearlings had a mean fork length of 159.0 mm and mean condition factor of 1.10. Of the 2,420 PIT tagged fish released, a total of 979 unique tags were detected at mainstem Snake and Columbia River dams (Lower Monumental and McNary). Median travel times, based on all detections, of PIT tagged fish released from Pittsburg Landing were 10.5 days to Lower Granite Dam, 21.7 days to McNary Dam and 29.8 days to Bonneville Dam. Median migration rates were 16.4 rkm/d to Lower Granite Dam, 18.3 rkm/d to McNary Dam and 18.9 rkm/d to Bonneville Dam. The median arrival dates were April 25 at Lower Granite Dam, May 6 at McNary Dam and May 14 at Bonneville Dam. The 90% passage dates were May 5 at Lower Granite Dam, May 20 at McNary Dam and May 25 at Bonneville Dam. Median travel times, based on all detections, of PIT tagged 9.5 fpp yearlings released from Big Canyon were 13.3 days to Lower Granite Dam, 26.0 days to McNary Dam and 30.8 days to Bonneville Dam. Median migration rates were 13.0 rkm/d to Lower Granite Dam, 15.3 rkm/d to McNary Dam and 18.3 rkm/d to Bonneville Dam. The median arrival dates were April 27 at Lower Granite Dam, May 11 at McNary Dam and May 15 at Bonneville Dam. The 90% passage dates were May 9 at Lower Granite Dam, May 24 at McNary Dam and May 25 at Bonneville Dam. Median travel times, based on all detections, of PIT tagged 30 fpp yearlings released from Big Canyon were 20.8 days to Lower Granite Dam, 37.6 days to McNary Dam and 43.5 days to Bonneville Dam. Median migration rates were 8.3 rkm/d to Lower Granite Dam, 10.6 rkm/d to McNary Dam and 12.9 rkm/d to Bonneville Dam. The median arrival dates were May 5 at Lower Granite Dam, May 23 at McNary Dam and May 28 at Bonneville Dam. The 90% passage dates were May 22 at Lower Granite Dam, May 31 at McNary Dam and June 5 at Bonneville Dam. Median arrival dates, based on all detections, of PIT tagged yearlings released from Captain John Rapids were April 26 at Lower Granite Dam, May 8 at McNary Dam and May 14 at Bonneville Dam. The 90% passage dates were May 8 at Lower Granite Dam, May 23 at McNary Dam and May 26 at Bonneville Dam. Median travel times, based on all detections, of PIT tagged fish released from Lyons Ferry Hatchery were 16.9 days to Lower Monumental Dam, 20.9 days to McNary Dam and 30.3 days to Bonneville Dam. Median migration rates were 1.7 rkm/d to Lower Monumental Dam, 7.0 rkm/d to McNary Dam and 12.6 rkm/d to Bonneville Dam. The median arrival dates were April 27 at Lower Monumental Dam, May 1 at McNary Dam and May 8 at Bonneville Dam. The 90% passage dates were May 13 at Lower Monumental Dam, May 16 at McNary Dam and May 24 at Bonneville Dam.« less

Large-scale projects in the amazon and human exposure to mercury: The case-study of the Tucuruí Dam.

PubMed

Arrifano, Gabriela P F; Martín-Doimeadios, Rosa C Rodríguez; Jiménez-Moreno, María; Ramírez-Mateos, Vanesa; da Silva, Núbia F S; Souza-Monteiro, José Rogério; Augusto-Oliveira, Marcus; Paraense, Ricardo S O; Macchi, Barbarella M; do Nascimento, José Luiz M; Crespo-Lopez, Maria Elena

2018-01-01

The Tucuruí Dam is one of the largest dams ever built in the Amazon. The area is not highly influenced by gold mining as a source of mercury contamination. Still, we recently noted that one of the most consumed fishes (Cichla sp.) is possibly contaminated with methylmercury. Therefore, this work evaluated the mercury content in the human population living near the Tucuruí Dam. Strict exclusion/inclusion criteria were applied for the selection of participants avoiding those with altered hepatic and/or renal functions. Methylmercury and total mercury contents were analyzed in hair samples. The median level of total mercury in hair was above the safe limit (10µg/g) recommended by the World Health Organization, with values up to 75µg/g (about 90% as methylmercury). A large percentage of the participants (57% and 30%) showed high concentrations of total mercury (≥ 10µg/g and ≥ 20µg/g, respectively), with a median value of 12.0µg/g. These are among the highest concentrations ever detected in populations living near Amazonian dams. Interestingly, the concentrations are relatively higher than those currently shown for human populations highly influenced by gold mining areas. Although additional studies are needed to confirm the possible biomagnification and bioaccumulation of mercury by the dams in the Amazon, our data already support the importance of adequate impact studies and continuous monitoring. More than 400 hydropower dams are operational or under construction in the Amazon, and an additional 334 dams are presently planned/proposed. Continuous monitoring of the populations will assist in the development of prevention strategies and government actions to face the problem of the impacts caused by the dams. Copyright © 2017 Elsevier Inc. All rights reserved.

[Effects of cascading hydropower dams operation on the structure and distribution pattern of benthic macroinvertebrate assemblages in Manwan Reservoir, Southwest China].

PubMed

Li, Jin Peng; Dong, Shi Kui; Peng, Ming Chun; Wu, Xuan; Zhou, Fang; Yu, Yin

2017-12-01

Benthic macroinvertebrate assemblages are one of the biological groups in aquatic ecosystem most sensitive to the habitat change and degradation, and can be a biological indicator for the aquatic ecosystem change and succession in cascading hydropower dam reservoir. The middle and lower reaches of the Lancang River are key spot for international biodiversity conservation and ecological studies on the effects of cascading hydropower dam exploitation. In this study, the reservoir of Manwan hydropower dam, the first dam in Lancang-Mekong river main stream, was selected as the study site. The benthic macroinvertebrate assemblages were sampled in 2011 and 2016 respectively. Meanwhile, the survey data before impounding (natural river, 1996) and early stage of single dam (1997) were collected to conduct the overall analysis for structure, distribution pattern and evolution of benthic macroinvertebrate assemblages. The results showed that the dominant biological group was gradually changed from the Oligochaeta and Insecta to the Mollusca. Along the longitudinal gradient, the density and biomass of the benthic macroinvertebrate assemblages were remarkably increased in reservoir, especially in the lacustrine zone. As for the functional feeding group, the predator and gatherer-collector changed into filter-collector predominantly in lacustrine zone. With the cascading dams operation, the biotic index indicated that the water quality of reservoir in 2016 was better than in 2011. The evolution of benthic macroinvertebrate assemblages in the Manwan Reservoir was related to the operation of Xiaowan dam in the upper reach, the hydrological regime and siltation in the reservoir, and would continue with dynamic changes with the operation of the cascading hydropower dam.

Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

USGS Publications Warehouse

Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

2016-08-09

The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are considered within the model. The results of the hydrologic simulations indicated that for all hydrologic conditions scenarios, the Lago El Guineo Dam would not experience overtopping. For the dam breach hydraulic analysis, failure by piping was the selected hypothetical failure mode for the Lago El Guineo Dam.Results from the simulated dam failure of the Lago El Guineo Dam using the HEC–RAS model for the 6- and 24-hour probable maximum precipitation events indicated peak discharges below the dam of 1,342.43 and 1,434.69 cubic meters per second, respectively. Dam failure during the 24-hour, 100-year recurrence rainfall event resulted in a peak discharge directly downstream from Lago El Guineo Dam of 1,183.12 cubic meters per second. Dam failure during sunny-day conditions (no precipitation) produced a peak discharge at Lago El Guineo Dam of 1,015.31 cubic meters per second assuming the initial water-surface elevation was at the morning-glory spillway invert elevation.The results of the hydraulic analysis indicate that the flood would extend to many inhabited areas along the stream banks from the Lago El Guineo Dam to the mouth of the Río Grande as a result of the simulated failure of the Lago El Guineo Dam. Low-lying regions in the vicinity of Ciales, Manatí, and Barceloneta, Puerto Rico, are among the regions that would be most affected by failure of the Lago El Guineo Dam. Effects of the flood control (levee) structure constructed in 2000 to provide protection to the low-lying populated areas of Barceloneta, Puerto Rico, were considered in the hydraulic analysis of dam failure. The results indicate that overtopping can be expected in the aforementioned levee during 6- and 24-hour probable maximum precipitation events. The levee was not overtopped during dam failure scenarios under the 24-hour, 100-year recurrence rainfall event or sunny-day conditions.

Monitoring of Juvenile Yearling Chinook Salmon and Steelhead Survival and Passage at John Day Dam, Spring 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.

The purpose of this study was to compare dam passage survival, at two spill treatment levels, of yearling Chinook salmon and steelhead smolts at John Day Dam during spring 2010. The two treatments were 30% and 40% spill out of total project discharge. Under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp), dam passage survival should be greater than or equal to 0.96 and estimated with a standard error (SE) less than or equal 0.015. The study also estimated forebay residence time, tailrace egress time, and spill passage efficiency (SPE), as required in the Columbia Basin Fishmore » Accords. However, by agreement among the stakeholders, this study was not an official BiOp compliance test because the long-term passage measures at John Day Dam have yet to be finalized and another year of spill-treatment testing was desired.« less

Effects of Outlets on Cracking Risk and Integral Stability of Super-High Arch Dams

PubMed Central

Hu, Hang

2014-01-01

In this paper, case study on outlet cracking is first conducted for the Goupitan and Xiaowan arch dams. A nonlinear FEM method is then implemented to study effects of the outlets on integral stability of the Xiluodu arch dam under two loading conditions, i.e., normal loading and overloading conditions. On the basis of the case study and the numerical modelling, the outlet cracking mechanism, risk, and corresponding reinforcement measures are discussed. Furthermore, the numerical simulation reveals that (1) under the normal loading conditions, the optimal distribution of the outlets will contribute to the tensile stress release in the local zone of the dam stream surface and decrease the outlet cracking risk during the operation period. (2) Under the overloading conditions, the cracks initiate around the outlets, then propagate along the horizontal direction, and finally coalesce with those in adjacent outlets, where the yield zone of the dam has a shape of butterfly. Throughout this study, a dam outlet cracking risk control and reinforcement principle is proposed to optimize the outlet design, select the appropriate concrete material, strengthen the temperature control during construction period, design reasonable impounding scheme, and repair the cracks according to their classification. PMID:25152907

Dam failure analysis for the Lago de Matrullas Dam, Orocovis, Puerto Rico

USGS Publications Warehouse

Torres-Sierra, Heriberto; Gómez-Fragoso, Julieta

2015-01-01

Results from the simulated dam failure of the Lago de Matrullas Dam using the HEC–RAS model for the 6- and 24-hour PMP events showed peak discharges at the dam of 3,149.33 and 3,604.70 m3/s, respectively. Dam failure during the 100-year-recurrence, 24-hour rainfall event resulted in a peak discharge of 2,103.12 m3/s directly downstream from the dam. Dam failure under sunny day conditions produced a peak discharge of 1,695.91 m3/s at the dam assuming the antecedent lake level was at the morning-glory spillway invert elevation. Flood-inundation maps prepared as part of the study depict the flood extent and provide valuable information for preparing an Emergency Action Plan. Results of the failure analysis indicate that a failure of the Lago de Matrullas Dam could cause flooding to many of the inhabited areas along stream banks from the Lago de Matrullas Dam to the mouth of the Río Grande de Manatí. Among the areas most affected are the low-lying regions in the vicinity of the towns of Ciales, Manatí, and Barceloneta. The delineation of the flood boundaries near the town of Barceloneta considered the effects of a levee constructed during 2000 at Barceloneta in the flood plain of the Río Grande de Manatí to provide protection against flooding to the near-by low-lying populated areas. The results showed overtopping can be expected in the aforementioned levee during 6- and 24-hour probable-maximum-precipitation dam failure scenarios. No overtopping of the levee was simulated, however, during dam failure scenarios under the 100-year recurrence, 24-hour rainfall event or sunny day conditions.

Importance of using roller compacted concrete in techno-economic investigation and design of small dams

NASA Astrophysics Data System (ADS)

Rouissat, Bouchrit; Smail, N.; Zenagui, S.

2017-12-01

In recent years, and under constraints caused by persistent drought, Algeria has launched a new mobilization strategy for surface water resources from small and medium dams. However, by making a review of the studies and achievements of twenty small dams in the west of Algeria, some deficiencies appeared. In addition to reservoir siltation assessment, operation spillways have been the major constraint on the reliability of these types of dams. The objective of this paper is to use the roller compacted concrete (RCC) for small dams' design for the benefit it offers and its ability to incorporate spillways. The development of this reflection was applied to the Khneg Azir earth dam situated in southwest of Algeria. Its uncontrolled lateral spillway has registered significant damage following the flood of October 2005, amounted, at that time, to more than 100 million Algerian dinars (1 million US Dollars). The present research encompasses a technical and economical comparative analysis concerning multiple criteria dam design types coupled with the conjugation of the spillways. Thus, on the basis of financial estimates calculated for all design types, the variant RCC remains competitive with that of the earth dam's spillway isolated (Less than 40% of the cost). To assess the mechanical behavior of the foundations for both types of dams, (earth and RCC dams), numerical modeling has been undertaken, according to the comparative analysis of deformations in the foundations. Analysis of deformations showed that the average foundation deformations was between (0.052-0.85) m for earth dam and (0.023-0.373) m for RCC dam. These economical and technical considerations open up important prospects for the use of RCC in the design of small dams.

Using causal maps to support ex-post assessment of social impacts of dams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aledo, Antonio, E-mail: Antonio.Aledo@ua.es; García-Andreu, Hugo, E-mail: Hugo.Andreu@ua.es; Pinese, José, E-mail: pinese@uel.br

- Highlights: • We defend the usefulness of causal maps (CM) for ex-post impact assessment of dams. • Political decisions are presented as unavoidable technical measures. • CM enable the identification of multiple causes involved in the dam impacts. • An alternative management of the dams is shown from the precise tracking of the causes. • Participatory CM better the quality of information and the governance of the research. This paper presents the results of an ex-post assessment of two important dams in Brazil. The study follows the principles of Social Impact Management, which offer a suitable framework for analyzingmore » the complex social transformations triggered by hydroelectric dams. In the implementation of this approach, participative causal maps were used to identify the ex-post social impacts of the Porto Primavera and Rosana dams on the community of Porto Rico, located along the High Paraná River. We found that in the operation of dams there are intermediate causes of a political nature, stemming from decisions based on values and interests not determined by neutral, exclusively technical reasons; and this insight opens up an area of action for managing the negative impacts of dams.« less

Effects of Chiloquin Dam on spawning distribution and larval emigration of Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague Rivers, Oregon

USGS Publications Warehouse

Martin, Barbara A.; Hewitt, David A.; Ellsworth, Craig M.

2013-01-01

Chiloquin Dam was constructed in 1914 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River (Deltistes luxatusChasmistes brevirostris) suckers, as well as other fish species. In 2002, the Bureau of Reclamation led a working group that examined several alternatives to improve fish passage at Chiloquin Dam. Ultimately it was decided that dam removal was the best alternative and the dam was removed in the summer of 2008. The U.S. Geological Survey conducted a long-term study on the spawning ecology of Lost River, shortnose, and Klamath largescale suckers (Catostomus snyderi) in the Sprague and lower Williamson Rivers from 2004 to 2010. The objective of this study was to evaluate shifts in spawning distribution following the removal of Chiloquin Dam. Radio telemetry was used in conjunction with larval production data and detections of fish tagged with passive integrated transponders (PIT tags) to evaluate whether dam removal resulted in increased utilization of spawning habitat farther upstream in the Sprague River. Increased densities of drifting larvae were observed at a site in the lower Williamson River after the dam was removed, but no substantial changes occurred upstream of the former dam site. Adult spawning migrations primarily were influenced by water temperature and did not change with the removal of the dam. Emigration of larvae consistently occurred about 3-4 weeks after adults migrated into a section of river. Detections of PIT-tagged fish showed increases in the numbers of all three suckers that migrated upstream of the dam site following removal, but the increases for Lost River and shortnose suckers were relatively small compared to the total number of fish that made a spawning migration in a given season. Increases for Klamath largescale suckers were more substantial. Post-dam removal monitoring only included 2 years with below average river discharge during the spawning season; data from years with higher flows may provide a different perspective on the effects of dam removal on the spawning migrations of the two endangered sucker species.

Experimental study on mechanism and shape characteristics of suspended flexible dam

NASA Astrophysics Data System (ADS)

Wang, Jian-zhong; Fan, Hong-xia; Zhu, Li-jun

2014-12-01

Hydraulic structures such as groin, longitudinal dike and seawall are common in water conservancy and water transportation engineering projects at home and abroad, which have long been dominated by solid mass structural form. With brush and stone as building materials, this kind of structure has an obvious engineering effect. However, it not only requires huge capital investments, but also has negative impacts on the ecological environment. The suspended flexible dam is an innovative engineering measure, and few theoretical and experimental researches of this type dam can be found at present. This paper studies the mechanism and shape characteristics of this dam and obtains the dynamic equilibrium equation of flexible dam, the float buoyancy expression, and the condition for transformation among three forms of the underwater shape of the dam. The results are valuable in engineering application and can be used as the reference for the future work due to the distinctive design philosophy, the small negative effects on environment and the consistency for sustainable development.

Seismic Hazard and Ground Motion Characterization at the Itoiz Dam (Northern Spain)

NASA Astrophysics Data System (ADS)

Rivas-Medina, A.; Santoyo, M. A.; Luzón, F.; Benito, B.; Gaspar-Escribano, J. M.; García-Jerez, A.

2012-08-01

This paper presents a new hazard-consistent ground motion characterization of the Itoiz dam site, located in Northern Spain. Firstly, we propose a methodology with different approximation levels to the expected ground motion at the dam site. Secondly, we apply this methodology taking into account the particular characteristics of the site and of the dam. Hazard calculations were performed following the Probabilistic Seismic Hazard Assessment method using a logic tree, which accounts for different seismic source zonings and different ground-motion attenuation relationships. The study was done in terms of peak ground acceleration and several spectral accelerations of periods coinciding with the fundamental vibration periods of the dam. In order to estimate these ground motions we consider two different dam conditions: when the dam is empty ( T = 0.1 s) and when it is filled with water to its maximum capacity ( T = 0.22 s). Additionally, seismic hazard analysis is done for two return periods: 975 years, related to the project earthquake, and 4,975 years, identified with an extreme event. Soil conditions were also taken into account at the site of the dam. Through the proposed methodology we deal with different forms of characterizing ground motion at the study site. In a first step, we obtain the uniform hazard response spectra for the two return periods. In a second step, a disaggregation analysis is done in order to obtain the controlling earthquakes that can affect the dam. Subsequently, we characterize the ground motion at the dam site in terms of specific response spectra for target motions defined by the expected values SA ( T) of T = 0.1 and 0.22 s for the return periods of 975 and 4,975 years, respectively. Finally, synthetic acceleration time histories for earthquake events matching the controlling parameters are generated using the discrete wave-number method and subsequently analyzed. Because of the short relative distances between the controlling earthquakes and the dam site we considered finite sources in these computations. We conclude that directivity effects should be taken into account as an important variable in this kind of studies for ground motion characteristics.

Investigation on trophic state index by artificial neural networks (case study: Dez Dam of Iran)

NASA Astrophysics Data System (ADS)

Saghi, H.; Karimi, L.; Javid, A. H.

2015-06-01

Dam construction and surface runoff control is one of the most common approaches for water-needs supply of human societies. However, the increasing development of social activities and hence the subsequent increase in environmental pollutants leads to deterioration of water quality in dam reservoirs and eutrophication process could be intensified. So, the water quality of reservoirs is now one of the key factors in operation and water quality management of reservoirs. Hence, maintaining the quality of the stored water and identification and examination of changes along time has been a constant concern of humans that involves the water authorities. Traditionally, empirical trophic state indices of dam reservoirs often defined based on changes in concentration of effective factors (nutrients) and its consequences (increase in chlorophyll a), have been used as an efficient tool in the definition of dam reservoirs quality. In recent years, modeling techniques such as artificial neural networks have enhanced the prediction capability and the accuracy of these studies. In this study, artificial neural networks have been applied to analyze eutrophication process in the Dez Dam reservoir in Iran. In this paper, feed forward neural network with one input layer, one hidden layer and one output layer was applied using MATLAB neural network toolbox for trophic state index (TSI) analysis in the Dez Dam reservoir. The input data of this network are effective parameters in the eutrophication: nitrogen cycle parameters and phosphorous cycle parameters and parameters that will be changed by eutrophication: Chl a, SD, DO and the output data is TSI. Based on the results from estimation of modified Carlson trophic state index, Dez Dam reservoir is considered to be eutrophic in the early July to mid-November and would be mesotrophic with decrease in temperature. Therefore, a decrease in water quality of the dam reservoir during the warm seasons is expectable. The results indicated that artificial neural network (ANN) is a suitable tool for quality modeling of reservoir of dam and increment and decrement of nutrients in trend of eutrophication. Therefore, ANN is a suitable tool for quality modeling of reservoir of dam.

Downstream effects of hydropower production on aquatic macroinvertebrate assemblages in two rivers in Costa Rica.

PubMed

Chaves-Ulloa, Ramsa; Umaña-Villalobos, Gerardo; Springer, Monika

2014-04-01

Despite the fact that little is known about the consequences of hydropower production in tropical areas, many large dams (> 15 m high) are currently under construction or consideration in the tropics. We researched the effects of large hydroelectric dams on aquatic macroinvertebrate assemblages in two Costa Rican rivers. We measured physicochemical characteristics and sampled aquatic macroinvertebrates from March 2003 to March 2004 in two dammed rivers, Peñas Blancas and San Lorenzo, as well as in the undammed Chachagua River. Sites above and below the dam had differences in their physicochemical variables, with wide variation and extreme values in variables measured below the dam in the San Lorenzo River. Sites below the dams had reduced water discharges, velocities, and depths when compared with sites above the dams, as well as higher temperatures and conductivity. Sites above dams were dominated by collector-gatherer-scrapers and habitat groups dominated by swimmer-clingers, while sites below dams had a more even representation of groups. In contrast, a comparison between two sites at different elevation in the undammed river maintained a similar assemblage composition. Tributaries might facilitate macroinvertebrate recovery above the turbine house, but the assemblage below the turbine house resembled the one below the dam. A massive sediment release event from the dam decreased the abundance per sample and macroinvertebrate taxa below the dam in the Peñas Blancas River. Our study illustrates the effects of hydropower production on neotropical rivers, highlighting the importance of using multiple measures of macroinvertebrate assemblage structure for assessing this type of environmental impact.

High post-natal mortality associated with defects in lung maturation and reduced adiposity in mice with gestational exposure to high fat and N-acetylcysteine.

PubMed

Williams, Lyda; Charron, Maureen J; Sellers, Rani S

2017-10-01

Studies have demonstrated that maternal consumption of a high fat diet (HFD) increases offspring susceptibility to metabolic disease. This study was initiated to identify the mechanistic contribution of oxidative stress on this phenomenon. Two weeks prior to mating, dams were fed either HFD or Control diet with or without supplementation with the anti-oxidant N-acetylcysteine (NAC). Pups born to HFD dams had reduced crown rump length (CRL) at birth and higher neonatal mortality compared to pups from Control dams. Supplementation with NAC normalized CRL in pups from HFD dams, but notably increased mortality. Histological examination of the lungs postnatally and prenatally, revealed normal branching morphogenesis but delayed alveolarization in pups from dams fed HFD+NAC. Discontinuation of NAC at ED17.5 with re-introduction at PD3 improved offspring survival and lung maturation. Additionally, interscapular brown adipose tissue (BAT) was reduced in ED18.5 embryos from HFD dams. These findings suggest that increased mortality in offspring from dams fed HFD+NAC during pregnancy may in part be the result of delayed pulmonary alveolarization and decreased BAT. Copyright © 2017 Elsevier Ltd. All rights reserved.

77 FR 47628 - Archon Energy 1, Inc.; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

...), proposing to study the feasibility of the DaGuerre Point Dam Hydropower Project (DaGuerre Point Dam Project or project) to be located at the U.S. Army Corps of Engineers' (USACE) DaGuerre Point Dam, on the...

Risk Costs for New Dams: Economic Analysis and Effects of Monitoring

NASA Astrophysics Data System (ADS)

Paté-Cornell, M. Elisabeth; Tagaras, George

1986-01-01

This paper presents new developments and illustrations of the introduction of risk and costs in cost-benefit analysis for new dams. The emphasis is on a method of evaluation of the risk costs based on the structure of the local economy. Costs to agricultural property as well as residential, commercial, industrial, and public property are studied in detail. Of particular interest is the case of sequential dam failure and the evaluation of the risk costs attributable to a new dam upstream from an existing one. Three real cases are presented as illustrations of the method: the Auburn Dam, the Dickey-Lincoln School Project, and the Teton Dam, which failed in 1976. This last case provides a calibration tool for the estimation of loss ratios. For these three projects, the risk-modified benefit-cost ratios are computed to assess the effect of the risk on the economic performance of the project. The role of a warning system provided by systematic monitoring of the dam is analyzed: by reducing the risk costs, the warning system attenuates their effect on the benefit-cost ratio. The precursors, however, can be missed or misinterpreted: monitoring does not guarantee that the risks to human life can be reduced to zero. This study shows, in particular, that it is critical to consider the risk costs in the decision to build a new dam when the flood area is large and densely populated.

Spatial Multicriteria Decision Analysis of Flood Risks in Aging-Dam Management in China: A Framework and Case Study

PubMed Central

Yang, Meng; Qian, Xin; Zhang, Yuchao; Sheng, Jinbao; Shen, Dengle; Ge, Yi

2011-01-01

Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites. PMID:21655125

The Three Gorges Dam of China: Technology to Bridge Two Centuries

ERIC Educational Resources Information Center

Wahby, Wafeek S.

2003-01-01

Some of the most sophisticated 20th-century technologies have been applied to build the largest hydroelectric dam in the world, the Three Gorges Dam Project (TGDP) of China. The author administered a study abroad course in China from May 27 to June 10, 2000, to study the massive project as it approached the halfway mark of its second and most…

Parental sex effect of parthenogenesis on progeny production and performance of Chinese Painted Quail (Coturnix chinensis).

PubMed

Ramachandran, R; Nascimento Dos Santos, M; Parker, H M; McDaniel, C D

2018-06-01

Embryonic development of an unfertilized egg, parthenogenesis, is known to occur in Chinese Painted quail. However, selection for parthenogenesis in both the dam and sire leads to a reduction in hatchability following mating. Therefore, the objective of this study was to determine if selection for parthenogenesis in the dam, sire, or both also impact their progeny performance. There were 2 lines of birds used in this trial: 1 line selected for parthenogenesis and 1 line not selected for parthenogenesis (control) yielding breeding pairs as follows: control dams + control sires (CC), control dams + parthenogenetic sires (CP), parthenogenetic dams + control sires (PC), and parthenogenetic dams + parthenogenetic sires (PP). For all progeny, a dam line main effect revealed that the parthenogenetic line dams had heavier offspring hatch weight and 4 wk body weight as well as higher 1st wk chick mortality versus control line dams. However, control line dams had the highest 4th wk chick mortality versus parthenogenetic line dams. In female virgin progeny, a dam by sire interaction revealed that PP, PC, and CP had the heaviest 1st egg in the clutch position versus CC. Also, eggs from PP had the highest number of eggs and the most female progeny exhibiting parthenogenesis versus CC. There was a linear increase in egg weight as clutch position increased for progeny from PP and CC yet a linear decline for CP. In conclusion, it appears that both the dam and sire selected for parthenogenesis impact progeny performance as parthenogenetic dams and sires additively contribute to the degree of parthenogenesis exhibited by virgin female progeny. Moreover, because parthenogenesis is known to exist in the modern poultry industry, even the accidental selection of the parthenogenetic trait in either males or females could have a negative impact on overall chick production and performance. Published by Elsevier Inc.

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

USGS Publications Warehouse

Sokolow, Susanne H.; Jones, Isabel J.; Jocque, Merlijn M. T.; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L.; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M.; De Leo, Giulio A.

2017-01-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

NASA Astrophysics Data System (ADS)

Sokolow, S. H.; Jones, I. J.; La, D.; Cords, O.; Knight, A.; Lund, A.; Wood, C. L.; Lafferty, K. D.; Kuris, A. M.; Hoover, C.; Collender, P. A.; Remais, J.; Lopez-Carr, D.; De Leo, G.

2016-12-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socioeconomic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277 to 385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (1) upstream catchments within historical habitats of native prawns, (2) comparable undammed watersheds, and (3) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoring native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns.

PubMed

Sokolow, Susanne H; Jones, Isabel J; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Wood, Chelsea L; Lafferty, Kevin D; Hoover, Christopher M; Collender, Phillip A; Remais, Justin V; Lopez-Carr, David; Fisk, Jonathan; Kuris, Armand M; De Leo, Giulio A

2017-06-05

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277-385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. © 2017 The Authors.

Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns

PubMed Central

Jones, Isabel J.; Jocque, Merlijn; La, Diana; Cords, Olivia; Knight, Anika; Lund, Andrea; Lafferty, Kevin D.; Hoover, Christopher M.; Collender, Phillip A.; Remais, Justin V.; Lopez-Carr, David; Kuris, Armand M.; De Leo, Giulio A.

2017-01-01

Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’. PMID:28438916

Developmental treatment with bisphenol A or ethinyl estradiol causes few alterations on early preweaning measures.

PubMed

Ferguson, Sherry A; Law, Charles D; Abshire, Jordan S

2011-11-01

Because bisphenol A (BPA) exposure is nearly ubiquitous, increased knowledge of its potential effects on development will enable better risk assessment and regulatory guidance. Here, Sprague-Dawley rats were reared in low exogenous estrogen environments. After breeding at adulthood, dams were gavaged on gestational days (GDs) 6-21 with vehicle (VEH), 2.5 or 25.0 μg/kg/day BPA, or 5.0 or 10.0 μg/kg/day ethinyl estradiol (EE₂). Offspring were orally treated on postnatal days (PNDs) 1-21 with the same dose the dam received. Relative to the VEH group, dams of both EE₂-treated groups weighed less throughout gestation and lactation. PND 1 absolute anogenital distance and anogenital index were unaltered by any treatment. Ages at fur development and eye and ear opening were unaffected by any treatment. Despite a significant treatment effect, no group was significantly different from VEH in PNDs 3-6 righting latencies; although males had shorter latencies and all latencies decreased with age. PNDs 8-11 slant board behavior was unaffected by any treatment; however, males had shorter turning latencies and latencies decreased with age. Preweaning body weights of BPA- and EE₂-treated groups as well as naive controls were less than VEH. No treatment affected PND 21 whole or regional brain weights or levels of estradiol, testosterone, corticosterone, T3, T4, luteinizing hormone, ghrelin, or leptin. These results add to the literature indicating that developmental BPA treatment at these doses has no effects on gestational or lactational body weight, offspring anogenital distance, preweaning behaviors or hormone levels, and whole and regional brain weights measured at weaning.

Hydrological impact of high-density small dams in a humid catchment, Southeast China

NASA Astrophysics Data System (ADS)

Lu, W.; Lei, H.; Yang, D.

2017-12-01

The Jiulong River basin is a humid catchment with a drainage area of 14,741 km2; however, it has over 1000 hydropower stations within it. Such catchment with high-density small dams is scarce in China. Yet few is known about the impact of high-density small dams on streamflow changes. To what extent the large number of dams alters the hydrologic patterns is a fundamental scientific issue for water resources management, flood control, and aquatic ecological environment protection. Firstly, trend and change point analyses are applied to determine the characteristics of inter-annual streamflow. Based on the detected change point, the study period is divided into two study periods, the ``natural'' and ``disturbed'' periods. Then, a geomorphology-based hydrological model (GBHM) and the fixing-changing method are adopted to evaluate the relative contributions of climate variations and damming to the changes in streamflow at each temporal scale (i.e., from daily, monthly to annual). Based on the simulated natural streamflow, the impact of dam construction on hydrologic alteration and aquatic ecological environment will be evaluated. The hydrologic signatures that will be investigated include flood peak, seasonality of streamflow, and the inter-annual variability of streamflow. In particular, the impacts of damming on aquatic ecological environment will be investigated using eco-flow metrics and indicators of hydrologic alteration (IHA) which contains 33 individual streamflow statistics that are closely related to aquatic ecosystem. The results of this study expect to provide a reference for reservoir operation considering both ecological and economic benefits of such operations in the catchment with high-density dams.

Fragility Analysis of Concrete Gravity Dams

NASA Astrophysics Data System (ADS)

Tekie, Paulos B.; Ellingwood, Bruce R.

2002-09-01

Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

[Periodontal guided tissue regeneration with a rubber dam: short term clinical study].

PubMed

D'Archivio, D; Di Placido, G; Tumini, V; Paolantonio, M

1998-03-01

The guided regeneration of periodontal tissues demonstrated to represent a therapeutical technique with predictable results. It has been observed that different materials, used as regenerative membranes, offer very similar results. Unconventional materials too, like the rubber dam, seem to be useful in the guided tissues regeneration technique. The object of the present study has been to comparatively evaluate the effectiveness of Gore-Tex and rubber dam-made membranes in the therapy of intra-osseous periodontal defects. Six patients with two similar intra-osseous defects, participated in the study; one defect has been treated using, during the surgical intervention, a Gore-Tex membrane, while the other has received, a fragment of sterile rubber dam membranes. The principal clinical parameters of the periodontal health (probing depth -PD- and attachment loss -AL-) has been evaluated in both the defects before and 6 months after the periodontal surgery. The results have showed that there are not statistically significant differences (p > 0.05) in the healing of the intra-osseous defects treated by rubber dam or Gore-Tex. The conclusion is drawn that the rubber dam can represent a valid and cheap alternative to the materials traditionally used in the regenerative surgery of the periodontal tissues.

Stress and deformation analysis of double curvature arc dams using finite element method (FEM): A case of budhi gandaki hydropower project

NASA Astrophysics Data System (ADS)

Mishra, Aanand Kumar; Singh, Ajay; Bahadur Singh, Akal

2018-06-01

High rise arc dams are widely used in the development of storage type hydropower project because of the economic advantage. Among different phases considered during the lifetime of dam, control of dam’s safety and performance becomes more concerned during the lifetime. This paper proposed the 3 – D finite element method (FEM) for stress and deformation analysis of double curvature arc dam considering the non – linearity of foundation rock following the Hoek – Brown Criterion. The proposed methodology is implemented through MATLAB scripting language and studied the double curvature arc dam proposed for Budhi Gandaki hydropower project. The stress developed in the foundation rock, compressive and tensile stress acting on the dam are investigated and analysed for the reservoir level variation. Deformation at the top of the dam and in the foundation rock is also investigated. In addition to that, stress and deformation variation in the foundation rock is analysed for various rock properties.

Behavior and dam passage of juvenile Chinook salmon and juvenile steelhead at Detroit Reservoir and Dam, Oregon, March 2012-February 2013

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson W.; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin D.

2014-01-01

The in-reservoir movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) were studied at Detroit Reservoir and Dam, near Detroit, Oregon, during 2012 and 2013. The goal of the study was to provide data to inform decisions about future downstream passage alternatives and factors affecting downstream passage rates with the existing dam configuration. In 2012, 468 juvenile Chinook salmon and 200 juvenile steelhead were tagged and released during a 3-month period in the spring, and another 514 juvenile Chinook salmon were tagged and released during a 3-month period in the fall. The fish were surgically implanted with a small acoustic transmitter with an expected life of about 3 months and a passive integrated transponder tag with an indefinite life, and were released into the two main tributaries several kilometers upstream of the reservoir. Juvenile Chinook salmon migrated from the release sites to the reservoir in a greater proportion than juvenile steelhead, but once in the reservoir, juvenile steelhead migrated to the forebay faster and had a higher dam passage rate than juvenile Chinook salmon. The routes available for passing water and fish varied throughout the year, with low reservoir elevations in winter and high reservoir elevations in summer in accordance with the flood-control purpose of the dam. Most dam passage was through the spillway during the spring and summer, when the reservoir elevation was high and the spillway and powerhouse were the most common routes in operation, and via the powerhouse during the fall and winter period, when the reservoir elevation was low and the regulating outlet and powerhouse were the most common routes in operation. Few tagged fish passed when the powerhouse was the only route in operation. Dam passage rates during the spring and summer were greatest at night, increased with dam discharge, and were greater when water was passed freely over the spillway compared to when it was controlled by the spillway Tainter gates. Dam passage rates during the fall and winter, when the reservoir elevation usually was too low for spillway operation, were lower than during the spring and summer, negatively related to reservoir elevation, and positively related to dam discharge, though the latter relation diminished as reservoir elevation decreased. Fish locations near the dam from estimates of three-dimensional positions often were near the locations of dam discharge and fish depths were surface oriented relative to the depth of the forebay. Fish passage rates with the existing dam configuration were greatest when the spillway was in operation and were lowest when the powerhouse was the only route in operation; the latter result may be related to the relatively low magnitude or variability in discharge during that condition. The available data suggest that a properly designed surface outlet could be a viable passage route for juvenile Chinook salmon and juvenile steelhead at Detroit Dam. A second year of data collection based on a similar study design was complete at the time of this report.

Evaluation of Lower Umatilla River Channel Modifications Below Three Mile Dam, 1984 Annual Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nigro, Anthony A.; Ward, David L.

1985-05-01

This report summarizes results of the first year of a study initiated in September 1984 to evaluate the adequacy of channel modifications made in the lower Umatilla River to improve adult anadromous salmonid passage to Three Mile Dam (RKm 5.6), determine if fish passage or delay problems exist at Three Mile Dam and recommend site specific corrective measures if needed. Movements of steelhead (Salmo gairdneri) were monitored using mark and recapture and radio telemetry techniques. Thirty-four steelhead were marked with T-anchor tags and released in the lower river. Fifteen of those marked were also fitted with radio transmitters. Three radiotaggedmore » steelhead migrated through channel modifications to Three Mile Dam. Two of these fish migrated to the dam in less than 26 hours, but held just below the dam for 7 and 10 days before entering the ladders. The third steelhead delayed for 30 days and entered the west ladder within 24 hours of arrival at the dam. Two other radiotagged steelhead moved upstream through some of the channel modifications but did not migrate to the dam. Only one of 19 marked steelhead not fitted with transmitters was recovered at Three Mile Dam. 14 refs., 18 figs., 3 tabs.« less

The potential for dams to impact lowland meandering river floodplain geomorphology.

PubMed

Marren, Philip M; Grove, James R; Webb, J Angus; Stewardson, Michael J

2014-01-01

The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an "environmental sediment regime" to operate alongside environmental flows.

The Potential for Dams to Impact Lowland Meandering River Floodplain Geomorphology

PubMed Central

Marren, Philip M.; Grove, James R.; Webb, J. Angus; Stewardson, Michael J.

2014-01-01

The majority of the world's floodplains are dammed. Although some implications of dams for riverine ecology and for river channel morphology are well understood, there is less research on the impacts of dams on floodplain geomorphology. We review studies from dammed and undammed rivers and include influences on vertical and lateral accretion, meander migration and cutoff formation, avulsion, and interactions with floodplain vegetation. The results are synthesized into a conceptual model of the effects of dams on the major geomorphic influences on floodplain development. This model is used to assess the likely consequences of eight dam and flow regulation scenarios for floodplain geomorphology. Sediment starvation downstream of dams has perhaps the greatest potential to impact on floodplain development. Such effects will persist further downstream where tributary sediment inputs are relatively low and there is minimal buffering by alluvial sediment stores. We can identify several ways in which floodplains might potentially be affected by dams, with varying degrees of confidence, including a distinction between passive impacts (floodplain disconnection) and active impacts (changes in geomorphological processes and functioning). These active processes are likely to have more serious implications for floodplain function and emphasize both the need for future research and the need for an “environmental sediment regime” to operate alongside environmental flows. PMID:24587718

Rock Mass Behavior Under Hydropower Embankment Dams: A Two-Dimensional Numerical Study

NASA Astrophysics Data System (ADS)

Bondarchuk, A.; Ask, M. V. S.; Dahlström, L.-O.; Nordlund, E.

2012-09-01

Sweden has more than 190 large hydropower dams, of which about 50 are pure embankment dams and over 100 are concrete/embankment dams. This paper presents results from conceptual analyses of the response of typical Swedish rock mass to the construction of a hydropower embankment dam and its first stages of operation. The aim is to identify locations and magnitudes of displacements that are occurring in the rock foundation and grout curtain after construction of the dam, the first filling of its water reservoir, and after one seasonal variation of the water table. Coupled hydro-mechanical analysis was conducted using the two-dimensional distinct element program UDEC. Series of the simulations have been performed and the results show that the first filling of the reservoir and variation of water table induce largest magnitudes of displacement, with the greatest values obtained from the two models with high differential horizontal stresses and smallest spacing of sub-vertical fractures. These results may help identifying the condition of the dam foundation and contribute to the development of proper maintenance measures, which guarantee the safety and functionality of the dam. Additionally, newly developed dams may use these results for the estimation of the possible response of the rock foundation to the construction.

Lava Flows in the Grand Canyon

NASA Technical Reports Server (NTRS)

2003-01-01

Over vast expanses of time, natural processes like floods and volcanoes deposit layers of rock on the Earth's surface. To delve down through layers of rock is to explore our planet's history. Sometimes rock layers are exposed through human activity, such as drilling or excavation. Other times, rivers carve through the rock. One of the best, and most well-known, examples of a river exposing ancient rocks is Colorado River in Arizona's Grand Canyon. What fewer people know is that the Grand Canyon also has a history of relatively recent (on geologic time scales) volcanism. The evidence--hardened lava--spills down the canyon walls all the way to the river. On June 22, 2003, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the Grand Canyon, near 36.2 degrees north latitude and 113.2 degrees west longitude. ASTER detects light visible to human eyes as well as 'invisible' infrared light. Because different minerals reflect different portions of the light spectrum, ASTER can see varying mineral compositions of the rocks it observes, as well as detecting vegetation. In this three-dimensional visualization, lava fields appear brownish gray, darker than the layers of limestone, sandstone and other rock in the canyon. Vegetation appears green, and sparsely vegetated areas appear mustard. Water in the Colorado River is blue-purple. Geologists estimate that between 1.8 million and 400,000 years ago, lava flows actually dammed the Colorado River more than a dozen times. Some of the lava dams were as high as 600 meters (about 1,969 feet), forming immense reservoirs. Over time, enough water and sediment built up to push the river flow over the tops of these dams and eventually erode them away. Today, remnants of these lava dams remain throughout the area, along with the much older rock layers they cover. Among the most well known examples of these 'frozen' lava cascades is Lava Falls, which spills down to the river next to a cinder cone known as Volcan's Throne. Numerous flows spread down into Whitmore Canyon, a Colorado River tributary, as well.

Investigating passage of ESA-listed juvenile fall Chinook salmon at Lower Granite Dam during winter when the fish bypass system is not operated

USGS Publications Warehouse

Kock, Tobias J.; Tiffan, Kenneth F.; Connor, William P.

2007-01-01

During the winter of 2006-07, we radio and passive integrated transponder (PIT) tagged, and released 99 juvenile fall Chinook salmon to evaluate over-wintering behavior and dam passage in the lower Snake River, Washington. All fish were released 10 km upstream of Lower Granite Dam at Granite Point in early November, 2006. Fixed radio telemetry detection sites located in the forebay and tailrace areas of Lower Granite, Little Goose, Lower Monumental, Ice Harbor, Bonneville dams, and at Lyle, Washington were used to monitor fish movements and dam passage through early-May 2007. Of the 99 fish released during our study, 80 passed Lower Granite Dam and were detected at downstream detection sites, 37 passed Little Goose Dam, 41 passed Lower Monumental Dam, 31 passed Ice Harbor Dam, 18 passed Lyle, WA, and 13 passed Bonneville Dam. Of the fish that passed Lower Granite Dam in the fall, 63 fish did so during the extended bypass period from November 1 through December 16. Of these fish, 53 were also detected by the PIT-tag interrogation system. Fifteen of the fish that passed Lower Granite Dam in the fall continued to pass lower Snake River dams and exit the system by the end of January. The remaining fish either died, their tags failed, or they resided in Little Goose Reservoir until spring when relatively few continued their seaward migration. Passage of tagged fish past lower Snake River dams generally declined during the winter as temperatures decreased, but increased again in the spring as temperatures and flows increased. Fish residence times in reservoirs and forebays was lengthy during the winter (up to 160 d), and varied by reservoir and time of year. We observed no diel trends in fish passage. Very few fish were detected at PIT-tag interrogation sites in the spring compared to detection by radio telemetry detection sites indicating that fish may have passed via spill. We believe that passage of overwintering juvenile fall Chinook salmon during winter is due more to chance than directed downstream movement. Since the primary route of passage during the winter is through powerhouse turbines, the potential exists for increased mortality for over-wintering juvenile fall Chinook salmon in the Snake River. Our findings that some fish can pass undetected during the winter likely bias traditional smolt-to-adult return rate calculations that are typically used to measure the success of juvenile transportation studies.

Evaluation of the Pseudostatic Analyses of Earth Dams Using FE Simulation and Observed Earthquake-Induced Deformations: Case Studies of Upper San Fernando and Kitayama Dams

PubMed Central

Akhlaghi, Tohid

2014-01-01

Evaluation of the accuracy of the pseudostatic approach is governed by the accuracy with which the simple pseudostatic inertial forces represent the complex dynamic inertial forces that actually exist in an earthquake. In this study, the Upper San Fernando and Kitayama earth dams, which have been designed using the pseudostatic approach and damaged during the 1971 San Fernando and 1995 Kobe earthquakes, were investigated and analyzed. The finite element models of the dams were prepared based on the detailed available data and results of in situ and laboratory material tests. Dynamic analyses were conducted to simulate the earthquake-induced deformations of the dams using the computer program Plaxis code. Then the pseudostatic seismic coefficient used in the design and analyses of the dams were compared with the seismic coefficients obtained from dynamic analyses of the simulated model as well as the other available proposed pseudostatic correlations. Based on the comparisons made, the accuracy and reliability of the pseudostatic seismic coefficients are evaluated and discussed. PMID:24616636

Status after 5 Years of Survival Compliance Testing in the Federal Columbia River Power System (FCRPS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, John R.; Weiland, Mark A.; Ham, Kenneth D.

Survival studies of juvenile salmonids implanted with acoustic tags have been conducted at hydroelectric dams within the Federal Columbia River Power System (FCRPS) in the Columbia and Snake rivers between 2010 and 2014 to assess compliance with dam passage survival standards stipulated in the 2008 Biological Opinion (BiOp). For juvenile salmonids migrating downstream in the spring, dam passage survival defined as survival from the upstream dam face to the tailrace mixing zone must be ≥96% and for summer migrants, ≥93%, and estimated with a standard error ≤1.5% (i.e., 95% confidence interval of ±3%). A total of 29 compliance tests havemore » been conducted at 6 of 8 FCRPS main-stem dams, using over 109,000 acoustic-tagged salmonid smolts. Of these 29 compliance studies, 23 met the survival standards and 26 met the precision requirements. Of the 6 dams evaluated to date, individual survival estimates range from 0.9597 to 0.9868 for yearling Chinook Salmon, 0.9534 to 0.9952 for steelhead, and 0.9076 to 0.9789 for subyearling Chinook Salmon. These investigations suggest the large capital investment over the last 20 years to improve juvenile salmon passage through the FCRPS dams has been beneficial.« less

Feasibility of groundwater recharge dam projects in arid environments

NASA Astrophysics Data System (ADS)

Jaafar, H. H.

2014-05-01

A new method for determining feasibility and prioritizing investments for agricultural and domestic recharge dams in arid regions is developed and presented. The method is based on identifying the factors affecting the decision making process and evaluating these factors, followed by determining the indices in a GIS-aided environment. Evaluated parameters include results from field surveys and site visits, land cover and soils data, precipitation data, runoff data and modeling, number of beneficiaries, domestic irrigation demand, reservoir objectives, demography, reservoirs yield and reliability, dam structures, construction costs, and operation and maintenance costs. Results of a case study on more than eighty proposed dams indicate that assessment of reliability, annualized cost/demand satisfied and yield is crucial prior to investment decision making in arid areas. Irrigation demand is the major influencing parameter on yield and reliability of recharge dams, even when only 3 months of the demand were included. Reliability of the proposed reservoirs as related to their standardized size and net inflow was found to increase with increasing yield. High priority dams were less than 4% of the total, and less priority dams amounted to 23%, with the remaining found to be not feasible. The results of this methodology and its application has proved effective in guiding stakeholders for defining most favorable sites for preliminary and detailed design studies and commissioning.

Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2011 - February 2012

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Haner, Philip V.; Sprando, Jamie M.; Smith, Collin D.; Evans, Scott D.; Hatton, Tyson W.

2013-01-01

The movements and dam passage of juvenile Chinook salmon implanted with acoustic transmitters and passive integrated transponder tags were studied at Cougar Reservoir and Dam, near Springfield, Oregon. The purpose of the study was to provide information to aid with decisions about potential alternatives for improving downstream passage conditions for juvenile salmonids in this flood-control reservoir. In 2011, a total of 411 hatchery fish and 26 wild fish were tagged and released during a 3-month period in the spring, and another 356 hatchery fish and 117 wild fish were released during a 3-month period in the fall. A series of 16 autonomous hydrophones throughout the reservoir and 12 hydrophones in a collective system near the dam outlet were used to determine general movements and dam passage of the fish over the life of the acoustic transmitter, which was expected to be about 3 months. Movements within the reservoir were directional, and it was common for fish to migrate repeatedly from the head of the reservoir downstream to the dam outlet and back to the head of the reservoir. Most fish were detected near the temperature control tower at least once. The median time from release near the head of the reservoir to detection within about 100 meters of the dam outlet at the temperature control tower was between 5.7 and 10.8 days, depending on season and fish origin. Dam passage events occurred over a wider range of dates in the spring and summer than in the fall and winter, but dam passage numbers were greatest during the fall and winter. A total of 10.5 percent (43 of 411) of the hatchery fish and 15.4 percent (4 of 26) of the wild fish released in the spring are assumed to have passed the dam, whereas a total of 25.3 percent (90 of 356) of the hatchery fish and 16.9 percent (30 of 117) of the wild fish released in the fall are assumed to have passed the dam. A small number of fish passed the dam after their transmitters had stopped working and were detected at passive integrated transponder detectors at various locations downstream of the dam, indicating some tagged fish passed the dam undetected. The rate of dam passage was affected by diel period, discharge, and reservoir elevation. Diel period was the most influential factor of those examined, with nighttime dam passage rates about 9 times greater than daytime rates, depending on the distance of fish from the dam outlet. Dam passage rates also were positively related to dam discharge, and negatively related to reservoir elevation. In the operational condition used as an example, fish approached the dam outlet at the temperature control tower from the south and east and, when most fish got near the tower, they were directly in front of it. In many cases, the results for wild and hatchery fish were similar, or the results suggested hatchery fish could be reasonable surrogates for wild fish. Hatchery-origin and wild-origin fish behaved similarly in the following ways: their general movements in the reservoir; the timing of their dam passage; and the effects of diel period, discharge, and elevation on their passage rates. Parasitic copepods were present on most wild fish examined, and the mortality of wild fish during capture, handling and tagging was much greater than that of hatchery fish. This suggests that the ability of wild fish to cope with stressors may be less than that of fish directly from the hatchery.

Regulation of water resources for sustaining global future socioeconomic development

NASA Astrophysics Data System (ADS)

Chen, J.; SHI, H.; Sivakumar, B.

2016-12-01

With population projections indicating continued growth during this century, socio-economic problems (e.g., water, food, and energy shortages) will be most likely to occur, especially if proper planning, development, and management strategies are not adopted. In the present study, firstly, we explore the vital role of dams in promoting economic growth through analyzing the relationship between dams and Gross Domestic Product (GDP) at both global and national scales. Secondly, we analyze the current situation of global water scarcity based on the data representing water resources availability, dam development, and the level of economic development. Third, with comprehensive consideration of population growth as the major driving force, water resources availability as the basic supporting factor, and topography as the important constraint, this study addresses the question of dam development in the future and predicts the locations of future dams around the world.

Dynamic analysis of an inflatable dam subjected to a flood

NASA Astrophysics Data System (ADS)

Lowery, K.; Liapis, S.

A dynamic simulation of the response of an inflatable dam subjected to a flood is carried out to determine the survivability envelope of the dam where it can operate without rupture, or overflow. The free-surface flow problem is solved in two dimensions using a fully nonlinear mixed Eulerian-Lagrangian formulation. The dam is modeled as an elastic shell inflated with air and simply supported from two points. The finite element method is employed to determine the dynamic response of the structure using ABAQUS with a shell element. The problem is solved in the time domain which allows the prediction of a number of transient phenomena such as the generation of upstream advancing waves, the dynamic structural response and structural failure. Failure takes place when the dam either ruptures or overflows. Stresses in the dam material were monitored to determine when rupture occurs. An iterative study was performed to find the serviceability envelope of the dam in terms of the internal pressure and the flood Froude number for two flood depths. It was found that existing inflatable dams are quite effective in suppressing floods for a relatively wide range of flood velocities.

Incremental Dynamic Analysis of Koyna Dam under Repeated Ground Motions

NASA Astrophysics Data System (ADS)

Zainab Nik Azizan, Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar; Abdullah, Junaidah

2018-03-01

This paper discovers the incremental dynamic analysis (IDA) of concrete gravity dam under single and repeated earthquake loadings to identify the limit state of the dam. Seven ground motions with horizontal and vertical direction as seismic input considered in the nonlinear dynamic analysis based on the real repeated earthquake in the worldwide. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. The scaled was depends on the fundamental period, T1 of the dam. The Koyna dam has been selected as a case study for the purpose of the analysis by assuming that no sliding and rigid foundation, has been estimated. IDA curves for Koyna dam developed for single and repeated ground motions and the performance level of the dam identifies. The IDA curve of repeated ground motion shown stiffer rather than single ground motion. The ultimate state displacement for a single event is 45.59mm and decreased to 39.33mm under repeated events which are decreased about 14%. This showed that the performance level of the dam based on seismic loadings depend on ground motion pattern.

Quantifying the role of Trojan dams in the between-herd spread of bovine viral diarrhoea virus (BVDv) in Ireland.

PubMed

Reardon, Fiona; Graham, David A; Clegg, Tracy A; Tratalos, Jamie A; O'Sullivan, Padraig; More, Simon J

2018-04-01

A compulsory national programme to eradicate bovine viral diarrhoea virus (BVDv) began in Ireland on 1 January, 2013. The objective of the current study was to quantify the role of Trojan dams (animal(s) not persistently infected (PI) with BVDv but carrying PI foetus(es) and introduced to the herd while pregnant with the PI foetus(es)) in the farm-to-farm spread of BVDv in Ireland, and to identify herd-level risk factors for producing or introducing a Trojan dam. The study population included all BVD+ calves born in Ireland between 1 January, 2013 and 31 December, 2015, along with their dams. BVD+ calves included all calves on the national programme database with an initial positive or inconclusive virus test, without a confirmatory re-test (status BVDPOS) and those with an initial positive or inconclusive test and a positive confirmatory test (status BVDPI). The Trojan status of dams was determined after considering their history of movement and of potential BVDV exposure, relative to a defined window of susceptibility (WOS; days 30-120 of gestation). During 2013-15, there were 29,422 BVD+ birth events to dams that were not themselves BVD+, including 2526 (8.6%) most-likely attributable to Trojan dams. The percentage of these birth events attributable to Trojan dams was significantly different (P < 0.001) between years, being 7.1% in 2013, 9.2% in 2014 and 10.6% in 2015. During 2013, in 9.9% of herds with one or more BVD+ birth to non-BVD+ dams, at least one of these births was attributed to a Trojan dam. In 2014 and 2015, the percentages were 11.8% and 13.3%, respectively. In 2013, in 7.8% of herds with one or more BVD+ birth to non-BVD+ dams, all of these births were attributable to Trojan dams. In 2014 and 2015, the percentages were 9.2% and 10.7%, respectively. A logistic GEE regression identified dam parity, herd size and an interaction between herd type and season as significant predictors for the birth of a BVD+ calf to a Trojan dam. Significant predictors for the sale of a Trojan dam from BVD+ herds included those selling more than one pregnant female and those with more than 2 BVD+ animals in the herd. Introduction of pregnant adult females is a potential source of BVD+ births in BVD-free herds and may add to the burden of infection in non-BVD-free herds. Addressing this route of transmission will be critical for herds that are now free of infection and wish to continue to purchase animals without introducing it. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Assessing hydraulic conditions through Francis turbines using an autonomous sensor device

DOE PAGES

Fu, Tao; Deng, Zhiqun Daniel; Duncan, Joanne P.; ...

2016-08-19

Downstream migratory fish, including some endangered species, can be injured or killed during turbine passage. In this study an autonomous Sensor Fish device was deployed at Arrowrock Dam, Cougar Dam, and Detroit Dam to evaluate the hydraulic conditions and physical stresses that fish experienced when passing through these Francis turbines. Pressure data was used to identify the location of the Sensor Fish and to calculate the nadir pressure and the magnitude and the rate of change in pressure during turbine passage. Acceleration data was used to identify events (collisions or shear) Sensor Fish experienced and to categorize the severity levelmore » (severe, medium, and slight) of each event. The results showed that Sensor Fish experienced severe events mostly in the stay vane/wicket gate region and the runner region. In the stay vane/wicket gate region, almost all severe events were collisions. In the runner region, Sensor fish experienced both severe collisions and severe shear events. Sensor Fish data at three wicket gate opening treatments at Cougar Dam indicated that the wicket gate opening of the Francis turbine can affect the hydraulic conditions in the turbine runner region. Fewer Sensor Fish experienced severe collisions in the turbine runner region at the peak efficiency than at the minimum opening and the maximum opening treatments. Comparisons between the Francis turbines at the three dams and the AHT Kaplan turbine at Wanapum Dam showed that higher percentage of Sensor Fish experienced severe events in the runner region when passing through Francis turbines than the AHT Kaplan turbine. The nadir pressures of the Francis turbines were lower than those of the AHT Kaplan turbine at Wanapum Dam. Both the magnitude and the rate of change in pressure were higher in Francis turbines than in the AHT Kaplan turbine at Wanapum Dam in the runner region. This study can be used to guide future laboratory studies of fish passing through Francis turbine and help the design of more fish-friendly turbines for new hydroelectric dams or the rehabilitations of existing dams.« less

Monitoring displacements of an earthen dam using GNSS and remote sensing

NASA Astrophysics Data System (ADS)

Dardanelli, Gino; La Loggia, Goffredo; Perfetti, Nicola; Capodici, Fulvio; Puccio, Luigi; Maltese, Antonino

2014-10-01

This paper shows the results of a scientific research in which a GNSS continuous monitoring system for earth-dam deformations has been developed, then, deformations have been related with reservoir water surface and level. The experiment was conducted near Bivona (Sicily, Italy), on the Castello dam (Magazzolo Lake). On the top of the dam three control points were placed and three GNSS permanent stations were installed. The three stations continuously transmitted data to the control centre of the University of Palermo. The former has been determined using freely available satellite data (specifically Landsat 7 SLC-Off) collected during the whole study period (DOYs 101 to 348 2011). Issues related with the un-scanned rows filling and to better distinguish water from land pixels on the shoreline. The aim of this work is various: first of all, we want to evaluate whether the GPS post processing techniques can provide static results comparable to other monitoring techniques, such as spirit levelling. The study could take a significant importance given that the Italian legislation until today does not provide for the use of this technology to manage or monitor dams displacements or other civil engineering constructions. The use of GPS data in structural monitoring could in fact reduce some management costs. Usually the conventional GPS monitoring methods, where a base station GPS receiver must be located near the dam, did not ensure that the accuracy of results have been independent from the displacement of the crown (top end of dam). In this paper, a new approach in the area of study of the GNSS permanent network has been engaged to solve these problems. Field-testing results show that the new GNSS approach has excellent performances, and the monitoring of different section of the dam could reveal important information on its deformation, that its not operationally possible to retrieve elsewhere. The post-processing accuracy positioning is around 1-5 mm for the deformations monitoring of the Castello dam. Displacements of different sections of the dam reveal different behaviour (in time and periodicity) that looks to be related with water surface (and level) retrieved from remote sensing.

Assessing organic contaminant fluxes from contaminated sediments following dam removal in an urbanized river.

PubMed

Cantwell, Mark G; Perron, Monique M; Sullivan, Julia C; Katz, David R; Burgess, Robert M; King, John

2014-08-01

In this study, methods and approaches were developed and tested to assess changes in contaminant fluxes resulting from dam removal in a riverine system. Sediment traps and passive samplers were deployed to measure particulate and dissolved polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the water column prior to and following removal of a small, low-head dam in the Pawtuxet River, an urbanized river located in Cranston, RI, USA. During the study, concentrations of particulate and dissolved PAHs ranged from 21.5 to 103 μg/g and from 68 to 164 ng/L, respectively. Overall, temporal trends of PAHs showed no increases in either dissolved or particulate phases following removal of the dam. Dissolved concentrations of PCBs were very low, remaining below 1.72 ng/L at all sites. Particulate PCB concentrations across sites and time showed slightly greater variability, ranging from 80 to 469 ng/g, but with no indication that dam removal influenced any increases. Particulate PAHs and PCBs were sampled continuously at the site located below the dam and did not show sustained increases in concentration resulting from dam removal. The employment of passive sampling technology and sediment traps was highly effective in monitoring the concentrations and flux of contaminants moving through the river system. Variations in river flow had no effect on the concentration of contaminants in the dissolved or particulate phases, but did influence the flux rate of contaminants exiting the river. Overall, dam removal did not cause measurable sediment disturbance or increase the concentration or fluxes of dissolved or particulate PAHs and PCBs. This is due in large part to low volumes of impounded sediment residing above the dam and highly armored sediments in the river channel, which limited erosion. Results from this study will be used to improve methods and approaches that assess the short- and long-term impacts ecological restoration activities such as dam removal have on the release and transport of sediment-bound contaminants.

Assessing hydraulic conditions through Francis turbines using an autonomous sensor device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Tao; Deng, Zhiqun Daniel; Duncan, Joanne P.

Downstream migratory fish, including some endangered species, can be injured or killed during turbine passage. In this study an autonomous Sensor Fish device was deployed at Arrowrock Dam, Cougar Dam, and Detroit Dam to evaluate the hydraulic conditions and physical stresses that fish experienced when passing through these Francis turbines. Pressure data was used to identify the location of the Sensor Fish and to calculate the nadir pressure and the magnitude and the rate of change in pressure during turbine passage. Acceleration data was used to identify events (collisions or shear) Sensor Fish experienced and to categorize the severity levelmore » (severe, medium, and slight) of each event. The results showed that Sensor Fish experienced severe events mostly in the stay vane/wicket gate region and the runner region. In the stay vane/wicket gate region, almost all severe events were collisions. In the runner region, Sensor fish experienced both severe collisions and severe shear events. Sensor Fish data at three wicket gate opening treatments at Cougar Dam indicated that the wicket gate opening of the Francis turbine can affect the hydraulic conditions in the turbine runner region. Fewer Sensor Fish experienced severe collisions in the turbine runner region at the peak efficiency than at the minimum opening and the maximum opening treatments. Comparisons between the Francis turbines at the three dams and the AHT Kaplan turbine at Wanapum Dam showed that higher percentage of Sensor Fish experienced severe events in the runner region when passing through Francis turbines than the AHT Kaplan turbine. The nadir pressures of the Francis turbines were lower than those of the AHT Kaplan turbine at Wanapum Dam. Both the magnitude and the rate of change in pressure were higher in Francis turbines than in the AHT Kaplan turbine at Wanapum Dam in the runner region. This study can be used to guide future laboratory studies of fish passing through Francis turbine and help the design of more fish-friendly turbines for new hydroelectric dams or the rehabilitations of existing dams.« less

Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

NASA Astrophysics Data System (ADS)

Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

2018-03-01

The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

Effects of Hydroelectric Dam Operations on the Restoration Potential of Snake River Fall Chinook Salmon (Oncorhynchus tshawytscha) Spawning Habitat Final Report, October 2005 - September 2007.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanrahan, Timothy P.; Richmond, Marshall C.; Arntzen, Evan V.

2007-11-13

This report describes research conducted by the Pacific Northwest National Laboratory for the Bonneville Power Administration (BPA) as part of the Fish and Wildlife Program directed by the Northwest Power and Conservation Council. The study evaluated the restoration potential of Snake River fall Chinook salmon spawning habitat within the impounded lower Snake River. The objective of the research was to determine if hydroelectric dam operations could be modified, within existing system constraints (e.g., minimum to normal pool levels; without partial removal of a dam structure), to increase the amount of available fall Chinook salmon spawning habitat in the lower Snakemore » River. Empirical and modeled physical habitat data were used to compare potential fall Chinook salmon spawning habitat in the Snake River, under current and modified dam operations, with the analogous physical characteristics of an existing fall Chinook salmon spawning area in the Columbia River. The two Snake River study areas included the Ice Harbor Dam tailrace downstream to the Highway 12 bridge and the Lower Granite Dam tailrace downstream approximately 12 river kilometers. These areas represent tailwater habitat (i.e., riverine segments extending from a dam downstream to the backwater influence from the next dam downstream). We used a reference site, indicative of current fall Chinook salmon spawning areas in tailwater habitat, against which to compare the physical characteristics of each study site. The reference site for tailwater habitats was the section extending downstream from the Wanapum Dam tailrace on the Columbia River. Fall Chinook salmon spawning habitat use data, including water depth, velocity, substrate size and channelbed slope, from the Wanapum reference area were used to define spawning habitat suitability based on these variables. Fall Chinook salmon spawning habitat suitability of the Snake River study areas was estimated by applying the Wanapum reference reach habitat suitability criteria to measured and modeled habitat data from the Snake River study areas. Channel morphology data from the Wanapum reference reach and the Snake River study areas were evaluated to identify geomorphically suitable fall Chinook salmon spawning habitat. The results of this study indicate that a majority of the Ice Harbor and Lower Granite study areas contain suitable fall Chinook salmon spawning habitat under existing hydrosystem operations. However, a large majority of the currently available fall Chinook salmon spawning habitat in the Ice Harbor and Lower Granite study areas is of low quality. The potential for increasing, through modifications to hydrosystem operations (i.e., minimum pool elevation of the next downstream dam), the quantity or quality of fall Chinook salmon spawning habitat appears to be limited. Estimates of the amount of potential fall Chinook salmon spawning habitat in the Ice Harbor study area decreased as the McNary Dam forebay elevation was lowered from normal to minimum pool elevation. Estimates of the amount of potential fall Chinook salmon spawning habitat in the Lower Granite study area increased as the Little Goose Dam forebay elevation was lowered from normal to minimum pool elevation; however, 97% of the available habitat was categorized within the range of lowest quality. In both the Ice Harbor and Lower Granite study areas, water velocity appears to be more of a limiting factor than water depth for fall Chinook salmon spawning habitat, with both study areas dominated by low-magnitude water velocity. The geomorphic suitability of both study areas appears to be compromised for fall Chinook salmon spawning habitat, with the Ice Harbor study area lacking significant bedforms along the longitudinal thalweg profile and the Lower Granite study area lacking cross-sectional topographic diversity. To increase the quantity of available fall Chinook salmon spawning habitat in the Ice Harbor and Lower Granite study area, modifications to hydroelectric dam operations beyond those evaluated in this study likely would be necessary. Modifications may include operational and structural changes, such as lowering downstream dam forebay elevations to less than minimum pool. There is a large amount of uncertainty as to whether or not such modifications could increase the quantity of available fall Chinook salmon spawning habitat in the Ice Harbor and Lower Granite study area. The results from this study provide some certainty that the quantity and quality of fall Chinook salmon spawning habitat within the lower Snake River are not likely to be increased within the existing hydroelectric dam operations.« less

Influence of Partial Dam Removal on Change of Channel Morphology and Physical Habitats: A Case Study of Yu-Sheng River

NASA Astrophysics Data System (ADS)

Hao Weng, Chung; Yeh, Chao Hsien

2017-04-01

The rivers in Taiwan have the characteristic of large slope gradient and fast flow velocity caused by rugged terrain. And Taiwan often aces many typhoons which will bring large rainfall in the summer. In early Taiwan, river management was more focus on flood control, flood protection and disaster reduction. In recent years, the rise of ecological conservation awareness for the precious fish species brings spotlight on the Taiwan salmon (Oncorhynchus masou formosanus) which lives in the river section of this study. In order to make sure ecological corridor continuing, dam removal is the frequently discussed measure in recent years and its impact on environmental is also highly concerned. Since the dam removal may causes severe changes to the river channel, the action of dam removal needs careful evaluation. As one of the endangered species, Taiwan salmon is considered a national treasure of Taiwan and it was originally an offshore migration of the Pacific salmon. After the ice age and geographical isolation, it becomes as an unique subspecies of Taiwan and evolved into landlocked salmon. Now the Taiwan salmon habitats only exists in few upstream creeks and the total number of wild Taiwan salmon in 2015 was about 4,300. In order to expand the connectivity of the fish habitats in Chi-Jia-Wan creek basin, several dam removal projects had completed with good results. Therefore, this paper focuses on the dam removal of Yu-Sheng creek dam. In this paper, a digital elevation model (DEM) of about 1 kilometer channel of the Yu-Sheng creek dam is obtained by unmanned aerial vehicle (UAV). Using CCHE2D model, the simulation of dam removal will reveal the impact on channel morphology. After model parameter identification and verification, this study simulated the scenarios of three historical typhoon events with recurrence interval of two years, fifteen years, and three decades under four different patterns of dam removal to identify the the head erosion, flow pattern, and siltation and erosion of channel. With simulations by River2D under mean flow and ecological reference flow for the channels before and after dam removal, the habitat suitability curves of adult, two-aged juvenile, and one-aged juvenile salmons were applied to estimate the weighted usable areas. With results of two models on channel changes, infrastructure protection, and habitats improvement the best way for dam removal is then suggested.

Evaluating the Mosul Dam's Instability after Resumption of Maintenance

NASA Astrophysics Data System (ADS)

Al-husseinawi, Y.; Li, Z.; Clarke, P. J.; Edwards, S.

2017-12-01

There is serious concern about the safety of Mosul dam in the north of Iraq. Millions of people in the downstream area are exposed to risk of catastrophic collapse of this dam due to its soluble foundation. Recent study (Milillo et al., 2016, Scientific Report/10.1038/srep37408) reported that the dam deformation has accelerated since August 2014, when grouting operations were interrupted due to the conflict in the region. In this study, we investigate the health of Mosul dam since Jun 2016 using three independent datasets: Sentinel-1A/B SAR images, levelling, and GPS measurement. The latter are based on three epochs of terrestrial observation for levelling and GPS data: March 2016, December 2016 and July 2017. During this period, maintenance operations are being recovered to keep the dam stable. The monitoring network, on which the levelling and GPS observations are based, consists of eighty-seven pillars distributed on the dam surface. The results from InSAR and leveling data show that the dam crest is settling by 9 mm/yr. In contrast to previous studies, our results show a deceleration in the settlement. This may be due to the maintenance operations performed in the last few months. InSAR time series analysis was performed using the in-house tool TM-SBAS. When using the small baseline Sentinel-1 constellation, all possibilities of image choice are taken into consideration and the SRTM DEM accuracy is sufficient to generate the differential interferograms. Data from both Sentinel-1A and -1B images are used, and these results can be compared with multi-platform (Envisat, Sentinel-1, Cosmo-SkyMed, and TerraSar-X) data collected during the period between March 2003 and September 2016.

National Program for Inspection of Non-Federal Dams. Tihonet Pond Number 2 Dam (MA 00030), Massachusetts Coastal Basin, Wareham, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1981-07-01

INSPECTION REPORT IDENTIFICATION NO.: MA 00030 S NAME OF DAM : TIHONET POND NO.2 DAM TOWN : WAREHAM COUNTY AND STATE : PLYMOUTH , MASSACHUSETTS STREAM...northeast of this dam serves to impound the water of Tihonet Pond also. This dam is referred to as Dam # 14 on Plymouth County Inspection Reports and...1. Approximately 1800 ft. northeast of this dam a second dam is located. This dam is referred to as Dam # 14 on Plymouth County . Inspection Reports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faber, Derrek M.; Ploskey, Gene R.; Weiland, Mark A.

Pacific Northwest National Laboratory (PNNL) conducted an acoustic-telemetry study at Bonneville Dam in 2009 to evaluate the effects of a behavioral guidance structure (BGS) in the Bonneville Dam second powerhouse forebay on fish passage and survival through the second powerhouse (B2), the dam as a whole, and through the first powerhouse and spillway combined. The BGS was deployed to increase the survival of fish passing through B2 by increasing the percentage of outmigrating smolts entering the B2 Corner Collector (B2CC)—a surface flow outlet known to be a relatively benign route for downstream passage at this dam. The study relied onmore » releases of live Juvenile Salmon Acoustic Telemetry System tagged smolts in the Columbia River and used acoustic telemetry to evaluate the approach, passage, and survival of passing juvenile salmon. Study results indicated that having turbine 11 in service is important for providing flow conditions that are comparable to those observed in pre-BGS years (2004 and 2005) and in 2008. This study supports the U.S. Army Corps of Engineers continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.« less

Passage survival of juvenile steelhead, coho salmon, and Chinook salmon in Lake Scanewa and at Cowlitz Falls Dam, Cowlitz River, Washington, 2010–16

USGS Publications Warehouse

Liedtke, Theresa L.; Kock, Tobias J.; Hurst, William

2018-04-03

A multi-year evaluation was conducted during 2010–16 to evaluate passage survival of juvenile steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) in Lake Scanewa, and at Cowlitz Falls Dam in the upper Cowlitz River Basin, Washington. Reservoir passage survival was evaluated in 2010, 2011, and 2016, and included the tagging and release of 1,127 juvenile salmonids. Tagged fish were released directly into the Cowlitz and Cispus Rivers, 22.3 and 8.9 km, respectively, upstream of the reservoir, and were monitored as they moved downstream into, and through the reservoir. A single release-recapture survival model was used to analyze detection records and estimate reservoir passage survival, which was defined as successful passage from reservoir entry to arrival at Cowlitz Falls Dam. Tagged fish generally moved quickly downstream of the release sites and, on average, arrived in the dam forebay within 2 d of release. Median travel time from release to first detection at the dam ranged from 0.23 to 0.96 d for juvenile steelhead, from 0.15 to 1.11 d for juvenile coho salmon, and from 0.18 to 1.89 d for juvenile Chinook salmon. Minimum reservoir passage survival probabilities were 0.960 for steelhead, 0.855 for coho salmon and 0.900 for Chinook salmon.Dam passage survival was evaluated at the pilot-study level during 2013–16 and included the tagging and release of 2,512 juvenile salmonids. Juvenile Chinook salmon were evaluated during 2013–14, and juvenile steelhead and coho salmon were evaluated during 2015–16. A paired-release study design was used that included release sites located upstream and downstream of Cowlitz Falls Dam. The downstream release site was positioned at the downstream margin of the dam’s tailrace, which allowed dam passage survival to be measured in a manner that included mortality that occurred in the passage route and in the dam tailrace. More than one-half of the tagged Chinook salmon (52 percent) released upstream of Cowlitz Falls Dam moved downstream and passed the project; the remaining fish either remained upstream of the dam (37 percent) or were collected (11 percent). In 2015 and 2016, collection efficiencies at Cowlitz Falls Dam were abnormally high for juvenile steelhead and coho salmon, which resulted in few fish passing the dam. Seven percent of the tagged steelhead (40 fish) and 4 percent of the tagged coho salmon (18 fish) released upstream of the dam eventually passed the project, but these low numbers of fish precluded the estimation of meaningful survival estimates. Dam passage survival probability estimates for juvenile Chinook salmon were 0.828 in 2013 and 0.861 in 2014, lower than previously reported for turbine-specific passage Cowlitz Falls Dam.

Study on Reventment-Protected and Non-Bottom-Protected Plunge Pool of High Arch Dam

NASA Astrophysics Data System (ADS)

Yingkui, Wang; Quxiu, Cao; Fanhui, Kong

2018-05-01

Lots of high arch dam have the characteristics of “High head, Large discharge and Narrow river valley”, therefore, the security researches of energy dissipation were always the focus in these hydro-projects. Statistically, the trajectory type energy dissipation is the most widely used in the built high arch dams, and the water plunge poor were always set downstream the dam body. However, the widely used protected plunge poor need large investment with the disadvantage of complicated operation and maintenance. Along with the construction of concrete high arch dam in the Southwest China, the river overburden and water cushion were deep in dam site, which is becoming a new characteristic of these hydro-projects. Accordingly, the deep water cushion can be used for the energy dissipation design, such as the “Reventment-Protected and Non-Bottom-Protected Plunge Pool”, which has the advantage of more simplified project design and more economy investment.

Research on evaluation methods for water regulation ability of dams in the Huai River Basin

NASA Astrophysics Data System (ADS)

Shan, G. H.; Lv, S. F.; Ma, K.

2016-08-01

Water environment protection is a global and urgent problem that requires correct and precise evaluation. Evaluation methods have been studied for many years; however, there is a lack of research on the methods of assessing the water regulation ability of dams. Currently, evaluating the ability of dams has become a practical and significant research orientation because of the global water crisis, and the lack of effective ways to manage a dam's regulation ability has only compounded this. This paper firstly constructs seven evaluation factors and then develops two evaluation approaches to implement the factors according to the features of the problem. Dams of the Yin Shang ecological control section in the Huai He River basin are selected as an example to demonstrate the method. The results show that the evaluation approaches can produce better and more practical suggestions for dam managers.

Geomorphic responses to large check-dam removal on a mountain river in Taiwan

NASA Astrophysics Data System (ADS)

Wang, H.; Stark, C. P.; Cook, K. L.; Kuo, W.

2011-12-01

Dam removal has become an important aspect of river restoration in recent years, but studies documenting the physical and ecological response to dam removal are still lacking - particularly in mountain rivers and following major floods. This presentation documents the recent removal of a large dam on a coarse-grained, steep (an order of magnitude greater than on the Marmot) mountain channel in Taiwan. The Chijiawan river, a tributary of the Tachia River draining a 1236 km2 watershed, is the only habitat in Taiwan of the endangered Formosan landlocked salmon. The habitat of this fish has been cut significantly since the 1960s following construction of check dams designed to prevent reservoir sedimentation downstream. The largest and lowermost barrier on Chijiawan creek is the 15m high, "No. 1 Check Dam" built in 1971. Forty years later, in early 2011, the sediment wedge behind the dam had reached an estimated 0.2 million m3 and the dam toe had been scoured about 4m below its foundation, posing a serious risk of dam failure. For these reasons, the Shei-Pa National Park removed the dam in late May 2011. To monitor the response of the river to dam removal, we installed video cameras, time-lapse cameras, stage recorders, and turbidity sensors, conducted surveys of grain size distributions and longitudinal profiles, and carried out repeat photography. Channel changes were greatest immediately following removal as a result of the high stream power, steep energy slope, and unconsolidated alluvial fill behind the dam. Headcut propagation caused immediate removal of the sand-grade sediment and progressive channel widening. One month after dam removal, a minor flood event excavated a big wedge of sediment from the impoundment. Most of the subsequent downstream deposition occurred within 500m of the dam, with alluviation reaching up to 0.5m in places. Two months after dam removal, erosion had propagated 300m upstream into the impounded sediment along a bed profile of gradient at 1.4% at a headcut with a local gradient of 5.1%. The change in grain size was a fining of the sediment at the two downstream sites and a slight coarsening at the upstream site from April 2010 to July 2011. This is likely due to the increase in energy upstream of the dam post-removal, which has transported the fine-grained sediments downstream. As the river adjusts over coming months and years, we anticipate that observations such as these will help generate an important resource for all those concerned with dam removal and river restoration.

Investigating passage of ESA-listed juvenile fall Chinook salmon at Lower Granite Dam during winter when the fish bypass system is not operated. 2006 Annual Report

USGS Publications Warehouse

Tiffan, Kenneth F.; Kock, Tobias J.; Connor, William P.

2007-01-01

During the winter of 2005-06, we radio and PIT tagged and released 48 juvenile fall Chinook salmon to evaluate over-wintering behavior and dam passage in the lower Snake River, Washington. Fish were released at the upstream end of the Lower Granite Dam forebay in November and December 2005. Fixed radio telemetry detection sites located in forebay and tailrace areas of Lower Granite, Little Goose, Lower Monumental and Ice Harbor dams were used to monitor fish movements and dam passage through early-May 2006. Of the 48 fish released during our study, 39 (81 %) passed Lower Granite Dam and were detected at downstream detection sites, 29 (60%) passed Little Goose Dam, 25 (52%) passed Lower Monumental Dam, and 15 (31%) passed Ice Harbor Dam. Thirty-seven (95%), 23 (79%), 16 (64%), and 9 (60%) of the fish that passed Lower Granite, Little Goose, Lower Monumental, and Ice Harbor dams respectively, did so when the fish bypass system was not operated. Passage of tagged fish past lower Snake River dams generally declined during the winter, but increased again after bypass began in April. Fish residence times in reservoirs and forebays was lengthy during the winter (up to 118 d), and varied by reservoir and time of year. We observed no diel passage trends. Only 15 of the 48 fish were subsequently detected at a PIT-tag interrogation site the following spring. We believe that passage of overwintering juvenile fall Chinook salmon during winter is due more to chance than directed downstream movement. Since the primary route of passage during the winter is through powerhouse turbines, the potential exists for increased mortality for over-wintering juvenile fall Chinook salmon in the Snake River. Our findings also have implications for transportation studies of subyearling fall Chinook salmon in the Snake River. Specifically, the finding that some fish can pass undetected during the winter may bias smolt-to-adult return rate calculations that are typically used to measure the success of the aforementioned management actions.

Effect of dam weight and pregnancy nutrition on average lactation performance of ewe offspring over 5 years.

PubMed

Paten, A M; Pain, S J; Peterson, S W; Lopez-Villalobos, N; Kenyon, P R; Blair, H T

2017-06-01

The foetal mammary gland is sensitive to maternal weight and nutrition during gestation, which could affect offspring milk production. It has previously been shown that ewes born to dams offered maintenance nutrition during pregnancy (day 21 to 140 of gestation) produced greater milk, lactose and CP yields in their first lactation when compared with ewes born to dams offered ad libitum nutrition. In addition, ewes born to heavier dams produced greater milk and lactose yields when compared with ewes born to lighter dams. The objective of this study was to analyse and compare the 5-year lactation performance of the previously mentioned ewes, born to heavy or light dams that were offered maintenance or ad libitum pregnancy nutrition. Ewes were milked once per week, for the first 6 weeks of their lactation, for 5 years. Using milk yield and composition data, accumulated yields were calculated over a 42-day period for each year for milk, milk fat, CP, true protein, casein and lactose using a Legendre orthogonal polynomial model. Over the 5-year period, ewes born to heavy dams produced greater average milk (P=0.04), lactose (P=0.01) and CP (P=0.04) yields than offspring born to light dams. In contrast, over the 5-year period dam nutrition during pregnancy did not affect average (P>0.05) offspring milk yields or composition, but did increase milk and lactose accumulated yield (P=0.03 and 0.01, respectively) in the first lactation. These results indicate that maternal gestational nutrition appears to only affect the first lactational performance of ewe offspring. Neither dam nutrition nor size affected grand-offspring live weight gain to, or live weight at weaning (P>0.05). Combined these data indicate that under the conditions of the present study, manipulating dam weight or nutrition in pregnancy can have some effects of offspring lactational performance, however, these effects are not large enough to alter grand-offspring growth to weaning. Therefore, such manipulations are not a viable management tool for farmers to influence lamb growth to weaning.

Geophysical evaluation of the Success Dam foundation, Porterville, California

USGS Publications Warehouse

Hunter, L.E.; Powers, M.H.; Haines, S.; Asch, T.; Burton, B.L.; Serafini, D.C.

2006-01-01

Success Dam is a zonedearth fill embankment located near Porterville, CA. Studies of Success Dam by the recent Dam Safety Assurance Program (DSAP) have demonstrated the potential for seismic instability and large deformation of the dam due to relatively low levels of earthquake shaking. The U.S. Army Corps of Engineers conducted several phases of investigations to determine the properties of the dam and its underlying foundation. Detailed engineering studies have been applied using a large number of analytical techniques to estimate the response of the dam and foundation system when subjected to earthquake loading. Although a large amount of data have been acquired, most are 'point' data from borings and results have to be extrapolated between the borings. Geophysical techniques were applied to image the subsurface to provide a better understanding of the spatial distribution of key units that potentially impact the stability. Geophysical investigations employing seismic refraction tomography, direct current (DC) resistivity, audio magnetotellurics (AMT) and self-potential (SP) were conducted across the location of the foundation of a new dam proposed to replace the existing one. Depth to bedrock and the occurrence of beds potentially susceptible to liquefaction were the focus of the investigations. Seismic refraction tomography offers a deep investigation of the foundation region and looks at compressional and shear properties of the material. Whereas resistivity surveys determines conductivity relationships in the shallow subsurface and can produce a relatively high-resolution image of geological units with different electrical properties. AMT was applied because it has the potential to look considerably deeper than the other methods, is useful for confirming depth to bedrock, and can be useful in identifying deep seated faults. SP is a passive electrical method that measures the electrical streaming potential in the subsurface that responds to the movement of ground water. SP surveys were conducted at low pool and high pool conditions in order to look for evidence of seepage below the existing dam. In this paper, we summarize these techniques, present their results at Success Dam, and discuss general application of these techniques for investigating dams and their foundations.

National Dam Safety Program. Cadet Mine Tailings Dam (MO 30715), Mississippi - Kaskaskia - St. Louis Basin, Washington County, Missouri. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

Safety Inspection of Dams" are not available. These studies should be performed by a professional engineer experienced in the design and construction...engineer experienced in the design and construction of tailings dams. An inspection and maintenance program should be initiated. Periodic inspections...Page No. SECTION 1 - PROJECT INFORMATION 1.1 General 1 1.2 Description of Project 1 1.3 Pertinent Data 2 SECTION 2 - ENGINEERING DATA 2.1 Design 5 2.2

Seismic risk assessment for Poiana Uzului (Romania) buttress dam on Uz river

NASA Astrophysics Data System (ADS)

Moldovan, Iren-Adelina; Toma-Danila, Dragos; Paerele, Cosmin Marian; Emilian Toader, Victorin; Petruta Constantin, Angela; Ghita, Cristian

2017-04-01

The most important specific requirements towards dams' safety is the seismic risk assessment. This objective will be accomplished by rating the dams into seismic risk classes using the theory of Bureau and Ballentine, 2002, and Bureau (2003), taking into account the maximum expected peak ground motions at dams' site, the structures vulnerability and the downstream risk characteristics. The maximum expected values for ground motions at dams' site have been obtained using probabilistic seismic hazard assessment approaches. The structural vulnerability was obtained from dams' characteristics (age, high, water volume) and the downstream risk was assessed using human, economical, touristic, historic and cultural heritage information from the areas that might be flooded in the case of a dam failure. A couple of flooding scenarios have been performed. The results of the work consist of local and regional seismic information, specific characteristics of dam, seismic hazard values for different return periods and risk classes. The studies realized in this paper have as final goal to provide in the near future the local emergency services with warnings of a potential dam failure and ensuing flood as a result of a large earthquake occurrence, allowing further public training for evacuation. Acknowledgments This work was partially supported by the Partnership in Priority Areas Program - PNII, under MEN-UEFISCDI, DARING Project no. 69/2014 and the Nucleu Program - PN 16-35, Project no. 03 01 and 01 06.

Compliance Monitoring of Yearling Chinook Salmon and Juvenile Steelhead Survival and Passage at John Day Dam, Spring 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

2012-02-01

The study was designed to estimate dam passage survival at John Day Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and to provide additional fish passage performance measures at that site as stipulated in the Columbia Basin Fish Accords.

Compliance Monitoring of Yearling Chinook Salmon and Juvenile Steelhead Survival and Passage at John Day Dam, Spring 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Townsend, Richard L.; Seaburg, Adam

The study was designed to estimate dam passage survival at John Day Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and to provide additional fish passage performance measures at that site as stipulated in the Columbia Basin Fish Accords.

77 FR 34033 - American River Power IX, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-08

... generator; (3) a concrete tailrace releasing water into the river downstream of the dam; (4) a switchyard... study the feasibility of the Peoria Dam, Illinois--Hydroelectric Water Power Project (Peoria Dam Project...-long, 50-foot-wide, 55-foot-high powerhouse containing two horizontal Kaplan pit turbines each with a...

Landslides Triggered by the 12 May 2008, M 7.9 Wenchuan, China Earthquake

NASA Astrophysics Data System (ADS)

Harp, E.; Jibson, R.; Godt, J.

2009-04-01

The 12 May 2008, M 7.9 Wenchuan earthquake in eastern Sichuan Province of China triggered tens of thousands of rock falls, rock slides, rock avalanches, and deep, complex, landslides. Of the approximately 87,000 deaths caused by the earthquake, more than 20,000 have been attributed to landsides. Numerous villages were buried by large landslides. Air-blasts resulting from the rapid failure and movement of landslides were observed and documented from numerous eye-witness accounts. More than 100 landslide-dammed lakes were created by the earthquake, 33 of which were evaluated to determine if spillway construction was necessary to minimize flooding by future breaching of the landslide dams. Spillways were ultimately constructed on at least 16 landslide dams. Preliminary observations in the field and from satellite imagery indicate that the most common types of landslides were rock falls and rock slides that ranged in size from several hundred cubic meters to several hundred thousand cubic meters in volume. There were hundreds to perhaps as many as one thousand landslides exceeding 1 million cubic meters in volume. The largest landslide identified using Jaxa's Alos/Prism satellite imagery (2.5 m resolution) is nearly 1 billion cubic meters in volume and is located approximately 12 km north-northeast of the city of Hanwang. This landslide appears to have resulted from the failure of a 1.5-km section of ridge crest that now occupies most of the adjacent valley to the northeast; its toe spills over the next ridge crest to the northeast. The satellite imagery of 4 June 2008 shows two small lakes dammed by the slide debris. Within the mountainous areas in the near-field zone of shaking, rock slides dammed chains of lakes in many drainages. Sections of streams 2-3 km long have been completely covered by rock debris as of the 4 June imagery The debris from the triggered landslides is being redistributed rapidly by post-earthquake rainfall. A 100-year rainstorm in September 2008 remobilized many earthquake-triggered landslide deposits into debris flows, which resulted in additional fatalities, road closures, and flow restrictions of even large rivers such as the MinJiang River near Yingxiu. Increased sedimentation from the landslide debris triggered by the 12 May earthquake could significantly reduce storage capacities of the numerous reservoirs in the region. To assist with hazard mitigation and reconstruction efforts, the U.S. Geological Survey will collaborate with the China Geological Survey to transfer methods and technology to produce probabilistic landslide hazard maps for hazardous areas in Sichuan Province.

Climate change impact on operation of dams and hydroelectricity generation in the Northeastern United States

NASA Astrophysics Data System (ADS)

Ehsani, N.; Vorosmarty, C. J.; Fekete, B. M.

2016-12-01

We are using a large-scale, high-resolution, fully integrated hydrological/reservoir/hydroelectricity model to investigate the impact of climate change on the operation of 11037 dams and generation of electricity from 375 hydroelectric power plants in the Northeastern United States. Moreover, we estimate the hydropower potential of the region by energizing the existing non-powered dams and then studying the impact of climate change on the hydropower potential. We show that climate change increases the impact of dams on the hydrology of the region. Warmer temperatures produce shorter frozen periods, earlier snowmelt and elevated evapotranspiration rates, which when combined with changes in precipitation, are projected to increase water availability in winter but reduce it during summer. As a result, the water that is stored by dams will be more than ever a necessary part of the routine water systems operations to compensate for these seasonal imbalances. The function of dams as emergency water storage for creating drought resiliency will mostly diminish in the future. Building more dams to cope with the local impacts of climate change on water resources and to offset the increased drought vulnerability may thus be inevitable. Annual hydroelectricity generation in the region is 41 Twh. Our estimate of the annual hydropower potential of non-powered dams adds up to 350 Twh. Climate change may reduce hydropower potential from non-powered dams by up to 13% and reduce current hydroelectricity generation by up to 8% annually. Hydroelectricity generation and hydropower potential may increase in winter months and decline in months of summer and fall. These changes call for recalibration of dam operations and may raise conflict of interests in multipurpose dams.

Channel evolution on the dammed Elwha River, Washington, USA

USGS Publications Warehouse

Draut, A.E.; Logan, J.B.; Mastin, M.C.

2011-01-01

Like many rivers in the western U.S., the Elwha River, Washington, has changed substantially over the past century in response to natural and human forcing. The lower river is affected by two upstream dams that are slated for removal as part of a major river restoration effort. In preparation for studying the effects of dam removal, we present a comprehensive field and aerial photographic analysis of dam influence on an anabranching, gravel-bed river. Over the past century with the dams in place, loss of the upstream sediment supply has caused spatial variations in the sedimentary and geomorphic character of the lower Elwha River channel. Bed sediment is armored and better sorted than on the naturally evolving bed upstream of the dams. On time scales of flood seasons, the channel immediately below the lower dam is fairly stable, but progresses toward greater mobility downstream such that the lowermost portion of the river responded to a recent 40-year flood with bank erosion and bed-elevation changes on a scale approaching that of the natural channel above the dams. In general, channel mobility in the lowest 4 km of the Elwha River has not decreased substantially with time. Enough fine sediment remains in the floodplain that – given sufficient flood forcing – the channel position, sinuosity, and braiding index change substantially. The processes by which this river accesses new fine sediment below the dams (rapid migration into noncohesive banks and avulsion of new channels) allow it to compensate for loss of upstream sediment supply more readily than would a dammed river with cohesive banks or a more limited supply of alluvium. The planned dam removal will provide a valuable opportunity to evaluate channel response to the future restoration of natural upstream sediment supply.

The effect of river damming on vegetation: is it always unfavourable? A case study from the River Tiber (Italy).

PubMed

Ceschin, Simona; Tombolini, Ilaria; Abati, Silverio; Zuccarello, Vincenzo

2015-05-01

River damming leads to strong hydromorphological alterations of the watercourse, consequently affecting river vegetation pattern. A multitemporal and spatial analysis of the dam effect on composition, structure and dynamic of the upstream vegetation was performed on Tiber River at Nazzano-dam (Rome). The main research questions were as follows: How does plant landscape vary over time and along the river? Where does the dam effect on vegetation end? How does naturalistic importance of the vegetation affected by damming change over time? Data collection was performed mapping the vegetation in aerial photos related to the period before (1944), during (1954) and after dam construction (1984, 2000). The plant landscape has significantly changed over time and along the river, particularly as a result of the dam construction (1953). The major vegetation changes have involved riparian forests and macrophytes. Dam effect on vegetation is evident up to 3 km, and gradually decreases along an attenuation zone for about another 3 km. Despite the fact that the damming has caused strong local hydromorphological modification of the river ecosystem transforming it into a sub-lacustrine habitat, it has also led to the formation of wetlands of considerable naturalistic importance. Indeed, in these man-made wetlands, optimal hydrological conditions have been created by favouring both the expansion of pre-existing riparian communities and the rooting of new aquatic communities, albeit typical of lacustrine ecosystems. Some of these plant communities have become an important food resource, refuge or nesting habitats for aquatic fauna, while others fall into category of Natura 2000 habitats. Therefore, river damming seems to have indirectly had a "favourable" effect for habitat conservation and local biodiversity.

Distribution and abundance of stream fishes in relation to barriers: implications for monitoring stream recovery after barrier removal

USGS Publications Warehouse

Zydlewski, Joseph D.; Coghlan, Stephen M.; Gardner, C.; Saunders, R.

2011-01-01

Dams are ubiquitous in coastal regions and have altered stream habitats and the distribution and abundance of stream fishes in those habitats by disrupting hydrology, temperature regime and habitat connectivity. Dam removal is a common restoration tool, but often the response of the fish assemblage is not monitored rigorously. Sedgeunkedunk Stream, a small tributary to the Penobscot River (Maine, USA), has been the focus of a restoration effort that includes the removal of two low-head dams. In this study, we quantified fish assemblage metrics along a longitudinal gradient in Sedgeunkedunk Stream and also in a nearby reference stream. By establishing pre-removal baseline conditions and associated variability and the conditions and variability immediately following removal, we can characterize future changes in the system associated with dam removal. Over 2 years prior to dam removal, species richness and abundance in Sedgeunkedunk Stream were highest downstream of the lowest dam, lowest immediately upstream of that dam and intermediate farther upstream; patterns were similar in the reference stream. Although seasonal and annual variation in metrics within each site was substantial, the overall upstream-to-downstream pattern along the stream gradient was remarkably consistent prior to dam removal. Immediately after dam removal, we saw significant decreases in richness and abundance downstream of the former dam site and a corresponding increase in fish abundance upstream of the former dam site. No such changes occurred in reference sites. Our results show that by quantifying baseline conditions in a small stream before restoration, the effects of stream restoration efforts on fish assemblages can be monitored successfully. These data set the stage for the long-term assessment of Sedgeunkedunk Stream and provide a simple methodology for assessment in other restoration projects.

Impacts of settlement, damming, and hydromanagement in two boreal lakes: A comparative paleolimnological study

USGS Publications Warehouse

Serieyssol, C.A.; Edlund, M.B.; Kallemeyn, L.W.

2009-01-01

Namakan Lake, located in shared border waters in northeastern Minnesota and northwestern Ontario, was subjected to several anthropogenic impacts including logging, damming, water-level manipulations, and perhaps climate change. We used paleolimnology to determine how these stressors impacted Namakan Lake in comparison to a control lake (Lac La Croix) that was not subject to damming and hydromanagement. One core was retrieved from each lake for 210Pb dating and analysis of loss-on-ignition and diatom composition. 210Pb-derived chronologies from the cores indicated that sediment accumulation increased after logging and damming in Namakan Lake; Lac La Croix showed no significant change. Loss-on-ignition analysis also showed an increase in concentration and accumulation of inorganic material after damming in Namakan Lake; again, minimal changes were observed in Lac La Croix. Diatom communities in both lakes displayed community shifts at the peak of logging. Simultaneous, post-1970s diatom community changes may reflect regional climate warming. Taxonomic richness in Namakan Lake decreased sharply after damming and the peak of logging, and was followed by a slow recovery to taxonomic richness similar to that prior to damming. Ecological variability among post-damming diatom communities, however, was greater in Namakan Lake than in Lac La Croix. A diatom calibration set was used to reconstruct historical conductivity and total phosphorus (TP). Lac La Croix showed little historical change in conductivity and TP. In contrast, conductivity increased for several decades in Namakan Lake after damming, possibly in relation to several large fires and flooding. Total phosphorus also increased in Namakan Lake after damming, with a possible decrease in the last decade to pre-damming TP levels. ?? Springer Science+Business Media B.V. 2008.

Geomorphic and habitat response to a large-dam removal in a Mediterranean river

NASA Astrophysics Data System (ADS)

Harrison, L.; East, A. E.; Smith, D. P.; Bond, R.; Logan, J. B.; Nicol, C.; Williams, T.; Boughton, D. A.; Chow, K.

2017-12-01

The presence of large dams has fundamentally altered physical and biological processes in riverine ecosystems, and dam removal is becoming more common as a river restoration strategy. We used a before-after-control-impact study design to investigate the geomorphic and habitat response to removal of 32-m-high San Clemente Dam on the Carmel River, CA. The project represents the first major dam removal in a Mediterranean river and is also unique among large dam removals in that most reservoir sediment was sequestered in place. We found that in the first year post-removal, a sediment pulse migrated 3.5 km downstream, filling pools and the interstitial pore spaces of gravels with sand. These sedimentary and topographic changes initially reduced the overall quality of steelhead (O. mykiss) spawning and rearing habitat in impacted reaches. Over the second winter after dam removal, a sequence of high flows flushed large volumes of sand from pools and mobilized the river bed throughout much of the active channel. The floods substantially altered fluvial evolution in the upper part of the reservoir, promoting new avulsion and the subsequent delivery of gravel and large wood to below dam reaches. These geomorphic processes increased the availability of spawning-sized gravel and enhanced channel complexity in reaches within several km of the former dam, which should improve habitat for multiple life stages of steelhead. Results indicate that when most reservoir sediment remains impounded, high flows become more important drivers of geomorphic and habitat change than dam removal alone. In such cases, the rates at which biophysical processes are reestablished will depend largely on post-dam removal flow sequencing and the upstream supply of sediment and large wood.

Passage probabilities of juvenile Chinook salmon through the powerhouse and regulating outlet at Cougar Dam, Oregon, 2011

USGS Publications Warehouse

Beeman, John W.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hansel, Hal C.; Smith, Collin D.

2012-01-01

Cougar Dam near Springfield, Oregon, is one of several federally owned and operated flood-control projects within the Willamette Valley of western Oregon that were determined by the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service in 2008 to impact the long-term viability of several salmonid stocks. In response to this ruling, the U.S. Army Corps of Engineers is looking for means to reduce impacts to salmonids, including improving downstream passage of juvenile salmonids at Cougar Dam. This study of juvenile Chinook salmon (Oncorhynchus tshawytscha) passage at Cougar Dam was conducted to inform decisions about potential improvements for downstream fish passage. The primary objective of the study was to estimate route-specific passage probabilities of yearling Chinook salmon at Cougar Dam. The study was conducted using fish from a nearby hatchery surgically implanted with radio transmitters and passive integrated transponder (PIT) tags and released near the entrance of a temperature control tower through which all water going through the dam must pass. Water passing through the temperature control tower may be routed through a penstock to a powerhouse with two Francis turbines, or to a spillway-like structure called the regulating outlet. Secondary objectives of the study were to estimate the probability that fish enter a bypass at a non-federal facility downstream, and to estimate dam-passage and in-river fish survival. Dam operating conditions during the study included an average forebay elevation of 1,580 feet (National Geodetic Vertical Datum of 1929) and an average of 48.2 percent of the total dam discharge of 1,106 cubic feet per second passing through a regulating outlet opening of 1.25 feet. Dam passage probability was greatest at night (0.8741 standard error [SE] 0.0265) and primarily through the regulating outlet (0.8896 SE 0.0617 day; 0.9417 SE 0.0175 night). The joint probability of entering the bypass at Leaburg Dam and being detected at the PIT system within the bypass was 0.0755 (SE 0.0363), but some fish were known to pass the PIT system undetected, indicating that the true probability of entering the bypass was underestimated. The estimated survival of fish passing through the temperature control tower, through the dam, and to a site at a bridge over the South Fork of the McKenzie River 3.9 kilometers downstream was 0.3680 (SE 0.1322) for fish passing through the powerhouse, and 0.4247 (SE 0.0440) for fish passing through the regulating outlet. The estimated in-river survival through the 37.3 kilometers from the bridge to a site at Leaburg Hatchery on the McKenzie River was 0.5857 (SE 0.2227) for fish that had passed through the powerhouse, and 0.4537 (SE 0.0551) for fish that had passed through the regulating outlet.

Rubber dam may increase the survival time of dental restorations.

PubMed

Keys, William; Carson, Susan J

2017-03-01

Data sourcesCochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, LILACS, SciELO, Chinese BioMedical Literature Database, VIP, China National Knowledge Infrastructure, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online databases. Handsearches in a number of journals.Study selectionRandomised controlled trials, including split-mouth studies assessing the effects of rubber dam isolation for restorative treatments in dental patients.Data extraction and synthesisTwo review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies.ResultsFour studies involving a total of 1,270 patients were included. The studies were at high risk of bias. One trial was excluded from the analysis due to inconsistencies in the presented data. Restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). The rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations.ConclusionsWe found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct restorative treatments may lead to a lower failure rate of the restorations, compared with the failure rate for cotton roll usage. Further high quality research evaluating the effects of rubber dam usage on different types of restorative treatments is required.

The effect of exposure to hypergravity on pregnant rat dams, pregnancy outcome and early neonatal development

NASA Astrophysics Data System (ADS)

Ladd, B.; Nguon, K.; Sajdel-Sulkowska, E. M.

2006-01-01

We previously reported that hypergravity exposure affects food intake and mass gain during pregnancy. In the present study, we explored the hypothesis that changes in maternal body mass in hypergravity-exposed pregnant rat dams affect pregnancy outcome and early offspring development. Furthermore, we hypothesized that the changes observed at 1.5G will be magnified at higher gravity and by exposure during critical developmental periods. To test this hypothesis, we compared maternal body mass gain, food consumption, birth outcome and early offspring development between Sprague Dawley rat dams exposed to graded (1.5 1.75G) chronic hypergravity (HG) or rotation (rotational control, RC) on a 24-ft centrifuge for 22.5 h starting on gestational day (G) 10 with dams housed under identical conditions but not exposed to hypergravity (SC). We also compared maternal body mass, food consumption, birth outcome and early offspring development between rat dams exposed to 1.65G during different stages of pregnancy and nursing. Exposure to hypergravity resulted in transient loss in body mass and prolonged decrease in food consumption in HG dams, but the changes observed at 1.5G were not magnified at 1.65G or 1.75G. On the other hand RC dams gained more mass and consumed more food than SC dams. Exposure to hypergravity also affected pregnancy outcome as evidenced by decreased litter size, lowered neonatal mass at birth, and higher neonatal mortality; pregnancy outcome was not affected in RC dams. Neonatal changes evidenced by impaired righting response observed at 1.5G was magnified at higher gravity and was dependent on the period of hypergravity exposure. On the other hand, righting response was improved in RC neonates. Hypergravity exposure during early postpartum affected the food consumption of nursing mothers and affected early survival of their offspring. The changes observed in dams and neonates appear to be due to hypergravity exposure since animals exposed to the rotation during the same period are not affected. This study suggests that while pregnancy can proceed under altered gravity, exposure to hypergravity affects pregnant dams, pregnancy outcome and the developing fetus as well as nursing dams and neonates and raises an important question whether the mammalian system possess a gravisensing ability.

Managed aquifer recharge by a check dam to improve the quality of fluoride-rich groundwater: a case study from southern India.

PubMed

Gowrisankar, G; Jagadeshan, G; Elango, L

2017-04-01

In many regions around the globe, including India, degradation in the quality of groundwater is of great concern. The objective of this investigation is to determine the effect of recharge from a check dam on quality of groundwater in a region of Krishnagiri District of Tamil Nadu State, India. For this study, water samples from 15 wells were periodically obtained and analysed for major ions and fluoride concentrations. The amount of major ions present in groundwater was compared with the drinking water guideline values of the Bureau of Indian Standards. With respect to the sodium and fluoride concentrations, 38% of groundwater samples collected was not suitable for direct use as drinking water. Suitability of water for agricultural use was determined considering the electrical conductivity, sodium adsorption ratio, sodium percentage, permeability index, Wilcox and United States Salinity Laboratory diagrams. The influence of freshwater recharge from the dam is evident as the groundwater in wells nearer to the check dam was suitable for both irrigation and domestic purposes. However, the groundwater away from the dam had a high ionic composition. This study demonstrated that in other fluoride-affected areas, the concentration can be reduced by dilution with the construction of check dams as a measure of managed aquifer recharge.

Seasonal movements among river reaches, migration strategies, and population structure of the divided Connecticut River shortnose sturgeon population: the effects of Holyoke Dam

USGS Publications Warehouse

Kynard, Boyd; Kieffer, Micah; Vinogradov, Phil; Kynard, B.; Bronzi, P.; Rosenthal, H.

2012-01-01

Even after 155 years, each population segment seasonally migrates toward the other attempting to maintain the natural connection. Migration timing and style of pre-spawning and post-spawning males and females is discussed, as is homing. The impact of Holyoke Dam on population size and growth is characterized and turbine mortality of adult sturgeon passing through a Kaplan turbine at the dam is estimated. The chapter also identifies a behavioral dysfunction that results when migrations are blocked by a dam and are not completed at the correct stage of life. Many unknown effects of damming on other long-lived riverine fishes are likely captured in this 16-year study.

Hard choices in assessing survival past dams — a comparison of single- and paired-release strategies

USGS Publications Warehouse

Zydlewski, Joseph D.; Stich, Daniel S.; Sigourney, Douglas B.

2017-01-01

Mark–recapture models are widely used to estimate survival of salmon smolts migrating past dams. Paired releases have been used to improve estimate accuracy by removing components of mortality not attributable to the dam. This method is accompanied by reduced precision because (i) sample size is reduced relative to a single, large release; and (ii) variance calculations inflate error. We modeled an idealized system with a single dam to assess trade-offs between accuracy and precision and compared methods using root mean squared error (RMSE). Simulations were run under predefined conditions (dam mortality, background mortality, detection probability, and sample size) to determine scenarios when the paired release was preferable to a single release. We demonstrate that a paired-release design provides a theoretical advantage over a single-release design only at large sample sizes and high probabilities of detection. At release numbers typical of many survival studies, paired release can result in overestimation of dam survival. Failures to meet model assumptions of a paired release may result in further overestimation of dam-related survival. Under most conditions, a single-release strategy was preferable.

Crosstalk of PmCBFs and PmDAMs Based on the Changes of Phytohormones under Seasonal Cold Stress in the Stem of Prunus mume

PubMed Central

Zhou, Yuzhen; Li, Yushu; Zhuo, Xiaokang; Ahmad, Sagheer; Han, Yu; Yong, Xue; Zhang, Qixiang

2018-01-01

Plants facing the seasonal variations always need a growth restraining mechanism when temperatures turn down. C-repeat binding factor (CBF) genes work essentially in the cold perception. Despite lots of researches on CBFs, the multiple crosstalk is still interesting on their interaction with hormones and dormancy-associated MADS (DAM) genes in the growth and dormancy control. Therefore, this study highlights roles of PmCBFs in cold-induced dormancy from different orgens. And a sense-response relationship between PmCBFs and PmDAMs is exhibited in this process, jointly regulated by six PmCBFs and PmDAM4–6. Meantime, GA3 and ABA showed negative and positive correlation with PmCBFs expression levels, respectively. We also find a high correlation between IAA and PmDAM1–3. Finally, we display the interaction mode of PmCBFs and PmDAMs, especially PmCBF1-PmDAM1. These results can disclose another view of molecular mechanism in plant growth between cold-response pathway and dormancy regulation together with genes and hormones. PMID:29360732

Lipids, lipid genes, and incident age-related macular degeneration: the three continent age-related macular degeneration consortium.

PubMed

Klein, Ronald; Myers, Chelsea E; Buitendijk, Gabriëlle H S; Rochtchina, Elena; Gao, Xiaoyi; de Jong, Paulus T V M; Sivakumaran, Theru A; Burlutsky, George; McKean-Cowdin, Roberta; Hofman, Albert; Iyengar, Sudha K; Lee, Kristine E; Stricker, Bruno H; Vingerling, Johannes R; Mitchell, Paul; Klein, Barbara E K; Klaver, Caroline C W; Wang, Jie Jin

2014-09-01

To describe associations of serum lipid levels and lipid pathway genes to the incidence of age-related macular degeneration (AMD). Meta-analysis. setting: Three population-based cohorts. population: A total of 6950 participants from the Beaver Dam Eye Study (BDES), Blue Mountains Eye Study (BMES), and Rotterdam Study (RS). observation procedures: Participants were followed over 20 years and examined at 5-year intervals. Hazard ratios associated with lipid levels per standard deviation above the mean or associated with each additional risk allele for each lipid pathway gene were calculated using random-effects inverse-weighted meta-analysis models, adjusting for known AMD risk factors. main outcome measures: Incidence of AMD. The average 5-year incidences of early AMD were 8.1%, 15.1%, and 13.0% in the BDES, BMES, and RS, respectively. Substantial heterogeneity in the effect of cholesterol and lipid pathway genes on the incidence and progression of AMD was evident when the data from the 3 studies were combined in meta-analysis. After correction for multiple comparisons, we did not find a statistically significant association between any of the cholesterol measures, statin use, or serum lipid genes and any of the AMD outcomes in the meta-analysis. In a meta-analysis, there were no associations of cholesterol measures, history of statin use, or lipid pathway genes to the incidence and progression of AMD. These findings add to inconsistencies in earlier reports from our studies and others showing weak associations, no associations, or inverse associations of high-density lipoprotein cholesterol and total cholesterol with AMD. Copyright © 2014 Elsevier Inc. All rights reserved.

Displacements Study of an Earth Fill Dam Based on High Precision Geodetic Monitoring and Numerical Modeling.

PubMed

Acosta, Luis Enrique; de Lacy, M Clara; Ramos, M Isabel; Cano, Juan Pedro; Herrera, Antonio Manuel; Avilés, Manuel; Gil, Antonio José

2018-04-27

The aim of this paper is to study the behavior of an earth fill dam, analyzing the deformations determined by high precision geodetic techniques and those obtained by the Finite Element Method (FEM). A large number of control points were established around the area of the dam, and the measurements of their displacements took place during several periods. In this study, high-precision leveling and GNSS (Global Navigation Satellite System) techniques were used to monitor vertical and horizontal displacements respectively. Seven surveys were carried out: February and July 2008, March and July 2013, August 2014, September 2015 and September 2016. Deformations were predicted, taking into account the general characteristics of an earth fill dam. A comparative evaluation of the results derived from predicted (FEM) and observed deformations shows the differences on average being 20 cm for vertical displacements, and 6 cm for horizontal displacements at the crest. These differences are probably due to the simplifications assumed during the FEM modeling process: critical sections are considered homogeneous along their longitude, and the properties of the materials were established according to the general characteristics of an earth fill dam. These characteristics were taken from the normative and similar studies in the country. This could also be due to the geodetic control points being anchored in the superficial layer of the slope when the construction of the dam was finished.

Post-release behavior and movement patterns of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) after capture using alternative commercial fish gear, lower Columbia River, Washington and Oregon, 2013

USGS Publications Warehouse

Liedtke, Theresa L.; Kock, Tobias J.; Evans, Scott D.; Hansen, Gabriel S.; Rondorf, Dennis W.

2014-01-01

In 2011 and 2012, WDFW conducted post-release mortality studies of steelhead (Oncorhynchus mykiss), Chinook salmon (Oncorhynchus tshawytscha), and coho salmon (Oncorhynchus kisutch) that were captured using beach or purse seines. These studies were comprised of two groups of fish tagged with passive integrated transponder tags (PIT tags): (1) treatment fish that were captured by one of the gear types 9–25 river kilometers (rkm) downstream of Bonneville Dam (rkm 234); and (2) control fish that were captured at the Adult Fish Facility near the Washington shore fish ladder at Bonneville Dam, and then transported and released 8 rkm downstream of the Bonneville Dam. Fish were confirmed to have survived if they moved upstream and were detected on PIT-tag antennas at or upstream of Bonneville Dam, were recovered at hatcheries or at the dam, or were captured by commercial or sport fishers. Post-release survival estimates were higher for steelhead (89–98 percent) than for Chinook salmon and coho salmon (50–90 percent; Washington Department of Fish and Wildlife, unpub. data, 2014). However, some Chinook salmon and coho salmon return to hatcheries, or spawn in the mainstem Columbia River and in tributaries downstream of Bonneville Dam. The proportion of Chinook salmon and coho salmon in the treatment group that were destined for areas downstream of Bonneville Dam likely was higher than in the control group because the control fish were collected as they were attempting to pass the dam. If this assertion was true, mortality would have been overestimated in these studies, so WDFW developed a study plan to determine the post-release movements and intended location of Chinook salmon and coho salmon collected with beach and purse seines in the lower Columbia River.

Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA

USGS Publications Warehouse

Merritts, Dorothy; Walter, Robert; Rahnis, Michael; Hartranft, Jeff; Cox, Scott; Gellis, Allen; Potter, Noel; Hilgartner, William; Langland, Michael; Manion, Lauren; Lippincott, Caitlin; Siddiqui, Sauleh; Rehman, Zain; Scheid, Chris; Kratz, Laura; Shilling, Andrea; Jenschke, Matthew; Datin, Katherine; Cranmer, Elizabeth; Reed, Austin; Matuszewski, Derek; Voli, Mark; Ohlson, Erik; Neugebauer, Ali; Ahamed, Aakash; Neal, Conor; Winter, Allison; Becker, Steven

2011-01-01

Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision into historic reservoir sediment as thousands of ageing dams breach. Analysis of lidar and field data indicates that historic milldam building led to local base-level rises of 2-5 m (typical milldam height) and reduced valley slopes by half. Subsequent base-level fall with dam breaching led to an approximate doubling in slope, a significant base-level forcing. Case studies in forested, rural as well as agricultural and urban areas demonstrate that a breached dam can lead to stream incision, bank erosion and increased loads of suspended sediment, even with no change in land use. After dam breaching, key predictors of stream bank erosion include number of years since dam breach, proximity to a dam and dam height. One implication of this work is that conceptual models linking channel condition and sediment yield exclusively with modern upland land use are incomplete for valleys impacted by milldams. With no equivalent in the Holocene or late Pleistocene sedimentary record, modern incised stream-channel forms in the mid-Atlantic region represent a transient response to both base-level forcing and major changes in land use beginning centuries ago. Similar channel forms might also exist in other locales where historic milling was prevalent.

Putting Roman Dams in Context: a Virtual Approach

NASA Astrophysics Data System (ADS)

Decker, M. J.; Du Vernay, J. P.; Mcleod, J. B.

2017-08-01

Water resources and management have become a critical global issue. During the half-millennium of its existence, the Roman Empire developed numerous strategies to cope with water management, from large-scale urban aqueduct systems, to industrial-scale water mills designed to cope with feeding growing city populations. Roman engineers encountered, adopted, and adapted indigenous hydraulic systems, and left lasting imprints on the landscape of the Mediterranean and temperate Western Europe by employing a range of water technologies. A recent academic study has enabled the identification of remains of and references to seventy-two dams from the Roman era, constructed in Spain between the 1st and 4th century AD. Such unique heritage, without comparisons in the Mediterranean makes Spain an emblematic case study for the analysis of Roman hydraulic engineering and water management policies. Fifty dams have been located and detailed. The twenty-two outstanding, although identified on the ground, have not been able to be acceptably characterized, due in some cases to their being ruins in a highly degraded state, others due to their being masked by repairs and reconstructions subsequent to the Roman era. A good example of such neglected dams is the buttress dam of Consuegra , in Toledo province (Castilla-La Mancha). Dating to the 3rd - 4th century AD, the Dam of Consuegra, on the basin of the Guadiana, with its over 600 metres length and 4,80 metres height, is a remarkable case of Roman engineering mastery. It had a retaining wall upstream, numerous buttresses and perhaps an embankment downstream, of which no remains are left. The application of 3D digital imaging technique to create a high quality virtual model of such monuments has proved to be successful especially for the study of the technological aspects related its construction. The case study of the Roman dam of Muel (Zaragoza) has shown, in fact, as best practices in digital archaeology can provide an original and innovative perspective on a long time studied monument. In this paper it will be explored how deploying recent computer technologies to the Roman dam at Consuegra can advance our understanding of the history of local and regional landscape change and the technology of water management. In summer 2016, the dam has been documented with terrestrial laser scanning with two FARO Focus 3D x330 and aerial photogrammetry image capturing with a DJI Phantom 4 drone. Data was processed in various 3D software applications to generate 3D representations of the dam including 3D point clouds, animations, and meshed models.

Epidemiology of clinical feline herpesvirus infection in zoo-housed cheetahs (Acinonyx jubatus).

PubMed

Witte, Carmel L; Lamberski, Nadine; Rideout, Bruce A; Vaida, Florin; Citino, Scott B; Barrie, Michael T; Haefele, Holly J; Junge, Randall E; Murray, Suzan; Hungerford, Laura L

2017-10-15

OBJECTIVE To determine the incidence of and risk factors for clinical feline herpesvirus (FHV) infection in zoo-housed cheetahs and determine whether dam infection was associated with offspring infection. DESIGN Retrospective cohort study. ANIMALS 144 cheetah cubs born in 6 zoos from 1988 through 2007. PROCEDURES Data were extracted from the health records of cheetahs and their dams to identify incident cases of clinical FHV infection and estimate incidence from birth to 18 months of age. Univariate and multivariable Cox proportional hazards models, controlling for correlations among cheetahs with the same dam, were used to identify risk factors for incident FHV infection. RESULTS Cumulative incidence of FHV infection in cheetah cubs was 35% (50/144). No significant association between dam and offspring infection was identified in any model. Factors identified as significant through multivariable analysis varied by age group. For cheetahs up to 3 months of age, the most important predictor of FHV infection was having a dam that had received a preparturition FHV vaccine regimen that included a modified-live virus vaccine versus a dam that had received no preparturition vaccine. Other risk factors included being from a small litter, being born to a primiparous dam, and male sex. CONCLUSIONS AND CLINICAL RELEVANCE This study provided the first population-level characterization of the incidence of and risk factors for FHV infection in cheetahs, and findings confirmed the importance of this disease. Recognition that clinical FHV infection in the dam was not a significant predictor of disease in cubs and identification of other significant factors have implications for disease management.

Introduction to the special issue on discontinuity of fluvial systems

NASA Astrophysics Data System (ADS)

Burchsted, Denise; Daniels, Melinda; Wohl, Ellen E.

2014-01-01

Fluvial systems include natural and human-created barriers that modify local base level; as such, these discontinuities alter the longitudinal flux of water and sediment by storing, releasing, or changing the flow path of those materials. Even in the absence of distinct barriers, fluvial systems are typically discontinuous and patchy. The size of fluvial discontinuities ranges across scales from 100 m, such as riffles, to 104 m, such as lava dams or major landslides. The frequency of occurrence appears to be inversely related to size, with creation and failure of the small features, such as beaver dams, occurring on a time scale of 100 to 101 years and a frequency of occurrence at scales as low as 101 m. In contrast, larger scale discontinuities, such as lava dams, can last for time scales up to 105 years and have a frequency of occurrence of approximately 104 m. The heterogeneity generated by features is an essential part of river networks and should be considered as part of river management. Therefore, we suggest that "natural" dams are a useful analog for human dams when evaluating options for river restoration. This collection of papers on the studies of natural dams includes bedrock barriers, log jams and beaver dams. The collection also addresses the discontinuity generated by a floodplain — in the absence of an obvious barrier in the channel — and tools for evaluation of riverbed heterogeneity. It is completed with a study of impact of human dams on floodplain sedimentation. These papers will help geomorphologists and river managers understand the factors that control river heterogeneity across scales and around the world.

How big of an effect do small dams have? Using geomorphological footprints to quantify spatial impact of low-head dams and identify patterns of across-dam variation

USGS Publications Warehouse

Fencl, Jane S.; Mather, Martha E.; Costigan, Katie H.; Daniels, Melinda D.

2015-01-01

Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0–15.3 km) or 287 wetted widths (136–437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams.

How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation

PubMed Central

Costigan, Katie H.; Daniels, Melinda D.

2015-01-01

Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0–15.3 km) or 287 wetted widths (136–437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams. PMID:26540105

The Influence of Dams on Malaria Transmission in Sub-Saharan Africa.

PubMed

Kibret, Solomon; Wilson, G Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2017-06-01

The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

Evolution of an Interfacial Crack on the Concrete Embankment Boundary

NASA Astrophysics Data System (ADS)

Smith, J.; Ezzedine, S. M.; Lomov, I.; Kanarska, Y.; Antoun, T.; Glascoe, L. G.; Hall, R. L.; Woodson, S. C.

2013-12-01

Failure of a dam can have subtle beginnings: a small crack or dislocation at the interface of the concrete dam and the surrounding embankment soil initiated by a seismic event, for example, can: a) result in creating gaps between the concrete dam and the lateral embankments; b) initiate internal erosion of embankment; and c) lead to a catastrophic failure of the dam. The dam may ';self-rehabilitate' if a properly designed granular filter is engineered around the embankment. Currently, the design criteria for such filters have only been based on experimental studies. We demonstrate the numerical prediction of filter effectiveness at the soil grain scale and relate it to the larger dam scale. Validated computer predictions highlight that a resilient (or durable) filter is consistent with the current design specifications for dam filters. These predictive simulations, unlike the design specifications, can be used to assess filter success or failure under different soil or loading conditions and can lead to meaningful estimates of the timing and nature of full-scale dam failure. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate, Homeland Security Advanced Research Projects Agency (HSARPA).

Responses of riparian reptile communities to damming and urbanization

USGS Publications Warehouse

Hunt, Stephanie D.; Guzy, Jacquelyn C.; Price, Steven J.; Halstead, Brian J.; Eskew, Evan A.; Dorcas, Michael E.

2013-01-01

Various anthropogenic pressures, including habitat loss, threaten reptile populations worldwide. Riparian zones are critical habitat for many reptile species, but these habitats are also frequently modified by anthropogenic activities. Our study investigated the effects of two riparian habitat modifications-damming and urbanization-on overall and species-specific reptile occupancy patterns. We used time-constrained search techniques to compile encounter histories for 28 reptile species at 21 different sites along the Broad and Pacolet Rivers of South Carolina. Using a hierarchical Bayesian analysis, we modeled reptile occupancy responses to a site's distance upstream from dam, distance downstream from dam, and percent urban land use. The mean occupancy response by the reptile community indicated that reptile occupancy and species richness were maximized when sites were farther upstream from dams. Species-specific occupancy estimates showed a similar trend of lower occupancy immediately upstream from dams. Although the mean occupancy response of the reptile community was positively related to distance downstream from dams, the occupancy response to distance downstream varied among species. Percent urban land use had little effect on the occupancy response of the reptile community or individual species. Our results indicate that the conditions of impoundments and subsequent degradation of the riparian zones upstream from dams may not provide suitable habitat for a number of reptile species.

Water Management Models in Practice: A Case Study of the Aswan High Dam

NASA Astrophysics Data System (ADS)

El-Ashry, M. T.; Alford, D. L.

1984-04-01

The stated purpose of this volume is the development and evaluation of operating policies for the Aswan High Dam and their relation to the development of water resources policy in Egypt. That objective is admirably fulfilled through discussions of water use in Egypt and the operation objectives of the High Dam, the behavior of the physical system and simulation of the reservoir, a realtime management model of the dam, management of water shortages and trade-offs between major uses, and coordinated operation of the dam with new upstream as well as downstream developments.The High Dam has been a source of controversy, particularly with regard to its environmental impacts. Its adverse effects include changes in the water table and attendant salt buildup in irrigated areas, excessive growth of aquatic plants below the dam, shoreline erosion, and increases in water-borne diseases such as schistosomiasis (bilharzia). The dam was intended to offset rapid population growth by increasing food supplies through the transformation of irrigated land in southern Egypt from seasonal to perennial cultivation and by providing water for the reclamation of desert land. Unfortunately, such benefits have been outstripped by the rapidly growing population, and water shortages will be experienced by the end of the century.

77 FR 73651 - North Star Hydro Services, CA LLC; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-11

...), proposing to study the feasibility of the Marble Bluff Dam Hydropower Project to be located at the U.S. Bureau of Reclamation's Marble Bluff dam on the Truckee River, near Nixon, Washoe County, Nevada. The... east of the existing spillway of the Marble Bluff dam. Flow diverted at the sluice gate would be used...

WinDAM C earthen embankment internal erosion analysis software

USDA-ARS?s Scientific Manuscript database

Two primary causes of dam failure are overtopping and internal erosion. For the purpose of evaluating dam safety for existing earthen embankment dams and proposed earthen embankment dams, Windows Dam Analysis Modules C (WinDAM C) software will simulate either internal erosion or erosion resulting f...

Sustainability of dams-an evaluation approach

NASA Astrophysics Data System (ADS)

Petersson, E.

2003-04-01

Situated in the stream bed of a river, dams and reservoirs interrupt the natural hydrological cycle. They are very sensitive to all kinds of changes in the catchment, among others global impacts on land use, climate, settlement structures or living standards. Vice versa dams strongly affect the spatially distributed, complex system of ecology, economy and society in the catchment both up- and downstream of the reservoir. The occurrence of negative impacts due to large dams led to serious conflicts about future dams. Nevertheless, water shortages due to climatic conditions and their changes, that are faced by enormous water and energy demands due to rising living standards of a growing world population, seem to require further dam construction, even if both supply and demand management are optimised. Although environmental impact assessments are compulsory for dams financed by any of the international funding agencies, it has to be assumed that the projects lack sustainability. Starting from an inventory of today's environmental impact assessments as an integral part of a feasibility study the presentation will identify their inadequacies with regard to the sustainability of dams. To improve the sustainability of future dams and avoid the mistakes of the past, the planning procedures for dams have to be adapted. The highly complex and dynamical system of interrelated physical and non-physical processes, that involves many different groups of stakeholders, constitutes the need for a model-oriented decision support system. In line with the report of the World Commission of Dams an integrated analysis and structure of the complex interrelations between dams, ecology, economy and society will be presented. Thus the system, that a respective tool will be based on, is analysed. Furthermore an outlook will be given on the needs of the potential users of a DSS and how it has to be embedded in the overall planning process. The limits of computer-based decision-support in the very specific context of dam construction will be identified. Special focus will be on the constraints arising from the need to jointly evaluate qualitative and quantitative aspects and the methodological potential of multi-criteria evaluation in this respect.

Variability of Ecosystem State in Rivers Containing Natural Dams: A Chemical Analysis

NASA Astrophysics Data System (ADS)

Reynolds, Z. A.

2015-12-01

Flooding, and the resulting economic damage to roads and property, is associated with natural dams such as beaver dams or log jams. For this reason, humans often remove natural dams; however, river reaches with natural dams provide very different ecosystem services in comparison with free-flowing river reaches. Therefore, the goal of this project is to assess the differences in ecosystem state between these different river reach types in the northeastern United States. We focused on differences in basic chemistry (e.g., dissolved oxygen, pH, temperature, and organic carbon) to assess the impact of natural dams on river ecosystem state. Study sites include rivers in the White Mountains and southeastern New Hampshire at locations with beaver dams, beaver ponds, beaver meadows, log jams, and free-flowing reaches. Dissolved oxygen, ORP, pH, temperature, and conductivity were measured in the field with a YSI Professional Plus meter. Water samples were collected for subsequent laboratory analysis of total organic carbon with a Shimadzu TOC-L. Preliminary results show that the chemistry of river water varies with feature type. Most significantly, dissolved oxygen concentrations are highest in free-flowing reaches and lowest in beaver ponds. Although beaver ponds are often associated with lower pH, due the increased concentration of organic acids, some beaver ponds can increase pH when compared to free-flowing reaches on the same river. Early results also show that water chemistry returns quickly to the chemistry typical of the free-flowing river reaches after being altered by a natural dam. Overall, natural dams create a river system that has more heterogeneity, and therefore has opportunities to provide more ecosystem functions, than a purely free-flowing river; this can increase the number of supported instream and riparian species. By increasing the understanding of how natural dams affect the chemistry of river water, river engineers can improve their decisions on how to remove problematic natural dams that increase flooding risks; they can also investigate possibilities to mimic the ecosystem state generated by natural dams in places where these dams are regularly removed.

Application of a hierarchical framework for assessing environmental impacts of dam operation: changes in hydrology, channel hydraulics, bed mobility and recruitment of riparian trees in a western North American river

Treesearch

Michael Burke; Klaus Jorde; John M. Buffington

2009-01-01

River systems have been altered worldwide by dams and diversions, resulting in a broad array of environmental impacts. The use of a process-based, hierarchical framework for assessing environmental impacts of dams is explored here in terms of a case study of the Kootenai River, western North America. The goal of the case study is to isolate and quantify the relative...

Survival and Passage of Yearling and Subyearling Chinook Salmon and Juvenile Steelhead at McNary Dam, 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, James S.; Weiland, Mark A.; Woodley, Christa M.

The study was designed to evaluate the passage and survival of yearling and subyearling Chinook salmon and juvenile steelhead at McNary Dam as stipulated by the 2008 Biological Opinion and Fish Accords and to assess performance measures including route-specific fish passage proportions, travel times, and survival based upon a virtual/paired-release model. This study supports the USACE’s continual effort to improve conditions for juvenile anadromous fish passing through Columbia River dams.

Deer Creek Dam, Dam, 1,204 feet/238 degrees from intersection of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Deer Creek Dam, Dam, 1,204 feet/238 degrees from intersection of dam complex access road and U.S. Highway 189 to center of dam, 874 feet/352 degrees from Hydroelectric Powerplant (HAER UT-93-B) to center of dam, Charleston, Wasatch County, UT

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam with Emphasis on the Prototype Surface Flow Outlet, 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Ploskey, Gene R.; Hughes, James S.

The main purpose of the study was to evaluate the performance of Top Spill Weirs installed at two spillbays at John Day Dam and evaluate the effectiveness of these surface flow outlets at attracting juvenile salmon away from the powerhouse and reducing turbine passage. The Juvenile Salmonid Acoustic Telemetry System (JSATS) was used to estimate survival of juvenile salmonids passing the dam and also for calculating performance metrics used to evaluate the efficiency and effectiveness of the dam at passing juvenile salmonids.

Mathematical Modeling in Systems for Operational Evaluation of the Stress-Strain State of the Arch-Gravity Dam at the Sayano-Shushenskaya Hydroelectric Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellendir, E. N.; Gordon, L. A., E-mail: lev-gordon@mail.ru; Khrapkov, A. A.

Current studies of the stress-strain state of the dam at the Sayano-Shushenskaya Hydroelectric Power Plant at VNIIG based on mathematical modeling including full scale and experimental data are described. Applications and programs intended for automatic operational evaluation of the stress-strain state of the dam for optimizing control of the upper race level in the course of the annual filling-drawdown cycle and during seismic events are examined. Improvements in systems for monitoring the stress-strain state of concrete dams are proposed.

Downstream migration and multiple dam passage by Atlantic Salmon smolts

USGS Publications Warehouse

Nyqvist, D.; McCormick, Stephen; Greenberg, L.; Ardren, W.R.; Bergman, E.; Calles, O.; Castro-Santos, Theodore R.

2017-01-01

The purpose of this study was to investigate behavior and survival of radio-tagged wild and hatchery-reared landlocked Atlantic Salmon Salmo salar smolts as they migrated past three hydropower dams equipped with fish bypass solutions in the Winooski River, Vermont. Among hatchery-reared smolts, those released early were more likely to initiate migration and did so after less delay than those released late. Once migration was initiated, however, the late-released hatchery smolts migrated at greater speeds. Throughout the river system, hatchery-reared fish performed similarly to wild fish. Dam passage rates varied between the three dams and was highest at the dam where unusually high spill levels occurred throughout the study period. Of the 50 fish that did migrate downstream, only 10% managed to reach the lake. Migration success was low despite the presence of bypass solutions, underscoring the need for evaluations of remedial measures; simply constructing a fishway is not synonymous with providing fish passage.

Lactation Biology Symposium: maternal nutrition during early and mid-to-late pregnancy: Comparative effects on milk production of twin-born ewe progeny during their first lactation.

PubMed

Paten, A M; Kenyon, P R; Lopez-Villalobos, N; Peterson, S W; Jenkinson, C M C; Pain, S J; Blair, H T

2013-02-01

Studies using sheep models indicate that the fetal mammary gland is sensitive to maternal nutrition during gestation; however, results have been inconsistent and do not identify critical feeding periods. This study aimed to clarify previous findings by partitioning the period of maternal nutritional manipulation into 2 stages: early and mid-to-late pregnancy. Sixty-six twin-born, twin-bearing ewes, born to dams that were fed either submaintenance, maintenance, or ad libitum during early pregnancy (d 21 to 50 of pregnancy; SmP21-50, MP21-50, or AdP21-50, respectively) and then either maintenance or ad libitum during mid-to-late pregnancy (d 50 to 140 of pregnancy; MP50-140 or AdP50-140, respectively) were milked once a week, starting from d 7 ± 1 postpartum, for 7 subsequent weeks to enable estimation of daily milk yield and composition. Their lambs were weighed weekly. Ewes born to dams fed MP21-50 tended to have greater accumulated milk (P = 0.10), fat (P = 0.07), and NE (P = 0.06) yields over 50 d compared with ewes born to dams fed SmP21-50 and AdP21-50. In contrast, ewes born to dams fed AdP50-140 tended to have greater accumulated milk (P = 0.10) and lactose (P = 0.09) yields compared with ewes born to dams fed MP50-140. Grandoffspring birth weights were unaffected by granddam nutrition during pregnancy. Ewes born to dams fed AdP21-50 weaned lighter lambs (P = 0.05) than ewes born to dams fed AmP21-50 and tended to wean lighter lambs (P = 0.07) than ewes born to dams fed MP21-50 whereas there were no differences between the weaning weights of lambs (P = 0.43) from ewes born to dams fed AdP50-140 and MP50-140. Maintenance nutrition of dams during early pregnancy appears to be associated with an improved lactation performance of ewe offspring. Higher levels of nutrition during mid-to-late pregnancy also appears to improve the first-lactation performance of ewe offspring. Interestingly, although grandoffspring birth weights were unaffected, weaning weight appears to be influenced by granddam early pregnancy nutrition in a manner discordant with the lactational performance of their dam. Results from this study indicate that dam nutrition during early pregnancy can influence the lactational performance of ewe offspring and the BW at weaning of their grandoffspring, which may ultimately affect farmer profits. This highlights the importance of nutritional management of breeding ewes during this period.

Project Planning for Cougar Dam during 2010

USGS Publications Warehouse

Haskell, Craig A.; Tiffan, Kenneth F.

2011-01-01

Cougar Dam is a 158 m-tall, rock fill dam located about 63 km east of Springfield, Oregon. Completed in 1963, the dam is owned and operated by the U.S. Army Corps of Engineers (USACE). It impounds Cougar Reservoir, which is 9.7 km long, has a surface area of 518 ha, and is predominately used for flood control. The pool elevation typically ranges from a maximum conservation pool of 515 m (1,690 ft) National Geodetic Vertical Datum (NGVD) in summer to a minimum flood control elevation of 467 m (1,532 ft NGVD) in winter. The reservoir thermally stratifies in the summer, has an average depth of 37 m, and holds 153,500 acre-feet when full. Cougar Dam is located on the South Fork of the McKenzie River 7 km upstream from the mainstem McKenzie River, a tributary of the Willamette River. The McKenzie River Basin basin supports the largest remaining population of wild spawning spring Chinook salmon in the Willamette River Basin (National Oceanic and Atmospheric Administration; NOAA, 2008). Cougar Dam and others were collectively deemed to cause jeopardy to the sustainability of anadromous fish stocks in the Willamette River Basin (NOAA, 2008). Prior to dam construction, as many as 805 redds were observed in the South Fork of the McKenzie River (Willis and others, 1960) and it is estimated that 40 km of spawning habitat were lost when access was blocked after dam construction. The 2008 Willamette Biological Opinion (BIOP) requires improvements to operations and structures to reduce impacts on Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR steelhead (O. mykiss; NOAA, 2008). In 2010, an adult fish collection facility was completed below Cougar Dam to collect returning adult salmon for transport to spawning habitats above the dam. Before that time, returning adult spring Chinook salmon were transported to upstream spawning areas as part of a trap-and-haul program with adults passed ranging annually from 0 to 1,038 (Taylor, 2000). The progeny of adult fish that are allowed to spawn above Cougar Dam move downstream into Cougar Reservoir in the spring. Under the BIOP, the USACE is required to provide downstream fish passage or operational alternatives at Cougar Dam by 2014. Currently, there is little information about the seasonal timing of reservoir entry of juvenile Chinook salmon and what habitats they and other fishes use in the reservoir. However, rotary screw traps placed in the outlet channel below the dam indicate peak juvenile passage coinciding with seasonally low pool elevation in mid December and late January. It is unknown whether juveniles upstream of Cougar Dam can be captured in large enough numbers for tagging and subsequent survival studies to proceed. These studies are needed to examine the feasibility of installing downstream fish passage structures at Cougar Dam to meet BIOP requirements. Therefore, the USACE contracted with the U.S. Geological Survey (USGS) to test the efficacy of using a mid-water trawl and lampara seine to capture fish in Cougar Reservoir on three consecutive days in the fall of 2010. These collection methods could potentially provide fish for feasibility and subsequent survival studies and as verification of fish targets in future active hydroacoustic surveys.

Modeling the Impact of controlled flow and sediment releases for the restoration of the Nile Delta, Egypt

NASA Astrophysics Data System (ADS)

Al-Zaidi, B. M.; Moussa, A.; Viparelli, E.

2017-12-01

The construction of the High and Old Aswan Dams and of barrages significantly altered the flow and the sediment transport regimes in the Egyptian reach of the Nile River. The field data collected by the Nile Research Institute show that the post-High Aswan Dam Nile River hydrology is characterized by reductions of more than 70% in flow discharge and 98% in sediment load compared to pre-High Aswan Dam conditions. A significant portion of discharge released from the dams is diverted at the barrages for agricultural ( 80%) and municipal ( 15%) uses. Thus, virtually no water is reaching the Nile Delta and the Mediterranean Sea. Consequently, the sediment load delivered to the Mediterranean Sea is negligible compared to pre-dam conditions. Consequences of the flow regulation are delta wide wetland loss and shoreline retreat, widespread delta pollution, reduction soil quality, salination of cultivated land, wetland losses, and saltwater intrusion in the groundwater. Here we present the second part of a feasibility study for the restoration of the Nile River-Delta system characterized by controlled flow releases and sediment augmentations downstream of the High Aswan Dam. The controlled flow releases are obtained by regulating the current releases from the High Aswan Dam at the Old Aswan Dam, which is located 6.5 km downstream of the High Aswan Dam. Previous studies showed that 10 billion m3 of water can be saved annually by improving the Egyptian irrigation system. Here we propose to use the saved water to increase the water discharge to the Nile Delta, i.e., the total volume of water released from the dams does not change, what changes is the water used and the imposed hydrograph. We modulate the river flow by storing the saved water during the agriculture season upstream of the Old Aswan Dam and releasing it in the months coinciding with the natural river flood season. It is important to note that here we are considering the simplest possible scenario for water storage. In reality, additional storage volumes are available upstream of the major barrages, and these volumes can also be used during the proposed restoration project. The study consists in the implementation and validation of a laterally averaged delta growth model to quantify the impact of the proposed restoration project on the Nile Delta in terms of changes in shoreline position and channel-floodplain characteristics under the predicted rates of sea level rise.

Efficiency evaluation of agricultural underground dam in South Korea

NASA Astrophysics Data System (ADS)

Myoung, W.; Song, S. H.; Yong, H. H.

2017-12-01

Climate change has resulted in severe droughts in a rice-planting season (i.e., April to June) in South Korea since 2012. Therefore, all time high-amount water resources in rice-farming seasons (i.e., April to October) were required against natural crises like droughts. The underground dam, which is able to increase groundwater amounts in the alluvium aquifer, has been considered to be an alternative for securing more groundwater resources. In this study, irrigation efficiencies of five pre-existing agricultural underground dams in South Korea were evaluated during the drought periods. A total amount of groundwater storage capacities in alluvial aquifers of these five ones were estimated approximate 15 × 107 m3: above 4 × 106 m3 for two underground dams (Ian, Namsong), 2 3 × 106 m3, for 2 dams (Oksung, Wooil), below 2 × 106 m3 for 1 dam (Gocheon), respectively. Irrigating amounts of groundwater accounted for three underground dams (Ian, Namsong, Gocheon), supplied in rice-farming season are 8.5 × 105 m3/year, 8.3 × 105 m3/year, 6.3 × 105 m3/year, respectively. The total demand of agricultural water in these underground dams is 2.0 × 106 m3/year, 1.9 × 106 m3/year, 2.2 × 106 m3/year, respectively. Irrigating amounts of groundwater accounted for whole of rice-farming area in South Korea is 4.3 × 108 m3/year whereas total demand of agricultural water is 9.4 × 109 m3/year. Groundwater were pumped from the radial collector wells located in the upstream from the underground dams. Oksung underground dam, one representative underground dam located in Chungnam province in South Korea, irrigated approximate 3 × 105 m3 during a dried rice-planting season (between April to June) in 2017. It was three times more than usual (9 × 104 m3). Groundwater levels during the same period maintained above 5.55 m, which was slightly lower than usual (6.00 m). Results of Oksung underground dam demonstrated that underground dams in South Korea were effectively operated against drought. Recently, Korea Rural Community Corporation, a governmental institute of South Korea, plans to construct more underground dams against drought.

Evaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014

USGS Publications Warehouse

Courter, Ian; Garrison, Tommy; Kock, Tobias J.; Perry, Russell W.

2015-01-01

The influence of stream flow on survival of emigrating juvenile (smolts) Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss is of key management interest. However, few studies have quantified flow effects on smolt migration survival, and available information does not indicate a consistent flow-survival relationship within the typical range of flows under management control. It is hypothesized that smolt migration and dam passage survival are positively correlated with stream flow because higher flows increase migration rates, potentially reducing exposure to predation, and reduce delays in reservoirs. However, available empirical data are somewhat equivocal concerning the influence of flow on smolt survival and the underlying mechanisms driving this relationship. Stream flow effects on survival of emigrating anadromous salmonids in the Yakima Basin have concerned water users and fisheries managers for over 20 years, and previous studies do not provide sufficient information at the resolution necessary to inform water operations, which typically occur on a small spatiotemporal scale. Using a series of controlled flow releases from 2012-2014, combined with radio telemetry, we quantified the relationship between flow and smolt survival from Roza Dam 208 km downstream to the Yakima River mouth, as well as for specific routes of passage at Roza Dam. A novel multistate mark-recapture model accounted for weekly variation in flow conditions experienced by radio-tagged fish. Groups of fish were captured and radio-tagged at Roza Dam and released at two locations, upstream at the Big Pines Campground (river kilometer [rkm] 211) and downstream in the Roza Dam tailrace (rkm 208). A total of 904 hatchery-origin yearling Chinook salmon O. tshawytscha were captured in the Roza Dam fish bypass, radio-tagged and released upstream of Roza Dam. Two hundred thirty seven fish were released in the tailrace of Roza Dam. Fish released in the tailrace of Roza Dam were tagged concurrently with fish released upstream of the dam using identical tagging methods. Tagging and release events were conducted to target a range of flow conditions indicative of flows observed during the typical migration period (March-May) for juvenile spring Chinook salmon in the Yakima River. Three, five and four separate upstream releases were conducted in 2012, 2013, and 2014 respectively, and at least 43 fish were released alive on each occasion. The release sample sizes in 2014 were much larger (~130) compared to previous years for the purpose of increasing precision of survival estimates across the range of flows tested. Migration movements of radio-tagged spring Chinook salmon smolts were monitored with an array of telemetry receiver stations (fixed sites) that extended 208 rkm downstream from the forebay of Roza Dam to the mouth of the Yakima River. Fixed monitoring sites included the forebay of Roza Dam (rkm 208), the tailrace of Roza Dam (rkm 207.9), the mouth of Wenas Creek (rkm 199.2), the mouth of the Naches River (two sites, rkm 189.4), Sunnyside Dam (two sites, rkm 169.1), Prosser Dam (rkm 77.2), and the mouth of the Yakima River (two sites, rkm2 3). This array segregated the study area into four discrete reaches in which survival of tagged fish was estimated. Aerial and underwater antennas were also used to monitor tagged fish at Roza Dam. Aerial antennas were located in the forebay, on the East gate, on the West gate, and in the tailrace of Roza Dam. Underwater antennas were located in the fish bypass, upstream of the East gate, and upstream of the West gate to collect route-specific passage data for tagged fish. Additional years of data collection and analysis could alter or improve our understanding of the influence of flow and other environmental factors on smolt survival in the Yakima River. Nevertheless, during 2012-2014, yearling hatchery Chinook salmon smolt emigration survival was significantly associated with stream flow in the

6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND FOR MONITORING MOVEMENT OF DAM AND EARTH. - Gene Wash Reservoir & Dam, 2 miles west of Parker Dam, Parker Dam, San Bernardino County, CA

Prenatal toxicity of cyanide in goats--a model for teratological studies in ruminants.

PubMed

Soto-Blanco, Benito; Górniak, Silvana L

2004-09-15

Although exposure to cyanogenic plants or cyanide during pregnancy has adverse effects, no teratological study with cyanide has been conducted in goats or any other ruminant. The objective of the present study was to evaluate the effects of the maternal exposure to potassium cyanide (KCN) during pregnancy on both dams and offspring and furthermore, to develop a model for prenatal toxicological studies in ruminants. Twenty-six pregnant goats were allocated into four groups and given 0, 1.0, 2.0, or 3.0mg KCN/kg body weight per day orally (administered via twice-daily gavage) from Day 24 of pregnancy to term. However, one control dam and another from the 3.0mg KCN/kg per day group were sacrificed on Day 120. At birth, the kids were examined carefully for gross abnormalities. Three months after birth, the male kids and one dam from each group were sacrificed for histopathological study. Although clinical signs of poisoning were observed in dams, cyanide treatment did not alter the length of gestation or the number of live kids. Two prognata kids were born in the 3.0mg KCN/kg group, and one dam from the same group aborted two fetuses. There were histological lesions only in the KCN-treated dam (and its fetuses) sacrificed on Day 120; these consisted of an increased number of resorption vacuoles of thyroid follicular colloid, and status spongiosis of nervous white matter. This study proposes a new animal model for teratogenic trials that could be important to evaluate the effects of chemicals throughout pregnancy in goats and potentially other ruminants.

Seasonal And Intra-seasonal Hydrological Responses To Change In Climate Pattern And Small Dams of the Faga Watershed In Burkina-Faso

NASA Astrophysics Data System (ADS)

Mamounata, K.

2015-12-01

In response to the increasing demand for food linked to the substantial growth of population in Burkina Faso, irrigation has been widely used by the farming community to support agricultural production. Thus a promising option for water resources development in such a context is to increase the number of small dams. It is assumed that the great number of small dams may have effect on sub-basins' hydrological dynamic. This study aims to assess the seasonal and the intra-seasonal change in river basins hydrology with the case study of the Faga River sub-basin located in Burkina-Faso, West Africa, using Water Simulation Model (WaSiM). For this watershed the number of small dams is slightly very important (More than 60) and their impact on the watershed runoff has been estimated simultaneously with the change in climate pattern. The coefficient of variation for rainfall in this sub-basin from 1982 to 2010 is 0.097 and the stream flow presents a seasonal average of 25.58Km3 per month for the same period. The intra-seasonal climate variation for the same period is estimated at 0.087 in the scenario where any dam has not been considered. Results based on simulation including the five important dams over the sub-basin show that the overall effect of small dams is on average a 20.76% in runoff. Projections using the Representative Concentration Pathways (RCP) 4.5 and 8.5 climate scenarios with increase of 25% of dams' number show a probable decrease of about 29.54% and 35.25% of the average during the next fifty years runoff. The study findings show that small dams reduce significantly the runoff from their watershed and the uncertainties related to the sustainability of the resource seems to be increasing during the same period. Therefore, despite the very large number of water storage infrastructures, reservoirs operating strategies have to be achieved for water sustainability within the Faga sub-basin.

Assessing distribution of migratory fishes and connectivity following complete and partial dam removals in a North Carolina River

USGS Publications Warehouse

Raabe, Joshua K.; Hightower, Joseph E.

2014-01-01

Fish, especially migratory species, are assumed to benefit from dam removals that restore connectivity and access to upstream habitat, but few studies have evaluated this assumption. Therefore, we assessed the movement of migratory fishes in the springs of 2008 through 2010 and surveyed available habitat in the Little River, North Carolina, a tributary to the Neuse River, after three complete dam removals and one partial (notched) dam removal. We tagged migratory fishes with PIT tags at a resistance-board weir located at a dam removal site (river kilometer [rkm] 3.7) and followed their movements with an array of PIT antennas. The river-wide distribution of fish following removals varied by species. For example, 24–31% of anadromous American Shad Alosa sapidissima, 45–49% of resident Gizzard Shad Dorosoma cepedianum, and 4–11% of nonnative Flathead CatfishPylodictis olivaris passed the dam removal site at rkm 56 in 2009 and 2010. No preremoval data were available for comparison, but reach connectivity appeared to increase as tagged individuals passed former dam sites and certain individuals moved extensively both upstream and downstream. However, 17–28% did not pass the partially removed dam at rkm 7.9, while 20–39% of those that passed remained downstream for more than a day before migrating upstream. Gizzard Shad required the deepest water to pass this notched structure, followed by American Shad then Flathead Catfish. Fish that passed the notched dam accessed more complex habitat (e.g., available substrate size-classes) in the middle and upper reaches. The results provide strong support for efforts to restore currently inaccessible habitat through complete removal of derelict dams.

Coastal and lower Elwha River, Washington, prior to dam removal--history, status, and defining characteristics: Chapter 1 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

USGS Publications Warehouse

Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

2011-01-01

Characterizing the physical and biological characteristics of the lower Elwha River, its estuary, and adjacent nearshore habitats prior to dam removal is essential to monitor changes to these areas during and following the historic dam-removal project set to begin in September 2011. Based on the size of the two hydroelectric projects and the amount of sediment that will be released, the Elwha River in Washington State will be home to the largest river restoration through dam removal attempted in the United States. Built in 1912 and 1927, respectively, the Elwha and Glines Canyon Dams have altered key physical and biological characteristics of the Elwha River. Once abundant salmon populations, consisting of all five species of Pacific salmon, are restricted to the lower 7.8 river kilometers downstream of Elwha Dam and are currently in low numbers. Dam removal will reopen access to more than 140 km of mainstem, flood plain, and tributary habitat, most of which is protected within Olympic National Park. The high capture rate of river-borne sediments by the two reservoirs has changed the geomorphology of the riverbed downstream of the dams. Mobilization and downstream transport of these accumulated reservoir sediments during and following dam removal will significantly change downstream river reaches, the estuary complex, and the nearshore environment. To introduce the more detailed studies that follow in this report, we summarize many of the key aspects of the Elwha River ecosystem including a regional and historical context for this unprecedented project.

Feasibility of Tracking Fish with Acoustic Transmitters in the Ice Harbor Dam Tailrace

PubMed Central

Ingraham, John M.; Deng, Z. Daniel; Martinez, Jayson J.; Trumbo, Bradly A.; Mueller, Robert P.; Weiland, Mark A.

2014-01-01

The Juvenile Salmon Acoustic Telemetry System (JSATS) has been used at many dams but has never been deployed in the near-dam tailrace environment. The use of JSATS in the tailrace is of interest to fishery managers to evaluate downstream passage behavior of juvenile salmonids and dam approach behavior of upstream migrating adult salmon and lamprey. The acoustic noise level and detection range of JSATS were studied to determine the feasibility of deploying JSATS in the Ice Harbor Dam tailrace. The noise level measured from the powerhouse deck was less than 104 dB re 1 μPa except for the turbine outlet near the spillway, and 350 m downstream of the dam, the noise level was less than 106 dB. The measured noise levels would allow a theoretical detection range of 100 m to 350 m and 85 m to 320 m, respectively. Validation experiments showed that the detection range is 113 to 184 m using hydrophones deployed from the powerhouse deck and 148 m using hydrophones deployed 500 m downstream of the dam. PMID:24522516

Assessing potential removal of low-head dams in urban settings: an example from the Ottawa River, NW Ohio.

PubMed

Roberts, Sheila J; Gottgens, Johan F; Spongberg, Alison L; Evans, James E; Levine, Norman S

2007-01-01

This is a study of the scientific component of an effort to restore an urban river by removing a low-head dam. The Secor Dam is owned by a local government entity near Toledo, Ohio. The proposed removal of the last structure impeding flow on the Ottawa River has broad appeal, but the owner is concerned about liability issues, particularly potential changes to the flood regime, the presence of contaminated sediments behind the dam, and possible downstream transport of reservoir sediments. Assessing sediment contamination involved sediment sampling and analysis of trace metals and organic contaminants. Forecasting sediment transport involved field methods to determine the volume and textural properties of reservoir and upstream sediment and calculations to determine the fate of reservoir sediments. Forecasting changes in the flood regime involved HEC-RAS hydrological models to determine before and after dam removal flood scenarios using LiDAR data imported into an ArcGIS database. The resulting assessment found potential sediment contamination to be minor, and modeling showed that the removal of the dam would have minimal impacts on sediment transport and flood hazards. Based on the assessment, the removal of the dam has been approved by its owners.

Inflow forecasting model construction with stochastic time series for coordinated dam operation

NASA Astrophysics Data System (ADS)

Kim, T.; Jung, Y.; Kim, H.; Heo, J. H.

2014-12-01

Dam inflow forecasting is one of the most important tasks in dam operation for an effective water resources management and control. In general, dam inflow forecasting with stochastic time series model is possible to apply when the data is stationary because most of stochastic process based on stationarity. However, recent hydrological data cannot be satisfied the stationarity anymore because of climate change. Therefore a stochastic time series model, which can consider seasonality and trend in the data series, named SARIMAX(Seasonal Autoregressive Integrated Average with eXternal variable) model were constructed in this study. This SARIMAX model could increase the performance of stochastic time series model by considering the nonstationarity components and external variable such as precipitation. For application, the models were constructed for four coordinated dams on Han river in South Korea with monthly time series data. As a result, the models of each dam have similar performance and it would be possible to use the model for coordinated dam operation.Acknowledgement This research was supported by a grant 'Establishing Active Disaster Management System of Flood Control Structures by using 3D BIM Technique' [NEMA-NH-12-57] from the Natural Hazard Mitigation Research Group, National Emergency Management Agency of Korea.

The social impacts of dams: A new framework for scholarly analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirchherr, Julian, E-mail: julian.kirchherr@sant.ox.ac.uk; Charles, Katrina J., E-mail: katrina.charles@ouce.ox.ac.uk

No commonly used framework exists in the scholarly study of the social impacts of dams. This hinders comparisons of analyses and thus the accumulation of knowledge. The aim of this paper is to unify scholarly understanding of dams' social impacts via the analysis and aggregation of the various frameworks currently used in the scholarly literature. For this purpose, we have systematically analyzed and aggregated 27 frameworks employed by academics analyzing dams' social impacts (found in a set of 217 articles). A key finding of the analysis is that currently used frameworks are often not specific to dams and thus omitmore » key impacts associated with them. The result of our analysis and aggregation is a new framework for scholarly analysis (which we call ‘matrix framework’) specifically on dams' social impacts, with space, time and value as its key dimensions as well as infrastructure, community and livelihood as its key components. Building on the scholarly understanding of this topic enables us to conceptualize the inherently complex and multidimensional issues of dams' social impacts in a holistic manner. If commonly employed in academia (and possibly in practice), this framework would enable more transparent assessment and comparison of projects.« less

Evolution of an interfacial crack on the concrete-embankment boundary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glascoe, Lee; Antoun, Tarabay; Kanarska, Yuliya

2013-07-10

Failure of a dam can have subtle beginnings. A small crack or dislocation at the interface of the concrete dam and the surrounding embankment soil initiated by, for example, a seismic or an explosive event can lead to a catastrophic failure of the dam. The dam may ‘self-rehabilitate’ if a properly designed granular filter is engineered around the embankment. Currently, the design criteria for such filters have only been based on experimental studies. We demonstrate the numerical prediction of filter effectiveness at the soil grain scale. This joint LLNL-ERDC basic research project, funded by the Department of Homeland Security’s Sciencemore » and Technology Directorate (DHS S&T), consists of validating advanced high performance computer simulations of soil erosion and transport of grain- and dam-scale models to detailed centrifuge and soil erosion tests. Validated computer predictions highlight that a resilient filter is consistent with the current design specifications for dam filters. These predictive simulations, unlike the design specifications, can be used to assess filter success or failure under different soil or loading conditions and can lead to meaningful estimates of the timing and nature of full-scale dam failure.« less

Dynamic decision making for dam-break emergency management - Part 1: Theoretical framework

NASA Astrophysics Data System (ADS)

Peng, M.; Zhang, L. M.

2013-02-01

An evacuation decision for dam breaks is a very serious issue. A late decision may lead to loss of lives and properties, but a very early evacuation will incur unnecessary expenses. This paper presents a risk-based framework of dynamic decision making for dam-break emergency management (DYDEM). The dam-break emergency management in both time scale and space scale is introduced first to define the dynamic decision problem. The probability of dam failure is taken as a stochastic process and estimated using a time-series analysis method. The flood consequences are taken as functions of warning time and evaluated with a human risk analysis model (HURAM) based on Bayesian networks. A decision criterion is suggested to decide whether to evacuate the population at risk (PAR) or to delay the decision. The optimum time for evacuating the PAR is obtained by minimizing the expected total loss, which integrates the time-related probabilities and flood consequences. When a delayed decision is chosen, the decision making can be updated with available new information. A specific dam-break case study is presented in a companion paper to illustrate the application of this framework to complex dam-breaching problems.

Calculated hydrographs for unsteady research flows at selected sites along the Colorado River downstream from Glen Canyon Dam, Arizona, 1990 and 1991

USGS Publications Warehouse

Griffin, Eleanor R.; Wiele, Stephen M.

1996-01-01

A one-dimensional model of unsteady discharge waves was applied to research flowr that were released from Glen Canyon Dam in support of the Glen Canyon Environmental Studies. These research flows extended over periods of 11 days during which the discharge followed specific, regular patterns repeated on a daily cycle that were similar to the daily releases for power generation. The model was used to produce discharge hydrographs at 38 selected sites in Marble and Grand Canyons for each of nine unsteady flows released from the dam in 1990 and 1991. In each case, the discharge computed from stage measurements and the associated stage-discharge relation at the streamflow-gaging station just below the dam (09379910 Colorado River Hlow Glen Canyon Dam) was routed to Diamond Creek, which is 386 kilometers downstream. Steady and unsteady tributary inflows downstream from the dam were included in the model calculations. Steady inflow to the river from tributaries downstream from the dam was determined for each case by comparing the steady base flow preceding and following the unsteady flow measured at six streamflow-gaging stations between Glen Canyon Dam and Diamond Creek. During three flow periods, significant unsteady inflow was received from the Paria River, or the Little Colorado River, or both. The amount and timing of unsteady inflow was determined using the discharge computed from records of streamflow-gaging stations on the tributaries. Unsteady flow then was added to the flow calculated by the model at the appropriate location. Hydrographs were calculated using the model at 5 streamflow-gaging stations downstream from the dam and at 33 beach study sites. Accuracy of model results was evaluated by comparing the results to discharge hydrographs computed from the records of the five streamflow-gaging stations between Lees Ferry and Lake Mead. Results show that model predictions of wave speed and shape agree well with data from the five streamflow-gaging stations.

Adjustments in channel morphology due to land-use changes and check dam installation in mountain torrents of Calabria (Southern Italy)

NASA Astrophysics Data System (ADS)

Fortugno, Diego; Zema, Demetrio Antonio; Bombino, Giuseppe; Tamburino, Vincenzo; Quinonero Rubio, Juan Manuel; Boix-Fayos, Carolina

2016-04-01

In Mediterranean semi-arid conditions the geomorphic effects of land-use changes and check dam installation on active channel headwater morphology are not completely understood. In such environments, the availability of specific studies, which monitor channel adjustments as a response to reforestation and check dams over representative observation periods, could help develop new management strategies and erosion control measures. This investigation is an integrated approach assessing the adjustments of channel morphology in a typical torrent (Sant'Agata, Calabria, Southern Italy) after land-use changes (e.g. fire, reforestation, land abandonment) and check dam construction across a period of about 60 years (1955-2012). A statistical analysis of historical rainfall records, an analysis of land-use change in the catchment area and a geomorphological mapping of channel adjustments were carried out and combined with field surveys of bed surface grain-size over a 5-km reach including 14 check dams. The analysis of the historical rainfall records showed a slight decrease in the amount and erosivity of precipitation. Mapping of land-use changes highlighted a general increase of vegetal coverage on the slopes adjacent to the monitored reaches. Together with the check dam network installation, this increase could have induced a reduction in water and sediment supply. The different erosional and depositional forms and adjustments showed a general narrowing between consecutive check dams together with local modifications detected upstream (bed aggradation and cross section expansion together with low-flow realignments) and downstream (local incision) of the installed check dams. Changes in the torrent bends were also detected as a response to erosional and depositional processes with different intensities. The study highlighted: (i) the efficiency of check dams against the disrupting power of the most intense floods by stabilising the active channel; and (ii) the influence of reforestation in increasing hillslope protection from erosion and disconnectivity of water and sediment flows towards the active channel. The residual sediment deficit circulating in the watershed suggests the need of slight management interventions, as, for instance, the conversion of the existing check dams into open structures, allowing a definite channel and coast stability.

33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

Code of Federal Regulations, 2011 CFR

2011-07-01

... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are... Roadrunner Resort and Headgate Dam). Bullhead City Boat Drags Sponsor: Sunshine Promotions Date: 2 to 4...

33 CFR 100.1102 - Marine Events on the Colorado River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam...

Code of Federal Regulations, 2010 CFR

2010-07-01

... River, between Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). 100.1102 Section... Davis Dam (Bullhead City, Arizona) and Headgate Dam (Parker, Arizona). (a) General. Sponsors are... Roadrunner Resort and Headgate Dam). Bullhead City Boat Drags Sponsor: Sunshine Promotions Date: 2 to 4...

106. DAM EARTH DIKE SUBMERSIBLE DAMS & DIKE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

106. DAM - EARTH DIKE - SUBMERSIBLE DAMS & DIKE CONN. AT MOVABLE DAM (ML-8-52/2-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

The Effects of Dams on Downstream Channel Characteristics in Pennsylvania and Maryland: Assessing the Potential Consequences of Dam Removal

NASA Astrophysics Data System (ADS)

Skalak, K. J.; Pizzuto, J. E.; Jenkins, P.

2003-12-01

The potential downstream effects of dam removal were assessed on fifteen sites of varying dam size and characteristics in Pennsylvania and Maryland. The dams ranged in size from a 30 cm high fish weir to a water supply dam 57 m high. Stream order ranged from 1 to 4. The dams are located in watersheds with varying degrees of human disturbance and urbanization. The dams are also operated differently, with significant consequences for hydraulic residence time and downstream flow variability. Most streams were alluvial, but 6 of the reaches were clearly bedrock channels. We hypothesize that the channel upstream, which is unaffected by the dam, will provide an accurate model for the channel downstream of the dam long after dam removal. Therefore, reaches upstream and downstream of the dam were compared to determine the effects of the dam as well as the condition of the stream that will ultimately develop decades after dam removal. Surprisingly, the dams had no consistent influence on channel morphology. However, the percentage of sand is significantly lower downstream than upstream: the mean % sand downstream is 11.47%, while the mean % sand upstream is 21.39%. The coarser fractions of the bed, as represented by the 84th percentile grain diameter, are unaffected by the presence of the dam. These results imply that decades after dam removal, the percentage of sand on the bed will increase, but the coarse fraction of the bed will remain relatively unchanged.

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paluch, Mark; Scholz, Allan; McLellan, Holly

2009-07-13

This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acousticmore » radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other fish was large enough to be mature, but at the time of capture its sex was unable to be determined, indicating it may not have been mature at the time of capture. These fish are expected to enter their natal tributaries in early summer or fall of 2009.« less

The sensitive hare: sublethal effects of predator stress on reproduction in snowshoe hares.

PubMed

Sheriff, Michael J; Krebs, Charles J; Boonstra, Rudy

2009-11-01

1. Prey responses to high predation risk can be morphological or behavioural and ultimately come at the cost of survival, growth, body condition, or reproduction. These sub-lethal predator effects have been shown to be mediated by physiological stress. We tested the hypothesis that elevated glucocorticoid concentrations directly cause a decline in reproduction in individual free-ranging female snowshoe hares, Lepus americanus. We measured the cortisol concentration from each dam (using a faecal analysis enzyme immunoassay) and her reproductive output (litter size, offspring birth mass, offspring right hind foot (RHF) length) 30 h after birth. 2. In a natural monitoring study, we monitored hares during the first and second litter from the population peak (2006) to the second year of the decline (2008). We found that faecal cortisol metabolite (FCM) concentration in dams decreased 52% from the first to the second litter. From the first to the second litter, litter size increased 122%, offspring body mass increased 130%, and offspring RHF length increased 112%. Dam FCM concentrations were inversely related to litter size (r(2) = 0.19), to offspring birth mass (r(2) = 0.32), and to offspring RHF length (r(2) = 0.64). 3. In an experimental manipulation, we assigned wild-caught, pregnant hares to a control and a stressed group and held them in pens. Hares in the stressed group were exposed to a dog 1-2 min every other day before parturition to simulate high predation risk. At parturition, unsuccessful-stressed dams (those that failed to give birth to live young) and stressed dams had 837% and 214%, respectively, higher FCM concentrations than control dams. Of those females that gave birth, litter size was similar between control and stressed dams. However, offspring from stressed dams were 37% lighter and 16% smaller than offspring from control dams. Increasing FCM concentration in dams caused the decline of offspring body mass (r(2) = 0.57) and RHF (r(2) = 0.52). 4. This is the first study in a free-ranging population of mammals to show that elevated, predator-induced, glucocorticoid concentrations in individual dams caused a decline in their reproductive output measured both by number and quality of offspring. Thus, we provide evidence that any stressor, not just predation, which increases glucocorticoid concentrations will result in a decrease in reproductive output.

Local Economic Development and Hydropower Along the Brahmaputra River Basin in Northeast India

NASA Astrophysics Data System (ADS)

Mock, A.

2014-12-01

Large dams have long been controversial. They offer benefits, such as reduced greenhouse gas emissions, energy security, and local development, yet produce negative social and ecological impact, such as wildlife habitat destruction, human displacement, and the disruption of downstream fishing or agricultural industries. In the past decade, the Indian government has signed Memoranda of Understanding with hydroelectric power companies for the building of over 130 large dams on the Brahmaputra River in the state of Arunachal Pradesh in Northeast India. These dams can generate 43% of India's assessed hydropower potential to sustain India's growing economy. In addition, the Indian government claims that these dams will bring local development with needed jobs. However, local Arunachali people have protested and temporarily halted hydropower projects because of the impact of dams on their existing livelihoods. Using the North Eastern Electric Power Corporation's (NEEPCO) Ranganadi Hydroelectric Project as a case study, our project examined whether dams in Northeast India provide jobs for local people, and whether distance from the dam or work colony to a worker's hometown affects the type of job the worker received. Survey data from residents at NEEPCO's work colony in Doimukh, Arunachal Pradesh, was analyzed using SPSS (n = 18). Our research found that 100% of workers at the dam originally resided in Northeast India, with 33% from Arunachal Pradesh, and 67% from the nearby states of Assam, and Tripura. Further, our analysis revealed no statistically significant relationship between the distance to a worker's hometown and job type (p = .609). Where workers come from did not affect the type of job they received. More research using a larger sample size and additional hydroelectric project case studies is needed to further explore the relationship between worker home location and their job types.

Evaluating the effects of dam breach methodologies on Consequence Estimation through Sensitivity Analysis

NASA Astrophysics Data System (ADS)

Kalyanapu, A. J.; Thames, B. A.

2013-12-01

Dam breach modeling often includes application of models that are sophisticated, yet computationally intensive to compute flood propagation at high temporal and spatial resolutions. This results in a significant need for computational capacity that requires development of newer flood models using multi-processor and graphics processing techniques. Recently, a comprehensive benchmark exercise titled the 12th Benchmark Workshop on Numerical Analysis of Dams, is organized by the International Commission on Large Dams (ICOLD) to evaluate the performance of these various tools used for dam break risk assessment. The ICOLD workshop is focused on estimating the consequences of failure of a hypothetical dam near a hypothetical populated area with complex demographics, and economic activity. The current study uses this hypothetical case study and focuses on evaluating the effects of dam breach methodologies on consequence estimation and analysis. The current study uses ICOLD hypothetical data including the topography, dam geometric and construction information, land use/land cover data along with socio-economic and demographic data. The objective of this study is to evaluate impacts of using four different dam breach methods on the consequence estimates used in the risk assessments. The four methodologies used are: i) Froehlich (1995), ii) MacDonald and Langridge-Monopolis 1984 (MLM), iii) Von Thun and Gillete 1990 (VTG), and iv) Froehlich (2008). To achieve this objective, three different modeling components were used. First, using the HEC-RAS v.4.1, dam breach discharge hydrographs are developed. These hydrographs are then provided as flow inputs into a two dimensional flood model named Flood2D-GPU, which leverages the computer's graphics card for much improved computational capabilities of the model input. Lastly, outputs from Flood2D-GPU, including inundated areas, depth grids, velocity grids, and flood wave arrival time grids, are input into HEC-FIA, which provides the consequence assessment for the solution to the problem statement. For the four breach methodologies, a sensitivity analysis of four breach parameters, breach side slope (SS), breach width (Wb), breach invert elevation (Elb), and time of failure (tf), is conducted. Up to, 68 simulations are computed to produce breach hydrographs in HEC-RAS for input into Flood2D-GPU. The Flood2D-GPU simulation results were then post-processed in HEC-FIA to evaluate: Total Population at Risk (PAR), 14-yr and Under PAR (PAR14-), 65-yr and Over PAR (PAR65+), Loss of Life (LOL) and Direct Economic Impact (DEI). The MLM approach resulted in wide variability in simulated minimum and maximum values of PAR, PAR 65+ and LOL estimates. For PAR14- and DEI, Froehlich (1995) resulted in lower values while MLM resulted in higher estimates. This preliminary study demonstrated the relative performance of four commonly used dam breach methodologies and their impacts on consequence estimation.

Upstream movements of Atlantic Salmon in the Lower Penobscot River, Maine following two dam removals and fish passage modifications

USGS Publications Warehouse

Izzo, Lisa K.; Maynard, George A.; Zydlewski, Joseph D.

2016-01-01

The Penobscot River Restoration Project (PRRP), to be completed in 2016, involved an extensive plan of dam removal, increases in hydroelectric capacity, and fish passage modifications to increase habitat access for diadromous species. As part of the PRRP, Great Works and Veazie dams were removed, making Milford Dam the first impediment to federally endangered Atlantic Salmon Salmo salar. Upstream habitat access for Atlantic Salmon is dependent upon successful and timely passage at Milford Dam because nearly all suitable spawning habitat is located upstream. In 2014 and 2015, a total of 73 adult salmon were radio-tagged to track their upstream movements through the Penobscot River to assess potential delays at (1) the dam remnants, (2) the confluence of the Stillwater Branch and the main stem of the Penobscot River below the impassable Orono Dam, and (3) the Milford Dam fish lift (installed in 2014). Movement rates through the dam remnants and the Stillwater confluence were comparable to open river reaches. Passage efficiency of the fish lift was high in both years (95% and 100%). However, fish experienced long delays at Milford Dam, with approximately one-third of fish taking more than a week to pass in each year, well below the Federal Energy Regulatory Commission passage standard of 95% within 48 h. Telemetry indicates most fish locate the fishway entrance within 5 h of arrival and were observed at the entrance at all hours of the day. These data indicate that overall transit times through the lower river were comparable to reported movement rates prior to changes to the Penobscot River due to the substantial delays seen at Milford Dam. The results of this study show that while adult Atlantic Salmon locate the new fish lift entrance quickly, passage of these fish was significantly delayed under 2014–2015 operations.

Prenatal maternal effects on body condition score, female fertility, and milk yield of dairy cows.

PubMed

Banos, G; Brotherstone, S; Coffey, M P

2007-07-01

In this study, maternal effects were described as age of dam at first and second calving, first-lactation body condition score (BCS) of the dam during gestation, and milk yield of the dam. The impact of these effects on first-lactation daughter BCS, fertility, and test-day milk yield was assessed. The effect of milk yield of dam on daughter 305-d yield in the latter's first 3 lactations was also investigated. The proportion of total phenotypic variance in daughter traits accounted for by maternal effects was calculated. Dams calving early for the first time (18 to 23 mo of age) had daughters that produced 4.5% more first-lactation daily milk, had 7% higher BCS, and had their first service 3 d earlier than cows whose dams calved late (30 to 36 mo). However, daughters of dams that calved early had difficulties conceiving as they needed 7% more inseminations and had a 7.5% higher return rate. Cows from second calvings of relatively young (36 to 41 mo) dams produced 6% more first-lactation daily milk, had 2% higher BCS, and showed a significantly better fertility profile than cows whose dams calved at a late age (47 to 55 mo). High maternal BCS during gestation had a favorable effect on daughter BCS, nonreturn rate, and number of inseminations per conception. However, it was also associated with a small decrease in daughter daily milk yield. Changes in dam BCS during gestation did not affect daughter performance significantly. Maternal effects of milk yield of the dam, expressed as her permanent environment during lactation, adversely affected daughter 305-d milk, fat, and protein yield. However, although the effect was significant, it was practically negligible (<0.3% of the mean). Finally, overall maternal effects accounted for a significant proportion of the total phenotypic variance of calving interval (1.4 +/- 0.6%) and nonreturn rate (1.1 +/- 0.5%).

Histological and Metabolic State of Dams Suckling Small Litter or MSG-Treated Pups.

PubMed

Capriglioni Cancian, Claudia Regina; Leite, Nayara Carvalho; Montes, Elisangela Gueiber; Fisher, Stefani Valeria; Waselcoski, Leticia; Lopes Stal, Emily Caroline; Christoforo, Renata Zanardini; Grassiolli, Sabrina

Lactation is an important function that is dependent on changes in the maternal homeostasis and sustained by histological maternal adjustments. We evaluated how offspring manipulations during the lactational phase can modulate maternal morphologic aspects in the mammary gland, adipose tissue, and pancreatic islets of lactating dams. Two different models of litter-manipulation-during-lactation were used: litter sizes, small litters (SL) or normal litters (NL) and subcutaneous injections in the puppies of monosodium glutamate (MSG), or saline (CON). SL Dams and MSG Dams presented an increase in WAT content and higher plasma levels of glucose, triglycerides, and insulin, in relation to NL Dams and CON Dams, respectively. The MG of SL Dams and MSG Dams presented a high adipocyte content and reduced alveoli development and the milk of the SL Dams presented a higher calorie and triglyceride content, compared to that of the NL Dams. SL Dams presented a reduction in islet size and greater lipid droplet accumulation in BAT, in relation to NL Dams. SL Dams and MSG Dams present similar responses to offspring manipulation during lactation, resulting in changes in metabolic parameters. These alterations were associated with higher fat accumulation in BAT and changes in milk composition only in SL Dams.

Histological and Metabolic State of Dams Suckling Small Litter or MSG-Treated Pups

PubMed Central

Capriglioni Cancian, Claudia Regina; Montes, Elisangela Gueiber; Fisher, Stefani Valeria; Waselcoski, Leticia; Lopes Stal, Emily Caroline; Christoforo, Renata Zanardini; Grassiolli, Sabrina

2016-01-01

Lactation is an important function that is dependent on changes in the maternal homeostasis and sustained by histological maternal adjustments. We evaluated how offspring manipulations during the lactational phase can modulate maternal morphologic aspects in the mammary gland, adipose tissue, and pancreatic islets of lactating dams. Two different models of litter-manipulation-during-lactation were used: litter sizes, small litters (SL) or normal litters (NL) and subcutaneous injections in the puppies of monosodium glutamate (MSG), or saline (CON). SL Dams and MSG Dams presented an increase in WAT content and higher plasma levels of glucose, triglycerides, and insulin, in relation to NL Dams and CON Dams, respectively. The MG of SL Dams and MSG Dams presented a high adipocyte content and reduced alveoli development and the milk of the SL Dams presented a higher calorie and triglyceride content, compared to that of the NL Dams. SL Dams presented a reduction in islet size and greater lipid droplet accumulation in BAT, in relation to NL Dams. SL Dams and MSG Dams present similar responses to offspring manipulation during lactation, resulting in changes in metabolic parameters. These alterations were associated with higher fat accumulation in BAT and changes in milk composition only in SL Dams. PMID:28004032

Risk Perception Analysis Related To Existing Dams In Italy

NASA Astrophysics Data System (ADS)

Solimene, Pellegrino

2013-04-01

In the first part of this work, the progress of Italian National Rules about dams design, construction and operation are presented to highlight the strong connection existing between the promulgation of new decrees, as a consequence of a dam accidents, and the necessity to prevent further loss of lives and goods downstream. Following the Gleno Dam failure (1923), a special Ministerial Committee wrote out the first Regulations and made the proposal to establish, within the High Council of Public Works, a special department that become soon the "Dam Service", with the tasks of control and supervision about construction and operation phases of the dams and their reservoirs. A different definition of tasks and the structure of Dam Service were provided in accordance with law n° 183/1989, which transferred all the technical services to the Office of the Prime Minister; the aim was to join the Dam Office with the Department for National Technical Services, with the objective of increasing the knowledge of the territory and promoting the study on flood propagation downstream in case of operations on bottom outlet or hypothetical dam-break. In fact, population living downstream is not ready to accept any amount of risk because has not a good knowledge of the efforts of experts involved in dam safety, both from the operators and from the safety Authority. So it's important to optimize all the activities usually performed in a dam safety program and improve the emergency planning as a response to people's primary needs and feeling about safety from Civil Protection Authority. In the second part of the work, a definition of risk is provided as the relationship existing between probability of occurrence and loss, setting out the range within to plan for prevention (risk mitigation), thanks to the qualitative assessment of the minimum safety level that is suited to assign funds to plan for Civil Protection (loss mitigation). The basic meaning of the reliability of a zoned earthfill dam is illustrated by defining the risk analysis during its construction and operation. A qualitative "Event Tree Analysis" makes clear with an example the probability of occurrence of the events triggered by an earthquake, and leads to a classification of the damage level. Finally, a System Dynamics (SD) approach is presented to investigate possibilities of a preventive planning in relationship to the risk, so that it's possible to establish shared procedures to achieve the correct management in any crisis phase. As a qualitative result of a SD application, figure 1 presents a flow-chart about a case study on the same dam so to illustrate the emergency planning in a step by step procedure according to the Regulations.

Historical and simulated changes in channel characteristics of the Kalamazoo River, Plainwell to Otesgo, Michigan

USGS Publications Warehouse

Rachol, Cynthia M.; Fitzpatrick, Faith A.; Rossi, Tiffiny

2005-01-01

In a study to understand the historical effects of the construction and decommissioning of dams on the Kalamazoo River, Plainwell to Otesgo, Michigan, and to simulate channel changes that may result if the dams were removed, early to mid-1800s General Land Office surveys and aerial photographs from 1938, 1981, and 1999 were compared in order to identify historical changes in the river’s planform. This analysis of the 80-mile reach from Morrow Dam to the river mouth at Saugatuck provided insight into how susceptible the river has been to channel migration. The comparison showed that changes in channel width and location were caused mainly by construction of dams and subsequent water-level adjustments in the impounded reaches upstream from the dams. Braiding also occurred downstream from one of the dams. Minor changes in channel form that were not caused by the dams, such as the development and cutoff of meander bends, were observed. A more detailed study in a 5-mile reach passing through the Plainwell and Otsego City Dams included compiling existing valley cross section and longitudinal profile data into a database, assessing bank stability, and using a hydrologic model to simulate the channel as if the dams were removed. Fifty-four valley cross sections compiled from United States Geological Survey and consultant data sets were used as a base for a bank-stability assessment and to design a hypothetical stable channel without the two dams. The channel design involved adjusting the slope, hydraulic geometry, and floodplain width to ensure that water could be transferred through the reach without increasing flooding or erosion problems. The bank-stability assessment focused on conditions that are critical to failure. This was accomplished through the use of a two step process. The first involved evaluating the sediment removed from the bank toe when the stage is high. The second involved calculating the factor of safety for the bank based on the water table being elevated higher than the stage, mimicing a bank storage effect. Using these paired proccesses, two scenarios of critical conditions were evaluated: dams present and dams removed. Results of the bank assessments showed that, under both critical-condition scenarios, the streambanks were more susceptible to toe erosion than to block failure. As toe erosion progresses, the banks will eventually collapse as supporting material underneath is removed. Toe erosion for the damsremoved scenario resulted in higher amounts of erosion than for the dams-present scenario, leading to an overall decrease in bank stability. Effects of vegetation on the bank stability were variable; stability for some banks increase if vegetation was present but remain the same for other banks.

Re-Adaptation to 1-G of Pregnant Rats Following Exposure to Spaceflight or Centrifugation

NASA Technical Reports Server (NTRS)

Johnson, K. E.; Ronca, A. E.; Alberts, J. R.

2003-01-01

Late-pregnant rat dams were flown on a 9-day Space Shuttle mission or exposed to 1.5, 1.75 or 2-g centrifugation and compared with 1 .O-g vivarium controls. Exposure to altered gravity began on the 11th day and recovery occurred on the 20th day of the dams' 22-day pregnancy. In the 1 st experiment, comparisons were made between Flight (FLT), Synchronous (SYN; identically-housed) and Vivarium (VIV) controls. In the 2nd experiment, comparisons were made between dams centrifuged at 2-G, 1.75-G, 1.5-G, Rotational controls (1.08-G) or Stationary controls (1 G). Within three hours of recovery from either spaceflight or centrifugation, the dams' locomotor behavior was videotaped for 2 min. FLT dams showed dramatically reduced movement relative to both SYN and VIV control conditions, with significantly greater amounts of locomotor activity observed in SYN as compared to VIV dams. Significantly greater locomotor activity was observed in SYN as compared to VIV controls. In the second experiment, no differences were observed between dams exposed either 1, 1.5, 1.75, or 2-G. In both studies, the dams showed similar patterns of hindlimb rearing. Together, these findings provide quantitative evidence for decreased locomotor activity during re-adaptation to 1-g following spaceflight, but not centrifugation.

Negligible contribution of reservoir dams to organic and inorganic transport in the lower Mimi River, Japan

NASA Astrophysics Data System (ADS)

Nukazawa, Kei; Kihara, Kousuke; Suzuki, Yoshihiro

2017-12-01

Rivers fulfill an essential ecological role by forming networks for material transport from upland forests to coastal areas. The way in which dams affect the organic and inorganic cycles in such systems is not well understood. Herein, we investigated the longitudinal profiles of the various components of the water chemistry across three cascade dams in Japan: the Yamasubaru Dam, Saigou Dam, and Ohuchibaru Dam, which are situated along the sediment-productive Mimi River in different flow conditions. We analyzed the following water quality components: suspended solids (SS), turbidity, total iron (TFe), dissolved iron (DFe), total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), humic substance (HS), and major ionic components (Na+, Mg2+, Ca2+, Cl-, NO3-, and SO42-) in the downstream channels of the three dams during the low-intermediate-flow and high-flow events from 2012 to 2014. We estimated hourly loads of each component using hourly turbidity data and discharge data (i.e., L-Q model) separately, and the results are integrated to estimate the annual fluxes. The annual fluxes between the methods were compared to verify predictability of the conventional L-Q models. Annual flux of TOC, TN, DFe, and HS estimated by the turbidity displayed similar values, whereas the flux of SS, TFe, and TP tended to increase downstream of the dams. Among the dams, estimated flux proportions for TP and TFe were higher during high-flow events (74%-94%). Considering geographic conditions (e.g., absence of major tributary between the dams), the result implies that accumulated TP and TFe in the reservoirs may be flushed and transported downstream with SS over the short height dams during flood events. Assuming this process, the reservoir dams probably make only a fractional contribution to the organic and inorganic transport in the catchment studied. The percent flux errors for SS, TFe, and TP fluxes ranged from -7.2% to -97% (except for the TP flux in 2013), which highlights the risk of underestimating these components when using an L-Q model.

Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.

2012-01-01

A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.

Modeling Potential Surface and Shallow Groundwater Storage Provided by Beaver Ponds Across Watersheds

NASA Astrophysics Data System (ADS)

Hafen, K.; Wheaton, J. M.; Macfarlane, W.

2016-12-01

Damming of streams by North American Beaver (Castor canadensis) has been shown to provide a host of potentially desirable hydraulic and hydrologic impacts. Notably, increases in surface water storage and groundwater storage may alter the timing and delivery of water around individual dams and dam complexes. Anecdotal evidence suggests these changes may be important for increasing and maintaining baseflow and even helping some intermittent streams flow perennially. In the arid west, these impacts could be particularly salient in the face of climate change. However, few studies have examined the hydrologic impacts of beaver dams at scales large enough to provide insight for water management, in part because understanding or modeling these impacts at large spatial scales has been precluded by uncertainty concerning the number of beaver dams a drainage network can support. Using the recently developed Beaver Restoration Assessment Tool (BRAT) to identify possible densities and spatial configurations of beaver dams, we developed a model that predicts the area and volume of surface water storage associated with dams of various sizes, and applied this model at different dam densities across multiple watersheds (HUC12) in northern Utah. We then used model results as inputs to the MODFLOW groundwater model to identify the subsequent changes to shallow groundwater storage. The spatially explicit water storage estimates produced by our approach will be useful in evaluating potential beaver restoration and conservation, and will also provide necessary information for developing hydrologic models to specifically identify the effects beaver dams may have on water delivery and timing.

Sluiceway Operations for Adult Steelhead Downstream Passage at The Dalles Dam, Columbia River, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Fenton; Royer, Ida M.; Johnson, Gary E.

2013-10-01

This study evaluated adult steelhead (Oncorhynchus mykiss; fallbacks and kelts) downstream passage at The Dalles Dam in the Columbia River, USA, during the late fall, winter, and early spring months between 2008 and 2011. The purpose of the study was to determine the efficacy of operating the dam’s ice-and-trash sluiceway during non-spill months to provide a relatively safe, non-turbine, surface outlet for overwintering steelhead fallbacks and downstream migrating steelhead kelts. We applied the fixed-location hydroacoustic technique to estimate fish passage rates at the sluiceway and turbines of the dam. The spillway was closed during our sampling periods, which generally occurredmore » in late fall, winter, and early spring. The sluiceway was highly used by adult steelhead (91–99% of total fish sampled passing the dam) during all sampling periods. Turbine passage was low when the sluiceway was not operated. This implies that lack of a sluiceway route did not result in increased turbine passage. However, when the sluiceway was open, adult steelhead used it to pass through the dam. The sluiceway may be operated during late fall, winter, and early spring to provide an optimal, non-turbine route for adult steelhead (fallbacks and kelts) downstream passage at The Dalles Dam.« less

Modeling the capacity of riverscapes to support beaver dams

NASA Astrophysics Data System (ADS)

Macfarlane, William W.; Wheaton, Joseph M.; Bouwes, Nicolaas; Jensen, Martha L.; Gilbert, Jordan T.; Hough-Snee, Nate; Shivik, John A.

2017-01-01

The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel-floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100 m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561 km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8 dams/km. We validated model performance using 2852 observed dams across 1947 km of streams. The model showed excellent agreement with observed dam densities where beaver dams were present. Model performance was spatially coherent and logical, with electivity indices that effectively segregated capacity categories. That is, beaver dams were not found where the model predicted no dams could be supported, beaver avoided segments that were predicted to support rare or occasional densities, and beaver preferentially occupied and built dams in areas predicted to have pervasive dam densities. The resulting spatially explicit reach-scale (250 m long reaches) data identifies where dam-building activity is sustainable, and at what densities dams can occur across a landscape. As such, model outputs can be used to determine where channel-floodplain and wetland connectivity are likely to persist or expand by promoting increases in beaver dam densities.

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.

This report presents survival, behavioral, and fish passage results for tagged yearling Chinook salmon and juvenile steelhead as part of a survival study conducted at John Day Dam during spring 2011. This study was designed to evaluate the passage and survival of yearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a paired-release survival model.

Dam-breach analysis and flood-inundation mapping for Lakes Ellsworth and Lawtonka near Lawton, Oklahoma

USGS Publications Warehouse

Rendon, Samuel H.; Ashworth, Chad E.; Smith, S. Jerrod

2012-01-01

Dams provide beneficial functions such as flood control, recreation, and reliable water supplies, but they also entail risk: dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or misoperation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning the emergency response if a dam breach occurs. Accurate topographic data are vital for developing flood-inundation maps. This report presents results of a cooperative study by the city of Lawton, Oklahoma, and the U.S. Geological Survey (USGS) to model dam-breach scenarios at Lakes Ellsworth and Lawtonka near Lawton and to map the potential flood-inundation areas of such dam breaches. To assist the city of Lawton with completion of the emergency action plans for Lakes Ellsworth and Lawtonka Dams, the USGS collected light detection and ranging (lidar) data that were used to develop a high-resolution digital elevation model and a 1-foot contour elevation map for the flood plains downstream from Lakes Ellsworth and Lawtonka. This digital elevation model and field measurements, streamflow-gaging station data (USGS streamflow-gaging station 07311000, East Cache Creek near Walters, Okla.), and hydraulic values were used as inputs for the dynamic (unsteady-flow) model, Hydrologic Engineering Center's River Analysis System (HEC-RAS). The modeled flood elevations were exported to a geographic information system to produce flood-inundation maps. Water-surface profiles were developed for a 75-percent probable maximum flood scenario and a sunny-day dam-breach scenario, as well as for maximum flood-inundation elevations and flood-wave arrival times for selected bridge crossings. Some areas of concern near the city of Lawton, if a dam breach occurs at Lakes Ellsworth or Lawtonka, include water treatment plants, wastewater treatment plants, recreational areas, and community-services offices.

An index-based framework for assessing patterns and trends in river fragmentation and flow regulation by global dams at multiple scales

NASA Astrophysics Data System (ADS)

Grill, Günther; Lehner, Bernhard; Lumsdon, Alexander E.; MacDonald, Graham K.; Zarfl, Christiane; Reidy Liermann, Catherine

2015-01-01

The global number of dam constructions has increased dramatically over the past six decades and is forecast to continue to rise, particularly in less industrialized regions. Identifying development pathways that can deliver the benefits of new infrastructure while also maintaining healthy and productive river systems is a great challenge that requires understanding the multifaceted impacts of dams at a range of scales. New approaches and advanced methodologies are needed to improve predictions of how future dam construction will affect biodiversity, ecosystem functioning, and fluvial geomorphology worldwide, helping to frame a global strategy to achieve sustainable dam development. Here, we respond to this need by applying a graph-based river routing model to simultaneously assess flow regulation and fragmentation by dams at multiple scales using data at high spatial resolution. We calculated the cumulative impact of a set of 6374 large existing dams and 3377 planned or proposed dams on river connectivity and river flow at basin and subbasin scales by fusing two novel indicators to create a holistic dam impact matrix for the period 1930-2030. Static network descriptors such as basin area or channel length are of limited use in hierarchically nested and dynamic river systems, so we developed the river fragmentation index and the river regulation index, which are based on river volume. These indicators are less sensitive to the effects of network configuration, offering increased comparability among studies with disparate hydrographies as well as across scales. Our results indicate that, on a global basis, 48% of river volume is moderately to severely impacted by either flow regulation, fragmentation, or both. Assuming completion of all dams planned and under construction in our future scenario, this number would nearly double to 93%, largely due to major dam construction in the Amazon Basin. We provide evidence for the importance of considering small to medium sized dams and for the need to include waterfalls to establish a baseline of natural fragmentation. Our versatile framework can serve as a component of river fragmentation and connectivity assessments; as a standardized, easily replicable monitoring framework at global and basin scales; and as part of regional dam planning and management strategies.

Behavior and dam passage of juvenile Chinook salmon at Cougar Reservoir and Dam, Oregon, March 2012 - February 2013

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin

2014-01-01

The movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) were studied at Cougar Reservoir and Dam, near Springfield, Oregon, during 2012 and 2013. Cougar Dam is a high-head flood-control reservoir with a temperature control tower as its outlet enabling selective withdrawals of water at various depths to control the temperature of water passed downstream. This report describes the second year of a 2-year study with the goal of providing information to inform decisions about future downstream passage alternatives. Inferences were based on the behavior of yearling-size juvenile Chinook salmon implanted with acoustic transmitters. The fish were released near the head of the reservoir during the spring (March, April, and May) and fall (September, October, and November) of 2012. Most tagged fish were of hatchery origin (468 spring, 449 fall) because of the low number of wild fish captured from within the reservoir (0 spring, 65 fall). Detections at hydrophones placed in several lines across the reservoir and within a collective system used to estimate three-dimensional positions near the temperature control tower were used to determine fish behavior and factors affecting dam passage rates. Most tagged fish made repeated non-random migrations from one end of the reservoir to the other and took a median of 3.7–11.7 days to travel about 7 kilometers from the release site to within about 100 meters of the temperature control tower, depending on season and origin. Reservoir passage efficiency (percentage of tagged fish detected at the head of the forebay) was 97.8 percent for hatchery fish and 74.2 percent for wild fish. Tagged fish commonly were within about 100 meters of the temperature control tower, and often spent considerable time near the entrance to the tower; however, the dam passage efficiency (percentage of dam passage of fish detected at the head of the forebay) was low for fish released during the spring (11.1 percent) and moderate for fish released during the fall (58.1 percent for hatchery fish, 65.2 percent for wild fish) over the 90th percentile of the empirically determined tag life, which was about 90 days. The primary factors affecting the dam passage rate were diel period, dam discharge, and reservoir elevation, and most passage occurred during conditions of night, high dam discharge, and low reservoir elevation. Most fish entering the temperature control tower passed the dam without returning to the reservoir. The common presence of tagged fish near the tower entrance and high proportion of dam passage after tower entry suggests that the primary cause of the poor dam passage rate was the low rate of tower entry. We hypothesize that fish reject the tower entrance because of low water velocities contributing to a small flow field, an abrupt deceleration at the trash rack, or a combination of those two conditions. Results of a controlled test of head differential (the difference between water elevation outside and inside the temperature control tower) indicated weak statistical support (P= 0.0930) for a greater tower entry rate when the differential was 0.65–1.00 foot compared to 0.00–0.30 foot. Results from hatchery and wild fish were similar, with the exception of the reservoir passage efficiency, indicating hatchery fish were suitable surrogates for the wild fish for the purpose of this study.

Yakima River Radio-Telemetry Study: Spring Chinook Salmon, 1991-1992 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hockersmith, Eric

1994-09-01

As part of the presupplementation planning, baseline data on the productivity of spring chinook salmon (Oncorhynchus tshawytscha) in the Yakima River have been collected. However, for adult salmonids, data on habitat use, delays in passage at irrigation diversions, migration rates, and substock separation had not been previously collected. In 1991, the National Marine Fisheries Service began a 2-year radio-telemetry study of adult spring chinook salmon in the Yakima River Basin. Specific objectives addressed in this study were: to determine spawning populations` run timing, passage patterns at irrigation diversion dams, and morphometric characteristics to determine where and when substocks become separated;more » to evaluate fish passage at Yakima River Basin diversion dams including Prosser, Sunnyside, Wapato, Roza, Town Diversion, Easton, Cowiche, and Wapatox Dams; to determine spring chinook salmon migration rates between Yakima River Basin dams, prespawning behavior, temporal distribution, and habitat utilization; to identify spawning distribution and timing of spring chinook salmon; to determine the amount and cause of prespawning mortality of spring chinook salmon; and to evaluate adult fish-handling procedures for the right-bank, adult-trapping facility at Prosser Dam.« less

National Program for Inspection of Non-Federal Dams. Lovejoy Pond Dam ME-00022, Androscoggin River Basin, North Wayne, Maine. Phase I Inspection Report.

DTIC Science & Technology

1979-04-01

programs for non-Federal dams. (3) To update, verify and complete the National Inventory of Dams. 1.2 DESCRIPTION OF PROJECT a. Location. The Lovejoy Pond...BUREAU OF STANDARDS- 1963-A 41 ANDROSCOGGIN RIVER BASIN NORTH WAYNE ,MAINE LOVEJOY POND DAM ME-00022 0 PHASE I INSPECTION REPORT NATIONAL DAM INSPECTION...side of necessar mnd idenifIr bioc Sigmmber) DAMS, INSPECTION, DAM SAFETY, * Androscoggin River Basin North Wayne, Maine Lovejoy Pond * 20. ABSTRACT

The formation and failure of natural dams

USGS Publications Warehouse

Costa, J.E.; Schuster, R.L.

1987-01-01

Of the numerous kinds of dams that form by natural processes, dams formed from landslides, glacial ice, and neoglacial moraines present the greatest threat to people and property. The most common types of mass movements that form landslide dams are rock and debris avalanches, rock and soil slumps and slides, and mud, debris, and earth flows. The most common initiation mechanisms for dam-forming landslides are excessive rainfall and snowmelt and earthquakes. Landslide dams can be classified into six categories based on their relation with the valley floor. Type I dams (11%) of the 81 landslide dams around the world that were classifed do not reach from one valley side to the other. Type II dams (44%) span the entire valley flood, occasionally depositing material high up on opposite valley sides. Type III dams (41%) move considerable distances both upstream and downstream from the landslide failure. Type IV dams (1%) are rare and involve the contemporaneous failure of material from both sides of a valley. Type V dams (1%) are also rare, and are created when a single landslide sends multiple tongues of debris into a valley forming two or more landslide dams in the same surfaces, that extend under the stream or valley and emerge on the opposite valley side. Many landslide dams fail shortly after formation. Overtopping is by far the most common cause of failure. Glacial ice dams can produce at least nine kinds of ice-dammed lakes. The most dangerous are lakes formed in main valleys dammed by tributary glaciers. Failure can occur by erosion of a drainage tunnel under or through the ice dam or by a channel over the ice dam. Cold polar ice dams generally drain supraglacially or marginally by downmelting of an outlet channel. Warmer temperate-ice dams tend to fail by sudden englacial or subglacial breaching and drainage. Late neoglacial moraine-dammed lakes are located in steep mountain areas affected by the advances and retreats of valley glaciers in the last several centuries. The most common reported failure mechanism is overtopping and breaching by a wave or series of waves in the lake, generated by icefalls, rockfalls, or snow or rock avalanches. Melting of ice-cores or frozen ground and piping and seepage are other possible failure mechanisms. (Lantz-PTT)

Upstream effects of dams on alluvial channels: state-of-the-art and future challenges

NASA Astrophysics Data System (ADS)

Liro, Maciej

2017-04-01

More than 50,000 large dams (with the height above 15 m) operate all over the world and, thus, they significantly disturb water and sediment transport in river systems. These disturbances are recognized as one of the most important factors shaping river morphology in the Anthropocene. Downstream effects of dams have been well documented in numerous case studies and supported by predictions from existing models. In contrast, little is known on the upstream effects of dams on alluvial channels. This review highlights the lack of studies on sedimentological, hydromorphological and biogeomorphological adjustments of alluvial rivers in the base-level raised zones of backwater upstream of dam reservoirs where water level fluctuations occur. Up to date, it has been documented that backwater effects may facilitate fine and coarse sediment deposition, increase groundwater level, provide higher and more frequent channel and floodplain inundation and lead to significant morphological changes. But there have been no studies quantifying short- and long-term consequences of these disturbances for the hydromorphological and biogeomorphological feedbacks that control development of alluvial channels. Some recent studies carried out on gravel-bed and fine-grained bed rivers show that the above mentioned disturbances facilitate vegetation expansion on exposed channel sediments and floodplain influencing river morphology, which suggests that backwater area of alluvial rivers may be treated as the hotspot of bio-geomorphological changes in a fluvial system. To set the stage for future research on upstream effects of dams, this work presents the existing state-of-art and proposes some hypotheses which may be tested in future studies. This study was carried out within the scope of the Research Project 2015/19/N/ST10/01526 financed by the National Science Centre of Poland

Malaria and water resource development: the case of Gilgel-Gibe hydroelectric dam in Ethiopia.

PubMed

Yewhalaw, Delenasaw; Legesse, Worku; Van Bortel, Wim; Gebre-Selassie, Solomon; Kloos, Helmut; Duchateau, Luc; Speybroeck, Niko

2009-01-29

Ethiopia plans to increase its electricity power supply by five-fold over the next five years to fulfill the needs of its people and support the economic growth based on large hydropower dams. Building large dams for hydropower generation may increase the transmission of malaria since they transform ecosystems and create new vector breeding habitats. The aim of this study was to assess the effects of Gilgel-Gibe hydroelectric dam in Ethiopia on malaria transmission and changing levels of prevalence in children. A cross-sectional, community-based study was carried out between October and December 2005 in Jimma Zone, south-western Ethiopia, among children under 10 years of age living in three 'at-risk' villages (within 3 km from dam) and three 'control' villages (5 to 8 km from dam). The man-made Gilgel-Gibe dam is operating since 2004. Households with children less than 10 years of age were selected and children from the selected households were sampled from all the six villages. This included 1,081 children from 'at-risk' villages and 774 children from 'control' villages. Blood samples collected from children using finger prick were examined microscopically to determine malaria prevalence, density of parasitaemia and identify malarial parasite species. Overall 1,855 children (905 girls and 950 boys) were surveyed. A total of 194 (10.5%) children were positive for malaria, of which, 117 (60.3%) for Plasmodium vivax, 76 (39.2%) for Plasmodium falciparum and one (0.5%) for both P. vivax and P. falciparum. A multivariate design-based analysis indicated that, while controlling for age, sex and time of data collection, children who resided in 'at-risk' villages close to the dam were more likely to have P. vivax infection than children who resided farther away (odds ratio (OR) = 1.63, 95% CI = 1.15, 2.32) and showed a higher OR to have P. falciparum infection than children who resided in 'control' villages, but this was not significant (OR = 2.40, 95% CI = 0.84, 6.88). A classification tree revealed insights in the importance of the dam as a risk factor for malaria. Assuming that the relationship between the dam and malaria is causal, 43% of the malaria occurring in children was due to living in close proximity to the dam. This study indicates that children living in close proximity to a man-made reservoir in Ethiopia are at higher risk of malaria compared to those living farther away. It is recommended that sound prevention and control programme be designed and implemented around the reservoir to reduce the prevalence of malaria. In this respect, in localities near large dams, health impact assessment through periodic survey of potential vectors and periodic medical screening is warranted. Moreover, strategies to mitigate predicted negative health outcomes should be integral parts in the preparation, construction and operational phases of future water resource development and management projects.

Malaria and water resource development: the case of Gilgel-Gibe hydroelectric dam in Ethiopia

PubMed Central

Yewhalaw, Delenasaw; Legesse, Worku; Van Bortel, Wim; Gebre-Selassie, Solomon; Kloos, Helmut; Duchateau, Luc; Speybroeck, Niko

2009-01-01

Background Ethiopia plans to increase its electricity power supply by five-fold over the next five years to fulfill the needs of its people and support the economic growth based on large hydropower dams. Building large dams for hydropower generation may increase the transmission of malaria since they transform ecosystems and create new vector breeding habitats. The aim of this study was to assess the effects of Gilgel-Gibe hydroelectric dam in Ethiopia on malaria transmission and changing levels of prevalence in children. Methods A cross-sectional, community-based study was carried out between October and December 2005 in Jimma Zone, south-western Ethiopia, among children under 10 years of age living in three 'at-risk' villages (within 3 km from dam) and three 'control' villages (5 to 8 km from dam). The man-made Gilgel-Gibe dam is operating since 2004. Households with children less than 10 years of age were selected and children from the selected households were sampled from all the six villages. This included 1,081 children from 'at-risk' villages and 774 children from 'control' villages. Blood samples collected from children using finger prick were examined microscopically to determine malaria prevalence, density of parasitaemia and identify malarial parasite species. Results Overall 1,855 children (905 girls and 950 boys) were surveyed. A total of 194 (10.5%) children were positive for malaria, of which, 117 (60.3%) for Plasmodium vivax, 76 (39.2%) for Plasmodium falciparum and one (0.5%) for both P. vivax and P. falciparum. A multivariate design-based analysis indicated that, while controlling for age, sex and time of data collection, children who resided in 'at-risk' villages close to the dam were more likely to have P. vivax infection than children who resided farther away (odds ratio (OR) = 1.63, 95% CI = 1.15, 2.32) and showed a higher OR to have P. falciparum infection than children who resided in 'control' villages, but this was not significant (OR = 2.40, 95% CI = 0.84, 6.88). A classification tree revealed insights in the importance of the dam as a risk factor for malaria. Assuming that the relationship between the dam and malaria is causal, 43% of the malaria occurring in children was due to living in close proximity to the dam. Conclusion This study indicates that children living in close proximity to a man-made reservoir in Ethiopia are at higher risk of malaria compared to those living farther away. It is recommended that sound prevention and control programme be designed and implemented around the reservoir to reduce the prevalence of malaria. In this respect, in localities near large dams, health impact assessment through periodic survey of potential vectors and periodic medical screening is warranted. Moreover, strategies to mitigate predicted negative health outcomes should be integral parts in the preparation, construction and operational phases of future water resource development and management projects. PMID:19178727

Factors Affecting Route Selection and Survival of Steelhead Kelts at Snake River Dams in 2012 and 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harnish, Ryan A.; Colotelo, Alison HA; Li, Xinya

2014-12-01

In 2012 and 2013, Pacific Northwest National Laboratory conducted a study that summarized the passage proportions and route-specific survival rates of steelhead kelts that passed through Federal Columbia River Power System (FCRPS) dams. To accomplish this, a total of 811 steelhead kelts were tagged with Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters. Acoustic receivers, both autonomous and cabled, were deployed throughout the FCRPS to monitor the downstream movements of tagged-kelts. Kelts were also tagged with Passive Integrated Transponder tags to monitor passage through juvenile bypass systems and detect returning fish. The current study evaluated data collected in 2012 and 2013more » to identify individual, behavioral, environmental and dam operation variables that were related to passage and survival of steelhead kelts that passed through FCRPS dams. Bayesian model averaging of multivariable logistic regression models was used to identify the environmental, temporal, operational, individual, and behavioral variables that had the highest probability of influencing the route of passage and the route-specific survival probabilities for kelts that passed Lower Granite (LGR), Little Goose (LGS), and Lower Monumental (LMN) dams in 2012 and 2013. The posterior probabilities of the best models for predicting route of passage ranged from 0.106 for traditional spill at LMN to 0.720 for turbine passage at LGS. Generally, the behavior (depth and near-dam searching activity) of kelts in the forebay appeared to have the greatest influence on their route of passage. Shallower-migrating kelts had a higher probability of passing via the weir and deeper-migrating kelts had a higher probability of passing via the JBS and turbines than other routes. Kelts that displayed a higher level of near-dam searching activity had a higher probability of passing via the spillway weir and those that did less near-dam searching had a higher probability of passing via the JBS and turbines. The side of the river in which kelts approached the dam and dam operations also affected route of passage. Dam operations and the size and condition of kelts were found to have the greatest effect on route-specific survival probabilities for fish that passed via the spillway at LGS. That is, longer kelts and those in fair condition had a lower probability of survival for fish that passed via the spillway weir. The survival of spillway weir- and deep-spill passed kelts was positively correlated with the percent of the total discharge that passed through turbine unit 4. Too few kelts passed through the traditional spill, JBS, and turbine units to evaluate survival through these routes. The information gathered in this study describes Snake River steelhead kelt passage behavior, rates, and distributions through the FCRPS as well as provide information to biologists and engineers about the dam operations and abiotic conditions that are related to passage and survival of steelhead kelts.« less

Geomorphic and Ecological Issues in Removal of Sediment-Filled Dams in the California Coast Ranges (Invited)

NASA Astrophysics Data System (ADS)

Kondolf, G. M.; Oreilly, C.

2010-12-01

Water-supply reservoirs in the actively eroding California Coast Ranges are vulnerable to sediment filling, thus creating obsolete impounding dams (Minear & Kondolf 2009). Once full of sediment, there is more impetus to remove dams for public safety and fish passage, but managing accumulated sediments becomes a dominant issue in dam removal planning. We analyzed the planning process and sediment management analyses for five dams, all of which have important ecological resources but whose dam removal options are constrained by potential impacts to downstream urban populations. Ringe Dam on Malibu Ck, Matilija Dam on the Ventura River, Searsville Dam on San Francisquito Ck, and Upper York Creek Dam on York Ck cut off important habitat for anadromous steelhead trout (Oncorhynchus mykiss). San Clemente Dam on the Carmel River has a working fish ladder, but only some of the migratory steelhead use it. By virtue of having filled with sediment, all five dams are at greater risk of seismic failure. San Clemente Dam is at greater risk because its foundation is on alluvium (not bedrock), and the poor-quality concrete in Matilija Dam is deteriorating from an akali-aggregate reaction. Simply removing the dams and allowing accumulated sediments to be transported downstream is not an option because all these rivers have extremely expensive houses along downstream banks and floodplains, so that allowing the downstream channel to aggrade with dam-dervied sediments could expose agencies to liability for future flood losses. Analyses of potential sediment transport have been based mostly on application of tractive force models, and have supported management responses ranging from in-situ stabilization (San Clemente and Matilija) to removal of stored sediment (York) to annual dredging to maintain capacity and prevent sediment passing over the dam (proposed for Searsville).

Effects of removing Good Hope Mill Dam on selected physical, chemical, and biological characteristics of Conodoguinet Creek, Cumberland County, Pennsylvania

USGS Publications Warehouse

Chaplin, Jeffrey J.; Brightbill, Robin A.; Bilger, Michael D.

2005-01-01

The implications of dam removal on channel characteris-tics, water quality, benthic invertebrates, and fish are not well understood because of the small number of removals that have been studied. Comprehensive studies that document the effects of dam removal are just beginning to be published, but most research has focused on larger dams or on the response of a sin-gle variable (such as benthic invertebrates). This report, pre-pared in cooperation with the Conodoguinet Creek Watershed Association, provides an evaluation of how channel morphol-ogy, bed-particle-size distribution, water quality, benthic inver-tebrates, fish, and aquatic habitat responded after removal of Good Hope Mill Dam (a small 'run of the river' dam) from Conodoguinet Creek in Cumberland County, Pa. Good Hope Mill Dam was a 6-foot high, 220-foot wide concrete structure demolished and removed over a 3-day period beginning with the initial breach on November 2, 2001, at 10:00 a.m. eastern standard time. To isolate the effects of dam removal, data were collected before and after dam removal at five monitoring stations and over selected reaches upstream, within, and downstream of the impoundment. Stations 1, 2, and 5 were at free-flowing control locations 4.9 miles upstream, 2.5 miles upstream, and 5 miles downstream of the dam, respec-tively. Stations 3 and 4 were located where the largest responses were anticipated, 115 feet upstream and 126 feet downstream of the dam, respectively Good Hope Mill Dam was not an effective barrier to sedi-ment transport. Less than 3 inches of sediment in the silt/clay-size range (less than 0.062 millimeters) coated bedrock within the 7,160-foot (1.4-mile) impoundment. The bedrock within the impoundment was not incised during or after dam removal, and the limited sediment supply resulted in no measurable change in the thalweg elevation downstream of the dam. The cross-sec-tional areas at stations 3 and 4, measured 17 days and 23 months after dam removal, were within 3 percent of the area measured before removal. Some of the impounded silt/clay at station 3 and other sed-iment in the work area downstream of the dam were initially entrained over the 3-day removal period and deposited on sub-strate at station 4. Remaining silt/clay at station 3 and deposits at station 4 were transported downstream by the flows mea-sured over the 23 months after removal (daily mean flow ranged from 38 to 5,180 cubic feet per second). The median bed-parti-cle size at station 3 increased by approximately 32 millimeters in the 23-month period after removal. Bed-particle-size distri-bution at station 4 became finer when silt/clay was initially deposited but coarsened as high flows flushed it downstream; median bed-particle size was 77.7 millimeters before removal compared to 31.3 millimeters 17 days after removal and 99 mil-limeters 23 months after removal. Good Hope Mill Dam had either no effect on water-quality characteristics or the effect was so small it was masked by sea-sonal and periodic variability. Measurements of daily mean temperature, dissolved-oxygen concentration, pH, and specific conductance on a short time scale (every 15 minutes) indicate the daily range of temperature was suppressed under impounded conditions and daily extremes of temperature, dis-solved-oxygen concentration, pH, and specific conductance at station 2 were out of phase by approximately 12 hours with station 3. Once the dam was removed, the pattern at station 3 shifted and converged with the pattern at station 2. The offset before removal may be related to a lag time resulting from a decrease in velocity through the impoundment. Total nitrogen and suspended-sediment concentrations increased upon the initial dam breach but were within the range of concentrations measured from March 2001 through April 2002 over varying flow conditions at station 1. Total nitrogen concentration at station 4 was 4.66 milligrams per liter upon the initial breach of the dam,

Recent vegetation changes along the Colorado River between Glen Canyon Dam and Lake Mead, Arizona

USGS Publications Warehouse

Turner, Raymond Marriner; Karpiscak, Martin M.

1980-01-01

Vegetation changes in the canyon of the Colorado River between Glen Canyon Dam and Lake Mead were studied by comparing photographs taken prior to completion of Glen Canyon Dam in 1963 with photographs taken afterwards at the same sites. In general, the older pictures show an absence of riparian plants along the banks of the river. The newer photographs of each pair were taken in 1972 through 1976 and reveal an increased density of many plant species. Exotic species, such as saltcedar and camel-thorn, and native riparian plants such as sandbar willow, arrowweed, desert broom and cattail, now form a new riparian community along much of the channel of the Colorado River between Glen Canyon Dam and Lake Mead. The matched photographs also reveal that changes have occurred in the amount of sand and silt deposited along the banks. Detailed maps are presented showing distribution of 25 plant species along the reach of the Colorado River studied. Data showing changes in the hydrologic regime since completion of Glen Canyon Dam are presented. (Kosco-USGS)

The invisibility of fisheries in the process of hydropower development across the Amazon.

PubMed

Doria, Carolina Rodrigues da Costa; Athayde, Simone; Marques, Elineide E; Lima, Maria Alice Leite; Dutka-Gianelli, Jynessa; Ruffino, Mauro Luis; Kaplan, David; Freitas, Carlos E C; Isaac, Victoria N

2018-05-01

We analyze the invisibility of fisheries and inadequacy of fishers' participation in the process of hydropower development in the Amazon, focusing on gaps between legally mandated and actual outcomes. Using Ostrom's institutional design principles for assessing common-pool resource management, we selected five case studies from Brazilian Amazonian watersheds to conduct an exploratory comparative case-study analysis. We identify similar problems across basins, including deficiencies in the dam licensing process; critical data gaps; inadequate stakeholder participation; violation of human rights; neglect of fishers' knowledge; lack of organization and representation by fishers' groups; and lack of governmental structure and capacity to manage dam construction activities or support fishers after dam construction. Fishers have generally been marginalized or excluded from decision-making regarding planning, construction, mitigation, compensation, and monitoring of the social-ecological impacts of hydroelectric dams. Addressing these deficiencies will require concerted investments and efforts by dam developers, government agencies and civil society, and the promotion of inter-sectorial dialogue and cross-scale participatory planning and decision-making that includes fishers and their associations.

Authorized and Operating Purposes of Corps of Engineers Reservoirs

DTIC Science & Technology

1992-07-01

Puerto Rico CERRILLOS DAM AND RESERVOIR Jacksonville E-9O PORTUGUES DAM AND RESERVOIR Jacksonville E-92 South Carolina HARTWELL DAM AND LAKE Savannah E...LAKE Missouri Kansas City E-12 POMONA LAKE Kansas Kansas City E-12 PORTUGUES DAM AND RESERVOIR Puerto Rico Jacksonville E-92 PRADO DAM (SANTA ANA...PROJECT Florida Jacksonville E-92 PORTUGUES DAM AND RESERVOIR Puerto Rico Jacksonville E-92 RODMAN LOCK AND DAM (CROSS FLORIDA BARGE CANAL Florida

National Program for Inspection of Non-Federal Dams. Lake Mark Dam (CT 00337), Thames River Basin, Stafford, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-08-01

detected. Phase I inspections are not intended to provide detailed hydrologic and hydraulic analyses. In accordance with the esta- blished Guidelines, the...the need for more detailed hydrologic and hydraulic studies, considering the size of the dam, its general condition and the downstream damage...SECTION 5: EVALUATION OF HYDRAULIC /HYDROLOGIC FEATURES U 5.1 General........................................ 5-1 5.2 Design Data

Engineering and Ecological Aspects of Dam Removal-An Overview

DTIC Science & Technology

2006-09-01

indicated. Figure 3. Teton Dam failure, Idaho, 1976 BENEFITS AND COSTS OF DAMS Dams have provided and continue to provide a diverse...ERDC TN-EMRRP-SR-80 1 Engineering and Ecological Aspects of Dam Removal—An Overview September 2006 By Jock Conyngham1, J. Craig Fischenich1...High ______________________________________________________________________ OVERVIEW Decommissioning and removing dams has

18. DETAIL AT JUNCTION OF MAIN DAM AT LEFT AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. DETAIL AT JUNCTION OF MAIN DAM AT LEFT AND DIVERSION DAM AT RIGHT SHOWING LOG CRIBBING. SPACES INSIDE CRIBBING WERE FILLED WITH STONE TO ANCHOR DAM; DETERIORATION OF DAM HAS ALLOWED STONE BALLAST TO WASH AWAY. Photographed July 18, 1938. - Forge Creek Dam-John Cable Mill, Townsend, Blount County, TN

1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. GORGE HIGH DAM. THIS THIN ARCH DAM WITH A GRAVITY SECTION IS THE THIRD DAM BUILT BY SEATTLE CITY LIGHT TO PROVIDE WATER FOR GORGE POWERHOUSE AND WAS COMPLETED IN 1961, 1989. - Skagit Power Development, Gorge High Dam, On Skagit River, 2.9 miles upstream from Newhalem, Newhalem, Whatcom County, WA

Annual Peak-Flow Frequency Characteristics and (or) Peak Dam-Pool-Elevation Frequency Characteristics of Dry Dams and Selected Streamflow-Gaging Stations in the Great Miami River Basin, Ohio

USGS Publications Warehouse

Koltun, G.F.

2009-01-01

This report describes the results of a study to determine frequency characteristics of postregulation annual peak flows at streamflow-gaging stations at or near the Lockington, Taylorsville, Englewood, Huffman, and Germantown dry dams in the Miami Conservancy District flood-protection system (southwestern Ohio) and five other streamflow-gaging stations in the Great Miami River Basin further downstream from one or more of the dams. In addition, this report describes frequency characteristics of annual peak elevations of the dry-dam pools. In most cases, log-Pearson Type III distributions were fit to postregulation annual peak-flow values through 2007 (the most recent year of published peak-flow values at the time of this analysis) and annual peak dam-pool storage values for the period 1922-2008 to determine peaks with recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. For one streamflow-gaging station (03272100) with a short period of record, frequency characteristics were estimated by means of a process involving interpolation of peak-flow yields determined for an upstream and downstream gage. Once storages had been estimated for the various recurrence intervals, corresponding dam-pool elevations were determined from elevation-storage ratings provided by the Miami Conservancy District.

Rubber dam use during root canal treatment: findings from The Dental Practice-Based Research Network

PubMed Central

Anabtawi, Mona F.; Gilbert, Gregg H.; Bauer, Michael R.; Reams, Gregg; Makhija, Sonia K.; Benjamin, Paul L.; Williams, O. Dale

2012-01-01

Background The Dental Practice-Based Research Network (DPBRN) provides a venue to investigate whether certain procedures are performed routinely. Study objectives were to: (1) quantify rubber dam use during root canal treatment (RCT) among general dentists; (2) test the hypothesis that certain dentist or practice characteristics are associated with its use. Methods DPBRN practitioner-investigators participated in a questionnaire that included items about rubber dam use and other forms of isolation during root RCT. DPBRN Enrollment Questionnaire data provided certain practitioner and practice characteristics. Results A total of 729 practitioners responded (74%); 524 were general dentists and indicated they do RCT and the percentage of RCT in which they use a rubber dam. Of these 524, 44% use rubber dam for all RCTs; 24% use it for 51%–99% of RCTs; 17% use it for 1%–50%; 15% never use it during RCT. Usage varied significantly by geographic region and practice type. Cotton rolls and other forms of isolation were also reported. Conclusions Similar to other reports in the literature, not all DPBRN general dentists use a rubber dam during RCT. Clinical implications Because the current clinical standard of care is to use a rubber dam during RCT, increasing its use may be important. PMID:23372134

Hydrologic response of streams restored with check dams in the Chiricahua Mountains, Arizona

USGS Publications Warehouse

Norman, Laura M.; Brinkerhoff, Fletcher C.; Gwilliam, Evan; Guertin, D. Phillip; Callegary, James B.; Goodrich, David C.; Nagler, Pamela L.; Gray, Floyd

2016-01-01

In this study, hydrological processes are evaluated to determine impacts of stream restoration in the West Turkey Creek, Chiricahua Mountains, southeast Arizona, during a summer-monsoon season (June–October of 2013). A paired-watershed approach was used to analyze the effectiveness of check dams to mitigate high flows and impact long-term maintenance of hydrologic function. One watershed had been extensively altered by the installation of numerous small check dams over the past 30 years, and the other was untreated (control). We modified and installed a new stream-gauging mechanism developed for remote areas, to compare the water balance and calculate rainfall–runoff ratios. Results show that even 30 years after installation, most of the check dams were still functional. The watershed treated with check dams has a lower runoff response to precipitation compared with the untreated, most notably in measurements of peak flow. Concerns that downstream flows would be reduced in the treated watershed, due to storage of water behind upstream check dams, were not realized; instead, flow volumes were actually higher overall in the treated stream, even though peak flows were dampened. We surmise that check dams are a useful management tool for reducing flow velocities associated with erosion and degradation and posit they can increase baseflow in aridlands.

Three Experimental High-Flow Releases from Glen Canyon Dam, Arizona-Effects on the Downstream Colorado River Ecosystem

USGS Publications Warehouse

Melis, Theodore S.; Grams, Paul E.; Kennedy, Theodore A.; Ralston, Barbara E.; Robinson, Christopher T.; Schmidt, John C.; Schmit, Lara M.; Valdez, Richard A.; Wright, Scott A.

2011-01-01

Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine whether high flows could be used to benefit important downstream resources in Glen Canyon National Recreation Area and Grand Canyon National Park that have been affected by the existence and operation of Glen Canyon Dam. These downstream resources include native fish, particularly endangered humpback chub (Gila cypha), terrestrial and aquatic sandbar habitats, cultural sites, and recreational resources. This Fact Sheet summarizes HFE-related studies published since 1996 and outlines a possible strategy for implementing future HFEs.

Dams, Hydrology and Risk in Future River Management

NASA Astrophysics Data System (ADS)

Wegner, D. L.

2017-12-01

Across America there are over 80,000 large to medium dams and globally the number is in excess of 800,000. Currently there are over 1,400 dams and diversion structures being planned or under construction globally. In addition to these documented dams there are thousands of small dams populating watersheds. Governments, agencies, native tribes, private owners and regulators all have a common interest in safe dams. Often dam safety is characterized as reducing structural risk while providing for maximum operational flexibility. In the 1970's there were a number of large and small dam failures in the United States. These failures prompted the federal government to issue voluntary dam safety guidelines. These guidelines were based on historic information incorporated into a risk assessment process to analyze, evaluate and manage risk with the goal to improve the quality of and support of dam management and safety decisions. We conclude that historic and new risks need to be integrated into dam management to insure adequate safety and operational flexibility. A recent assessment of the future role of dams in the United States premises that future costs such as maintenance or removal beyond the economic design life have not been factored into the long-term operations or relicensing of dams. The converging risks associated with aging water storage infrastructure, multiple dams within watersheds and uncertainty in demands policy revisions and an updated strategic approach to dam safety. Decisions regarding the future of dams in the United States may, in turn, influence regional water planning and management. Leaders in Congress and in the states need to implement a comprehensive national water assessment and a formal analysis of the role dams play in our water future. A research and national policy agenda is proposed to assess future impacts and the design, operation, and management of watersheds and dams.

National Dam Safety Program. Tomahawk Lake Dam (Inventory Number N.Y. 618), Lower Hudson River Basin, Orange County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-08-14

Guidelines for Safety Inspection of Dams. d. Hazard Classification - Cherry Hill Road crosses the channel 1600 feet downstream from the dam and Tuthill...Road crosses the channel 1.5 miles below the dam. A home is located within 5 feet of the stream elevation, about 10 feet from the stream, and...below the dam. Cherry Hill Road crosses the channel 1600 feet downstream of the dam and Tuthill Road crosses the channel 1.5 miles below the dam. A home

Impacts of artificial reservoirs on floristic diversity and plant functional traits in dry forests after 15 years.

PubMed

Lopes, S F; Vale, V S; Prado Júnior, J A; Schiavini, I

2015-08-01

Dams are of paramount importance to a wide variety of human services and many of their environmental problems are known; however, there are few studies in the world addressing the impacts on the native vegetation previously distant from water bodies which became close to the lakeshore created by a dam. Thus, this paper aims to analyze the responses of a dry forest to a dam after 15 years. For this, 20 random samples of 40 trees were made, 10 close to the lakeshore and 10 distant from it, by applying the central square point method. Close to the dam, we found higher values regarding basal area, number of trees, number of evergreen trees, and zoochoric syndrome, but there were lower values of Shannon's diversity index. Therefore, the impacts of the dam after 15 years caused several changes to the tree community. The greater basal area close to the dam suggests that water deficit during the dry season was decreased and plants have thicker trunks. On the other hand, this sector had much more zoochoric syndrome and a larger number of evergreen trees than plots which are distant from water, suggesting changes with regard to the community's ecological functions. Furthermore, structural floristic data shows that the sector close to the dam is less similar to other deciduous forests within the same geographical region than the sector distant from water, thus providing evidence of the impacts of dams on the tree community.

Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

NASA Astrophysics Data System (ADS)

Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

2015-01-01

Beaver dams affect hydrologic processes, channel complexity, and stream temperature by increasing inundated areas and influencing groundwater-surface water interactions. We explored the impacts of beaver dams on hydrologic and temperature regimes at different spatial and temporal scales within a mountain stream in northern Utah over a three-year period spanning pre- and post-beaver colonization. Using continuous stream discharge, stream temperature, synoptic tracer experiments, and groundwater elevation measurements we documented pre-beaver conditions in the first year of the study. In the second year, we captured the initial effects of three beaver dams, while the third year included the effects of ten dams. After beaver colonization, reach scale discharge observations showed a shift from slightly losing to gaining. However, at the smaller sub-reach scale, the discharge gains and losses increased in variability due to more complex flow pathways with beaver dams forcing overland flow and increasing surface and subsurface storage. At the reach scale, temperatures were found to increase by 0.38 °C (3.8%), which in part is explained by a 230% increase in mean reach residence time. At the smallest, beaver dam scale, there were notable increases in the thermal heterogeneity where warmer and cooler niches were created. Through the quantification of hydrologic and thermal changes at different spatial and temporal scales, we document increased variability during post-beaver colonization and highlight the need to understand the impacts of beaver dams on stream ecosystems and their potential role in stream restoration.

Probabilistic mapping of urban flood risk: Application to extreme events in Surat, India

NASA Astrophysics Data System (ADS)

Ramirez, Jorge; Rajasekar, Umamaheshwaran; Coulthard, Tom; Keiler, Margreth

2016-04-01

Surat, India is a coastal city that lies on the banks of the river Tapti and is located downstream from the Ukai dam. Given Surat's geographic location, the population of five million people are repeatedly exposed to flooding caused by high tide combined with large emergency dam releases into the Tapti river. In 2006 such a flood event occurred when intense rainfall in the Tapti catchment caused a dam release near 25,000 m3 s-1 and flooded 90% of the city. A first step towards strengthening resilience in Surat requires a robust method for mapping potential flood risk that considers the uncertainty in future dam releases. Here, in this study we develop many combinations of dam release magnitude and duration for the Ukai dam. Afterwards we use these dam releases to drive a two dimensional flood model (CAESAR-Lisflood) of Surat that also considers tidal effects. Our flood model of Surat utilizes fine spatial resolution (30m) topography produced from an extensive differential global positioning system survey and measurements of river cross-sections. Within the city we have modelled scenarios that include extreme conditions with near maximum dam release levels (e.g. 1:250 year flood) and high tides. Results from all scenarios have been summarized into probabilistic flood risk maps for Surat. These maps are currently being integrated within the city disaster management plan for taking both mitigation and adaptation measures for different scenarios of flooding.

Geomorphic responses to dam removal in the United States – a two-decade perspective

USGS Publications Warehouse

Major, Jon J.; East, Amy; O'Connor, Jim E.; Grant, Gordon E.; Wilcox, Andrew C.; Magirl, Christopher S.; Collins, Matthias J.; Tullos, Desiree D.; Tsutsumi, Daizo; Laronne, Jonathan B.

2017-01-01

Recent decades have seen a marked increase in the number of dams removed in the United States. Investigations following a number of removals are beginning to inform how, and how fast, rivers and their ecosystems respond to released sediment. Though only a few tens of studies detail physical responses to removals, common findings have begun to emerge. They include: (1) Rivers are resilient and respond quickly to dam removals, especially when removals are sudden rather than prolonged. Rivers can swiftly evacuate large fractions of reservoir sediment (≥50% within one year), especially when sediment is coarse grained (sand and gravel). The channel downstream typically takes months to years—not decades—to achieve a degree of stability within its range of natural variability. (2) Modest streamflows (<2-year return interval flows) can erode and transport large amounts of reservoir sediment. Greater streamflows commonly are needed to access remnant reservoir sediment and transport it downstream. (3) Dam height, sediment volume, and sediment caliber strongly influence downstream response to dam removal. Removals of large dams (≥10 m tall) have had longer-lasting and more widespread downstream effects than more common removals of small dams. (4) Downstream valley morphology and position of a dam within a watershed influence the distribution of released sediment. Valley confinement, downstream channel gradient, locations and depths of channel pools, locations and geometries of extant channel bars, and locations of other reservoirs all influence the downstream fate of released sediment.

Potential role of maternal lineage in the thoroughbred breeding strategy.

PubMed

Lin, Xiang; Zhou, Shi; Wen, Li; Davie, Allan; Yao, Xinkui; Liu, Wujun; Zhang, Yong

2015-05-05

Many studies have focused on identifying the genes or single nucleotide polymorphisms associated with the athletic ability of thoroughbreds, but few have considered differences in maternal and paternal heritability of athletic ability. Herein, we report on our association study of career race performances of 675 Australian thoroughbreds with their pedigrees. Racing performance data (prize money per start) were collected from the Bloodhound database. The performance of all horses was categorised as either poor or elite athletic achievement. Then, 675 foals were divided by their parents' performance (elite or poor) into four groups: (1) elite dams and elite sires; (2) elite dams and poor sires; (3) poor dams and elite sires; and (4) poor dams and poor sires. The performance of foals was then compared between the four groups. The results show that the heritability of race performance between dams and foals (r = 0.141, P < 0.001) is much higher than that between sires and foals (r = 0.035, P = 0.366), and that this difference is statistically significant (P < 0.05). We also examined the effect of the child-bearing age of dams and sires on the ratio of elite foals. We found a strong correlation between the number of elite foals and dams' child-bearing age (r = -0.105, P < 0.001), with the ratio of elite offspring reaching a high level between a child-bearing age of 8 and 11 years (χ2 = 14.31, d.f. = 1, P < 0.001). These findings suggest that the maternal line may play an important role in the selective breeding of athletic performance in thoroughbreds.

Environmental management through sluice gated bed-dam: a revived strategy for the control of Anopheles fluviatilis breeding in streams

PubMed Central

Sahu, S.S.; Gunasekaran, K.; Jambulingam, P.

2014-01-01

Background & objectives: Integrated vector management (IVM) emphasizes sustainable eco-friendly methods and minimal use of chemicals. In this context, the present study highlights the environmental control of breeding of Anopheles fluviatilis, the primary malaria vector, through water management in a natural stream in Koraput district, Odisha, India. Methods: The District Rural Development Agency (DRDA), Koraput, constructed two bed-dams across streams, one in Barigaon and the other in Pipalapodar village. The bed-dam in the former village was fitted with two sluice gates whereas the bed dam constructed in the latter village was without the sluice gate. The sluice gates were opened once in a week on a fixed day to flush out the water from the dam. Anopheles immatures were sampled systematically in the streams using a dipper for density measurement and species composition. Results: There was a reduction of 84.9 per cent in the proportion of positive dips for Anopheles larvae/pupae and a reduction of 98.4 per cent in immature density (number/dip) of An. fluviatilis in the experimental downstream compared to the control following opening of the sluice gates. Interpretation & conclusions: Our findins showed that opening of sluice gates of the bed-dam regularly once in a week resulted in the control of vector breeding in the downstream due to the flushing effect of the water released with a high flow from the bed-dam that stagnated water in the upstream. The outcome of the study encourages upscaling this measure to other areas, wherever feasible. PMID:25297364

Maternal Oxytocin Administration Before Birth Influences the Effects of Birth Anoxia on the Neonatal Rat Brain.

PubMed

Boksa, Patricia; Zhang, Ying; Nouel, Dominique

2015-08-01

Ineffective contractions and prolonged labor are common birth complications in primiparous women, and oxytocin is the most common agent given for induction or augmentation of labor. Clinical studies in humans suggest oxytocin might adversely affect the CNS response to hypoxia at birth. In this study, we used a rat model of global anoxia during Cesarean section birth to test if administering oxytocin to pregnant dams prior to birth affects the acute neonatal CNS response to birth anoxia. Anoxic pups born from dams pre-treated with intravenous injections or infusions of oxytocin before birth showed significantly increased brain lactate, a metabolic indicator of CNS hypoxia, compared to anoxic pups from dams pre-treated with saline. Anoxic pups born from dams given oxytocin before birth also showed decreased brain ATP compared to anoxic pups from saline dams. Direct injection of oxytocin to postnatal day 2 rat pups followed by exposure to anoxia also resulted in increased brain lactate and decreased brain ATP, compared to anoxia exposure alone. Oxytocin pre-treatment of the dam decreased brain malondialdehyde, a marker of lipid peroxidation, as well as protein kinase C activity, both in anoxic pups and controls, suggesting oxytocin may reduce aspects of oxidative stress. Finally, when dams were pretreated with indomethacin, a cyclooxygenase (COX) inhibitor, maternal oxytocin no longer potentiated effects of anoxia on neonatal brain lactate, suggesting this effect of oxytocin may be mediated via prostaglandin production or other COX-derived products. The results indicate that maternal oxytocin administration may have multiple acute effects on CNS metabolic responses to anoxia at birth.

Developing a Water Quality Index (WQI) for an Irrigation Dam.

PubMed

De La Mora-Orozco, Celia; Flores-Lopez, Hugo; Rubio-Arias, Hector; Chavez-Duran, Alvaro; Ochoa-Rivero, Jesus

2017-04-29

Pollution levels have been increasing in water ecosystems worldwide. A water quality index (WQI) is an available tool to approximate the quality of water and facilitate the work of decision-makers by grouping and analyzing numerous parameters with a single numerical classification system. The objective of this study was to develop a WQI for a dam used for irrigation of about 5000 ha of agricultural land. The dam, La Vega, is located in Teuchitlan, Jalisco, Mexico. Seven sites were selected for water sampling and samples were collected in March, June, July, September, and December 2014 in an initial effort to develop a WQI for the dam. The WQI methodology, which was recommended by the Mexican National Water Commission (CNA), was used. The parameters employed to calculate the WQI were pH, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), total hardness (TH), alkalinity (Alk), total phosphorous (TP), Cl - , NO₃, SO₄, Ca, Mg, K, B, As, Cu, and Zn. No significant differences in WQI values were found among the seven sampling sites along the dam. However, seasonal differences in WQI were noted. In March and June, water quality was categorized as poor. By July and September, water quality was classified as medium to good. Quality then decreased, and by December water quality was classified as medium to poor. In conclusion, water treatment must be applied before waters from La Vega dam reservoir can be used for irrigation or other purposes. It is recommended that the water quality at La Vega dam is continually monitored for several years in order to confirm the findings of this short-term study.

Flood hydrology and dam-breach hydraulic analyses of five reservoirs in Colorado

USGS Publications Warehouse

Stevens, Michael R.; Hoogestraat, Galen K.

2013-01-01

The U.S. Department of Agriculture Forest Service has identified hazard concerns for areas downstream from five Colorado dams on Forest Service land. In 2009, the U.S. Geological Survey, in cooperation with the Forest Service, initiated a flood hydrology analysis to estimate the areal extent of potential downstream flood inundation and hazard to downstream life, property, and infrastructure if dam breach occurs. Readily available information was used for dam-breach assessments of five small Colorado reservoirs (Balman Reservoir, Crystal Lake, Manitou Park Lake, McGinnis Lake, and Million Reservoir) that are impounded by an earthen dam, and no new data were collected for hydraulic modeling. For each reservoir, two dam-breach scenarios were modeled: (1) the dam is overtopped but does not fail (break), and (2) the dam is overtopped and dam-break occurs. The dam-breach scenarios were modeled in response to the 100-year recurrence, 500-year recurrence, and the probable maximum precipitation, 24-hour duration rainstorms to predict downstream flooding. For each dam-breach and storm scenario, a flood inundation map was constructed to estimate the extent of flooding in areas of concern downstream from each dam. Simulation results of the dam-break scenarios were used to determine the hazard classification of the dam structure (high, significant, or low), which is primarily based on the potential for loss of life and property damage resulting from the predicted downstream flooding.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ploskey, Gene R.; Weiland, Mark A.; Carlson, Thomas J.

The purpose of this study was to estimate dam passage and route specific survival rates for subyearling Chinook salmon smolts to a primary survival-detection array located 81 km downstream of the dam, evaluate a BGS located in the B2 forebay, and evaluate effects of two spill treatments. The 2010 study also provided estimates of forebay residence time, tailrace egress time, spill passage efficiency (SPE), and spill + B2 Corner Collector (B2CC) efficiency, as required in the Columbia Basin Fish Accords. In addition, the study estimated forebay passage survival and survival of fish traveling from the forebay entrance array, through themore » dam and downstream through 81 km of tailwater.« less

Flood hydrology and dam-breach hydraulic analyses of four reservoirs in the Black Hills, South Dakota

USGS Publications Warehouse

Hoogestraat, Galen K.

2011-01-01

Extensive information about the construction of dams or potential downstream hazards in the event of a dam breach is not available for many small reservoirs within the Black Hills National Forest. In 2009, the U.S. Forest Service identified the need for reconnaissance-level dam-breach assessments for four of these reservoirs within the Black Hills National Forest (Iron Creek, Horsethief, Lakota, and Mitchell Lakes) with the potential to flood downstream structures. Flood hydrology and dam-breach hydraulic analyses for the four selected reservoirs were conducted by the U.S. Geological Survey in cooperation with the U.S. Forest service to estimate the areal extent of downstream inundation. Three high-flow breach scenarios were considered for cases when the dam is in place (overtopped) and when a dam break (failure) occurs: the 100-year recurrence 24-hour precipitation, 500-year recurrence peak flow, and the probable maximum precipitation. Inundation maps were developed that show the estimated extent of downstream floodwaters from simulated scenarios. Simulation results were used to determine the hazard classification of a dam break (high, significant, or low), based primarily on the potential for loss of life or property damage resulting from downstream inundation because of the flood surge.The inflow design floods resulting from the two simulated storm events (100-year 24-hour and probable maximum precipitation) were determined using the U.S. Army Corps of Engineers Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS). The inflow design flood for the 500-year recurrence peak flow was determined by using regional regression equations developed for streamflow-gaging stations with similar watershed characteristics. The step-backwater hydraulic analysis model, Hydrologic Engineering Center's River Analysis System (HEC-RAS), was used to determine water-surface profiles of in-place and dam-break scenarios for the three inflow design floods that were simulated. Inundation maps for in-place and dam-break scenarios were developed for the area downstream from the dam to the mouth of each stream.Dam-break scenarios for three of the four reservoirs assessed in this study were rated as low hazards owing to absence of permanent structures downstream from the dams. Iron Creek Lake's downstream channel to its mouth does not include any permanent structures within the inundation flood plains. For the two reservoirs with the largest watershed areas, Lakota and Mitchell Lake, the additional floodwater surge resulting from a dam break would be minor relative to the magnitude of the large flood streamflow into the reservoirs, based on the similar areal extent of inundation for the in-place and dam-break scenarios as indicated by the developed maps. A dam-break scenario at Horsethief Lake is rated as a significant hazard because of potential lives-in-jeopardy in downstream dwellings and appreciable economic loss.

107. DAM EARTH DIKE SUBMERSIBLE DAMS PLANS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

107. DAM - EARTH DIKE - SUBMERSIBLE DAMS - PLANS & SECTIONS (ML-8-52/3-FS) March 1940 - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

Immunization with a DNA adenine methylase over-producing Yersinia pseudotuberculosis vaccine confers robust cross-protection against heterologous pathogenic serotypes.

PubMed

Kubicek-Sutherland, Jessica Z; Heithoff, Douglas M; Ersoy, Selvi C; Shimp, William R; Mahan, Michael J

2014-03-14

Yersinia pseudotuberculosis is a foodborne pathogen that can cause serious human illness. Although the source and route of transmission often remain obscure, livestock have been implicated in some cases. The diversity of yersiniae present on farms and their widespread distribution in animal and environmental reservoirs necessitates the use of broad prophylactic strategies that are efficacious against many serotypes simultaneously. Herein, immunization of mice with a modified, live attenuated Y. pseudotuberculosis vaccine that overproduces the DNA adenine methylase (Dam(OP)) conferred robust protection against virulent challenge (150-fold LD50) with homologous and heterologous serotypes that have been associated with human disease (O:1, O:1a, O:3). Further, the dam gene was shown to be essential for cell viability in all (7 of 7) Y. pseudotuberculosis strains tested. Direct selection for the inheritance of dam mutant alleles in Y. pseudotuberculosis resulted in dam strain variants that contained compensatory (second-site suppressor) mutations in genes encoding methyl-directed mismatch repair proteins (mutHLS) that are involved in suppression of the non-viable cell phenotype in all (19/19) strains tested. Such dam mutH variants exhibited a significant increase in virulence and spontaneous mutation frequency relative to that of a Dam(OP) vaccine strain. These studies indicate that Y. pseudotuberculosis Dam(OP) strains conferred potent cross-protective efficacy as well as decreased virulence and spontaneous mutation frequency relative to those that lack Dam, which have compensatory mutations in mutHLS loci. These data suggest that development of yersiniae livestock vaccines based on Dam overproduction is a viable mitigation strategy to reduce these potential foodborne contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Check Dams on Erosion and Flow Dynamics on Small Semi-Arid Watersheds

NASA Astrophysics Data System (ADS)

Polyakov, V.; Nearing, M.; Nichols, M.; McClaran, M. P.

2012-12-01

Erosion dynamics in semi-arid environments is defined by high magnitude, low frequency rainfalls that produce runoff with high sediment concentration. Check dams were shown to be an effective sedimentation mitigation technique on small watersheds. Constructed of rocks, or other materials placed across the flow and anchored into the bottom and sides of the channel, these barriers produce upstream and downstream effects. By impounding runoff they reduce flow velocity, increase infiltration and allow sediment settling thus decreasing channel slope. Decreased sediment load downstream of the dam may result in accelerated channel scouring. While the effect of check dams on channel stability has been studied extensively their impact on overall watershed sediment balance is not well known. In 2008 a total of 37 loose rock semi permeable check dams were installed on two small (4.0 and 3.1 ha) watersheds located on the alluvial fan of the Santa Rita Mountains in southern Arizona, USA. Each watershed was equipped with high resolution weighing type rain gauge a supercritical flow flume and sediment sampler. Hyetographs, hydrographs, and sediment load data for the watersheds were collected since 1975. The erosion dynamics and flow characteristics following the check dam installation were compared with historical records. The volume of the sediment retained upstream of each dam was calculated through survey. After 4 years the check dams were filled to over 80% of their capacity and no significant increase in downstream scouring has been observed. Maximum 30-min intensity (I30) was overall best predictor variable for total runoff. After check dam installation the number ratio of runoff to rainfall events has been reduced by half. However, runoff peak rates were not significantly effected.

Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream

NASA Astrophysics Data System (ADS)

Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

2015-08-01

Beaver dams affect hydrologic processes, channel complexity, and stream temperature in part by inundating riparian areas, influencing groundwater-surface water interactions, and changing fluvial processes within stream systems. We explored the impacts of beaver dams on hydrologic and temperature regimes at different spatial and temporal scales within a mountain stream in northern Utah over a 3-year period spanning pre- and post-beaver colonization. Using continuous stream discharge, stream temperature, synoptic tracer experiments, and groundwater elevation measurements, we documented pre-beaver conditions in the first year of the study. In the second year, we captured the initial effects of three beaver dams, while the third year included the effects of ten dams. After beaver colonization, reach-scale (~ 750 m in length) discharge observations showed a shift from slightly losing to gaining. However, at the smaller sub-reach scale (ranging from 56 to 185 m in length), the discharge gains and losses increased in variability due to more complex flow pathways with beaver dams forcing overland flow, increasing surface and subsurface storage, and increasing groundwater elevations. At the reach scale, temperatures were found to increase by 0.38 °C (3.8 %), which in part is explained by a 230 % increase in mean reach residence time. At the smallest, beaver dam scale (including upstream ponded area, beaver dam structure, and immediate downstream section), there were notable increases in the thermal heterogeneity where warmer and cooler niches were created. Through the quantification of hydrologic and thermal changes at different spatial and temporal scales, we document increased variability during post-beaver colonization and highlight the need to understand the impacts of beaver dams on stream ecosystems and their potential role in stream restoration.

Administration of Non-Absorbable Antibiotics to Pregnant Mice to Perturb the Maternal Gut Microbiota Is Associated with Alterations in Offspring Behavior.

PubMed

Tochitani, Shiro; Ikeno, Takahiro; Ito, Tatsuhito; Sakurai, Asuka; Yamauchi, Tomoki; Matsuzaki, Hideo

2016-01-01

There is increasing evidence that the gut microbiota plays a major role in host health and disease. In this study, we examined whether perturbation of the maternal gut microbiota during pregnancy, induced by administration of non-absorbable antibiotics to pregnant dams, influences the behavior of offspring. Terminal restriction fragment length polymorphism analyses of fecal bacterial composition showed that the relative abundance of the bacterial order Lactobacillales was lower in offspring born from antibiotic-treated dams (20.7 ± 3.4%) than in control offspring (42.1 ± 6.2%) at P24, while the relative abundance of the bacterial family Clostridium subcluster XIVa was higher in offspring born from antibiotic-treated dams (34.2 ± 5.0%) than in control offspring (16.4 ± 3.3%). Offspring born from antibiotic-treated dams exhibited low locomotor activity in both familiar and novel environments, and preferred to explore in the peripheral area of an unfamiliar field at postnatal week 4. At postnatal weeks 7-8, no difference was observed in the level of locomotor activity between control offspring and offspring from antibiotic-treated dams, while the tendency for the offspring from antibiotic-treated dams to be less engaged in exploring the inside area was still observed. The behavioral phenotypes of the offspring from antibiotic-treated dams at postnatal week 4 could be rescued to a considerable extent through fostering of these offspring by normal dams from postnatal day 1. Although the detailed underlying mechanisms are not fully elucidated, the present results suggest that administration of non-absorbable antibiotics to pregnant dams to perturb the maternal gut microbiota during pregnancy leads to alterations in the behavior of their offspring.

Closed-system freezing of soils in linings and earth embankment dams

NASA Astrophysics Data System (ADS)

Jones, C. W.

1981-03-01

A brief review of studies of closed-system freezing (no source of water except that in voids) of compacted soil canal linings, laboratory and field test results show that under certain soil and temperature conditions, freezing decreases soil density near the surface, but increases density at depth. In two linings, the average density increased slightly during a 20-year period. Frost penetration measurements made during the 1978-79 winter on a 1,5-thick reservoir lining, on three earth dams under construction, and on the Teton Dam remnant are shown along with associated soil conditions, air freezing indexes, and insulating effects of snow and, for one dam, a loose soil cover.

Simulation analysis of temperature control on RCC arch dam of hydropower station

NASA Astrophysics Data System (ADS)

XIA, Shi-fa

2017-12-01

The temperature analysis of roller compacted concrete (RCC) dam plays an important role in their design and construction. Based on three-dimensional finite element method, in the computation of temperature field, many cases are included, such as air temperature, elevated temperature by cement hydration heat, concrete temperature during placing, the influence of water in the reservoir, and boundary temperature. According to the corresponding parameters of RCC arch dam, the analysis of temperature field and stress field during the period of construction and operation is performed. The study demonstrates that detailed thermal stress analysis should be performed for RCC dams to provide a basis to minimize and control the occurrence of thermal cracking.

Can water-level management reduce malaria mosquito abundance around large dams in sub-Saharan Africa?

PubMed Central

Wilson, G. Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2018-01-01

Background Water level management has been suggested as a potential tool to reduce malaria around large reservoirs. However, no field-based test has been conducted to assess the effect of water level management on mosquito larval abundance in African settings. The objective of the present study is to evaluate the effects of water level drawdown rates on mosquito larval abundance. Methods Twelve experimental dams were constructed on the foreshore of the Koka Dam in Ethiopia. These were grouped into four daily water drawdown treatments, each with three replicates: no water-level drawdown (Group 1; Control), 10 mm.d-1 (Group 2), 15 mm.d-1 (Group 3) and 20 mm.d-1 (Group 4). Larval sampling was conducted weekly for a period of 6 weeks each in the main malaria transmission season (October to November 2013) and subsequent dry season (February to March 2014). Larval densities were compared among treatments over time using repeated measures Analysis of Variance (ANOVA). Results A total of 284 Anopheles mosquito larvae were collected from the experimental dams during the study period. Most (63.4%; n = 180) were collected during the main malaria transmission season while the remaining (36.6%; n = 104) were collected during the dry season. Larvae comprised four Anopheles species, dominated by Anopheles arabiensis (48.1% of total larval samples; n = 136) and An. pharoensis (33.2%; n = 94). Mean larval density was highest in control treatment dams with stable water levels throughout the study, and decreased significantly (P < 0.05) with increasing water drawdown rates in both seasons. During the main transmission season, anopheline larval density was generally lower by 30%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, compared with the control dams (Group 1). In the dry season, larval density was reduced by 45%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, when compared to the control dams. Conclusion Increased water drawdown rates were associated with lower mosquito larval abundance. Water level management could thus serve as a potential control measure for malaria vectors around reservoirs by regulating the persistence of shallow shoreline breeding habitats. Dam operators and water resource managers should consider incorporating water level management as a malaria control mechanism into routine dam operations to manage the risk of malaria transmission to human populations around reservoirs. PMID:29672560

Analysis of Stream Channel Geometry Temporal and Spatial Evolution after Historic Dam Removal - two French case studies

NASA Astrophysics Data System (ADS)

Slawson, Deborah; Manière, Louis; Marchandeau, Florent

2014-05-01

IRSTEA, in partnership with the French Office national de l'eau et des milieux aquatiques (ONEMA), has begun a study of channel geomorphology in small streams where dams have been removed or breached between two and 200 years ago, without any subsequent restoration of the channel in the legacy sediments. A preliminary analysis of two sites in the Morvan, Burgundy, will be presented; a dam breached at the beginning of the 20th century and another in the last decade. Using ergodic reasoning, historical and recent upstream and downstream channel geometry is being used to predict the future temporal and spatial scales of channel physical habitat restoration. With the implementation of the European Water Framework Directive (WFD), dam removal has become a more frequently used method for restoring stream ecological continuity. In France, these obstacles are ubiquitous in medium and small streams and considerably reduce lateral and longitudinal connectivity. Improvement in the hydromorphologically controlled, physical habitat, particularly flow and sediment transport regimes, is often essential to improvement in stream biology. However, dam removal may cause long-term disturbances in flow and sediment transport regimes. In the absence of channel restoration measures in addition to dam removal, these disturbances may result in long-term negative impacts on fish, macroinvertebrate, and riparian plant physical habitat. These negative impacts may include channel incision and lowering of the water table, disconnection from floodplains, increased stream power and bed scouring, and increased sediment load from headcutting and bank erosion. Over time, these negative impacts may resolve themselves. However, the time frame necessary for reestablishing adequate physical habitat is not well-known. Some studies have indicated that many decades or longer may be required, depending on a variety of factors. Under the WFD, the REstoring rivers FOR effective catchment Management (REFORM) project is stressing the use of reference condition benchmarks when identifying objectives for and designing stream restoration projects. To identify appropriate reference condition benchmarks, it is important to understand over what temporal and spatial scales physical habitat improvement may take place after dam removal, including: 1. defining the spatial and temporal objectives for physical habitat restoration as a result of dam removal and 2. determining if dam removal alone will be sufficient to achieve those objectives or if additional channel restoration measures might be required.

Bed Sediment Monitoring of Multiple Contiguous Small Dam Removals

NASA Astrophysics Data System (ADS)

Galster, J. C.; Wyrick, J. R.

2010-12-01

Dam removal is crucial for reconnecting river habitats, restoring passage of fish and other aquatic organisms, and restoring the free flow of water and sediment. However, removal of obsolete dams is often resisted due to concerns of releasing sediment and initiating channel instability. Two dams on the Musconetcong River in northern New Jersey have been removed as part of a watershed-wide effort to remove or breach all major obstructions to restore the river to its original free-flowing state. The two dams were consecutively situated 1 kilometer apart and their removals provided an opportunity to study the geomorphic response in the form of bed elevation changes and sediment size through pre- and post-removal monitoring. Initial geomorphic surveys of the riverbed in the vicinity of and between the two dams have shown areas of erosion and deposition. These surveys have established a set of control points along the river channel between the two dams, and confirm the downstream movement of a sediment plume and localized areas of erosion. At the upstream dam, comparisons pre- and post-dam removal surveys show greater than 100 cubic meters of sediment being both eroded and deposited within the site. Most but not all of the erosion occurred around the newly exposed sediment bar upstream of the former dam, where the thalweg has reestablished itself following the dam’s removal. Areas that were excavated during removal have experienced deposition. Most of the deposition occurred downstream and on the left-hand bank. Due to the two low flow culverts in the former dam, a mid-channel sediment bar formed but has subsequently eroded. At the downstream dam site, erosion has removed up to 1.1 m of sediment from the bed in places while depositing up to 0.5 m sediment in others. As sediment from the former impoundment migrated through the project site, areas excavated during the removal became areas of deposition following the removal, and; alternately, areas in the channel margins where sediments were placed experienced gradual erosion. Grain size analysis shows a coarsening of the riverbed over the first nine months since removal. Grain size analyses were done upstream and downstream of the dam sites as well as at two locations between the sites. Pebble counts were completed using the random walk method at each of the six sites. The largest change in grain sizes at the four sites occurred upstream of the downstream dam site, where there was a significant coarsening of the sediment from October 2008 to June 2009. This has most likely occurred from the increase in energy upstream of the dam post-removal, which has transported many of the fine-grained sediments downstream. Downstream of this dam site sediment size has not significantly changed, suggesting that the fine sediments have been transported downstream far enough to leave the site. Surveys of the channel thalweg above and below both dams also show a pulse of sediment migrating slowing from the uppermost impoundment areas. Long-term monitoring of the channel thalweg may reveal reach-level changes in channel slope.

Assessing the Ecological and Geomorphic Context of Dam Removals in the United States

NASA Astrophysics Data System (ADS)

Magilligan, F. J.; Foley, M.; Torgersen, C. E.; Major, J. J.; Anderson, C.; Connolly, P. J.; Shafroth, P. B.; Evans, J. E.

2016-12-01

Dams have been a fundamental part of our national agenda over the past two hundred years; recently, however, dam removal has emerged as a significant national strategy and more than 1,100 dams have been removed since ca. 1970. A recent national assessment revealed that only 130 of these removals had any ecological or geomorphic assessments, and only 35 included both. To better assess the current state of dam-removal science, we utilized an extensive data set compiled by American Rivers, which contained geospatial attributes of more than 850 dams removed in the U.S. We used this geospatial information in combination with the National Hydrography Dataset (NHDPlus) and other watershed-scale assessment interfaces that provided data on eco-regions, national land cover attributes, and cumulative watershed disturbance to determine the geographic, ecological, and geomorphic context of removed dams. The highest concentration of removed dams is in the Northeast and Upper Midwest. Nationally, they have been removed mainly from 1st order streams, but more than 40% are on 3rd and 4th order streams. Geomorphically, most removals are in lowland settings with 87% at elevations < 450 m and 12% between 450 and 1000 m elevation. Watershed slopes were predominantly <5%. Ecologically, watersheds above removed dams are predominantly forested, mainly in broadleaf deciduous settings of the Ridge and Valley, Northern Piedmont, NE Highland, and NE Coastal Zone EPA Level III eco-region classes. Watershed scale assessments indicate most (37%) removals are in watersheds with the lowest cumulative disturbance scores, showing removals have made high-quality habitat available. Principal component analyses showed a strong correlation of removals based on low slope, low elevation, large watershed area, and low cumulative disturbance. Many of the studied removals also have these characteristics, suggesting that our understanding of responses to dam removals is based on a limited range of ecological and geomorphic settings, which limits predictive capacity in other environmental settings.

Evaluating the effects of check dams on channel geometry, bed sediment size and riparian vegetation in Mediterranean mountain torrents.

PubMed

Zema, Demetrio Antonio; Bombino, Giuseppe; Denisi, Pietro; Lucas-Borja, Manuel Esteban; Zimbone, Santo Marcello

2018-06-12

In mountain streams possible negative impacts of check dams on soil, water and riparian vegetation due to check dam installation can be noticed. In spite of the ample literature on the qualitative effects of engineering works on channel hydrology, morphology, sedimentary effects and riparian vegetation characteristics, quantitative evaluations of the changes induced by check dams on headwater characteristics are rare. In order to fill this gap, this study has evaluated the effects of check dams located in headwaters of Calabria (Southern Italy) on hydrological and geomorphological processes and on the response of riparian vegetation to these actions. The analysis has compared physical and vegetation indicators in transects identified around check dams (upstream and downstream) and far from their direct influence (control transects). Check dams were found to influence significantly unit discharge, surface and subsurface sediments (both upstream and downstream), channel shape and transverse distribution of riparian vegetation (upstream) as well as cover and structure of riparian complexes (downstream). The actions of the structures on torrent longitudinal slope and biodiversity of vegetation were less significant. The differences on bed profile slope were significant only between upstream and downstream transects. The results of the Agglomerative Hierarchical Cluster analysis confirmed the substantial similarity between upstream and control transects, thus highlighting that the construction of check dams, needed to mitigate the hydro-geological risks, has not strongly influenced the torrent functioning and ecology before check dam construction. Moreover, simple and quantitative linkages between torrent hydraulics, geomorphology and vegetation characteristics exist in the analysed headwaters; these relationships among physical adjustments of channels and most of the resulting characteristics of the riparian vegetation are specific for the transect locations with respect of check dams. Conversely, the biodiversity of the riparian vegetation basically eludes any quantitative relations with the physical and other vegetal characteristics of the torrent transects. Copyright © 2018 Elsevier B.V. All rights reserved.

How stakeholders frame dam removal: The role of current and anticipated future ecosystem service use

NASA Astrophysics Data System (ADS)

Reilly, Kate; Adamowski, Jan

2016-04-01

Many river restoration projects, including dam removal, are controversial and can trigger conflicts between stakeholders who are for and against the proposed project. The study of environmental conflicts suggests that differences in how stakeholders 'frame', or make sense of a situation based on their prior knowledge and experiences, can perpetuate conflicts. Understanding different stakeholders' frames, particularly how they converge, can form the basis of successful conflict resolution. In the case of dam removals, it is often assumed that emphasising increased provision of ecosystem services can be a point of convergence between those advocating for ecological restoration and those opposed to removal because of negative human impacts. However, how exactly stakeholders frame a contentious proposed dam removal and how those frames relate to ecosystem services has been little studied. Here we used the case of a potential dam removal in New Brunswick to investigate how people frame the issue and how that relates to their current and anticipated future use of ecosystem services. Based on in-depth interviews with 30 stakeholders in the area, including both people for and against dam removal, we found that both groups currently used ecosystem services and were in favour of ecosystem protection. However, they differed in how they framed the issue of the potential dam removal. The group against dam removal framed the issue as one of loss and risk - they thought that any potential benefits to the ecosystem would be outweighed by the high risk of negative social impacts caused by a loss of access to ecosystem services, such as recreation and aesthetic enjoyment. By contrast, the group in favour of the dam framed the issue as one of opportunity and justice. They thought that following a short transition period, all stakeholders would benefit from the restored river, particularly from a restored salmon fishery, improved aesthetic appeal and the long-term sustainability of an undammed river. Ultimately, we argue that increased provision of ecosystem services does not always represent a point of convergence between stakeholder groups, because both groups support ecosystem protection but differ in how they expect the benefits they derive from ecosystem services to change. Conflict resolution strategies may be better addressed by measures to mitigate the perceived loss of ecosystem services in the group against dam removal.

National Dam Safety Program. Lake Muskoday Dam (Inventory Number N.Y. 341) Delaware River Basin, Sullivan County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-09-14

DACW-51-81-C-0006 . PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT PROJECT. TASK AREA & WORK UNIT NUMBERS ~ Flaherty-Giauara Associates...olie It neceary and Idontily b block number) Dam Safety National Dam Safety Program Visual Inspection Lake Muskoday Dam Hydrology, Structural Stability...DELAWARE RIVER BASIN LAKE MUSKODAY DAM SULLIVAN COUNTY, NEW YORK INVENTORY No.NY341 PHASE I INSPECTION REPORT NATIONAL DAM SAFETY PROGRAM J T C NEW YORK

Using 3D acoustic telemetry to assess the response of resident salmonids to strobe lights in Lake Roosevelt, Washington: Chief Joseph Kokanee Enhancement Feasibility Study, 2001-2002 annual report

USGS Publications Warehouse

Perry, R.W.; Farley, M.J.; Hansen, G.S.; Shurtleff, D.J.; Rondorf, D.W.; LeCaire, R.

2003-01-01

In 1995, the Chief Joseph Kokanee Enhancement Project was established to mitigate the loss of anadromous fish due to the construction of Chief Joseph and Grand Coulee dams. The objectives of the Chief Joseph Enhancement Project are to determine the status of resident kokanee (Oncorhynchus nerka) populations above Chief Joseph and Grand Coulee dams and to enhance kokanee and rainbow trout (Oncorhynchus mykiss) populations. Studies conducted at Grand Coulee Dam documented substantial entrainment of kokanee through turbines at the third powerhouse.

Acoustic Telemetry Evaluation of Juvenile Salmonid Passage and Survival at John Day Dam, 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiland, Mark A.; Woodley, Christa M.; Ploskey, Gene R.

This report presents survival, behavioral, and fish passage results for yearling and subyearling Chinook salmon smolts and juvenile steelhead tagged with JSATS acoustic micro-transmitters as part of a survival study conducted at John Day Dam during 2010. This study was designed to evaluate the passage and survival of yearling and subyearling Chinook salmon and juvenile steelhead to assist managers in identifying dam operations for compliance testing as stipulated by the 2008 Federal Columbia River Power System Biological Opinion and the 2008 Columbia Basin Fish Accords. Survival estimates were based on a single-release survival estimate model.

Sharing Perspectives and Learning from One Another: Southern Paiutes, Scientists, and Policymakers in the Glen Canyon Dam Adaptive Management Program

NASA Astrophysics Data System (ADS)

Austin, D. E.; Bulletts, K.; Bulletts, C.

2017-12-01

The traditional lands of the Southern Paiute people in the United States are bounded by more than 600 miles of the Colorado River from the Kaiparowits Plateau in the north to Blythe, California in the south. According to Southern Paiute traditional knowledge, Southern Paiutes were the first inhabitants of this region and are responsible for protecting and managing this land along with the water and all that is upon and within it. In 1963, the Bureau of Reclamation completed construction of Glen Canyon Dam on the Colorado River, and in 1972, the Glen Canyon National Recreation Area was established, encompassing Lake Mead above the Dam and a world class trout fishery on the Colorado River between the Dam and Lees Ferry. Below Lees Ferry on its way to Lake Mead and Hoover Dam, the Colorado River flows through Grand Canyon National Park and the Navajo and Hualapai reservations. U.S. federal law requires that Glen Canyon Dam be operated with minimal impact to the natural, recreational, and cultural resources of the region of the Colorado River that is potentially impacted by flows from the Dam. The Grand Canyon Protection Act and the Environmental Impact Statement (EIS) for the Operation of the Glen Canyon Dam established a program of long-term research and monitoring of the effects of the Dam on these resources. In 1991, three Southern Paiute tribes - the Kaibab Band of Paiute Indians, the Paiute Indian Tribe of Utah, and the San Juan Southern Paiute Tribe - agreed to participate in studies to identify cultural resources impacted by Glen Canyon Dam and to recommend strategies for their protection, In 1995, the EIS was completed and transition to the Adaptive Management Program (AMP) called for in the Grand Canyon Protection Act was begun. At that time, Southern Paiute activities expanded to include assessing potential environmental and cultural impacts of the dam, developing monitoring procedures, and interacting with scientists, other tribal representatives, and policymakers in the AMP. This presentation summarizes an analysis of two decades of Southern Paiute participation in the AMP, highlighting key interactions and learning experiences as well as ongoing challenges for Southern Paiute participants.

Detecting fluid leakage of a reservoir dam based on streaming self-potential measurements

NASA Astrophysics Data System (ADS)

Song, Seo Young; Kim, Bitnarae; Nam, Myung Jin; Lim, Sung Keun

2015-04-01

Between many reservoir dams for agriculture in suburban area of South Korea, water leakage has been reported several times. The dam under consideration in this study, which is located in Gyeong-buk, in the south-east of the Korean Peninsula, was reported to have a large leakage at the right foot of downstream side of the reservoir dam. For the detection of the leakage, not only geological survey but also geophysical explorations have been made for precision safety diagnosis, since the leakage can lead to dam failure. Geophysical exploration includes both electrical-resistivity and self-potential surveys, while geological surveys water permeability test, standard penetration test, and sampling for undisturbed sample during the course of the drilling investigation. The geophysical explorations were made not only along the top of dam but also transverse the heel of dam. The leakage of water installations can change the known-heterogeneous structure of the dam body but also cause streaming spontaneous (self) potential (SP) anomaly, which can be detected by electrical resistivity and SP measurements, respectively. For the interpretation of streaming SP, we used trial-and-error method by comparing synthetic SP data with field SP data for model update. For the computation, we first invert the resistivity data to obtain the distorted resistivity structure of the dam levee then make three-dimensional electrical-resistivity modeling for the streaming potential distribution of the dam levee. Our simulation algorithm of streaming SP distribution based on the integrated finite difference scheme computes two-dimensional (2D) SP distribution based on the distribution of calculated flow velocities of fluid for a given permeability structure together with physical properties. This permeability is repeatedly updated based on error between synthetic and field SP data, until the synthetic data match the field data. Through this trial-and-error-based SP interpretation, we locate the leakage of reservoir-water formed locally inside the levee body of the reservoir dam within the limitation due to the 2D nature of stream SP simulation.

Evaluate the Restoration Potential of Snake River Fall Chinook Salmon Spawning Habitat, Status Report 2006.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanrahan, T.P.

2009-01-08

The Bonneville Power Administration (BPA) Project 2003-038-00, Evaluate the restoration potential of Snake River fall Chinook salmon spawning habitat, began in FY04 (15 December 2003) and continues into FY06. This status report is intended to summarize accomplishments during FY04 and FY05. Accomplishments are summarized by Work Elements, as detailed in the Statement of Work (see BPA's project management database PISCES). This project evaluates the restoration potential of mainstem habitats for fall Chinook salmon. The studies address two research questions: 'Are there sections not currently used by spawning fall Chinook salmon within the impounded lower Snake River that possess the physicalmore » characteristics for potentially suitable fall Chinook spawning habitat?' and 'Can hydrosystem operations affecting these sections be adjusted such that the sections closely resemble the physical characteristics of current fall Chinook salmon spawning areas in similar physical settings?' Efforts are focused at two study sites: (1) the Ice Harbor Dam tailrace downstream to the Columbia River confluence, and (2) the Lower Granite Dam tailrace. Our previous studies indicated that these two areas have the highest potential for restoring Snake River fall Chinook salmon spawning habitat. The study sites will be evaluated under existing structural configurations at the dams (i.e., without partial removal of a dam structure), and alternative operational scenarios (e.g., varying forebay/tailwater elevations). The areas studied represent tailwater habitat (i.e., riverine segments extending from a dam downstream to the backwater influence from the next dam downstream). We are using a reference site, indicative of current fall Chinook salmon spawning areas in tailwater habitat, against which to compare the physical characteristics of each study site. The reference site for tailwater habitats is the section extending downstream from the Wanapum Dam tailrace on the Columbia River. Escapement estimates for fall of 2000 indicate more than 9000 adult fall Chinook salmon returned to this area, accounting for more than 2100 redds within a 5 km section of river.« less

Influence of dams on river-floodplain dynamics in the Elwha River, Washington

USGS Publications Warehouse

Kloehn, K.K.; Beechie, T.J.; Morley, S.A.; Coe, H.J.; Duda, J.J.

2008-01-01

The Elwha dam removal project presents an ideal opportunity to study how historic reduction and subsequent restoration of sediment supply alter river-floodplain dynamics in a large, forested river floodplain. We used remote sensing and onsite data collection to establish a historical record of floodplain dynamics and a baseline of current conditions. Analysis was based on four river reaches, three from the Elwha River and the fourth from the East Fork of the Quinault River. We found that the percentage of floodplain surfaces between 25 and 75 years old decreased and the percentage of surfaces >75 years increased in reaches below the Elwha dams. We also found that particle size decreased as downstream distance from dams increased. This trend was evident in both mainstem and side channels. Previous studies have found that removal of the two Elwha dams will initially release fine sediment stored in the reservoirs, then in subsequent decades gravel bed load supply will increase and gradually return to natural levels, aggrading river beds up to 1 m in some areas. We predict the release of fine sediments will initially create bi-modal grain size distributions in reaches downstream of the dams, and eventual recovery of natural sediment supply will significantly increase lateral channel migration and erosion of floodplain surfaces, gradually shifting floodplain age distributions towards younger age classes.

ECHETA DAM SPILLWAY. COMING OUT BELOW THE DAM. AT CENTER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ECHETA DAM SPILLWAY. COMING OUT BELOW THE DAM. AT CENTER OF PHOTO. VIEW TO NORTHEAST. - Echeta Dam & Reservoir, 2.9 miles east of Echeta Road at Echeta Railroad Siding at County Road 293, Echeta, Campbell County, WY

Groundwater-Surface Water Interactions and Downstream Transport of Water, Heat, and Solutes in a Hydropeaked River

NASA Astrophysics Data System (ADS)

Ferencz, S. B.; Cardenas, M. B.; Neilson, B. T.; Watson, J.

2017-12-01

A majority of the world's largest river systems are regulated by dams. In addition to being used for water resources management and flood prevention, many large dams are also used for hydroelectric power generation. In the United States, dams account for 7% of domestic electricity, and hydropower accounts for 16% of worldwide electricity production. To help meet electricity demand during peak usage times, hydropower utilities often increase their releases of water during high demand periods. This practice, termed hydropeaking, can cause large transient flow regimes downstream of hydroelectric dams. These transient flow increases can result in order of magnitude daily fluctuations in discharge, and the released water can have different thermal and chemical properties than ambient river water. As hydropeaking releases travel downstream, the temporary rise in stage and increase in discharge can enhance surface water-groundwater (SW-GW) exchange between the river and its alluvial aquifer. This dam-induced SW-GW exchange, combined with hydrodynamic attenuation and heat exchange processes, result in complex responses downstream. The dam-regulated Lower Colorado River downstream of Austin, TX was used as a natural laboratory to observe SW-GW interactions and downstream transport of water, heat, and solutes under hydropeaking conditions. To characterize SW-GW interactions, well transects were installed in the banks of the river to observe exchanges between the river and alluvial aquifer. The well transects were installed at three different distances from the dam (15km, 35km, and 80km). At each well transect conductivity, temperature, and pressure sensors were deployed in the monitoring wells and in the channel. Additional conductivity and temperature sensors were deployed along the study reach to provide a more detailed record of heat and solute transport during hydropeaking releases. The field data spans over two months of daily dam releases that were punctuated by two large natural storm events. To our knowledge, this study is the first to use multiple downstream field sites to characterize how dam-induced SW-GW interactions and in-stream temperature and solute transport behave under hydropeaking conditions.

Endocrine-disruptor molecular responses, occurrence of intersex and gonado-histopathological changes in tilapia species from a tropical freshwater dam (Awba Dam) in Ibadan, Nigeria.

PubMed

Adeogun, Aina O; Onibonoje, Kolawole; Ibor, Oju R; Omiwole, Roseline A; Chukwuka, Azubuike V; Ugwumba, Alex O; Ugwumba, Adiaha A A; Arukwe, Augustine

2016-05-01

In the present study, the occurrence of endocrine disruptive responses in Tilapia species from Awba Dam has been investigated, and compared to a reference site (Modete Dam). The Awba Dam is a recipient of effluents from University of Ibadan (Nigeria) and several other anthropogenic sources. A total of 132 Tilapia species (Sarotherodon malenotheron (n=57 and 32, males and females, respectively) and Tilapia guineensis (n=23 and 20, males and females, respectively)) were collected from June to September 2014. At the reference site, samples of adult male and female S. melanotheron (48 males and 47 females) and T. guineensis (84 males and 27 females) were collected. Gonads were morphologically and histologically examined and gonadosomatic index (GSI) was calculated. Hepatic mRNA transcriptions of vitellogenin (Vtg) and zona radiata protein (Zrp) genes were analyzed using validated RT-qPCR. Significant increase in Vtg and Zrp transcripts were observed in male tilapias from Awba Dam, compared to males from the reference site. In addition, male tilapias from Awba Dam produced significantly higher Vtg and Zrp mRNA, compared to females in June and July. However, at the natural peak spawning period in August and September, females produced, significantly higher Vtg and Zrp mRNA, compared to males. Fish gonads revealed varying incidence of intersex with a striking presence of two (2) pairs of testes and a pair of ovary in S. melanotheron from Awba Dam. The entire fish population examined at Awba Dam showed a high prevalence of intersex (34.8%), involving phenotypic males and females of both species. Analysis of sediment contaminant levels revealed that As, Cd, Pb, Hg and Ni (heavy metals), monobutyltin cation, 4-iso-nonyphenol and PCB congeners (138, 153 and 180) were significantly higher in Awba Dam, compared to the reference site. Principal component analysis (PCA) showed that fish variables were positively correlated with sediment contaminant burden at Awba Dam, indicating that the observed endocrine disruptive responses are associated with contaminant concentrations. Overall, the occurrence of intersex and elevated expressions of Vtg and Zrp in male fish, suggest that the measured contaminants were eliciting severe endocrine disruptive effects in Awba Dam biota, which is an important source of domestic water supply and fisheries for the University of Ibadan community. Copyright © 2016 Elsevier B.V. All rights reserved.

Data collection and documentation of flooding downstream of a dam failure in Mississippi

USGS Publications Warehouse

Van Wilson, K.; ,

2005-01-01

On March 12, 2004, the Big Bay Lake dam failed, releasing water and affecting lives and property downstream in southern Mississippi. The dam is located near Purvis, Mississippi, on Bay Creek, which flows into Lower Little Creek about 1.9 miles downstream from the dam. Lower Little Creek flows into Pearl River about 16.9 miles downstream from the dam. Knowledge of the hydrology and hydraulics of floods caused by dam breaks is essential to the design of dams. A better understanding of the risks associated with possible dam failures may help limit the loss of life and property that often occurs downstream of a dam failure. The USGS recovered flood marks at the one crossing of Bay Creek and eight crossings of Lower Little Creek. Additional flood marks were also flagged at three other bridges crossing tributaries where backwater occurred. Flood marks were recovered throughout the stream reach of about 3/4 to 15 miles downstream of the dam. Flood marks that were flagged will be surveyed so that a flood profile can be documented downstream of the Big Bay Lake dam failure. Peak discharges are also to be estimated where possible. News reports stated that the peak discharge at the dam was about 67,000 cubic feet per second. Preliminary data suggest the peak discharge from the dam failure attenuated to about 13,000 cubic feet per second at Lower Little Creek at State Highway 43, about 15 miles downstream of the dam.

ECHETA DAM RIPRAP ON RESERVOIR SIDE OF THE DAM AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ECHETA DAM RIP-RAP ON RESERVOIR SIDE OF THE DAM AT BREACH. VIEW TO NORTH-NORTHEAST. - Echeta Dam & Reservoir, 2.9 miles east of Echeta Road at Echeta Railroad Siding at County Road 293, Echeta, Campbell County, WY

Maternal high-fat diet acts on the brain to induce baroreflex dysfunction and sensitization of angiotensin II-induced hypertension in adult offspring.

PubMed

Zhang, Yu-Ping; Huo, Yan-Li; Fang, Zhi-Qin; Wang, Xue-Fang; Li, Jian-Dong; Wang, Hai-Ping; Peng, Wei; Johnson, Alan Kim; Xue, Baojian

2018-05-01

Accumulating evidence indicates that maternal high-fat diet (HFD) is associated with metabolic syndrome and cardiovascular disease in adult offspring. The present study tested the hypothesis that maternal HFD modulates the brain renin-angiotensin system (RAS), oxidative stress, and proinflammatory cytokines that alter angiotensin II (ANG II) and TNF-α actions and sensitize the ANG II-elicited hypertensive response in adult offspring. All offspring were cross fostered by dams on the same or opposite diet to yield the following four groups: offspring from normal-fat control diet-fed dams suckled by control diet-fed dams (OCC group) or by HFD-fed dams (OCH group) and offspring from HFD-fed dams fed a HFD suckled by control diet-fed dams (OHC group) or by HFD-fed dams (OHH group). RT-PCR analyses of the lamina terminalis and paraventricular nucleus indicated upregulation of mRNA expression of several RAS components, NADPH oxidase, and proinflammatory cytokines in 10-wk-old male offspring of dams fed a HFD during either pregnancy, lactation, or both (OHC, OCH, and OHH groups). These offspring also showed decreased cardiac baroreflex sensitivity and increased pressor responses to intracerebroventricular microinjection of either ANG II or TNF-α. Furthermore, chronic systemic infusion of ANG II resulted in enhanced upregulation of mRNA expression of RAS components, NADPH oxidase, and proinflammatory cytokines in the lamina terminalis and paraventricular nucleus and an augmented hypertensive response in the OHC, OCH, and OHH groups compared with the OCC group. The results suggest that maternal HFD blunts cardiac baroreflex function and enhances pressor responses to ANG II or proinflammatory cytokines through upregulation of the brain RAS, oxidative stress, and inflammation. NEW & NOTEWORTHY The results of our study indicate that a maternal high-fat diet during either pregnancy or lactation is sufficient for perinatal programming of sensitization for hypertension, which is associated with hyperreactivity of central cardiovascular nuclei that, in all likelihood, involves elevated expression of the renin-angiotensin system, NADPH oxidase, and proinflammatory cytokines. The present study demonstrates, for the first time, the central mechanism underlying maternal high-fat diet sensitization of the hypertensive response in adult offspring.

Dam break analysis and flood inundation map of Krisak dam for emergency action plan

NASA Astrophysics Data System (ADS)

Juliastuti, Setyandito, Oki

2017-11-01

The Indonesian Regulation which refers to the ICOLD Regulation (International Committee on Large Dam required have the Emergency Action Plan (EAP) guidelines because of the dams have potential failure. In EAP guidelines there is a management of evacuation where the determination of the inundation map based on flood modeling. The purpose of the EAP is to minimize the risk of loss of life and property in downstream which caused by dam failure. This paper will describe about develop flood modeling and inundation map in Krisak dam using numerical methods through dam break analysis (DBA) using hydraulic model Zhong Xing HY-21. The approaches of dam failure simulation are overtopping and piping. Overtopping simulation based on quadrangular, triangular and trapezium fracture. Piping simulation based on cracks of orifice. Using results of DBA, hazard classification of Krisak dam is very high. The nearest village affected dam failure is Singodutan village (distance is 1.45 kilometer from dam) with inundation depth is 1.85 meter. This result can be used by stakeholders such as emergency responders and the community at risk in formulating evacuation procedure.

Migration depth and residence time of juvenile salmonids in the forebays of hydropower dams prior to passage through turbines or juvenile bypass systems: implications for turbine-passage survival.

PubMed

Li, Xinya; Deng, Zhiqun D; Brown, Richard S; Fu, Tao; Martinez, Jayson J; McMichael, Geoffrey A; Skalski, John R; Townsend, Richard L; Trumbo, Bradly A; Ahmann, Martin L; Renholds, Jon F

2015-01-01

Little is known about the three-dimensional depth distributions in rivers of individually marked fish that are in close proximity to hydropower facilities. Knowledge of the depth distributions of fish approaching dams can be used to understand how vulnerable fish are to injuries such as barotrauma as they pass through dams. To predict the possibility of barotrauma injury caused by pressure changes during turbine passage, it is necessary to understand fish behaviour relative to acclimation depth in dam forebays as they approach turbines. A guiding study was conducted using high-resolution three-dimensional tracking results of salmonids implanted with Juvenile Salmon Acoustic Telemetry System transmitters to investigate the depth distributions of subyearling and yearling Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) passing two dams on the Snake River in Washington State. Multiple approaches were evaluated to describe the depth at which fish were acclimated, and statistical analyses were performed on large data sets extracted from ∼28 000 individually tagged fish during 2012 and 2013. Our study identified patterns of depth distributions of juvenile salmonids in forebays prior to passage through turbines or juvenile bypass systems. This research indicates that the median depth at which juvenile salmonids approached turbines ranged from 2.8 to 12.2 m, with the depths varying by species/life history, year, location (which dam) and diel period (between day and night). One of the most enlightening findings was the difference in dam passage associated with the diel period. The amount of time that turbine-passed fish spent in the immediate forebay prior to entering the powerhouse was much lower during the night than during the day. This research will allow scientists to understand turbine-passage survival better and enable them to assess more accurately the effects of dam passage on juvenile salmon survival.

Dam Breach Release of Non-Cohesive Sediments: Channel Response and Recovery Rates

NASA Astrophysics Data System (ADS)

Collins, M. J.; Boardman, G.; Banks, W.; Andrews, M.; Conlon, M.; Dillow, J. J. A.; Gellis, A.; Lowe, S.; McClain, S.; Miller, A. J.; Snyder, N. P.; Wilcock, P. R.

2014-12-01

Dam removals featuring unchecked releases of non-cohesive sediments are excellent opportunities to learn more about stream channel response to abrupt increases in bed material supply that can occur deliberately or by natural processes like landslides and volcanic eruptions. Understanding channel response to sediment pulses, including response rates, is essential because human uses of river channels and floodplains are impacted by these events as are aquatic habitats. We had the opportunity to study a dam removal site at the Simkins Dam in Maryland, USA, that shares many important geophysical attributes of another well-studied dam removal in the humid northeast United States [Merrimack Village Dam, New Hampshire; Pearson et al., 2011]. The watershed sizes are the same order of magnitude (102 km2), and at both sites relatively low head dams were removed (~ 3-4 m) and ~60,000 m3 of dominantly sand-sized sediments discharged to low-gradient reaches immediately downstream. Analyzing four years of repeat morphometry and bed sediment grain size surveys at the Simkins site on the Patapsco River, as well as continuous discharge and suspended sediment gaging data, we clearly document a two-phase response in the upstream reach as described by Pearson et al. [2011] for their New Hampshire site and noted at other dam removals [e.g., Major et al., 2012]. In the early phase, approximately 50% of the impounded sediment mass was eroded rapidly over a period of about three months when flows were very modest (Figure 1). After incision to base level and channel widening in the former impoundment, a second phase began when further erosion depended on floods large enough to access impounded sediments more distant from the newly-formed channel. We also found important differences in the upstream responses at the Maryland and New Hampshire sites that appear to be related to valley type (non-glaciated versus glaciated, respectively). Response variances immediately downstream between the respective sites are potentially related to local gradient and hydraulics.

The effect of dams and seasons on malaria incidence and anopheles abundance in Ethiopia

PubMed Central

2013-01-01

Background Reservoirs created by damming rivers are often believed to increase malaria incidence risk and/or stretch the period of malaria transmission. In this paper, we report the effects of a mega hydropower dam on P. falciparum malaria incidence in Ethiopia. Methods A longitudinal cohort study was conducted over a period of 2 years to determine Plasmodium falciparum malaria incidence among children less than 10 years of age living near a mega hydropower dam in Ethiopia. A total of 2080 children from 16 villages located at different distances from a hydropower dam were followed up from 2008 to 2010 using active detection of cases based on weekly house to house visits. Of this cohort of children, 951 (48.09%) were females and 1059 (51.91%) were males, with a median age of 5 years. Malaria vectors were simultaneously surveyed in all the 16 study villages. Frailty models were used to explore associations between time-to-malaria and potential risk factors, whereas, mixed-effects Poisson regression models were used to assess the effect of different covariates on anopheline abundance. Results Overall, 548 (26.86%) children experienced at least one clinical malaria episode during the follow up period with mean incidence rate of 14.26 cases/1000 child-months at risk (95% CI: 12.16 - 16.36). P. falciparum malaria incidence showed no statistically significant association with distance from the dam reservoir (p = 0.32). However, P. falciparum incidence varied significantly between seasons (p < 0.01). The malaria vector, Anopheles arabiensis, was however more abundant in villages nearer to the dam reservoir. Conclusions P. falciparum malaria incidence dynamics were more influenced by seasonal drivers than by the dam reservoir itself. The findings could have implications in timing optimal malaria control interventions and in developing an early warning system in Ethiopia. PMID:23566411

Migration depth and residence time of juvenile salmonids in the forebays of hydropower dams prior to passage through turbines or juvenile bypass systems: implications for turbine-passage survival

PubMed Central

Li, Xinya; Deng, Zhiqun D.; Brown, Richard S.; Fu, Tao; Martinez, Jayson J.; McMichael, Geoffrey A.; Skalski, John R.; Townsend, Richard L.; Trumbo, Bradly A.; Ahmann, Martin L.; Renholds, Jon F.

2015-01-01

Little is known about the three-dimensional depth distributions in rivers of individually marked fish that are in close proximity to hydropower facilities. Knowledge of the depth distributions of fish approaching dams can be used to understand how vulnerable fish are to injuries such as barotrauma as they pass through dams. To predict the possibility of barotrauma injury caused by pressure changes during turbine passage, it is necessary to understand fish behaviour relative to acclimation depth in dam forebays as they approach turbines. A guiding study was conducted using high-resolution three-dimensional tracking results of salmonids implanted with Juvenile Salmon Acoustic Telemetry System transmitters to investigate the depth distributions of subyearling and yearling Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) passing two dams on the Snake River in Washington State. Multiple approaches were evaluated to describe the depth at which fish were acclimated, and statistical analyses were performed on large data sets extracted from ∼28 000 individually tagged fish during 2012 and 2013. Our study identified patterns of depth distributions of juvenile salmonids in forebays prior to passage through turbines or juvenile bypass systems. This research indicates that the median depth at which juvenile salmonids approached turbines ranged from 2.8 to 12.2 m, with the depths varying by species/life history, year, location (which dam) and diel period (between day and night). One of the most enlightening findings was the difference in dam passage associated with the diel period. The amount of time that turbine-passed fish spent in the immediate forebay prior to entering the powerhouse was much lower during the night than during the day. This research will allow scientists to understand turbine-passage survival better and enable them to assess more accurately the effects of dam passage on juvenile salmon survival. PMID:27293685

Physical and biological responses to an alternative removal strategy of a moderate-sized dam in Washington, USA.

Treesearch

Shannon Claeson; B. Coffin

2015-01-01

Dam removal is an increasingly practised river restoration technique, and ecological responses vary with watershed, dam and reservoir properties, and removal strategies. Moderate-sized dams, like Hemlock Dam (7.9m tall and 56m wide), are large enough that removal effects could be significant, but small enough that mitigation may be possible through a modified dam...

Lost opportunities and future avenues to reconcile hydropower and sediment transport in the Mekong Basin through optimal sequencing of dam portfolios.

NASA Astrophysics Data System (ADS)

Castelletti, A.; Schmitt, R. J. P.; Bizzi, S.; Kondolf, G. M.

2017-12-01

Dams are essential to meet growing water and energy demands. While dams cumulatively impact downstream rivers on network-scales, dam development is mostly based on ad-hoc economic and environmental assessments of single dams. Here, we provide evidence that replacing this ad-hoc approach with early strategic planning of entire dam portfolios can greatly reduce conflicts between economic and environmental objectives of dams. In the Mekong Basin (800,000km2), 123 major dam sites (status-quo: 56 built and under construction) could generate 280,000 GWh/yr of hydropower. Cumulatively, dams risk interrupting the basin's sediment dynamics with severe impacts on livelihoods and eco-systems. To evaluate cumulative impacts and benefits of the ad-hoc planned status-quo portfolio, we combine the CASCADE sediment connectivity model with data on hydropower production and sediment trapping at each dam site. We couple CASCADE to a multi-objective genetic algorithm (BORG) identifying a) portfolios resulting in an optimal trade-off between cumulative sediment trapping and hydropower production and b) an optimal development sequence for each portfolio. We perform this analysis first for the pristine basin (i.e., without pre-existing dams) and then starting from the status-quo portfolio, deriving policy recommendations for which dams should be prioritized in the near future. The status-quo portfolio creates a sub-optimal trade-off between hydropower and sediment trapping, exploiting 50 % of the basin's hydro-electric potential and trapping 60 % of the sediment load. Alternative optimal portfolios could have produced equivalent hydropower for 30 % sediment trapping. Imminent development of mega-dams in the lower basin will increase hydropower production by 20 % but increase sediment trapping to >90 %. In contrast, following an optimal development sequence can still increase hydropower by 30 % with limited additional sediment trapping by prioritizing dams in upper parts of the basin. Our findings argue for reconsidering some imminent dam developments in the Mekong. With nearly 3000 dams awaiting development world-wide, results from the Mekong are of global importance, demonstrating that strategic planning and sequencing of dams is instrumental for sustainable development of dams and hydropower.

Fish Assemblage Response to a Small Dam Removal in the Eightmile River System, Connecticut, USA

NASA Astrophysics Data System (ADS)

Poulos, Helen M.; Miller, Kate E.; Kraczkowski, Michelle L.; Welchel, Adam W.; Heineman, Ross; Chernoff, Barry

2014-11-01

We examined the effects of the Zemko Dam removal on the Eightmile River system in Salem, Connecticut, USA. The objective of this research was to quantify spatiotemporal variation in fish community composition in response to small dam removal. We sampled fish abundance over a 6-year period (2005-2010) to quantify changes in fish assemblages prior to dam removal, during drawdown, and for three years following dam removal. Fish population dynamics were examined above the dam, below the dam, and at two reference sites by indicator species analysis, mixed models, non-metric multidimensional scaling, and analysis of similarity. We observed significant shifts in fish relative abundance over time in response to dam removal. Changes in fish species composition were variable, and they occurred within 1 year of drawdown. A complete shift from lentic to lotic fishes failed to occur within 3 years after the dam was removed. However, we did observe increases in fluvial and transition (i.e., pool head, pool tail, or run) specialist fishes both upstream and downstream from the former dam site. Our results demonstrate the importance of dam removal for restoring river connectivity for fish movement. While the long-term effects of dam removal remain uncertain, we conclude that dam removals can have positive benefits on fish assemblages by enhancing river connectivity and fluvial habitat availability.

Fish assemblage response to a small dam removal in the Eightmile River system, Connecticut, USA.

PubMed

Poulos, Helen M; Miller, Kate E; Kraczkowski, Michelle L; Welchel, Adam W; Heineman, Ross; Chernoff, Barry

2014-11-01

We examined the effects of the Zemko Dam removal on the Eightmile River system in Salem, Connecticut, USA. The objective of this research was to quantify spatiotemporal variation in fish community composition in response to small dam removal. We sampled fish abundance over a 6-year period (2005-2010) to quantify changes in fish assemblages prior to dam removal, during drawdown, and for three years following dam removal. Fish population dynamics were examined above the dam, below the dam, and at two reference sites by indicator species analysis, mixed models, non-metric multidimensional scaling, and analysis of similarity. We observed significant shifts in fish relative abundance over time in response to dam removal. Changes in fish species composition were variable, and they occurred within 1 year of drawdown. A complete shift from lentic to lotic fishes failed to occur within 3 years after the dam was removed. However, we did observe increases in fluvial and transition (i.e., pool head, pool tail, or run) specialist fishes both upstream and downstream from the former dam site. Our results demonstrate the importance of dam removal for restoring river connectivity for fish movement. While the long-term effects of dam removal remain uncertain, we conclude that dam removals can have positive benefits on fish assemblages by enhancing river connectivity and fluvial habitat availability.

9. Excavation work at Pleasant Dam (now called Waddell Dam). ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Excavation work at Pleasant Dam (now called Waddell Dam). Photographer unknown, July, 22, 1926. Source: Maricopa County Municipal Water Conservation District Number One (MWD). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

32. AERIAL VIEW OF TIETON DAM, UPSTREAM FACE OF DAM ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

32. AERIAL VIEW OF TIETON DAM, UPSTREAM FACE OF DAM (Trashrack-structure for outlet at lower left in reservoir, spillway at upper left. Reservoir nearly empty due to drought.) - Tieton Dam, South & East of State Highway 12, Naches, Yakima County, WA

National Program for Inspection of Non-Federal Dams. Houghton Pond Dam (MA 00444), Charles River Basin, Holliston, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-07-01

RD-A154 892 NATIONAL PROGRAM FOR INSPECTION OF NON-FEDERAL DAMS i/I HOUGHTON POND DAM (MA..(U) CORPS OF ENGINEERS WALTHAM UNCLASSIFIED N NEN ENGLAND...HOUGHTON POND DAM MA 00444 PHASE I INSPECTION REPORT _ NATIONAL DAM INSPECTION PROGRAM DTIC EECTE CD JUN4 985 -LJE DEPARTMENT OF THE ARMY NEW ENGLAND...16 SUPPLEMENTARY NOTES Co ver program reads: Phase I Inspection Report, National Dam Inspection Program ; however, the official title of the program

National Dam Safety Program. Still Lake Dam (Inventory Number N.Y. 1266), Long Island Basin, Westchester County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-08-05

Location The dam is located in Ossining , Westchester County, New York. The dam is located approximately four miles north- east of the City of... Ossining . c. Size Classification The dam has a structural height of 16 feet and a reservoir storage capacity of 150 acre-feet. The dam is clas- sified as...President of the Association is Mr. Barry Shainman, Adams Road, Ossining , New York, 10562, Telephone No. (914) 762-118C. f. Purpose Still Lake Dam

77 FR 56189 - Proposed Information Collection; Comment Request; Elwha River Dam Removal and Floodplain...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

... approval for a new information collection to conduct a pilot study to test the Elwha River Dam Removal and... important gap in research on indirect and nonuse values provided by habitat restoration. A study of the... losses associated with the reservoir. The ability to link results of the study to precise measures of...

Deschutes estuary feasibility study: hydrodynamics and sediment transport modeling

USGS Publications Warehouse

George, Douglas A.; Gelfenbaum, Guy; Lesser, Giles; Stevens, Andrew W.

2006-01-01

- Provide the completed study to the CLAMP Steering Committee so that a recommendation about a long-term aquatic environment of the basin can be made. The hydrodynamic and sediment transport modeling task developed a number of different model simulations using a process-based morphological model, Delft3D, to help address these goals. Modeling results provide a qualitative assessment of estuarine behavior both prior to dam construction and after various post-dam removal scenarios. Quantitative data from the model is used in the companion biological assessment and engineering design components of the overall study. Overall, the modeling study found that after dam removal, tidal and estuarine processes are immediately restored, with marine water from Budd Inlet carried into North and Middle Basin on each rising tide and mud flats being exposed with each falling tide. Within the first year after dam removal, tidal processes, along with the occasional river floods, act to modify the estuary bed by redistributing sediment through erosion and deposition. The morphological response of the bed is rapid during the first couple of years, then slows as a dynamic equilibrium is reached within three to five years. By ten years after dam removal, the overall hydrodynamic and morphologic behavior of the estuary is similar to the pre-dam estuary, with the exception of South Basin, which has been permanently modified by human activities. In addition to a qualitative assessment of estuarine behavior, process-based modeling provides the ability address specific questions to help to inform decision-making. Considering that predicting future conditions of a complex estuarine environment is wrought with uncertainties, quantitative results in this report are often expressed in terms of ranges of possible outcomes.

Is Dam Removal a Benefit for Environment? Input of Sedimentary Archives

NASA Astrophysics Data System (ADS)

Debret, M.; Laberdesque, Y.; Patault, E.; Copard, Y.; Koltalo, F.; Marcotte, S.; Sabatier, P.; Develle, A. L.; Chaumillon, E.; Coulombier, T.; Deloffre, J.; Fournier, M.; Landemaine, V.; Laignel, B.; Desmet, M.

2016-12-01

In October 2015, the scientific news EOS entitled: « Contaminated sediment and dam removal: problem or opportunity? ». This title clearly highlights the problems that societies of every country are facing: many dam are about to exceed their engineered life expectancies and large quantities of contaminated sediments are stored by theses structures. Moreover in Europe, since the 2000s, the European legislative and regulatory framework highlights the consideration of the morphological operation for hydro-systems. The objective of achieving good ecological status of waters by 2015 brings watershed management authorities to consider the removal of dams to restore the free movement of sediment. But until now, the impacts associated with the removal of structures are poorly studied. The Martot dam, chosen in this study is located on the Eure River (Seine river tributary, north of France). It is an ideal case study, because its coming destruction, for ecological continuity restoration, is a "priority" and a large quantity of contaminated sediments is supposed to be stored upstream, related to high industrial concentration since decades. We investigated the evolution of the hydro-sedimentary transfers on the watershed of the Eure River and determined the nature of the contaminants stored in the sediments that are subject to be remobilized after the dam removal. To achieve these goals, we reconstructed the Eure catchment area history by studying seismic profiles, in-situt high frequency monitoring (since 2 years: flow, electrical conductivity, temperrature, turbidity, suspended particulate matter concentration) and sedimentary cores. Then, the nature, origin and timing of pollutants stored in the Eure sediments were determined. The next step will be to evaluate their bio-accessibility and the danger for trophic chain and evaluate if the removal was a benefit or problem for environment.

Alternatives to Dam Building: Deindustrialization and the Redevelopment of Waterways in the Northeast During the Twentieth Century

NASA Astrophysics Data System (ADS)

Taber, J. S.; Pompeii, B. J.; Nicoletti, C.; Lopez-Morales, C. A.

2010-12-01

The Northeast United States contains more dams than any other region in the country but it lacks structures on the scale of the Hoover or Bonneville dams in the American West. This work addresses why the Northeast lacks such large dams and how the pattern of small dams within the region shaped its social development. During the twentieth century, changing social and economic conditions rendered the initial purposes of many dams in the region moot, but these structures continued to influence hydrologic conditions and the provision of ecosystem services to an expanding population. The continued existence of many of these dams resulted from a worldview unable to conceive of dam removal as it did to the economic or environmental services provided by the structure. Documenting the process by which society developed alternatives to dam building in this region can contextualize the origins and contingent character of ideas about dam removal. The overarching theme in this process is the deindustrialization of the Northeast, which pitted the interests of industrial cities undergoing economic reorganization, emerging suburban communities, and growing service industries in the region. This paper considers changing attitudes toward dams as part of a four step process: (1) although the mill dams of the industrial revolution remained after electrification rendered manufacturers independent of direct water power in the early twentieth century, deindustrialization reshaped the political and legal responses to flooding by stregnthening the political and economic position of service industries and suburban residential interests; (2) the most tangible response to this development was proposed federal investment in dam building in the region between the 1930s and the 1950s; (3) political conflicts between local interests and federal proposals for dam construction slowed down the dam building process and enabled people to consider alternative strategies for flood control and power generation; and (4) these alternatives included conservation measures such as the preservation of wetlands, but they also included the construction of coal and nuclear power plants in place of hydroelectric dams. Documenting the complexities underlying dam building and its alternatives in a deindustrializing region saddled with obsolete dams can contextualize contemporary debates regarding the maintenance or removal of old dams.

Benthic invertebrates and periphyton in the Elwha river basin: Current conditions and predicted response to dam removal

USGS Publications Warehouse

Morley, S.A.; Duda, J.J.; Coe, H.J.; Kloehn, K.K.; McHenry, M.L.

2008-01-01

The impending removal of two dams on the Elwha River in Washington State offers a unique opportunity to study ecosystem restoration at a watershed scale. We examine how periphyton and benthic invertebrate assemblages vary across regulated and unregulated sections of the Elwha River and across different habitat types, and establish baseline data for tracking future changes following dam removal. We collected multiple years of data on physical habitat, water chemistry, periphyton, and benthic invertebrates from 52 sites on the Elwha River and a reference section on the Quinault River, a neighboring basin. We found that substrate in regulated river sections was coarser and less heterogeneous in size than in unregulated sections, and summer water temperature and specific conductivity higher. Periphyton biomass was also consistently higher in regulated than unregulated sections. Benthic invertebrate assemblage structure at sites above both dams was distinct from sites between and below the dams, due in large part to dominance of mayfly taxa compared to higher relative abundance of midges and non-insect taxa at downstream sites. Following dam removal, we anticipate that both periphyton and benthic invertebrate abundance and diversity will temporarily decrease between and below dams as a result of sediment released from behind the reservoirs. Over the long-term, increased floodplain heterogeneity and recolonization by anadromous fish will alter benthic invertebrate and periphyton assemblages via increases in niche diversity and inputs of marine-derived nutrients. The extended timeline predicted for Elwha River recovery and the complexities of forecasting ecological response highlights the need for more long-term assessments of dam removal and river restoration practices.

Water storage equity and safety assurance policy to mitigate potential 'dual-extreme cumulative threats' in agricultural catchments

NASA Astrophysics Data System (ADS)

Pisaniello, John D.; Tingey-Holyoak, Joanne L.

2017-02-01

Farm dams that are not managed properly at the individual level can create water storage equity and safety threats to downstream communities and the environment that aggregate at the catchment level: a potential 'dual-extreme cumulative' problem. The paper provides indicative evidence and develops understanding of this novel phenomenon and associated policy needs within the Australian setting comprising dual hydrologic extremes of floods and droughts, further exacerbated by climate change. This is achieved through comparative case studies involving surveys of both dam owner perceptions and dam management practices in four States representing a complete range of integrated policy approaches from weak to strong. Survey results find most farmers do not believe dam maintenance is important, will undertake spillway blocking and do not plan for emergencies. These results are supported by physical on-site findings of farmers neglecting dams and blocking or under-designing spillways, in turn storing more water than they are entitled and creating unsafe dams at both the individual and cumulative levels. From detailed cross-case comparative assessment against policy context, it emerges that on-farm perceptions and practices form a range of 'acceptability' of dam management that directly reflects policy strength and integration in each setting. The paper advances the international small dams policy, agricultural water management and hydrology literatures, evidencing the need for effective integrated policy to mitigate dual extreme cumulative threats. Importantly, guidance is provided to jurisdictions internationally with high inter-annual rainfall variation on how best to design integrated policy that can achieve both water storage equity and safety in agricultural catchments.

Dam regulation and riverine food-web structure in a Mediterranean river.

PubMed

Mor, Jordi-René; Ruhí, Albert; Tornés, Elisabet; Valcárcel, Héctor; Muñoz, Isabel; Sabater, Sergi

2018-06-01

Flow regimes are a major driver of community composition and structure in riverine ecosystems, and flow regulation by dams often induces artificially-stable flow regimes downstream. This represents a major source of hydrological alteration, particularly in regions where biota is adapted to strong seasonal and interannual flow variability. We hypothesized that dam-induced hydrological stability should increase the availability of autochthonous resources at the base of the food web. This, in turn, should favour herbivorous over detritivorous strategies, increasing the diversity of primary consumers, and the food-web width and length. We tested this hypothesis by studying the longitudinal variation in food-web structure in a highly-seasonal Mediterranean river affected by an irrigation dam. We compared an unregulated reach to several reaches downstream of the dam. Hydrological and sedimentological stability increased downstream of the dam, and altered the type and quantity of available resources downstream, prompting a change from a detritus-based to an algae-based food web. The fraction of links between top and intermediate species also increased, and the food web became longer and wider at the intermediate trophic levels. Food-web structure did not recover 14km downstream of the dam, despite a partial restitution of the flow regime. Our results advance the notion that hydrologic alteration affects riverine food webs via additions/deletions of taxa and variation in the strength and distribution of food-web interactions. Thus, flow regulation by dams may not only impact individual facets of biodiversity, but also food-web level properties across river networks. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Markers of inflammation, oxidative stress, and endothelial dysfunction and the 20-year cumulative incidence of early age-related macular degeneration: the Beaver Dam Eye Study.

PubMed

Klein, Ronald; Myers, Chelsea E; Cruickshanks, Karen J; Gangnon, Ronald E; Danforth, Lorraine G; Sivakumaran, Theru A; Iyengar, Sudha K; Tsai, Michael Y; Klein, Barbara E K

2014-04-01

IMPORTANCE Modifying levels of factors associated with age-related macular degeneration (AMD) may decrease the risk for visual impairment in older persons. OBJECTIVE To examine the relationships of markers of inflammation, oxidative stress, and endothelial dysfunction to the 20-year cumulative incidence of early AMD. DESIGN, SETTING, AND PARTICIPANTS This longitudinal population-based cohort study involved a random sample of 975 persons in the Beaver Dam Eye Study without signs of AMD who participated in the baseline examination in 1988-1990 and up to 4 follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010. EXPOSURES Serum markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and white blood cell count), oxidative stress (8-isoprostane and total carbonyl content), and endothelial dysfunction (soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1) were measured. Interactions with complement factor H (rs1061170), age-related maculopathy susceptibility 2 (rs10490924), complement component 3 (rs2230199), and complement component 2/complement factor B (rs4151667) were examined using multiplicative models. Age-related macular degeneration was assessed from fundus photographs. MAIN OUTCOMES AND MEASURES Early AMD defined by the presence of any size drusen and the presence of pigmentary abnormalities or by the presence of large-sized drusen (≥125-μm diameter) in the absence of late AMD. RESULTS The 20-year cumulative incidence of early AMD was 23.0%. Adjusting for age, sex, and other risk factors, high-sensitivity C-reactive protein (odds ratio comparing fourth with first quartile, 2.18; P = .005), tumor necrosis factor-α receptor 2 (odds ratio, 1.78; P = .04), and interleukin-6 (odds ratio, 1.78; P = .03) were associated with the incidence of early AMD. Increased incidence of early AMD was associated with soluble vascular cell adhesion molecule-1 (odds ratio per SD on the logarithmic scale, 1.21; P = .04). CONCLUSIONS AND RELEVANCE We found modest evidence of relationships of serum high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and soluble vascular cell adhesion molecule-1 to the 20-year cumulative incidence of early AMD independent of age, smoking status, and other factors. It is not known whether these associations represent a cause and effect relationship or whether other unknown confounders accounted for the findings. Even if inflammatory processes are a cause of early AMD, it is not known whether interventions that reduce systemic inflammatory processes will reduce the incidence of early AMD.

Knockout maternal adiponectin increases fetal growth in mice: potential role for trophoblast IGFBP-1.

PubMed

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Guo, Zhuyu; Schaack, Jerome; Hay, William W; Zita, Matteo Moretto; Parast, Mana; Shao, Jianhua

2016-11-01

The main objective of this study was to investigate whether maternal adiponectin regulates fetal growth through the endocrine system in the fetal compartment. Adiponectin knockout (Adipoq (-/-) ) mice and in vivo adenovirus-mediated reconstitution were used to study the regulatory effect of maternal adiponectin on fetal growth. Primary human trophoblast cells were treated with adiponectin and a specific peroxisome proliferator-activated receptor α (PPARα) agonist or antagonist to study the underlying mechanism through which adiponectin regulates fetal growth. The body weight of fetuses from Adipoq (-/-) dams was significantly greater than that of wild-type dams at both embryonic day (E)14.5 and E18.5. Adenoviral vector-mediated maternal adiponectin reconstitution attenuated the increased fetal body weight induced by maternal adiponectin deficiency. Significantly increased blood glucose, triacylglycerol and NEFA levels were observed in Adipoq (-/-) dams, suggesting that nutrient supply contributes to maternal adiponectin-regulated fetal growth. Although fetal blood IGF-1 concentrations were comparable in fetuses from Adipoq (-/-) and wild-type dams, remarkably low levels of IGF-binding protein 1 (IGFBP-1) were observed in the serum of fetuses from Adipoq (-/-) dams. IGFBP-1 was identified in the trophoblast cells of human and mouse placentas. Maternal fasting robustly increased IGFBP-1 levels in mouse placentas, while reducing fetal weight. Significantly low IGFBP-1 levels were found in placentas of Adipoq (-/-) dams. Adiponectin treatment increased IGFBP-1 levels in primary cultured human trophoblast cells, while the PPARα antagonist, MK886, abolished this stimulatory effect. These results indicate that, in addition to nutrient supply, maternal adiponectin inhibits fetal growth by increasing IGFBP-1 expression in trophoblast cells.

Study the impact of rainfall on the United Arab Emirates dams using remote sensing and image processing techniques

NASA Astrophysics Data System (ADS)

Al Marzouqi, Fatima A.; Al Besher, Shaikha A.; Al Mansoori, Saeed H.

2017-10-01

The United Arab Emirates (UAE) has given great attention to the environment and sustainable development through applications of best practices of global standards that ensure optimal investment in natural resources. Since the UAE is located in an arid region which is known as dry, sandy and get a small amount of rainfall, thus the water resources are limited and accordingly, the government has initiated an integrated water resources management (IWRM) strategy to meet the increasing demands of water. Dams are considered as one of the important strategies that are suitable for this arid region. An event of rainfall if between heavy to severe in a short duration could cause flash floods and damages to population centers and areas of agriculture nearby. To prevent that from happening, several dams and barriers were built to protect human life and infrastructure. Besides contribution to enhance the water resources and use them optimally to irrigate the growing agricultural areas across the country. Geographically, most of the dams were located in the northern and eastern part of the UAE, around mountainous areas. This study aims to monitor the changes that occurred to five dams of the north-eastern region of the UAE during 2015 and 2016 through the use of remote sensing technology of optical images captured by "DubaiSat-2". The segmentation approach utilized in this study is based on a band ratio technique called Normalized Difference Water Index (NDWI). The experimental results revealed that the proposed approach is efficient in detecting dams from multispectral satellite images.

The effect of androgen excess on maternal metabolism, placental function and fetal growth in obese dams.

PubMed

Fornes, Romina; Maliqueo, Manuel; Hu, Min; Hadi, Laila; Jimenez-Andrade, Juan M; Ebefors, Kerstin; Nyström, Jenny; Labrie, Fernand; Jansson, Thomas; Benrick, Anna; Stener-Victorin, Elisabet

2017-08-14

Pregnant women with polycystic ovary syndrome (PCOS) are often overweight or obese. To study the effects of maternal androgen excess in obese dams on metabolism, placental function and fetal growth, female C57Bl6J mice were fed a control (CD) or a high fat/high sucrose (HF/HS) diet for 4-10 weeks, and then mated. On gestational day (GD) 15.5-17.5, dams were injected with dihydrotestosterone (CD-DHT, HF/HS-DHT) or a vehicle (CD-Veh, HF/HS-Veh). HF/HS dams had higher fat content, both before mating and on GD18.5, with no difference in glucose homeostasis, whereas the insulin sensitivity was higher in DHT-exposed dams. Compared to the CD groups, the livers from HF/HS dams weighed more on GD18.5, the triglyceride content was higher, and there was a dysregulation of liver enzymes related to lipogenesis and higher mRNA expression of Fitm1. Fetuses from HF/HS-Veh dams had lower liver triglyceride content and mRNA expression of Srebf1c. Maternal DHT exposure, regardless of diet, decreased fetal liver Pparg mRNA expression and increased placental androgen receptor protein expression. Maternal diet-induced obesity, together with androgen excess, affects maternal and fetal liver function as demonstrated by increased triglyceride content and dysfunctional expression of enzymes and transcription factors involved in de novo lipogenesis and fat storage.

Seeking more Opportunities of Check Dams' harmony with nearby Circumstances via Design Thinking Process

NASA Astrophysics Data System (ADS)

Lin, Huan-Chun; Chen, Su-Chin; Tsai, Chen-Chen

2014-05-01

The contents of engineering design should indeed contain both science and art fields. However, the art aspect is too less discussed to cause an inharmonic impact with natural surroundings, and so are check dams. This study would like to seek more opportunities of check dams' harmony with nearby circumstances. According to literatures review of philosophy and cognition science fields, we suggest a thinking process of three phases to do check dams design work for reference. The first phase, conceptualization, is to list critical problems, such as the characteristics of erosion or deposition, and translate them into some goal situations. The second phase, transformation, is to use cognition methods such as analogy, association and metaphors to shape an image and prototypes. The third phase, formation, is to decide the details of the construction, such as stable safety analysis of shapes or materials. According to the previous descriptions, Taiwan's technological codes or papers about check dam design mostly emphasize the first and third phases, still quite a few lacks of the second phase. We emphases designers shouldn't ignore any phase of the framework especially the second one, or they may miss some chances to find more suitable solutions. Otherwise, this conceptual framework is simple to apply and we suppose it's a useful tool to design a more harmonic check dam with nearby natural landscape. Key Words: check dams, design thinking process, conceptualization, transformation, formation.

National Dam Safety Program. Watchung Lake Dam (NJ00767), Raritan River Basin, Stony Brook, Somerset County, New Jersey Phase I Inspection Report.

DTIC Science & Technology

1981-07-01

Safety Program Erosion Embankmients Watchung Lake Dam, N.J. Visual InspectionSeae IStructural Analysis Spillways 12M~ A0ST Acr (cathiue samvwgip @ta N...determined by a qualified professional consultant engaged by the owner using more sophisticated methods , procedures and studies within six months...be overtopped. (The SDF, in this instance, is one half of the Probable Maximum Flood). The decision to consider the spillway " inaae - quate" instead of

Survival and migration behavior of juvenile salmonids at McNary Dam, 2004, Final report of research

USGS Publications Warehouse

Perry, Russell W.; Braatz, Amy C.; Fielding, Scott D.; Lucchesi, Joel N.; Plumb, John M.; Adams, Noah S.; Rondorf, Dennis W.

2005-01-01

During 2004, the USGS Columbia River Research Laboratory conducted a study at McNary Dam using radio telemetry to estimate passage and survival parameters of juvenile salmonids. Our primary objective was to estimate these parameters under ambient environmental and operational conditions, and thus project-wide treatments were not implemented. The primary dam operation consisted of “biop” spill, where spill occurred at night between 1800 and 0600 hours, and no spill occurred between 0600 and 1800 hours for the majority of our study period. During the spring study period, we radio-tagged and released 1,896 yearling Chinook salmon and 1,888 juvenile steelhead. During the summer study period, we radio-tagged and released 1,919 subyearling Chinook salmon. All fish were tagged using gastric techniques to implant transmitters weighing 1.58 g for yearling Chinook salmon, 1.93 g for juvenile steelhead, and 0.96 g for subyearling Chinook salmon. Minimum fish sizes were based on a 6.5% tag:fish weight ratio, and the size of tagged fish represented about 91%, 100%, and 17% of the population, respectively for yearling Chinook salmon, juvenile steelhead, and subyearling Chinook salmon. About 60% of radio-tagged fish were released 10 km upstream of McNary Dam at Hat Rock State Park, Oregon, with the remainder released as control groups 400 m downstream of the dam.

Developing a Water Quality Index (WQI) for an Irrigation Dam

PubMed Central

De La Mora-Orozco, Celia; Flores-Lopez, Hugo; Rubio-Arias, Hector; Chavez-Duran, Alvaro; Ochoa-Rivero, Jesus

2017-01-01

Pollution levels have been increasing in water ecosystems worldwide. A water quality index (WQI) is an available tool to approximate the quality of water and facilitate the work of decision-makers by grouping and analyzing numerous parameters with a single numerical classification system. The objective of this study was to develop a WQI for a dam used for irrigation of about 5000 ha of agricultural land. The dam, La Vega, is located in Teuchitlan, Jalisco, Mexico. Seven sites were selected for water sampling and samples were collected in March, June, July, September, and December 2014 in an initial effort to develop a WQI for the dam. The WQI methodology, which was recommended by the Mexican National Water Commission (CNA), was used. The parameters employed to calculate the WQI were pH, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), total hardness (TH), alkalinity (Alk), total phosphorous (TP), Cl−, NO3, SO4, Ca, Mg, K, B, As, Cu, and Zn. No significant differences in WQI values were found among the seven sampling sites along the dam. However, seasonal differences in WQI were noted. In March and June, water quality was categorized as poor. By July and September, water quality was classified as medium to good. Quality then decreased, and by December water quality was classified as medium to poor. In conclusion, water treatment must be applied before waters from La Vega dam reservoir can be used for irrigation or other purposes. It is recommended that the water quality at La Vega dam is continually monitored for several years in order to confirm the findings of this short-term study. PMID:28468230

Ecological consequences of hydropower development in Central America: Impacts of small dams and water diversion on neotropical stream fish assemblages

USGS Publications Warehouse

Anderson, Elizabeth P.; Freeman, Mary C.; Pringle, C.M.

2006-01-01

Small dams for hydropower have caused widespread alteration of Central American rivers, yet much of recent development has gone undocumented by scientists and conservationists. We examined the ecological effects of a small hydropower plant (Dona Julia Hydroelectric Center) on two low-order streams (the Puerto Viejo River and Quebradon stream) draining a mountainous area of Costa Rica. Operation of the Dona Julia plant has dewatered these streams, reducing discharge to ~ 10% of average annual flow. This study compared fish assemblage composition and aquatic habitat upstream and downstream of diversion dams on two streams and along a ~ 4 km dewatered reach of the Puerto Viejo River in an attempt to evaluate current instream flow recommendations for regulated Costa Rican streams. Our results indicated that fish assemblages directly upstream and downstream of the dam on the third order Puerto Viejo River were dissimilar, suggesting that the small dam (< 15 in high) hindered movement of fishes. Along the ~ 4 km dewatered reach of the Puerto Viejo River, species count increased with downstream distance from the dam. However, estimated species richness and overall fish abundance were not significantly correlated with downstream distance from the dam. Our results suggested that effects of stream dewatering may be most pronounced for a subset of species with more complex reproductive requirements, classified as equilibrium-type species based on their life-history. In the absence of changes to current operations, we expect that fish assemblages in the Puerto Viejo River will be increasingly dominated by opportunistic-type, colonizing fish species. Operations of many other small hydropower plants in Costa Rica and other parts of Central America mirror those of Doha Julia; the methods and results of this study may be applicable to some of those projects.

Changes in liveweight and behaviour of alpaca dams and offspring following weaning.

PubMed

Pollard, J C; Littlejohn, R P; Davis, G H

1993-12-01

The effects of offspring sex, weight, age, and level of interaction with the dam on responses to weaning were examined to assist in the development of a weaning protocol for alpacas. In the first study, preand post-weaning activities, and weight change over Days -12-0,0-7 and 7-16 with respect to weaning, were recorded for 20 dam-offspring (hembra-cria) pairs aged 81-200 days. Pre-weaning changes in dam and offspring weights were positively related (P<0.05). Although heavier crias tended to be found closer to their dams than lighter crias (P<0.05) no additional effect of age on the dam-offspring relationship was found. Following weaning, cria growth rates were low over Days 0-7 but improved over Days 7-16, and hembra weight change followed the same pattern. Over Days 0-2, grazing and sitting activities of hembras and crias were replaced by standing and walking along paddock fencelines, although by Day 2 fenceline activities had decreased (P<0.05). Crias which were more frequently observed at fencelines had lower post-weaning growth rates (P<0.05). In the second study, pre-weaning sucking behaviour, and weight change over Days -30-0, 0-8 and 8-16 with respect to weaning, were recorded for 19 hembra-cria pairs aged 124-160 days. During 10 hours of observation on Days -5 and -4, the total duration of sucking by individual crias varied from 0-18 minutes, and the mean +/- SEM duration of sucking was 1.94 +/- 0.113 minutes. Cria sucking behaviour was positively related to growth rate prior to and weight at weaning (P<0.05). As in the first study, pre-weaning changes in dam and offspring weights were positively related (P<0.05). Following weaning, growth rates of the crias were depressed and the hembras lost weight over Days 0-8 and 8-16. The changes in growth rate and behaviour in Studies 1 and 2 indicated that weaning can be stressful for hembras and crias. However, there was no evidence from either study that pre-weaning behavioural or physical characteristics were related to the changes.

Dam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam

USGS Publications Warehouse

Perry, Russell W.; Kock, Tobias J.; Couter, Ian I; Garrison, Thomas M; Hubble, Joel D; Child, David B

2016-01-01

Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we used radio telemetry to understand how dam operations and river discharge in the 18-km reach downstream of the dam affected route-specific passage and survival. We found evidence of direct mortality associated with dam passage and indirect mortality associated with migration through the reach below the dam. Survival of fish passing over a surface spill gate (the west gate) was positively related to river discharge, and survival was similar for fish released below the dam, suggesting that passage via this route caused little additional mortality. However, survival of fish that passed under a sub-surface spill gate (the east gate) was considerably lower than survival of fish released downstream of the dam, with the difference in survival decreasing as river discharge increased. The probability of fish passing the dam via three available routes was strongly influenced by dam operations, with passage through the juvenile fish bypass and the east gate increasing with discharge through those routes. By simulating daily passage and route-specific survival, we show that variation in total survival is driven by river discharge and moderated by the proportion of fish passing through low-survival or high-survival passage routes.

Water temperature effects from simulated dam operations and structures in the Middle Fork Willamette River, western Oregon

USGS Publications Warehouse

Buccola, Norman L.; Turner, Daniel F.; Rounds, Stewart A.

2016-09-14

Significant FindingsStreamflow and water temperature in the Middle Fork Willamette River (MFWR), western Oregon, have been regulated and altered since the construction of Lookout Point, Dexter, and Hills Creek Dams in 1954 and 1961, respectively. Each year, summer releases from the dams typically are cooler than pre-dam conditions, with the reverse (warmer than pre-dam conditions) occurring in autumn. This pattern has been detrimental to habitat of endangered Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR winter steelhead (O. mykiss) throughout multiple life stages. In this study, scenarios testing different dam-operation strategies and hypothetical dam-outlet structures were simulated using CE-QUAL-W2 hydrodynamic/temperature models of the MFWR system from Hills Creek Lake (HCR) to Lookout Point (LOP) and Dexter (DEX) Lakes to explore and understand the efficacy of potential flow and temperature mitigation options.Model scenarios were run in constructed wet, normal, and dry hydrologic calendar years, and designed to minimize the effects of Hills Creek and Lookout Point Dams on river temperature by prioritizing warmer lake surface releases in May–August and cooler, deep releases in September–December. Operational scenarios consisted of a range of modified release rate rules, relaxation of power-generation constraints, variations in the timing of refill and drawdown, and maintenance of different summer maximum lake levels at HCR and LOP. Structural scenarios included various combinations of hypothetical floating outlets near the lake surface and hypothetical new outlets at depth. Scenario results were compared to scenarios using existing operational rules that give temperature management some priority (Base), scenarios using pre-2012 operational rules that prioritized power generation over temperature management (NoBlend), and estimated temperatures from a without-dams condition (WoDams).Results of the tested model scenarios led to the following conclusions:The existing outlets at Lookout Point Dam, because of the range of depths, allow for greater temperature control than the two existing outlets at Hills Creek Dam that are relatively deep.Temperature control at HCR through operational scenarios generally was minimal near Hills Creek Dam, but improved downstream toward the head of LOP when decreased release rates held HCR at a low lake elevation year-round.Inflows from unregulated streams between HCR and LOP helped to dilute the effects of HCR and achieve more natural stream temperatures before the MFWR entered LOP.The relative benefit of any particular scenario depended on the location in the MFWR system used to assess the potential change, with most scenarios involving changes to Hills Creek Dam being less effective with increasing downstream distance, such as downstream of DEX.To achieve as much temperature control as the most successful structural scenarios, which were able to resemble without-dam conditions for part of the year, most operational scenarios had to be free of any power-generation requirements at Lookout Point Dam.Downstream of DEX, scenarios incorporating a hypothetical floating outlet at either HCR or LOP resulted in similar temperatures, with both scenarios causing a delay in the estimated spring Chinook egg emergence by about 9–10 days compared to base-case temperature-management scenarios.

Transport, dam passage, and size selection of adult Atlantic Salmon in the Penobscot River, Maine

USGS Publications Warehouse

Sigourney, Douglas B.; Zydlewski, Joseph D.; Hughes, Edward; Cox, Oliver

2015-01-01

Prior to 2012, returning adult Atlantic Salmon Salmo salar had to pass through fishways at three dams in the lower section of the Penobscot River, Maine: Veazie Dam (river kilometer [rkm] 48; removed in 2013), Great Works Dam (rkm 60; removed in 2012), and Milford Dam (rkm 62). To facilitate better passage through the lower river, a fish transport program was implemented in 2010 and 2011. Fish were captured at Veazie Dam and were either transported by truck above Milford Dam (TRKD group) or released into the head pond above Veazie Dam (run-of-the-river [ROR] group). To assess the efficacy of transport, we used PIT telemetry to compare the performance and passage of TRKD and ROR fish based on their (1) success in reaching one of the three dams upstream of Milford Dam, (2) time taken to reach an upstream dam (transit time), and (3) success in passing that upstream dam. In both years, the percentage of fish detected at upstream dams was higher for the TRKD group (82.4% in 2010; 78.6% in 2011) than for the ROR group (41.3% in 2010; 22.4% in 2011). In addition, median transit time was faster for TRKD fish (7 d in 2010; 5 d in 2011) than for ROR fish (23 d in 2010; 25 d in 2011). However, passage success through the upstream dams did not differ between the two release groups. Our analysis also revealed a strong, negative size-selective force on dam passage: larger fish were consistently less likely to successfully pass dams than smaller fish. Finally, environmental conditions also influenced passage success. Our analysis shows that the transport of adult Atlantic Salmon can be an effective means by which to increase migration success in systems where upstream passage is poor.

Assessing Risks of Mine Tailing Dam Failures

NASA Astrophysics Data System (ADS)

Concha Larrauri, P.; Lall, U.

2017-12-01

The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, John R.; Townsend, Richard L.; Seaburg, Adam

The study was designed to estimate dam passage survival at Bonneville Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and to provide additional fish passage performance measures at that site as stipulated in the Columbia Basin Fish Accords.

Three-dimensional earthquake analysis of roller-compacted concrete dams

NASA Astrophysics Data System (ADS)

Kartal, M. E.

2012-07-01

Ground motion effect on a roller-compacted concrete (RCC) dams in the earthquake zone should be taken into account for the most critical conditions. This study presents three-dimensional earthquake response of a RCC dam considering geometrical non-linearity. Besides, material and connection non-linearity are also taken into consideration in the time-history analyses. Bilinear and multilinear kinematic hardening material models are utilized in the materially non-linear analyses for concrete and foundation rock respectively. The contraction joints inside the dam blocks and dam-foundation-reservoir interaction are modeled by the contact elements. The hydrostatic and hydrodynamic pressures of the reservoir water are modeled with the fluid finite elements based on the Lagrangian approach. The gravity and hydrostatic pressure effects are employed as initial condition before the strong ground motion. In the earthquake analyses, viscous dampers are defined in the finite element model to represent infinite boundary conditions. According to numerical solutions, horizontal displacements increase under hydrodynamic pressure. Besides, those also increase in the materially non-linear analyses of the dam. In addition, while the principle stress components by the hydrodynamic pressure effect the reservoir water, those decrease in the materially non-linear time-history analyses.

Coupled dam safety analysis using WinDAM

USDA-ARS?s Scientific Manuscript database

Windows® Dam Analysis Modules (WinDAM) is a set of modular software components that can be used to analyze overtopping and internal erosion of embankment dams. Dakota is an extensive software framework for design exploration and simulation. These tools can be coupled to create a powerful framework...

76 FR 13601 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

... opportunities for fish passage improvements or dam removal that may fit into existing funding programs directed... uses of dams, anticipated uses of dams, important issues or concerns to dam owners, and owners... dams will also be identified. Affected Public: Business or other for-profit organizations. Frequency...

Landscape change and sediment yield of rivers in the northeastern US during 19th century

NASA Astrophysics Data System (ADS)

Urbanova, T.; Wreschnig, A. J.; Ruffing, C. M.; McCormack, S. M.; Bain, D. J.; Hermans, C. M.

2009-12-01

During the 19th century, population growth, dam construction, and large scale forest clearing, particularly for agriculture, was followed by a massive migration to urban and industrialized centers. This led to the high degree of rural land abandonment in many parts of northeastern US. Such significant changes in land use and demography impacted sediment loading and delivery to receiving waters. The objective of this study is to assess the historical changes in sediment loading to waters as a result of land use change and related change in soil erosion, dam dynamics and sediment trapping. Various methods for assessing soil erosion, sediment yield and dam influence will be used and compared (RUSLE, BQART model, dam trapping efficiency). We expect to see 1) an accelerated erosion rates and sediment yield following forest clearing and intensification of agriculture and 2) decreased sediment delivery to estuaries with an increasing number of dams. While sediment management often focuses on fluvial corridors, our understanding of historic upland dynamics remains rudimentary. This study aims to highlight and explain the interconnectedness of the landscape-hydro system; with a particular emphasis on anthropogenic forcing and influences.

Influence of Beaver Dams on Channel Complexity, Hydrology, and Temperature Regime in a Mountainous Stream

NASA Astrophysics Data System (ADS)

Majerova, M.; Neilson, B. T.; Schmadel, N. M.; Wheaton, J. M.; Snow, C. J.

2013-12-01

Beaver dams and beaver activity affect hydrologic processes, sediment transport, channel complexity and water quality of streams. Beaver ponds, which form behind beaver dams, increase in-channel water storage affecting the timing and volume of flow and resulting in the attenuation and flattening of the hydrograph. Channel complexity also increases the potential for transient storage (both surface and subsurface) and influences stream temperature. Impacts of beaver dams and beaver activity on stream responses are difficult to quantify because responses are dynamic and spatially variable. Few studies have focused on the reach scale temporal influences on stream responses and further research is needed particularly in quantifying the influence of beaver dams and their role in shaping the stream habitat. This study explores the changing hydrology and temperature regime of Curtis Creek, a mountainous stream located in Northern Utah, in a 560 m long reach where groundwater exchanges and temperature differences were observed over a three-year period. We have collected continuous stream discharge, stream temperature data and performed tracer experiments. During the first year, we were able to capture the pre-beaver activity. In the second year, we captured the impacts of some beaver activity with only a few dams built in the reach, while the third year included the effects of an entire active beaver colony. By the end of the study period, a single thread channel had been transformed into a channel with side channels and backwaters at multiple locations therefore increasing channel complexity. The cumulative influence of beaver dams on reach scale discharge resulted in a slightly losing reach that developed into a gaining reach. At the smaller sub-reach scale, both losing to gaining and gaining to losing transformations were observed. Temperature differences showed a warming effect of beaver dams at the reach scale. The reach stream temperature difference increased on average 0.3°C when comparing the first to the third year of our study period. This warming trend was more pronounced in summer stream temperatures where differences were about 0.7°C. During winter months cooling was observed and temperatures decreased about -0.2°C over the reach. Annual tracer studies also captured an 81min (238%) increase in residence times due primarily to the increased channel complexity and storage over the three-year period. Our study provides reach scale understanding regarding the temporal influence of beavers to not only change physical template of the channel, but also influence the hydrology and temperature regime of streams.

Characterization of channel substrate, and changes in suspended-sediment transport and channel geometry in white sturgeon spawning habitat in the Kootenai River near Bonners Ferry, Idaho, following the closure of Libby Dam

USGS Publications Warehouse

Barton, Gary J.

2004-01-01

Many local, State, and Federal agencies have concerns over the declining population of white sturgeon (Acipenser transmontanus) in the Kootenai River and the possible effects of the closure and subsequent operation of Libby Dam in 1972. In 1994, the Kootenai River white sturgeon was listed as an Endangered Species. A year-long field study was conducted in cooperation with the Kootenai Tribe of Idaho along a 21.7-kilometer reach of the Kootenai River including the white sturgeon spawning reach near Bonners Ferry, Idaho, approximately 111 to 129 kilometers below Libby Dam. During the field study, data were collected in order to map the channel substrate in the white sturgeon spawning reach. These data include seismic subbottom profiles at 18 cross sections of the river and sediment cores taken at or near the seismic cross sections. The effect that Libby Dam has on the Kootenai River white sturgeon spawning substrate was analyzed in terms of changes in suspended-sediment transport, aggradation and degradation of channel bed, and changes in the particle size of bed material with depth below the riverbed. The annual suspended-sediment load leaving the Kootenai River white sturgeon spawning reach decreased dramatically after the closure of Libby Dam in 1972: mean annual pre-Libby Dam load during 1966–71 was 1,743,900 metric tons, and the dam-era load during 1973–83 was 287,500 metric tons. The amount of sand-size particles in three suspended-sediment samples collected at Copeland, Idaho, 159 kilometers below Libby Dam, during spring and early summer high flows after the closure of Libby Dam is less than in four samples collected during the pre-Libby Dam era. The supply of sand to the spawning reach is currently less due to the reduction of high flows and a loss of 70 percent of the basin after the closure of Libby Dam. The river's reduced capacity to transport sand out of the spawning reach is compensated to an unknown extent by a reduced load of sand entering the spawning reach. Since the closure of Libby Dam, the most notable change in channel geometry at the Copeland streamflow gaging station was the initiation of cyclical aggradation and degradation of the riverbed in the center of the channel. The aggradation and degradation of the riverbed are reflected in a twofold increase, from 1.3 to 2.5 meters, in the fluctuation of the minimum riverbed elevation, which suggests that during the Libby Dam era, parts of the riverbed in the spawning reach may have aggraded or degraded by as much as 2.5 meters. Before the closure of Libby Dam, there was a greater propensity for aggradation and degradation of sand over the discontinuous gravel and cobble layers in the buried gravelcobble reach at Bonners Ferry. The gravel and cobble in this reach, 111.3 to 115.9 kilometers below Libby Dam, are buried by sand. Unregulated spring snowmelt-runoff flows flushed part of the sand layer and exposed some of the buried gravel-cobble layer because streamflow velocities were higher at that time. Unregulated autumn-winter base flows gradually deposited silt and sand and reestablished a sand layer, burying the gravel-cobble layer. This cyclical process of aggradation and degradation of the riverbed sediment is reflected in the alternating gravel-cobble layers and sand layers found in sediment core K18-TH taken as part of this project. White sturgeon spawning substrate in the Kootenai River meander reach is currently composed of alluvial sand that forms sand dunes and of minor amounts of lacustrine clay and silt that generally are found in the river's thalweg. The present substrate composition in the meander reach is considered similar to that which existed prior to closure of Libby Dam, with one possible exception. Prior to closure of Libby Dam, minor amounts of gravel and cobble may have been exposed on the riverbed in the spawning reach just below the mouth of Myrtle Creek 230 kilometers below Libby Dam. The substrate composition near Shorty Island, 234 kilometers below Libby Dam, a notable white sturgeon spawning reach, is predominantly sand and is similar to that which existed prior to closure of Libby Dam.

Marine and Hydrokinetic Maps | Geospatial Data Science | NREL

Science.gov Websites

production. Nonpowered Dams Assessment: An Assessment of Energy Potential at Non-Powered Dams in the United States The Nonpowered Dams Assessment, created by Oak Ridge National Laboratory, assesses non-powered dams across the nation to determine their ability to generate electricity. Non-powered dam electric

53. AVALON DAM Photographic copy of historic photo, August ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

53. AVALON DAM - Photographic copy of historic photo, August 9, 1893 (original print located at the Carlsbad Irrigation District offices, Carlsbad, New Mexico) photographer unknown 'EDDY DAM. LOOKING EAST.' VIEW OF COLLAPSED DAM - Carlsbad Irrigation District, Avalon Dam, On Pecos River, 4 miles North of Carlsbad, Carlsbad, Eddy County, NM

National Dam Inspection Program. Bentleyville Dam (NDI ID Number PA- 1096, DER ID Number 63-49), Ohio River Basin, Tributary North Branch Pigeon Creek, Washington County, Pennsylvania. Phase I Inspection Report

DTIC Science & Technology

1981-06-01

controlled manner.V The Bentleyville Dam is a significant hazard-small size dam. TK2 recommended spillway design flood (SDF) for a dam of this size and...the dam was completed in 1938. 9. Evaluation. No major deficiencies were observed during the inspection which were considered as having an immediate

National Program for Inspection of Non-Federal Dams. Pleasant Lake Dam (NH 00362) (NHWRB 176.02), Merrimack River Basin, New London, New Hampshire. Phase I Inspection Report.

DTIC Science & Technology

1978-11-01

the - full PMF. The selected TF inflow of 16,000 cfs results in a discharge at the dam of 12,460 cfs . Since the maximum capacity .* of the dam prior...to overtopping is only approximately 640 cfs , the TF would overtop the dam by over 4 feet. The dam is in POOR condition at the present time, due...accompanied the hurricane of 1938 and resulted [- in the dam being overtopped by two feet. This lake level indicates a discharge of approximately 4500 cfs

National Dam Inspection Program. Converse Lake Dam (CT 00044). Connecticut Coastal Basin, Greenwich, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1980-02-01

Guidelines for Safety Inspection of Dams, and with good engineering judgement and practice, and is hereby submitted for approval. ’ /00s~rs H W. NT’EGAN...below the top of the dam, with water flowing over the spillway. b. Dam Crest - The top of the dam is a concrete cap and is in good condition (Photo 1...the masonry portion is not substantial the dam is not safe. Masonry on water side is a good job of cement rubble. Top width is 7’. But it is doubtful

Have Large Dams Altered Extreme Precipitation Patterns?

NASA Astrophysics Data System (ADS)

Hossain, Faisal; Jeyachandran, Indumathi; Pielke, Roger

2009-12-01

Dams and their impounded waters are among the most common civil infrastructures, with a long heritage of modern design and operations experience. In particular, large dams, defined by the International Commission on Large Dams (ICOLD) as having a height greater than 15 meters from the foundation and holding a reservoir volume of more than 3 million cubic meters, have the potential to vastly transform local climate, landscapes, regional economics, and urbanization patterns. In the United States alone, about 75,000 dams are capable of storing a volume of water equaling almost 1 year's mean runoff of the nation [Graf, 1999]. The World Commission on Dams (WCD) reports that at least 45,000 large dams have been built worldwide since the 1930s. These sheer numbers raise the question of the extent to which large dams and their impounded waters alter patterns that would have been pervasive had the dams not been built.

Harvesting river water through small dams promote positive environmental impact.

PubMed

Agoramoorthy, Govindasamy; Chaudhary, Sunita; Chinnasamy, Pennan; Hsu, Minna J

2016-11-01

While deliberations relating to negative consequences of large dams on the environment continue to dominate world attention, positive benefits provided by small dams, also known as check dams, go unobserved. Besides, little is known about the potential of check dams in mitigating global warming impacts due to less data availability. Small dams are usually commissioned to private contractors who do not have clear mandate from their employers to post their work online for public scrutiny. As a result, statistics on the design, cost, and materials used to build check dams are not available in public domain. However, this review paper presents data for the first time on the often ignored potential of check dams mitigating climate-induced hydrological threats. We hope that the scientific analysis presented in this paper will promote further research on check dams worldwide to better comprehend their eco-friendly significance serving society.

Dynamic decision making for dam-break emergency management - Part 2: Application to Tangjiashan landslide dam failure

NASA Astrophysics Data System (ADS)

Peng, M.; Zhang, L. M.

2013-02-01

Tangjiashan landslide dam, which was triggered by the Ms = 8.0 Wenchuan earthquake in 2008 in China, threatened 1.2 million people downstream of the dam. All people in Beichuan Town 3.5 km downstream of the dam and 197 thousand people in Mianyang City 85 km downstream of the dam were evacuated 10 days before the breaching of the dam. Making such an important decision under uncertainty was difficult. This paper applied a dynamic decision-making framework for dam-break emergency management (DYDEM) to help rational decision in the emergency management of the Tangjiashan landslide dam. Three stages are identified with different levels of hydrological, geological and social-economic information along the timeline of the landslide dam failure event. The probability of dam failure is taken as a time series. The dam breaching parameters are predicted with a set of empirical models in stage 1 when no soil property information is known, and a physical model in stages 2 and 3 when knowledge of soil properties has been obtained. The flood routing downstream of the dam in these three stages is analyzed to evaluate the population at risk (PAR). The flood consequences, including evacuation costs, flood damage and monetized loss of life, are evaluated as functions of warning time using a human risk analysis model based on Bayesian networks. Finally, dynamic decision analysis is conducted to find the optimal time to evacuate the population at risk with minimum total loss in each of these three stages.

Trading river services: optimizing dam decisions at the basin scale to improve socio-ecological resilience

NASA Astrophysics Data System (ADS)

Roy, S. G.; Gold, A.; Uchida, E.; McGreavy, B.; Smith, S. M.; Wilson, K.; Blachly, B.; Newcomb, A.; Hart, D.; Gardner, K.

2017-12-01

Dam removal has become a cornerstone of environmental restoration practice in the United States. One outcome of dam removal that has received positive attention is restored access to historic habitat for sea-run fisheries, providing a crucial gain in ecosystem resilience. But dams also provide stakeholders with valuable services, and uncertain socio-ecological outcomes can arise if there is not careful consideration of the basin scale trade offs caused by dam removal. In addition to fisheries, dam removals can significantly affect landscape nutrient flux, municipal water storage, recreational use of lakes and rivers, property values, hydroelectricity generation, the cultural meaning of dams, and many other river-based ecosystem services. We use a production possibility frontiers approach to explore dam decision scenarios and opportunities for trading between ecosystem services that are positively or negatively affected by dam removal in New England. Scenarios that provide efficient trade off potentials are identified using a multiobjective genetic algorithm. Our results suggest that for many river systems, there is a significant potential to increase the value of fisheries and other ecosystem services with minimal dam removals, and further increases are possible by including decisions related to dam operations and physical modifications. Run-of-river dams located near the head of tide are often found to be optimal for removal due to low hydroelectric capacity and high impact on fisheries. Conversely, dams with large impoundments near a river's headwaters can be less optimal for dam removal because their value as nitrogen sinks often outweighs the potential value for fisheries. Hydropower capacity is negatively impacted by dam removal but there are opportunities to meet or exceed lost capacity by upgrading preserved hydropower dams. Improving fish passage facilities for dams that are critical for safety or water storage can also reduce impacts on fisheries. Our method is helpful for identifying efficient decision scenarios, but finding the optimal decision requires a deep and mutual understanding of stakeholder preferences. We outline how to interpret these preferences, identify overlaps with the efficient decision scenarios, and estimate the monetary budget required to act on these decisions.

Benthic macroinvertebrates as indicators of biological condition below hydropower dams on west slope Sierra Nevada streams, California, USA

EPA Science Inventory

Over 50 hydropower dams in California will undergo relicensing by the Federal Energy Regulatory Commission (FERC) in the next 15 years. An interpretive framework for biological data collected by relicensing studies is lacking. This study developed a multi-metric index of biotic...

Investigating Groundwater/Surface Water Interaction at the Diversion Dam Site: Report Documentary 2007-2008

DTIC Science & Technology

2011-05-01

operations, and soil properties. Key findings of this study indicate that soils within the study reach are conductive, with groundwater responding...16 3 Develop Detailed Map of Soils and Their Properties in Bosque Adjacent to...27 4 Evaluate Ecological Impact of River Levels, Soil Types, and Dam

Rubber dam isolation for restorative treatment in dental patients.

PubMed

Wang, Yan; Li, Chunjie; Yuan, He; Wong, May Cm; Zou, Jing; Shi, Zongdao; Zhou, Xuedong

2016-09-20

Successful restorations in dental patients depend largely on the effective control of moisture and microbes during the procedure. The rubber dam technique has been one of the most widely used isolation methods in dental restorative treatments. The evidence on the effects of rubber dam usage on the longevity of dental restorations is conflicting. Therefore, it is important to summarise the available evidence to determine the effects of this method. To assess the effects of rubber dam isolation compared with other types of isolation used for direct and indirect restorative treatments in dental patients. We searched the following electronic databases: Cochrane Oral Health's Trials Register (searched 17 August 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 7) in the Cochrane Library (searched 17 August 2016), MEDLINE Ovid (1946 to 17 August 2016), Embase Ovid (1980 to 17 August 2016), LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 17 August 2016), SciELO BIREME Virtual Health Library (1998 to 17 August 2016), Chinese BioMedical Literature Database (CBM, in Chinese) (1978 to 30 August 2016), VIP (in Chinese) (1989 to 30 August 2016), and China National Knowledge Infrastructure (CNKI, in Chinese) (1994 to 30 August 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, OpenGrey and Sciencepaper Online (in Chinese) for ongoing trials. There were no restrictions on the language or date of publication when searching the electronic databases. We included randomised controlled trials (including split-mouth trials) assessing the effects of rubber dam isolation for restorative treatments in dental patients. Two review authors independently screened the results of the electronic searches, extracted data and assessed the risk of bias of the included studies. We resolved disagreement by discussion. We included four studies that analysed 1270 participants (among which 233 participants were lost to follow-up). All the included studies were at high risk of bias. We excluded one trial from the analysis due to inconsistencies in the presented data.The results indicated that dental restorations had a significantly higher survival rate in the rubber dam isolation group compared to the cotton roll isolation group at six months in participants receiving composite restorative treatment of non-carious cervical lesions (risk ratio (RR) 1.19, 95% confidence interval (CI) 1.04 to 1.37, very low-quality evidence). It also showed that the rubber dam group had a lower risk of failure at two years in children undergoing proximal atraumatic restorative treatment in primary molars (hazard ratio (HR) 0.80, 95% CI 0.66 to 0.97, very low-quality evidence). One trial reported limited data showing that rubber dam usage during fissure sealing might shorten the treatment time. None of the included studies mentioned adverse effects or reported the direct cost of the treatment, or the level of patient acceptance/satisfaction. There was also no evidence evaluating the effects of rubber dam usage on the quality of the restorations. We found some very low-quality evidence, from single studies, suggesting that rubber dam usage in dental direct restorative treatments may lead to a lower failure rate of the restorations, compared with the failure rate for cotton roll usage. Further high quality research evaluating the effects of rubber dam usage on different types of restorative treatments is required.

The Impact of the Dachaoshan Dam on Seasonal Hydrological Dynamics in the Main Stream of the Mekong River

NASA Astrophysics Data System (ADS)

Kameyama, S.; Shimazaki, H.; Nohara, S.; Fukushima, M.; Kudo, K.; Sato, T.

2008-12-01

In the Mekong River watershed, traditional social and industrial systems have long existed in harmony with water and biological resources. Since the 1950s, many dam-construction projects have been started to develop power and water resources to meet increasing demand for energy and food production. Since the 1970s, there have been temporary interruptions to these projects because of civil war or regional volatility of international relations. Many of these projects have been restarted in the last 15 years. This raises international interest, as there are transboundary issues cross-border issues related to both development assistance and environmental conservation. By 2008, two Chinese dams had already been completed (the Manwan dam in 1996 and the Dachaoshan dam in 2003) on the Mekong River in Yunnan province. Dam construction has some positive impacts, such as electricity production, management of water resources, and flood control. However, upstream control of water discharge can have negative impacts on traditional agricultural systems and fisheries downstream from the dams, such as drastic changes in flow volume and sediment load. We used hydrological simulation of the watershed to quantify the impact of the construction of the Dachaoshan dam by comparing annual water discharge and sediment transport before and after the dam was completed. Our main objectives were to use watershed hydrologic modeling to simulate changes to annual hydrological parameters and sediment transport, and to map spatio-temporal changes of these data before and after dam construction. Our study area covered the part of the Mekong River main channel that extends about 100 km downstream from the junction of the borders of Myanmar, Thailand, and the Lao People's Democratic Republic. We used five data validation points at 25-km intervals along this section of the river and calculated model parameters every 1 km. The years we modeled were 1990 (began dam construction) and 2006 (after dam completed). We used the MIKE-SHE and MIKE11-Enterprise (developed by DHI) to calculate seasonal changes of water level, water velocity, and sediment transport. These models provided both water discharge and sediment transport dynamics at each modeled point along the river. The sediment budget was calculated as the difference of sediment load by volume between adjacent modeled points. All parameters used in the model were calibrated with field survey data; the river structure and water flows were measured in November 2007. To validate our simulated results we used historical water-level records from the towns of Chensean and Chencone. To determine the relationship between water discharge and sediment load, we analyzed the turbidity of monthly river water samples collected in the study region between November 2007 and November 2008. Our watershed runoff models simulated water discharge and sediment load at 1-km intervals and 1-h time steps for 1990 and 2006. The model results were compiled in GIS format and maps were produced to provide simple spatial displays of modeled parameters. Our simulations show that after construction of the dam, there was a moderate decrease in peak discharge volume and water velocity during the rainy season from August to September.

Juvenile Radio-Tag Study: Lower Granite Dam, 1985 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stuehrenberg, Lowell C.

The concept of using mass releases of juvenile radio tags represents a new and potentially powerful research tool that could be effectively applied to juvenile salmonid passage problems at dams on the Columbia and Snake Rivers. A system of detector antennas, strategically located, would automatically detect and record individually tagged juvenile salmonids as they pass through the spillway, powerhouse, bypass system, or tailrace areas below the dam. Accurate measurements of spill effectiveness, fish guiding efficiency (FGE), collection efficiency (CE), spillway survival, powerhouse survival, and bypass survival would be possible without handling large numbers of unmarked fish. A prototype juvenile radio-tagmore » system was developed and tested by the National Marine Fisheries Service (NMFS) and Bonneville Power Administration (BPA) at John Day Dam and at Lower Granite Dam. This report summarizes research to: (1) evaluate the effectiveness of the prototype juvenile radio-tag system in a field situation and (2) to test the basic assumptions inherent in using the juvenile radio tag as a research tool.« less

Estimating and Comparing Dam Deformation Using Classical and GNSS Techniques.

PubMed

Barzaghi, Riccardo; Cazzaniga, Noemi Emanuela; De Gaetani, Carlo Iapige; Pinto, Livio; Tornatore, Vincenza

2018-03-02

Global Navigation Satellite Systems (GNSS) receivers are nowadays commonly used in monitoring applications, e.g., in estimating crustal and infrastructure displacements. This is basically due to the recent improvements in GNSS instruments and methodologies that allow high-precision positioning, 24 h availability and semiautomatic data processing. In this paper, GNSS-estimated displacements on a dam structure have been analyzed and compared with pendulum data. This study has been carried out for the Eleonora D'Arborea (Cantoniera) dam, which is in Sardinia. Time series of pendulum and GNSS over a time span of 2.5 years have been aligned so as to be comparable. Analytical models fitting these time series have been estimated and compared. Those models were able to properly fit pendulum data and GNSS data, with standard deviation of residuals smaller than one millimeter. These encouraging results led to the conclusion that GNSS technique can be profitably applied to dam monitoring allowing a denser description, both in space and time, of the dam displacements than the one based on pendulum observations.

The effect of dam construction on the movement of dwarf caimans, Paleosuchus trigonatus and Paleosuchus palpebrosus, in Brazilian Amazonia.

PubMed

Campos, Zilca; Mourão, Guilherme; Magnusson, William E

2017-01-01

Run-of-the-river hydroelectric dams cause changes in seasonal inundation of the floodplains, and this may cause displacement of semi-aquatic vertebrates present before dam construction. This study evaluated the movement of crocodilians before and after the filling of the Santo Antônio hydroelectric reservoir on the Madeira River in the Brazilian Amazon, which occurred in November 2011. We radio-tracked four adult male Paleosuchus palpebrosus and four adult male Paleosuchus trigonatus before and after the formation of the reservoir between 2011 and 2013. The home ranges of the P. palpebrosus varied from < 1 km2 to 91 km2 and the home ranges of the P. trigonatus varied from < 1km2 to 5 km2. The species responded differently to time since filling and water level in weekly movement and home range. However, overall the dam appears to have had little effect on the use of space by the individuals that were present before dam construction.

Coastal change from a massive sediment input: Dam removal, Elwha River, Washington, USA

USGS Publications Warehouse

Warrick, Jonathan A.; Gelfenbaum, Guy R.; Stevens, Andrew; Miller, Ian M.; Kaminsky, George M.; Foley, Melissa M.

2015-01-01

The removal of two large dams on the Elwha River, Washington, provides an ideal opportunity to study coastal morphodynamics during increased sediment supply. The dam removal project exposed ~21 million cubic meters (~30 million tonnes) of sediment in the former reservoirs, and this sediment was allowed to erode by natural river processes. Elevated rates of sand and gravel sediment transport in the river occurred during dam removal. Most of the sediment was transported to the coast, and this renewed sediment supply resulted in hundreds of meters of seaward expansion of the river delta since 2011. Our most recent survey in January 2015 revealed that a cumulative ~3.5 million m3 of sediment deposition occurred at the delta since the beginning of the dam removal project, and that aggradation had exceeded 8 m near the river mouth. Some of the newly deposited sediment has been shaped by waves and currents into a series of subaerial berms that appear to move shoreward with time.

Accident study of torrential protective structures based on the French RTM database

NASA Astrophysics Data System (ADS)

Boncompain, Ingrid; Quefféléan, Yann; Carladous, Simon

2017-04-01

Torrential protective structures such as dikes, sediment traps, and check dams aim to reduce damage on elements at risk. They are built given a reference scenario. Nevertheless, this scenario can be exceeded or structures can fail because of their design or their ageing. We later talk about "accidents". The 1996 Aras disaster near Biescas (Spain) showed that consequences can be significant: 35 of 40 check dams were destroyed which involved 87 fatalities in a campsite. The accident probability and its consequences must be taken into account to analyze risk. Databases are useful tools to extract needed information. In France, the Restoration of Mountainous Areas department (RTM) has been public funded to develop a database, specific to mountainous areas (the Alps and the Pyrenees). Almost 12 500 check dams, 80 sediment traps and 600 dikes were registered in public forests in 2011. These samples were assumed significant for check dams and sediment traps but not for dikes because the most part was missing. In parallel, more than 31 000 torrential events were registered. Given these elements, an accident study was developed. We first extracted 1 925 events with accidents on protective structures: 39 % occurred during the 19th century and 53 % have occurred since 1900. Sediment traps were involved in 37 events, check dams in 336, and dikes in 1488. Then, a detailed analysis was specifically carried out for check dams. Event phenomena were extracted: torrential flood, liquid flood, snow avalanche, rock fall, and landslide. Accident typology was also specified: scouring, breaking of several check dams, total or partial destruction of one structure, overflowing. Causes of accidents on check dams were first analyzed. Torrential floods were responsible of 85 % of events (284 of 336) even if other phenomena must be also taken into account. Almost 45 % of events (152 of 336) involved total destruction of one or several check dams. Taking into account events for the last 150 years, 30 events were registered with destruction of several check dams: the annual probability of occurrence is 3.10-4. Analyzing consequences, only 11 of previously retained events (1925) were registered with fatalities. Finally, these quantitative elements were compared to qualitative feedback analysis from field practitioners and were illustrated with the 1987 Saint-Antoine event, in Modane. The total or partial destruction of 25 check dams released between 20 000 and 30 000 m3, which was one third of the estimated debris flow volume (85 000 m3) which damaged an industrial area. The lack of their maintenance partially explained this accident. As a conclusion, we must keep in mind that these results are limited to available data (all events have not been necessarily reported). Accidents on check dams are rare according to these data. It can be due to their general maintenance. This first analysis could be improved taking into account expert analysis, completing with information from other countries databases and formalizing the approach through a dependability analysis framework.

Does route of methamphetamine exposure during pregnancy have an impact on neonatal development and behaviour in rat offspring?

PubMed

McDonnell-Dowling, Kate; Kelly, John P

2016-04-01

Many preclinical studies have aimed to elucidate the effects of methamphetamine (MA) exposure during pregnancy on the offspring in recent years. However, the severity of effects on the neonate may be related to the subcutaneous (sc) route of administration of the drug that is often employed (88% of preclinical studies) and consequently the delivered dose that the foetus is exposed to. To date there is a paucity of comparative studies investigating different routes of administration for MA during pregnancy and it is not known how these different routes compare when it comes to neonatal outcome. Thus, the aim of this study was to determine if the route of administration of MA (oral gavage or sc injection) during pregnancy at a pharmacological dose affects the magnitude of neurodevelopmental and behavioural effects in the resultant rat offspring. Pregnant Sprague-Dawley dams (n=10 dams/group) received MA (3.75 mg/kg) or control (distilled water) via oral gavage or sc injection from gestation day 7-21. A range of well-recognised neurodevelopmental parameters were examined in the offspring. When administered sc, MA significantly reduced maternal weight gain and altered maternal behaviour; mothers spent less time in the nest with pups and spent less time nursing compared to controls. Significant impairments in neurodevelopmental parameters were evident in both MA treatment groups. Somatic development such as pinna unfolding, fur appearance and eye opening were all delayed after MA exposure but these impairments were more pronounced in the MA sc group. Other somatic parameters such as ano-genital distance and body length were only impeded by sc MA. Behavioural development in the surface righting, inclined plane and forelimb grip tests were also altered for both MA treatment groups. This study demonstrates that prenatal MA can have a profound effect on neonatal outcome, but this can be exacerbated if given via the subcutaneous route, as well as producing additional effects not seen with the oral gavage route. Consequently, the route of administration should be considered when interpreting preclinical studies investigating prenatal MA exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Familial occurrence of diprosopus in German Holstein calves].

PubMed

Schulze, Ursula; Kuiper, Heidi; Doeleke, Renate; Ulrich, Reiner; Gerdwilker, Axel; Distl, Ottmar

2006-01-01

Diprosopus was diagnosed in six German Holstein calves born on different dairy farms. The degree of facial duplication varied from a partial doubling of the nostrils and upper jaw to complete duplication of the face with formation of two mouths, four eyes and four ears. Further calves descending from the same parents or dams and calves from the same farms were not affected. A joint pedigree was ascertained for the calves with diprosopus. Furthermore, a previously reported case of diprosopus could be traced back to the same ancestors of this pedigree. Consequently, we detected the first time a familial accumulation of diprosopus. Since the ancestors showed no signs of diprosopus and the frequency of diprosopus in German Holsteins is presumably low, an oligogenic inheritance is likely. Recessive genes or a combination of recessive and dominant genes may cause this anomaly.

Brazil's Amazonian dams: Ecological and socioeconomic impacts

NASA Astrophysics Data System (ADS)

Fearnside, P. M.

2016-12-01

Brazil's 2015-2024 Energy Expansion Plan calls for 11 hydroelectric dams with installed capacity ≥ 30 MW in the country's Amazon region. Dozens of other large dams are planned beyond this time horizon, and dams with < 30 MW installed capacity number in the hundreds. Amazonian dams have substantial environmental and socioeconomic impacts. Loss of forest to flooding is one, the Balbina and Tucuruí Dams being examples (each 3000 km2). If the Babaquara/Altamira Dam is built it will flood as much forest as both of these combined. Some planned dams imply loss of forest in protected areas, for example on the Tapajós River. Aquatic and riparian ecosystems are lost, including unique biodiversity. Endemic fish species in rapids on the Xingu and Tapajós Rivers are examples. Fish migrations are blocked, such as the commercially important "giant catfish" of the Madeira River. Dams emit greenhouse gases, including CO2 from the trees killed and CH4 from decay under anoxic conditions at the bottom of reservoirs. Emissions can exceed those from fossil-fuel generation, particularly over the 20-year period during which global emissions must be greatly reduced to meet 1.5-2°C limit agreed in Paris. Carbon credit for dams under the Climate Convention causes further net emission because the dams are not truly "additional." Anoxic environments in stratified reservoirs cause methylation of mercury present in Amazonian soils, which concentrates in fish, posing a health risk to human consumers. Population displacement is a major impact; for example, the Marabá Dam would displace 40,000 people, mostly traditional riverside dwellers (ribeirinhos). Various dams impact indigenous peoples, such as the Xingu River dams (beginning with Belo Monte) and the São Luiz do Tapajós and Chacorão Dams on the Tapajós River. Brazil has many energy options other than dams. Much energy use has little benefit for the country, such as exporting aluminum. Electric showerheads use 5% of the country's power. Losses in transmission lines (20%) are far above global averages and can be expected to increase as Amazonian hydroelectric dams far from consumer centers come on line. Brazil has tremendous wind and solar potential, but these do not have the same priority as dams. At the root of many questionable policies is a decision-making process in need of reform.

75 FR 47808 - Alabama Municipal Electric Authority; Notice of Competing Preliminary Permit Application Accepted...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

..., proposing to study the feasibility of the George W. Andrews Lock and Dam Hydroelectric Project. The proposed project would be located at the existing George W. Andrews Lock and Dam on the Chattahoochee River in...

Mitigating Dam Impacts Using Environmental Flow Releases

NASA Astrophysics Data System (ADS)

Richter, B. D.

2017-12-01

One of the most ecologically disruptive impacts of dams is their alteration of natural river flow variability. Opportunities exist for modifying the operations of existing dams to recover many of the environmental and social benefits of healthy ecosystems that have been compromised by present modes of dam operation. The potential benefits of dam "re-operation" include recovery of fish, shellfish, and other wildlife populations valued both commercially and recreationally, including estuarine species; reactivation of the flood storage and water purification benefits that occur when floods are allowed to flow into floodplain forests and wetlands; regaining some semblance of the naturally dynamic balance between river erosion and sedimentation that shapes physical habitat complexity, and arresting problems associated with geomorphic imbalances; cultural and spiritual uses of rivers; and many other socially valued products and services. Assessing the potential benefits of dam re-operation begins by characterizing the dam's effects on the river flow regime, and formulating hypotheses about the ecological and social benefits that might be restored by releasing water from the dam in a manner that more closely resembles natural flow patterns. These hypotheses can be tested by implementing a re-operation plan, tracking the response of the ecosystem, and continually refining dam operations through adaptive management. This presentation will highlight a number of land and water management strategies useful in implementing a dam re-operation plan, with reference to a variety of management contexts ranging from individual dams to cascades of dams along a river to regional energy grids. Because many of the suggested strategies for dam re-operation are predicated on changes in the end-use of the water, such as reductions in urban or agricultural water use during droughts, a systemic perspective of entire water management systems will be required to attain the fullest possible benefits of dam re-operations.

Large-scale dam removal on the Elwha River, Washington, USA: source-to-sink sediment budget and synthesis

USGS Publications Warehouse

Warrick, Jonathan A.; Bountry, Jennifer A.; East, Amy E.; Magirl, Christopher S.; Randle, Timothy J.; Gelfenbaum, Guy R.; Ritchie, Andrew C.; Pess, George R.; Leung, Vivian; Duda, Jeff J.

2015-01-01

Understanding landscape responses to sediment supply changes constitutes a fundamental part of many problems in geomorphology, but opportunities to study such processes at field scales are rare. The phased removal of two large dams on the Elwha River, Washington, exposed 21 ± 3 million m3, or ~ 30 million tonnes (t), of sediment that had been deposited in the two former reservoirs, allowing a comprehensive investigation of watershed and coastal responses to a substantial increase in sediment supply. Here we provide a source-to-sink sediment budget of this sediment release during the first two years of the project (September 2011–September 2013) and synthesize the geomorphic changes that occurred to downstream fluvial and coastal landforms. Owing to the phased removal of each dam, the release of sediment to the river was a function of the amount of dam structure removed, the progradation of reservoir delta sediments, exposure of more cohesive lakebed sediment, and the hydrologic conditions of the river. The greatest downstream geomorphic effects were observed after water bodies of both reservoirs were fully drained and fine (silt and clay) and coarse (sand and gravel) sediments were spilling past the former dam sites. After both dams were spilling fine and coarse sediments, river suspended-sediment concentrations were commonly several thousand mg/L with ~ 50% sand during moderate and high river flow. At the same time, a sand and gravel sediment wave dispersed down the river channel, filling channel pools and floodplain channels, aggrading much of the river channel by ~ 1 m, reducing river channel sediment grain sizes by ~ 16-fold, and depositing ~ 2.2 million m3 of sand and gravel on the seafloor offshore of the river mouth. The total sediment budget during the first two years revealed that the vast majority (~ 90%) of the sediment released from the former reservoirs to the river passed through the fluvial system and was discharged to the coastal waters, where slightly less than half of the sediment was deposited in the river-mouth delta. Although most of the measured fluvial and coastal deposition was sand-sized and coarser (> 0.063 mm), significant mud deposition was observed in and around the mainstem river channel and on the seafloor. Woody debris, ranging from millimeter-size particles to old-growth trees and stumps, was also introduced to fluvial and coastal landforms during the dam removals. At the end of our two-year study, Elwha Dam was completely removed, Glines Canyon Dam had been 75% removed (full removal was completed 2014), and ~ 65% of the combined reservoir sediment masses—including ~ 8 Mt of fine-grained and ~ 12 Mt of coarse-grained sediment—remained within the former reservoirs. Reservoir sediment will continue to be released to the Elwha River following our two-year study owing to a ~ 16 m base level drop during the final removal of Glines Canyon Dam and to erosion from floods with larger magnitudes than occurred during our study. Comparisons with a geomorphic synthesis of small dam removals suggest that the rate of sediment erosion as a percent of storage was greater in the Elwha River during the first two years of the project than in the other systems. Comparisons with other Pacific Northwest dam removals suggest that these steep, high-energy rivers have enough stream power to export volumes of sediment deposited over several decades in only months to a few years. These results should assist with predicting and characterizing landscape responses to future dam removals and other perturbations to fluvial and coastal sediment budgets.

National Program of Inspection of Non-Federal Dams.

DTIC Science & Technology

1982-05-01

actions to improve the .;,.fety of Federal dams . 3 B. PROGRAM REVITALIZATION Subsequent to the failure of the Teton Dam , near Newdale, Idaho, in June...development of hydrostatic heads sufficient to create in the area downstream of the dam sand boils that erode materials by the phenomenon known as " piping " and...Eh irmmhhhommlm mhhhhmmmmhhlo US Arm op National Program of Inspection of Non-Federal Dams Final Report to Congress The National Dam Inspection Act of

Performance of Koyna dam based on static and dynamic analysis

NASA Astrophysics Data System (ADS)

Azizan, Nik Zainab Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar

2017-10-01

This paper discusses the performance of Koyna dam based on static pushover analysis (SPO) and incremental dynamic analysis (IDA). The SPO in this study considered two type of lateral load which is inertial load and hydrodynamic load. The structure was analyse until the damage appears on the structure body. The IDA curves were develop based on 7 ground motion, where the characteristic of the ground motions: i) the distance from the epicenter is less than 15km, (ii) the magnitude is equal to or greater than 5.5 and (iii) the PGA is equal to or greater than 0.15g. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. Elastic respond spectrum developed based on soil type B by using Eurocode 8. By using SPO and IDA method are able to determine the limit states of the dam. The limit state proposed in this study are yielding and ultimate state which is identified base on crack pattern perform on the structure model. The comparison of maximum crest displacement for both methods is analysed to define the limit state of the dam. The displacement of yielding state for Koyna dam is 23.84mm and 44.91mm for the ultimate state. The results are able to be used as a guideline to monitor Koyna dam under seismic loadings which are considering static and dynamic.

Study of the optical properties and the carbonaceous clusters in DAM-ADC solid state nuclear track detectors

NASA Astrophysics Data System (ADS)

Rammah, Y. S.; Abdalla, A. M.

2017-12-01

The optical properties of DAM-ADC solid state nuclear track detectors (SSNTDs) were investigated. Samples of DAM-ADC detector were irradiated at room temperature with gamma doses in the range of 100-500 kGy using 1.25 MeV 60Co source of dose rate 4 kGy/h. The optical characterization of these detectors have been studied through the measurements of UV-visible absorption spectra of blank and γ- irradiated samples. The optical energy band gaps, Eg for the detectors were obtained from the direct and the indirect allowed transitions in K-space using two methods (Tauc's model and absorption spectrum fitting (ASF) method). The absorbance of DAM-ADC detector was found to increase with increasing of the gamma absorbed dose. The width of the tail of localized states in the band gap, Eu was evaluated with the Urbach's method. The number of carbon atoms per conjugated length (N), the number of carbon atoms per cluster (M), and refractive index (n) for the present samples were determined. Both of the direct and the indirect band gaps of DAM-ADC detector decrease with increasing of the gamma absorbed dose. Urbach's energy decreased significantly for the detector. An increase in N, M, and n with increasing of the gamma absorbed dose was noticed. Results shed light on the effect of gamma irradiations of DAM-ADC SSNTDs to suitable industrial applications and to modify the optical properties through gamma-induced modifications of the polymer structure.

Synthesis of the effects to fish species of two management scenarios for the secretarial determination on removal of the lower four dams on the Klamath

USGS Publications Warehouse

Hamilton,; Rondorf, Dennis W.; Hampton,; Quinones,; Simondet,; Smith,

2011-01-01

For decades the long-standing conflict in the Klamath River Basin over water and fish resources has persisted. In an effort to resolve these disputes, PacifiCorp and interested parties negotiated, wrote, and signed the Klamath Hydroelectric Settlement Agreement (KHSA) in 2010, calling for the potential removal of the four lower dams on the Klamath River mainstem. The KHSA established a process known as the Secretarial Determination, which includes 1) conducting new scientific studies and a re-evaluation of existing studies found in the FERC record and from other sources, and 2) evaluating the potential environmental and human effects of such an action pursuant to National Environmental Policy Act, California Environmental Quality Act, and other applicable laws.  In March 2012, the Secretary of the Interior will decide whether removal of these dams on the Klamath River: 1) will advance salmonid fisheries, and 2) is in the public interest. In this report, we summarize anticipated effects to fish resources under two management scenarios: 1) current conditions with dams in place and without the programs and actions in the Klamath Basin Restoration Agreement (KBRA), and 2) removal of the lower four dams plus programs and actions called for in the KBRA and KHSA. This information will aid the Secretary of the Interior in determining whether dam removal and implementation of KBRA will advance restoration of salmonid (salmon and trout) fisheries.

Meta-analysis of environmental effects of beaver in relation to artificial dams

NASA Astrophysics Data System (ADS)

Ecke, Frauke; Levanoni, Oded; Audet, Joachim; Carlson, Peter; Eklöf, Karin; Hartman, Göran; McKie, Brendan; Ledesma, José; Segersten, Joel; Truchy, Amélie; Futter, Martyn

2017-11-01

Globally, artificial river impoundment, nutrient enrichment and biodiversity loss impair freshwater ecosystem integrity. Concurrently, beavers, ecosystem engineers recognized for their ability to construct dams and create ponds, are colonizing sites across the Holarctic after widespread extirpation in the 19th century, including areas outside their historical range. This has the potential to profoundly alter hydrology, hydrochemistry and aquatic ecology in both newly colonized and recolonized areas. To further our knowledge of the effects of beaver dams on aquatic environments, we extracted 1366 effect sizes from 89 studies on the impoundment of streams and lakes. Effects were assessed for 16 factors related to hydrogeomorphology, biogeochemistry, ecosystem functioning and biodiversity. Beaver dams affected concentrations of organic carbon in water, mercury in water and biota, sediment conditions and hydrological properties. There were no overall adverse effects caused by beaver dams or ponds on salmonid fish. Age was an important determinant of effect magnitude. While young ponds were a source of phosphorus, there was a tendency for phosphorus retention in older systems. Young ponds were a source methylmercury in water, but old ponds were not. To provide additional context, we also evaluated similarities and differences between environmental effects of beaver-constructed and artificial dams (767 effect sizes from 75 studies). Both are comparable in terms of effects on, for example, biodiversity, but have contrasting effects on nutrient retention and mercury. These results are important for assessing the role of beavers in enhancing and/or degrading ecological integrity in changing Holarctic freshwater systems.

Barriers impede upstream spawning migration of flathead chub

USGS Publications Warehouse

Walters, David M.; Zuellig, Robert E.; Crockett, Harry J.; Bruce, James F.; Lukacs, Paul M.; Fitzpatrick, Ryan M.

2014-01-01

Many native cyprinids are declining throughout the North American Great Plains. Some of these species require long reaches of contiguous, flowing riverine habitat for drifting eggs or larvae to develop, and their declining populations have been attributed to habitat fragmentation or barriers (e.g., dams, dewatered channels, and reservoirs) that restrict fish movement. Upstream dispersal is also needed to maintain populations of species with passively drifting eggs or larvae, and prior researchers have suggested that these fishes migrate upstream to spawn. To test this hypothesis, we conducted a mark–recapture study of Flathead Chub Platygobio gracilis within a 91-km reach of continuous riverine habitat in Fountain Creek, Colorado. We measured CPUE, spawning readiness (percent of Flathead Chub expressing milt), and fish movement relative to a channel-spanning dam. Multiple lines of evidence indicate that Flathead Chub migrate upstream to spawn during summer. The CPUE was much higher at the base of the dam than at downstream sites; the seasonal increases in CPUE at the dam closely tracked seasonal increases in spawning readiness, and marked fish moved upstream as far as 33 km during the spawning run. The upstream migration was effectively blocked by the dam. The CPUE of Flathead Chub was much lower upstream of the OHDD than at downstream sites, and <0.2% of fish marked at the dam were recaptured upstream. This study provides the first direct evidence of spawning migration for Flathead Chub and supports the general hypothesis that barriers limit adult dispersal of these and other plains fishes.

Increased renal sympathetic nerve activity leads to hypertension and renal dysfunction in offspring from diabetic mothers.

PubMed

de Almeida Chaves Rodrigues, Aline Fernanda; de Lima, Ingrid Lauren Brites; Bergamaschi, Cássia Toledo; Campos, Ruy Ribeiro; Hirata, Aparecida Emiko; Schoorlemmer, Guus Hermanus Maria; Gomes, Guiomar Nascimento

2013-01-15

The exposure of the fetus to a hyperglycemic environment promotes the development of hypertension and renal dysfunction in the offspring at adult age. We evaluated the role of renal nerves in the hypertension and renal changes seen in offspring of diabetic rats. Diabetes was induced in female Wistar rats (streptozotocin, 60 mg/kg ip) before mating. Male offspring from control and diabetic dams were studied at an age of 3 mo. Systolic blood pressure measured by tail cuff was increased in offspring of diabetic dams (146 ± 1.6 mmHg, n = 19, compared with 117 ± 1.4 mmHg, n = 18, in controls). Renal function, baseline renal sympathetic nerve activity (rSNA), and arterial baroreceptor control of rSNA were analyzed in anesthetized animals. Glomerular filtration rate, fractional sodium excretion, and urine flow were significantly reduced in offspring of diabetic dams. Two weeks after renal denervation, blood pressure and renal function in offspring from diabetic dams were similar to control, suggesting that renal nerves contribute to sodium retention in offspring from diabetic dams. Moreover, basal rSNA was increased in offspring from diabetic dams, and baroreceptor control of rSNA was impaired, with blunted responses to infusion of nitroprusside and phenylephrine. Thus, data from this study indicate that in offspring from diabetic mothers, renal nerves have a clear role in the etiology of hypertension; however, other factors may also contribute to this condition.

Understanding the Amazon Hydrology for Sustainable Hydropower Development

NASA Astrophysics Data System (ADS)

Pokhrel, Y. N.; Chaudhari, S. N.

2017-12-01

Construction of 147 new hydropower dams, many of which are large, has been proposed in the Amazon river basin, despite the continuous stacking of negative impacts from the existing ones. These dams are continued to be built in a way that disrupts river ecology, causes large-scale deforestation, and negatively affects both the food systems nearby and downstream communities. In this study, we explore the impacts of the existing and proposed hydropower dams on the hydrological fluxes across the Amazonian Basin by incorporating human impact modules in an extensively validated regional hydrological model called LEAF-Hydro-Flood (LHF). We conduct two simulations, one in offline mode, forced by observed meteorological data for the historical period of 2000-2016 and the other in a coupled mode using the Weather Research and Forecasting (WRF) regional climate model. We mainly analyze terrestrial water storage and streamflow changes during the period of dam operations with and without human impacts. It is certain that the Amazon will undergo some major hydrological changes such as decrease in streamflow downstream in the coming decades caused due to these proposed dams. This study helps us understand and represent processes in a predictable manner, and provides the ability to evaluate future scenarios with dams and other major human influences while considering climate change in the basin. It also provides important insights on how to redesign the hydropower systems to make them truly renewable in terms of energy production, hydrology and ecology.

30 CFR 715.18 - Dams constructed of or impounding waste material.

Code of Federal Regulations, 2011 CFR

2011-07-01

... existing or new dams without the approval of the regulatory authority. The permittee shall design, locate... design precipitation event within 10 days. (viii) During construction of dams subject to this section... adjacent to each dam within 30 days of certification of design pursuant to this section. (4) All dams...

75 FR 30805 - Gibson Dam Hydroelectric Company, LLC; Notice Soliciting Comments, and Final Terms and Conditions...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 12478-003] Gibson Dam... of Application: Major Project--Existing Dam. b. Project No.: P-12478-003. c. Date filed: August 28, 2009. d. Applicant: Gibson Dam Hydroelectric Company, LLC. e. Name of Project: Gibson Dam Hydroelectric...

SpDamID: Marking DNA Bound by Protein Complexes Identifies Notch-Dimer Responsive Enhancers

PubMed Central

Hass, Matthew R.; Liow, Hien-haw; Chen, Xiaoting; Sharma, Ankur; Inoue, Yukiko U.; Inoue, Takayoshi; Reeb, Ashley; Martens, Andrew; Fulbright, Mary; Raju, Saravanan; Stevens, Michael; Boyle, Scott; Park, Joo-Seop; Weirauch, Matthew T.; Brent, Michael; Kopan, Raphael

2015-01-01

SUMMARY We developed Split DamID (SpDamID), a protein complementation version of DamID, to mark genomic DNA bound in vivo by interacting or juxtapositioned transcription factors. Inactive halves of DAM (DNA Adenine Methyltransferase) were fused to protein pairs to be queried Interaction or proximity enabled DAM reconstitution and methylation of adenine in GATC. Inducible SpDamID was used to analyze Notch-mediated transcriptional activation. We demonstrate that Notch complexes label RBP sites broadly across the genome, and show that a subset of these complexes that recruit MAML and p300 undergo changes in chromatin accessibility in response to Notch signaling. SpDamID differentiates between monomeric and dimeric binding thereby allowing for identification of half-site motifs used by Notch dimers. Motif enrichment of Notch enhancers coupled with SpDamID reveals co-targeting of regulatory sequences by Notch and Runx1. SpDamID represents a sensitive and powerful tool that enables dynamic analysis of combinatorial protein-DNA transactions at a genome-wide level. PMID:26257285

Understanding the Role of Reservoir Size on Probable Maximum Precipitation

NASA Astrophysics Data System (ADS)

Woldemichael, A. T.; Hossain, F.

2011-12-01

This study addresses the question 'Does surface area of an artificial reservoir matter in the estimation of probable maximum precipitation (PMP) for an impounded basin?' The motivation of the study was based on the notion that the stationarity assumption that is implicit in the PMP for dam design can be undermined in the post-dam era due to an enhancement of extreme precipitation patterns by an artificial reservoir. In addition, the study lays the foundation for use of regional atmospheric models as one way to perform life cycle assessment for planned or existing dams to formulate best management practices. The American River Watershed (ARW) with the Folsom dam at the confluence of the American River was selected as the study region and the Dec-Jan 1996-97 storm event was selected for the study period. The numerical atmospheric model used for the study was the Regional Atmospheric Modeling System (RAMS). First, the numerical modeling system, RAMS, was calibrated and validated with selected station and spatially interpolated precipitation data. Best combinations of parameterization schemes in RAMS were accordingly selected. Second, to mimic the standard method of PMP estimation by moisture maximization technique, relative humidity terms in the model were raised to 100% from ground up to the 500mb level. The obtained model-based maximum 72-hr precipitation values were named extreme precipitation (EP) as a distinction from the PMPs obtained by the standard methods. Third, six hypothetical reservoir size scenarios ranging from no-dam (all-dry) to the reservoir submerging half of basin were established to test the influence of reservoir size variation on EP. For the case of the ARW, our study clearly demonstrated that the assumption of stationarity that is implicit the traditional estimation of PMP can be rendered invalid to a large part due to the very presence of the artificial reservoir. Cloud tracking procedures performed on the basin also give indication of the formation of mesoscale convective systems (MCS) in the vicinity of dams/reservoirs that may have explicitly been triggered by their presence. The significance of this finding is that water resources managers need to consider the post-dam impact of water cycle and local climate due to the very reservoir and land use change triggered if efficient water resources management is desired. Future works of the study will include incorporation of the anthropogenic changes that occur as a result of the presence of dams/reservoirs in the forms of irrigation, urbanization and downstream wetland reduction. Similar hypothesis testing procedures will be applied to understand the combined effects of the reservoir size variation and anthropogenic changes in the extreme precipitation patterns.

Sedimentology of new fluvial deposits on the Elwha River, Washington, USA, formed during large-scale dam removal

USGS Publications Warehouse

Draut, Amy; Ritchie, Andrew C.

2015-01-01

Removal of two dams 32 m and 64 m high on the Elwha River, Washington, USA, provided the first opportunity to examine river response to a dam removal and controlled sediment influx on such a large scale. Although many recent river-restoration efforts have included dam removal, large dam removals have been rare enough that their physical and ecological effects remain poorly understood. New sedimentary deposits that formed during this multi-stage dam removal result from a unique, artificially created imbalance between fluvial sediment supply and transport capacity. River flows during dam removal were essentially natural and included no large floods in the first two years, while draining of the two reservoirs greatly increased the sediment supply available for fluvial transport. The resulting sedimentary deposits exhibited substantial spatial heterogeneity in thickness, stratal-formation patterns, grain size and organic content. Initial mud deposition in the first year of dam removal filled pore spaces in the pre-dam-removal cobble bed, potentially causing ecological disturbance but not aggrading the bed substantially at first. During the second winter of dam removal, thicker and in some cases coarser deposits replaced the early mud deposits. By 18 months into dam removal, channel-margin and floodplain deposits were commonly >0.5 m thick and, contrary to pre-dam-removal predictions that silt and clay would bypass the river system, included average mud content around 20%. Large wood and lenses of smaller organic particles were common in the new deposits, presumably contributing additional carbon and nutrients to the ecosystem downstream of the dam sites. Understanding initial sedimentary response to the Elwha River dam removals will inform subsequent analyses of longer-term sedimentary, geomorphic and ecosystem changes in this fluvial and coastal system, and will provide important lessons for other river-restoration efforts where large dam removal is planned or proposed.

Geophysical Investigations at Hidden Dam, Raymond, California: Summary of Fieldwork and Data Analysis

USGS Publications Warehouse

Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

2010-01-01

Geophysical field investigations have been carried out at the Hidden Dam in Raymond, California for the purpose of better understanding the hydrogeology and seepage-related conditions at the site. Known seepage areas on the northwest right abutment area of the downstream side of the dam are documented by Cedergren. Subsequent to the 1980 seepage study, a drainage blanket with a subdrain system was installed to mitigate downstream seepage. Flow net analysis provided by Cedergren suggests that the primary seepage mechanism involves flow through the dam foundation due to normal reservoir pool elevations, which results in upflow that intersects the ground surface in several areas on the downstream side of the dam. In addition to the reservoir pool elevations and downstream surface topography, flow is also controlled by the existing foundation geology as well as the presence or absence of a horizontal drain within the downstream portion of the dam. The purpose of the current geophysical work is to (1) identify present-day seepage areas that may not be evident due to the effectiveness of the drainage blanket in redirecting seepage water, and (2) provide information about subsurface geologic structures that may control subsurface flow and seepage. These tasks are accomplished through the use of two complementary electrical geophysical methods, self-potentials (SP) and direct-current (DC) electrical resistivity, which have been commonly utilized in dam-seepage studies. SP is a passive method that is primarily sensitive to active subsurface groundwater flow and seepage, whereas DC resistivity is an active-source method that is sensitive to changes in subsurface lithology and groundwater saturation. The focus of this field campaign was on the downstream area on the right abutment, or northwest side of the dam, as this is the main area of interest regarding seepage. Two exploratory self-potential lines were also collected on the downstream left abutment of the dam to identify potential seepage in that area. This report is primarily a summary of the field geophysical data acquisition, with some preliminary results and interpretation. Further work will involve a more rigorous analysis of the geophysical datasets and an examination of a large dataset of historical observations of water levels in a number of observation wells and piezometers compared with reservoir elevation. In addition, a partially saturated flow model will be developed to better understand seepage patterns given the available information about dam construction, geophysical results, and data from installed observation wells and piezometers.

Damming the rivers of the Amazon basin

NASA Astrophysics Data System (ADS)

Latrubesse, Edgardo M.; Arima, Eugenio Y.; Dunne, Thomas; Park, Edward; Baker, Victor R.; D'Horta, Fernando M.; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A.; Ribas, Camila C.; Norgaard, Richard B.; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C.

2017-06-01

More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin’s floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

Damming the rivers of the Amazon basin.

PubMed

Latrubesse, Edgardo M; Arima, Eugenio Y; Dunne, Thomas; Park, Edward; Baker, Victor R; d'Horta, Fernando M; Wight, Charles; Wittmann, Florian; Zuanon, Jansen; Baker, Paul A; Ribas, Camila C; Norgaard, Richard B; Filizola, Naziano; Ansar, Atif; Flyvbjerg, Bent; Stevaux, Jose C

2017-06-14

More than a hundred hydropower dams have already been built in the Amazon basin and numerous proposals for further dam constructions are under consideration. The accumulated negative environmental effects of existing dams and proposed dams, if constructed, will trigger massive hydrophysical and biotic disturbances that will affect the Amazon basin's floodplains, estuary and sediment plume. We introduce a Dam Environmental Vulnerability Index to quantify the current and potential impacts of dams in the basin. The scale of foreseeable environmental degradation indicates the need for collective action among nations and states to avoid cumulative, far-reaching impacts. We suggest institutional innovations to assess and avoid the likely impoverishment of Amazon rivers.

Evaluation of two low-flow releases from Big Tujunga Reservoir, Los Angeles County, California, 2003

USGS Publications Warehouse

Mendez, Gregory O.

2005-01-01

Since 1973, the Santa Ana Sucker (Catostomus santaanae) has been listed as a threatened species under the Endangered Species Act. The Lower Big Tujunga Creek, in Los Angeles County, is one of the areas in southern California where the Santa Ana Sucker is still present. This study was designed to assess two flow releases from Big Tujunga Dam that may contribute to favorable habitat conditions for the Santa Ana Sucker. It is important for the Santa Ana Sucker's survival that pools in the lower reach of the study area are replenished periodically. The focus of the study area was on the Lower Big Tujunga Creek within a reach extending approximately 6 miles downstream from the Big Tujunga Reservoir. Six sites were established from the Big Tujunga Dam to Delta Flats day-use area for data collection. This report describes the study design, discharge measurements, and the flow data collected from the two releases. Two scheduled flows (phases 1 and 2) were released from the Big Tujunga Reservoir in August and September 2003. During the first phase, which lasted 50 hours, travel times from the dam to four sites downstream were determined. Arrival times at the four sites were determined on the basis of temperature data. Travel time from the dam to site 6 (the furthest downstream site) was about 51.5 hours. Travel times for subreaches were 3 hours from site 1 to site 2, 6.5 hours from site 2 to site 3, almost 18 hours from site 3 to site 4, and 24 hours from site 4 to site 6. The temperature probe at site 5 was destroyed, and thus the arrival time could not be estimated. A probe that measures stage was placed in one of the many pools downstream from site 4 to evaluate a typical pool response to a low-flow release. Also, discharge measurements were taken at four sites along the study reach. In phase 2, which lasted 5 days (121 hours), flow losses along the 6-mile reach were analyzed. Losses were estimated by measuring difference in flow from the dam to sites 3, 4, 5, and 6, when flow was most stable at each site or when the last measurement made before flow decreased due to flow from dam being shut off. Losses in the plunge pool, directly below the dam were assumed to be negligible for this study. Overall creek loss between the dam and site 6 (the last site) was estimated to be between 4.0 and 4.2 ft3/s (cubic feet per second). Estimated losses between the dam and intermediate sites were about 1.5 ft3/s to site 3; 2.5 ft3/s to site 4; and between 3.7 and 4.1 ft3/s to site 5.

Behavioural interactions between West African dwarf nanny goats and their single-born kids during the first 48 hours post-partum.

PubMed

Addae; Awotwi; Oppong-Anane; Oddoye

2000-03-22

West African dwarf nanny goats and their single-born kids were tested to find out their behavioural response to separation and their mutual recognition during the first 48 h post-partum. The tests were conducted at 18, 24, 36 or 48 h post partum. Chi-square analyses were used to determine whether age, sex and birth weight of kids as well as h partum and parity of dams had an effect on post-partum bahaviours.In a preliminary study where the kids were not prevented from sucking prior to the tests, the majority of kids (93%) and does (86%) exhibited apparant minimal concern to separation (i.e., had scores of less than 3) and also failed to seek each other. When the kids were prevented from sucking 2 h prior to the tests, the couple showed some response to separation and made attempts to seek each other. This suggests that in goats the state of the neonate's nourishment and the fullness of the dam's udder may be important factors that determine the willingness of the kid and the dam to seek each other when separated. The behavioural response of 48-h-old kids to separation from their dams when they had not sucked for 2 h was significantly higher (P<0.05) than that of 18-h-old kids. The sex and birth-weight of 48-h-old kids did not affect their response to separation from their dams. Hours post-partum and parity of does did not affect their response to separation from their kids even though the proportion of does exhibiting the highest response was much higher in primiparous then multiparous animals (44% vs. 13%). Recognition of dams by kids was poor at 18 and 24 h with more than half (71%) the kids failing to recognize their dams. Dam recognition ability improved with age and at 48 h the majority of kids (88%) were able to recognize their dams. Does tested at 48 h post partum had better (P0.05) kid recognition than those tested at 18 and 24 h. The sex and birth weight of kids and the parity of dams had no effect on the mutual recognition of kids and their dams at 48 h post-partum.

Analysis of the typical small watershed of warping dams in the sand properties

NASA Astrophysics Data System (ADS)

Li, Li; Yang, Ji Shan; Sun, Wei Ying; Shen, Sha Sha

2018-06-01

Coarse sediment with a particle size greater than 0.05mm is the main deposit of riverbed in the lower Yellow River, the Loess Plateau is one of the concentrated source of coarse sediment, warping dam is one of the important engineering measures for gully control. Jiuyuangou basin is a typical small basin in the first sub region of hilly-gullied loess region, twenty warping dams in Jiuyuangou basin was selected as research object, samples of sediment along the main line of dam from upper, middle to lower reaches of dam fields and samples of undisturbed soil in slope of dam control basin were taken to carry out particle gradation analysis, in the hope of clearing reducing capacity on coarse sediment of different types of warping dam through the experimental data. The results show that the undisturbed soil in slope of dam control basin has characteristics of standard loess, the particle size are mainly distributed in 0.025 0.05mm, and the 0.05mm particle size of Jiuyuangou basinof loess is an obvious boundary; Particle size of sediment in 15 warping dam of Jiuyuangou basin are mainly distributed in 0.031 0.05mm with the dam tail is greater than dam front in general. The separation effect of horizontal pipe drainage is better than shaft drainage for which particle size greater than 0.05mm, notch dam is for particle size between 0.025 0.1 mm, and fill dam is for particle size between 0.016 0.1 mm, they all have a certain function in the sediment sorting.

Innovative resettlement schemes planned for the Numata Dam project

NASA Astrophysics Data System (ADS)

Nakayama, Mikiyasu

2003-10-01

The Numata Dam, planned for the Tone River basin of Gunma Prefecture, was the largest dam construction project ever considered in Japan. This dam construction project, however, did not materialize. The proposal for the Numata Dam was first launched in 1959, at a time when the Tokyo Metropolitan area was mushrooming, both in population and industrial activity. The Numata Dam was supposed to be a prioritized dam construction project to alleviate the then anticipated water shortage in the Tokyo Metropolitan area. The Numata Dam plan experienced fierce opposition from those who would have been obliged to resettle, whereas those in Tokyo and the surrounding metropolitan area welcomed the plan. The major concern of the planned Numata Dam was the number of resettlers, which was then estimated to be around 3000 families. The resettlement plan developed for the Numata Dam included some innovative concepts, which may be applicable even today, for dam construction projects in the developing world. The plan included such ideas as (a) having resettlers share existing farmland with the present owners provided improvements were made to increase productivity, (b) paying rent to resettlers, and (c) establishing the Tone River Development Agency. After more than a decade of debate, both at national and local levels, the Numata Dam project was finally discarded through a decision of the Prime Minister in 1972. The resettlement schemes elaborated for the Numata Dam still appear to be innovative. Such schemes may be applied to projects in the developing world, in particular, in nations that are about to take off with economic development. Copyright

Murine lethal milk mutation causes maternal accumulation of zinc in intestine and kidney and reduced zinc transport to milk

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dohyeel Lee; Cousins, R.J.

1991-03-15

The lethal milk (Lm) mutation is autosomal recessive in C57BL/6J mice and causes Zn deficiency in pups nursed by Lm dams. The genetic defect may cause a shift in the tissue Zn distribution in Lm dams since their milk has a 34-45% lower Zn concentration than milk of normal (N) dams. To examine tissue Zn distribution and Zn transport to milk and pups, 1 {mu}Ci of {sup 65}Zn was administered ip to lactating N and Lm dams. They also received 800 {mu}g Zn/ml in their drinking water to preclude short term, terminal zinc deficiency in the neonates nursed by Lmmore » dams. {sup 65}Zn content of milk and tissues of dams and tissues of pups was measured. Transport of {sup 65}Zn to milk of Lm dams was about 50% compared to milk of N dams. The percentage of the {sup 65}Zn dose recovered in the intestine, liver, and kidney of N pups nursed by LM dams was markedly lower than those of N pups nursed by N dams. In contrast, the percentage of {sup 65}Zn in the intestine and kidney of Lm dams was about twice that of N dams. The elevated intestinal {sup 65}Zn was paralleled by and elevated metallothionein concentration, but the increased {sup 65}Zn in the kidney was not. The Lm gene defect might limit Zn transport to milk by shifting the Zn distribution in lactating dams to the intestine, kidney, and perhaps other tissues.« less

Development of the Circadian Timing System in Rat Pups Exposed to Microgravity during Gestation

NASA Technical Reports Server (NTRS)

Fuller, Charles A.

2000-01-01

Ten pregnant Sprague Dawley rat dams were exposed to spaceflight aboard the Space Shuttle (STS-70) for gestational days 11-20 (G 11-20; FILT group). Control dams were maintained in either a flight-like (FIDS group) or vivarium cage environment (VIV group) on earth. All dams had ad lib access to food and water and were exposed to a light-dark cycle consisting of 12 hours of light (- 30 lux) followed by 12 hours of darkness. The dams were closely monitored from G 22 until parturition. All pups were cross-fostered at birth; each foster dam had a litter of 10 pups. Pups remained with their foster dam until post-natal day 21 (PN 21). Pup body mass was measured twice weekly. At PN14 FILT pups had a smaller body mass than did the VIV pups (p < 0.01). Circadian rhythms of body temperature and activity of pups from two FILT dams (n = 8), two FIDS dams (n = 9) and two VIV dams (n = 7) were studied starting from age PN 21. All pups had circadian rhythms of temperature and activity at this age. There were no significant differences in rhythms between groups that could be attributed to microgravity exposure. We also examined the development of neural structures involved in circadian rhythmicity: the retina, the intergeniculate leaflet (IGL) and the circadian pacemaker, the suprachiasmatic nucleus (SCN). There were small differences between the flight and control groups at very early stages of development (G 20 and PN3) which indicated that the development of both the SCN and the IGL. These results indicate that exposure to the microgravity environment of spaceflight during this embryonic development period does not affect the development of the circadian rhythms of body temperature and activity, but may affect the early development of the neural structures involved in circadian timing.

Anadromous sea lampreys recolonize a Maine coastal river tributary after dam removal

USGS Publications Warehouse

Hogg, Robert; Coghlan, Stephen M.; Zydlewski, Joseph D.

2013-01-01

Sedgeunkedunk Stream, a third-order tributary to the Penobscot River, Maine, historically supported several anadromous fishes, including the Atlantic Salmon Salmo salar, AlewifeAlosa pseudoharengus, and Sea Lamprey Petromyzon marinus. However, two small dams constructed in the 1800s reduced or eliminated spawning runs entirely. In 2009, efforts to restore marine–freshwater connectivity in the system culminated with removal of the lowermost dam, thus providing access to an additional 4.6 km of lotic habitat. Because Sea Lampreys utilized accessible habitat prior to dam removal, they were chosen as a focal species with which to quantify recolonization. During spawning runs of 2008–2011 (before and after dam removal), individuals were marked with PIT tags and their activity was tracked with daily recapture surveys. Open-population mark–recapture models indicated a fourfold increase in the annual abundance of spawning-phase Sea Lampreys, with estimates rising from 59±4 () before dam removal (2008) to 223±18 and 242±16 after dam removal (2010 and 2011, respectively). Accompanying the marked increase in annual abundance was a greater than fourfold increase in nesting sites: the number of nests increased from 31 in 2008 to 128 and 131 in 2010 and 2011, respectively. During the initial recolonization event (i.e., in 2010), Sea Lampreys took 6 d to move past the former dam site and 9 d to expand into the furthest upstream reaches. Conversely, during the 2011 spawning run, Sea Lampreys took only 3 d to penetrate into the upstream reaches, thus suggesting a potential positive feedback in which larval recruitment into the system may have attracted adult spawners via conspecific pheromone cues. Although more research is needed to verify the migratory pheromone hypothesis, our study clearly demonstrates that small-stream dam removal in coastal river systems has the potential to enhance recovery of declining anadromous fish populations.

Integrated Flood Forecast and Virtual Dam Operation System for Water Resources and Flood Risk Management

NASA Astrophysics Data System (ADS)

Shibuo, Yoshihiro; Ikoma, Eiji; Lawford, Peter; Oyanagi, Misa; Kanauchi, Shizu; Koudelova, Petra; Kitsuregawa, Masaru; Koike, Toshio

2014-05-01

While availability of hydrological- and hydrometeorological data shows growing tendency and advanced modeling techniques are emerging, such newly available data and advanced models may not always be applied in the field of decision-making. In this study we present an integrated system of ensemble streamflow forecast (ESP) and virtual dam simulator, which is designed to support river and dam manager's decision making. The system consists of three main functions: real time hydrological model, ESP model, and dam simulator model. In the real time model, the system simulates current condition of river basins, such as soil moisture and river discharges, using LSM coupled distributed hydrological model. The ESP model takes initial condition from the real time model's output and generates ESP, based on numerical weather prediction. The dam simulator model provides virtual dam operation and users can experience impact of dam control on remaining reservoir volume and downstream flood under the anticipated flood forecast. Thus the river and dam managers shall be able to evaluate benefit of priori dam release and flood risk reduction at the same time, on real time basis. Furthermore the system has been developed under the concept of data and models integration, and it is coupled with Data Integration and Analysis System (DIAS) - a Japanese national project for integrating and analyzing massive amount of observational and model data. Therefore it has advantage in direct use of miscellaneous data from point/radar-derived observation, numerical weather prediction output, to satellite imagery stored in data archive. Output of the system is accessible over the web interface, making information available with relative ease, e.g. from ordinary PC to mobile devices. We have been applying the system to the Upper Tone region, located northwest from Tokyo metropolitan area, and we show application example of the system in recent flood events caused by typhoons.

Riparian Vegetation Encroachment Ratios in rivers below large Dams

NASA Astrophysics Data System (ADS)

Garcia de Jalón, Diego; Martínez-Fernández, Vanesa; González del Tánago, Marta

2017-04-01

Large Dams and reservoirs change the natural flow regime and consequently cause many alterations in riparian vegetation dynamics which may be assessed at different spatial and temporal scales. In Mediterranean regions flow regulation is frequently associated with irrigation. Regulated rivers with this purpose very often show reduced discharges during the wet season when the reservoir is being filled and increased discharges during the dry season when irrigation takes place. This type of regulation frequently promotes riparian vegetation growth as soil moisture levels are increased during summer when a natural drought would otherwise limit its growth. Additionally, flow regulation by large dams promotes the aging of late seral riparian vegetation reducing the frequency of flood disturbance and consequently, the potential recruitment of pioneer species. In this work we study the response of woody riparian vegetation to flow regulation by large dams in four rivers from Central Spain: Jarama, Manzanares, Guadalix and Alberche. The aim is to quantify the annual vegetation encroachment ratios and to develop a model to understand the main controlling factors, such as floodplain and channel traits; flow regulation intensity; type of regulation; present vegetation canopy; distance to the dam; and time since dam commissioning. A temporal comparison using aerial photographs from 1956, 1966, 1972, 1991, 2011 and 2014 was done in thirteen river reaches downstream from large dams, to evaluate their morphological evolution.. Floodplain dimensions and channel and riparian vegetation changes were assessed by comparing different pre-dam and post-dam conditions. Recent coloured photographs with 0.5 m spatial resolution and older black-and-white photographs at 1:33 000 spatial scale were supplied by the National Geographic Institute of Spain (www.ign.es) and the Statistical Institute (www.madrid.org/nomecalles/Inicio.icm) from Madrid Community. Similar visual scales were used to cope with different air photographs resolution. Results show a generalized natural vegetation encroachment process. Two exceptions were found associated with farming (Jarama 3) and poplar plantation (Alberche 1) that occupied riparian soils.. Annual encroachment ratios, range from 1 to 55 Ha/km, with a mean value of 12 Ha per km of river length. Higher values are found in the lowest reaches, which are far from the dam (5 cases), and also in the years following the beginning of dam operation. However, other reaches showed a delay of several years in the encroaching process, likely associated to scarcity or absence of initial woody vegetation at the time when dam started working.

Effects of a network of sand-storage dams on the hydrology on catchment scale

NASA Astrophysics Data System (ADS)

Ertsen, Maurits; Strohschein, Paul; Onencan, Abby; van de Giesen, Nick

2015-04-01

Water conservation is a high priority in the drier areas of sub-Saharan Africa. Storage of water from the rainy season to the dry season, or even from wet years to dry years is highly important. Small multi-purpose sub-surface water reservoirs recharged through infiltration are used to provide water for humans, livestock and crops in the Kitui region in Kenya. The groundwater dams obstruct the natural flow of water in wet seasons or periods, and provide storage of water during dry seasons or periods. This paper links the hydrology of the sand-storage dams to human agency. When is a dam a success in hydrological terms? When it provides water every year? Every two years? How many months? What happens in very dry years? Obviously, water use will decrease the water volume and thus the water level upstream of the dam, but to what extent typically depends on the amounts used compared to the size of the dam and the water use itself. Longer-term effects on groundwater levels to be expected depend strongly on the way the water is used. Household water use and river banks infiltration increasing seasonal storage can go hand in hand. However, when water in dams is used for higher water demanding activities such as (motorized) irrigation, the infiltration effect into banks may be minimal. A dam can also be "too effective" and decrease water availability for water users further downstream. It is unlikely, however, that an individual farmer will effect on the downstream users of the resources he/she is tapping, but a network of dams as in Kitui may have considerable effect. Measurements indicate that only about 2% to 3% of the total yearly runoff within the catchment directly associated with a single dam is stored in its reservoir. Therefore only this small percentage of the total flow of a seasonal river with dams is blocked. The paper will detail these general concepts with a case study of the Kiindu catchment. The hydrology of the Kiindu catchment is dependent on different aspects which influence each other. The physical environment determines the living conditions of the people directly and indirectly through the availability of water. The society on the other hand changes the physical environment directly by building sand dams or digging terraces directly and by the water use indirectly. Within the catchment, different sub-catchments show specific outcomes of this interaction. This means that even on a small scale of a catchment of some 20 kilometres, significant differences in water availability and quality can be found.

Spatial distribution and temporal development of high-mountain lakes in western Austria

NASA Astrophysics Data System (ADS)

Merkl, Sarah; Emmer, Adam; Mergili, Martin

2015-04-01

Glacierized high-mountain environments are characterized by active morphodynamics, favouring the rapid appearance and disappearance of lakes. On the one hand, such lakes indicate high-mountain environmental changes such as the retreat of glaciers. On the other hand, they are sometimes susceptible to sudden drainage, leading to glacial lake outburst floods (GLOFs) putting the downstream population at risk. Whilst high-mountain lakes have been intensively studied in the Himalayas, the Pamir, the Andes or the Western Alps, this is not the case for the Eastern Alps. A particular research gap, which is attacked with the present work, concerns the western part of Austria. We consider a study area of approx. 6,140 km², covering the central Alps over most of the province of Tyrol and part of the province of Salzburg. All lakes ≥250 m² located higher than 2000 m asl are mapped from high-resolution Google Earth imagery and orthophotos. The lakes are organized into seven classes: (i) ice-dammed; near-glacial (ii) moraine-dammed and (iii) bedrock-dammed; (iv) moraine-dammed and (v) bedrock-dammed distant to the recent glaciers; (vi) landslide-dammed; (vii) anthropogenic. The temporal development of selected lakes is investigated in detail, using aerial photographs dating back to the 1950s. 1045 lakes are identified in the study area. Only eight lakes are ice-dammed (i). One third of all lakes is located in the immediate vicinity of recent glacier tongues, half of them impounded by moraine (ii), half of them by bedrock (iii). Two thirds of all lakes are impounded by features (either moraines or bedrock) shaped by LIA or Pleistocenic glaciers at some distance to the present glacier tongues (iv and v). Only one landslide-dammed lake (vi) is identified in the study area, whilst 21 lakes are of anthropogenic origin (vii). 72% of all lakes are found at 2250-2750 m asl whilst less than 2% are found above 3000 m asl. The ratio of rock-dammed lakes increases with increasing elevation at the cost of moraine-dammed lakes. Multi-temporal analysis of selected near-glacial lakes reveals cases where lakes have appeared as proglacial lakes, but lost contact to the glacier within few decades or even years, or have even been decoupled from the glacial water supply. This goes hand in hand with rapid changes of lake shape and size, with merging or separating of lakes, and with the disappearance of short-lived lakes or lake systems. Consequently, we distinguish three stages of lake development: (a) a pro-glacial, (b) a periglacial and (c) a non-glacial stage. The dynamics - and also the susceptibility of a lake to sudden drainage - decrease substantially from (a) to (c). Lakes in the stages (a) and (b) are less prominent in our study area, compared to other glacierized high-mountain regions, leading us to the conclusion that (1) the current threat to the population by GLOFs is lower but (2) the future development of emerging lakes has to be monitored carefully.

Phase I Inspection Report. National Dam Safety Program. Round Valley South Dam, Hunterdon County, New Jersey.

DTIC Science & Technology

1978-05-01

1 . REPORT NUMB» NJ00015 2. GOVT ACCESSION NO ’base I Inspection Report* lational Dam Safety Program* found Valley South Dam> ’Hunterdon...Springfield, Virginia, 22151. 1 «. KEY WOROS (Continue on rereree elde II neeeeeery end Identity by block number) National Dam Safety Program Dam...IW,. 1 ,W,,.^U„UI,H..l,. 1 ,«.M,.„—II SECURITY CLASSIFICATION OP THIS PAOEfWhan Dmtm gnlafQ SECURITY CLASSIFICATION OF THIS PAGEfWhan Data Fnr.r.di

A Preliminary Assessment of Corps of Engineers’ Reservoirs, Their Purposes and Susceptibility to Drought

DTIC Science & Technology

1990-12-01

ROAD LOCK AND DAM ILLINOIS RIVER L IL CEDARS LOCK AND DAM (KIMBERLY DAM) FOX RIVER L WI CORALVILLE LAKE AND DAM IOWA RIVER R IA DEPERE LOCK AND DAM FOX...Mississippi upstream to Sioux City, Iowa below Gavins Point Dam. Drought results in lower streamflow and a shorter navigation season. Lower streamflow may...897 of the previous month. Classification system. Palmer (1965) used drought data from central Iowa and western Kansas to plot a graph of accumulated

Selection of Breeding Stock among Australian Purebred Dog Breeders, with Particular Emphasis on the Dam

PubMed Central

Czerwinski, Veronika; McArthur, Michelle; Smith, Bradley; Hynd, Philip; Hazel, Susan

2016-01-01

Simple Summary One of the most important factors influencing the health and welfare of puppies is the decision made by the breeder on which dam and sire they will breed from. Unfortunately, our understanding of what dog breeders consider important when selecting their dogs, particularly the dam, is limited. In order to bridge this gap, we conducted an online survey of Australian purebred dog breeders. We identified four major factors that the breeder considered important in relation to the dam: Maternal Care; Offspring Potential; Dam Temperament; and Dam Genetics and Health. Overall, the priorities and practices of dog breeders surveyed were variable across breeds. Importantly, it seemed that not all breeders understood the importance of maternal care behaviour, despite the significant role it may play on future puppy behaviour. Abstract Every year, thousands of purebred domestic dogs are bred by registered dog breeders. Yet, little is known about the rearing environment of these dogs, or the attitudes and priorities surrounding breeding practices of these dog breeders. The objective of this study was to explore some of the factors that dog breeders consider important for stock selection, with a particular emphasis on issues relating to the dam. Two-hundred and seventy-four Australian purebred dog breeders, covering 91 breeds across all Australian National Kennel Club breed groups, completed an online survey relating to breeding practices. Most breeders surveyed (76%) reported specialising in one breed of dog, the median number of dogs and bitches per breeder was two and three respectively, and most breeders bred two litters or less a year. We identified four components, relating to the dam, that were considered important to breeders. These were defined as Maternal Care, Offspring Potential, Dam Temperament, and Dam Genetics and Health. Overall, differences were observed in attitudes and beliefs across these components, showing that there is variation according to breed/breed groups. In particular, the importance of Maternal Care varied according to dog breed group. Breeders of brachycephalic breeds tended to differ the most in relation to Offspring Potential and Dam Genetics and Health. The number of breeding dogs/bitches influenced breeding priority, especially in relation to Dam Temperament, however no effect was found relating to the number of puppies bred each year. Only 24% of breeders used their own sire for breeding. The finding that some breeders did not test for diseases relevant to their breed, such as hip dysplasia in Labrador Retrievers and German Shepherds, provides important information on the need to educate some breeders, and also buyers of purebred puppies, that screening for significant diseases should occur. Further research into the selection of breeding dams and sires will inform future strategies to improve the health and behaviour of our best friend. PMID:27854338

Environmental effects of the Big Rapids dam remnant removal, Big Rapids, Michigan, 2000-02

USGS Publications Warehouse

Healy, Denis F.; Rheaume, Stephen J.; Simpson, J. Alan

2003-01-01

The U.S. Geological Survey (USGS), in cooperation with the city of Big Rapids, investigated the environmental effects of removal of a dam-foundation remnant and downstream cofferdam from the Muskegon River in Big Rapids, Mich. The USGS applied a multidiscipline approach, which determined the water quality, sediment character, and stream habitat before and after dam removal. Continuous water-quality data and discrete water-quality samples were collected, the movement of suspended and bed sediment were measured, changes in stream habitat were assessed, and streambed elevations were surveyed. Analyses of water upstream and downstream from the dam showed that the dam-foundation remnant did not affect water quality. Dissolved-oxygen concentrations downstream from the dam remnant were depressed for a short period (days) during the beginning of the dam removal, in part because of that removal effort. Sediment transport from July 2000 through March 2002 was 13,800 cubic yards more at the downstream site than the upstream site. This increase in sediment represents the remobilized sediment upstream from the dam, bank erosion when the impoundment was lowered, and contributions from small tributaries between the sites. Five habitat reaches were monitored before and after dam-remnant removal. The reaches consisted of a reference reach (A), upstream from the effects of the impoundment; the impoundment (B); and three sites below the impoundment where habitat changes were expected (C, D, and E, in downstream order). Stream-habitat assessment reaches varied in their responses to the dam-remnant removal. Reference reach A was not affected. In impoundment reach B, Great Lakes and Environmental Assessment Section (GLEAS) Procedure 51 ratings went from fair to excellent. For the three downstream reaches, reach C underwent slight habitat degradation, but ratings remained good; reach D underwent slight habitat degradation with ratings changing from excellent to good; and, in an area affected by a 1966 sediment release, reach E habitat rated fair in April 2000 and remained fair in September 2001. The most noticeable habitat change in the three reaches downstream from the dam site was a measurable increase in siltation and embeddedness. Bed-elevation profiles show that bed material upstream from the dam site was remobilized as suspended sediment and bedload, and was redeposited in the reaches below the cofferdam. Deposition was greater in the deep, slow-moving pools than the shallow, fast-moving riffles. For the most part, where deposition took place, deposits were less than 1 foot in thickness. In the year following the removal of the cofferdam, much of the sediment deposited below the dam was moved out of the study reach.

Evaluation of spatial and temporal water quality in the Akkaya dam watershed (Niğde, Turkey) and management implications

NASA Astrophysics Data System (ADS)

Yaşar Korkanç, Selma; Kayıkçı, Sedef; Korkanç, Mustafa

2017-05-01

The aim of this study is to investigate the water pollution in the Akkaya Dam watershed spatially and temporally and put forward management suggestions in a watershed scale. For this purpose, monthly water sampling was performed from 11 sampling stations on streams that fed the dam. According to land surveys they have a potential to inflict pollution to the dam. Thus the physical and chemical parameters (i.e. pH, dissolved oxygen, electrical conductivity, temperature, chemical oxygen demand, turbidity and suspended solids) were monitored monthly for 1-year period. Chloride, sulfate, total nitrogen, ammonium, nitrite, nitrate were monitored for a 6-month period, and the results were evaluated in accordance with the Turkish Regulation of Surface Water Quality Management. Results of the study show that the most important reasons for the pollution in the dam are caused by domestic and industrial wastewaters, which were released to the system without being treated, or without being sufficiently treated, and also of agricultural activities. It was determined that electrical conductivity, dissolved oxygen, turbidity, chemical oxygen demand, suspended solids, nitrite, nitrate, total nitrogen, sulfate, and chloride parameters which were high at the sampling stations where domestic and industrial wastewaters discharge were present. pH and temperature demonstrate a difference at a significant level by seasons. As a result of the study, it was determined that the water was of IVth quality in terms of nitrate, chemical oxygen demand, and total nitrogen, and it was of IIIrd quality water with respect to ammonium, electrical conductivity, and dissolved oxygen. It was observed that the dam outflow water was of IVth quality with respect to nitrate, chemical oxygen demand, and total nitrogen, and of IIIrd quality with respect to dissolved oxygen and electrical conductivity. It is considered that the pollution problem in the Akkaya Dam can only be resolved with prevention studies on a watershed scale. Therefore, coordination between the institutions is necessary. The preparation for the integrated water management plan of the watershed will provide a significant contribution to the solution of the water quality problem.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, John R.; Townsend, Richard L.; Seaburg, Adam

The study estimated dam passage survival at The Dalles Dam as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) and provided additional performance measures as stipulated in the Columbia Basin Fish Accords. This summary report focuses on spring run stocks, yearling Chinook salmon and steelhead.

Reconstructing Sediment Supply, Transport and Deposition Behind the Elwha River Dams

NASA Astrophysics Data System (ADS)

Beveridge, C.

2017-12-01

The Elwha River watershed in Olympic National Park of Washington State, USA is predominantly a steep, mountainous landscape where dominant geomorphic processes include landslides, debris flows and gullying. The river is characterized by substantial variability of channel morphology and fluvial processes, and alternates between narrow bedrock canyons and wider alluvial reaches for much of its length. Literature suggests that the Elwha watershed is topographically and tectonically in steady state. The removal of the two massive hydropower dams along the river in 2013 marked the largest dam removal in history. Over the century long lifespan of the dams, approximately 21 million cubic meters of sediment was impounded behind them. Long term erosion rates documented in this region and reservoir sedimentation data give unprecedented opportunities to test watershed sediment yield models and examine dominant processes that control sediment yield over human time scales. In this study, we aim to reconstruct sediment supply, transport and deposition behind the Glines Canyon Dam (most upstream dam) over its lifespan using a watershed modeling approach. We developed alternative models of varying complexity for sediment production and transport at the network scale driven by hydrologic forcing. We simulate sediment supply and transport in tributaries upstream of the dam. The modeled sediment supply and transport dynamics are based on calibrated formulae (e.g., bedload transport is simulated using Wilcock-Crowe 2003 with modification based on observed bedload transport in the Elwha River). Observational data that aid in our approach include DEM, channel morphology, meteorology, and streamflow and sediment (bedload and suspended load) discharge. We aim to demonstrate how the observed sediment yield behind the dams was influenced by upstream transport supply and capacity limitations, thereby demonstrating the scale effects of flow and sediment transport processes in the Elwha River watershed.

Close-range photogrammetric reconstruction of moraine dam failures

NASA Astrophysics Data System (ADS)

Westoby, M. J.; Brasington, J.; Glasser, N. F.; Hambrey, M. J.; Reynolds, J. M.

2012-04-01

Glacial Lake Outburst Floods (GLOFs) from moraine-dammed lakes represent a high magnitude, low frequency catastrophic glacio-fluvial phenomena, with the potential to cause significant damage to property and infrastructure in high-mountain regions. Detailed accounts of GLOF dynamics, in particular the initiation and propagation of dam breaching are extremely rare, owing to their occurrence in often remote, inaccessible areas, as well as the impracticalities associated with attempting to directly instrument such high magnitude, turbulent flows. In addition to the dearth of detailed, first-hand observations of dam failures, reconstruction of breaches and failure mechanisms derived from morphological evidence is hampered by the lack of high-quality, high-resolution DTMs of remote alpine areas. Previous studies have therefore resorted to the use of coarse resolution data products (SRTM, ASTER GDEM) to quantify characteristics of failure events, e.g. pre-flood lake volume, dam height/width, which may give rise to considerable uncertainty in related numerical simulations and assessments of downstream flood hazards. In this paper we employ a novel low-cost, close-range photogrammetric technique, termed 'Structure-from-Motion' (SfM) to provide detailed in-situ reconstructions of dam and valley topography for two moraine dam complexes which have produced historical GLOFs in the Khumbu Himal, Nepal. Requiring little more than a consumer-grade digital camera and suitable ground control for implementation, the resolution of the final data products are comparable to that obtained using ground-based or airborne LiDAR. These data facilitate the extraction of precise estimates of dam (and breach) geometry, volumes of water and sediment removed during the outburst events, and the downstream channel topography. We conclude by directly comparing such key metrics derived from low-resolution topographic datasets, with those acquired in situ using the SfM technique, and discuss the implications for the reconstruction of flood dynamics.

Endocannabinoid receptor deficiency affects maternal care and alters the dam's hippocampal oxytocin receptor and brain-derived neurotrophic factor expression.

PubMed

Schechter, M; Weller, A; Pittel, Z; Gross, M; Zimmer, A; Pinhasov, A

2013-10-01

Maternal care is the newborn's first experience of social interaction, and this influences infant survival, development and social competences throughout life. We recently found that postpartum blocking of the endocannabinoid receptor-1 (CB1R) altered maternal behaviour. In the present study, maternal care was assessed by the time taken to retrieve pups, pups' ultrasonic vocalisations (USVs) and pup body weight, comparing CB1R deleted (CB1R KO) versus wild-type (WT) mice. After culling on postpartum day 8, hippocampal expression of oxytocin receptor (OXTR), brain-derived neurotrophic factor (BDNF) and stress-mediating factors were evaluated in CB1R KO and WT dams. Comparisons were also performed with nulliparous (NP) CB1R KO and WT mice. Compared to WT, CB1R KO dams were slower to retrieve their pups. Although the body weight of the KO pups did not differ from the weight of WT pups, they emitted fewer USVs. This impairment of the dam-pup relationship correlated with a significant reduction of OXTR mRNA and protein levels among CB1R KO dams compared to WT dams. Furthermore, WT dams exhibited elevated OXTR mRNA expression, as well as increased levels of mineralocorticoid and glucocorticoid receptors, compared to WT NP mice. By contrast, CB1R KO dams showed no such elevation of OXTR expression, alongside lower BDNF and mineralocorticoid receptors, as well as elevated corticotrophin-releasing hormone mRNA levels, when compared to CB1R KO NP. Thus, it appears that the disruption of endocannabinoid signalling by CB1R deletion alters expression of the OXTR, apparently leading to deleterious effects upon maternal behaviour. © 2013 British Society for Neuroendocrinology.

Ecosystem-level consequences of migratory faunal depletion caused by dams

USGS Publications Warehouse

Freeman, Mary C.; Pringle, C.M.; Greathouse, E.A.; Freeman, B.J.; Limburg, K.E.; Waldman, J.R.

2003-01-01

Humans have been damming rivers for millennia, and our more ambitious efforts over the past century have arguably altered river ecosystems more extensively than any other anthropogenic activity. Effects of damming on river biota include decimation of migratory fauna (e.g., diadromous and potamodromous fishes and crustaceans), lost fisheries, and imperilment of obligate riverine taxa. Although effects of dams on biota have been widely documented, ecosystem-level consequences of faunal depletion caused by dams are only beginning to be appreciated. We discuss consequences to river ecosystems of altering distributions and abundances of migratory fauna, which often provide trophic subsidies and may strongly influence the structure of local habitats and communities. It is well documented that anadromous fishes can provide a major input of nutrients and energy to freshwater systems when spawning adults return from the sea. Other less-studied taxa that migrate between distinct portions of riverine systems (e.g., acipencerids, catostomids, and prochilodontids) may similarly provide trophic transfers within undammed river systems, in addition to modifying local communities and habitats through feeding and spawning activities. Experimental faunal exclusions have demonstrated strong potential effects of some amphidromous shrimps and potamodromous fishes on benthic organic matter and algal and invertebrate communities. Depletion of these animals above dams is likely to significantly affect ecosystem processes such as primary production and detrital processing. The decline of freshwater mussels isolated by dams from their migratory fish hosts has likely lowered stream productivity, nutrient retention and benthic stability. Greater focus on effects of dams on ecosystem processes, as mediated by faunal change, would improve our ability to assess the costs and benefits of future river management strategies.

Contaminated Sediment Management in Dam Removals and River Restoration Efforts: Critical Need for Research and Policy Development

NASA Astrophysics Data System (ADS)

Evans, J. E.

2015-12-01

Over 1,000 U.S. dams have been removed (1975-2015) for reasons including obsolescence, liability concerns, water quality upgrades, fisheries, or ecosystem enhancements. Contaminated sediment can significantly complicate the approval process, cost, and timeline of a dam removal, or stop it entirely. In a dam removal, reservoir sediment changes from a sink to a source of contaminants. Recently, the Sierra Club sued to stop the removal of a large dam in Ohio because of the potential impact of phosphate releases on toxic algal blooms in Lake Erie. Heavy metals, PCBs, PAHs, pesticides, and petroleum hydrocarbons can be present in reservoir sediments. In a non-dam removal scenario, reservoir management tools range from "no action" to dredging, dewatering and removal, or sediment capping. But it is not clear how these reservoir management techniques apply to dam removals. Case studies show typically >80% of the reservoir sediment is eventually eroded, precluding sediment capping as a containment option. However, the released contaminants are diluted by mixing with "clean" sediment and are transported to different physio-chemical environments which may immobilize or biodegrade the contaminants. Poorly understood options include phased drawdown/reseeding the former reservoir to contain sediments, diking contaminant "hot spots," and addressing contaminant stratigraphy (where historical use created "hot layers" in the reservoir sediment). Research and policy development needs include: (1) assessment methods based on synergistic effects of multiple contaminants being present; (2) ways to translate the pre-removal contaminant concentrations to post-removal health risks downstream; (3) evaluation of management practices for contaminant "hot spots" and "hot layers;" (4) tools to forecast the presence of contaminated sediment using easily accessible information; and (5) ways to limit liability risk for organizations participating in dam removals involving contaminated sediment.

Is there enough sand? Evaluating the fate of Grand Canyon sandbars

USGS Publications Warehouse

Wright, S.A.; Schmidt, J.C.; Meles, T.S.; Topping, D.J.; Rubin, D.M.

2008-01-01

Large dams have the potential to dramatically alter the flow regime, geomorphology, and aquatic ecosystem of downstream river reaches. Development of flow release regimes in order to meet multiple objectives is a challenge facing dam operators, resource managers, and scientists. Herein, we review previous work and present new analyses related to the effects of Glen Canyon Dam on the downstream reach of the Colorado River in Marble and Grand Canyons. The dam traps the entire incoming sediment load in Lake Powell and modulates the hydrologic regime by, for example, eliminating spring snowmelt floods, resulting in changes in the geomorphology of the river downstream. The primary geomorphic impact has been the erosion of sandbars along the banks of the river. Recognition of this impact has led to many scientific studies and a variety of experimental operations of Glen Canyon Dam with the goal of rebuilding the eroding sandbars. These efforts have thus far been generally unsuccessful and the question remains as to whether or not the dam can be operated such that sandbars can be rebuilt and maintained over extended periods with the existing sediment supply. We attempt to answer this question by evaluating a dam operation that may be considered a "best-case scenario" for rebuilding and maintaining eroded sandbars. Our analysis suggests that this best-case scenario may indeed have viability for rebuilding sandbars, and that the initial rate at which sandbars could be rebuilt is comparable to the rate at which sandbars have been eroded since dam construction. The question remains open as to the viability of operations that deviate from the best-case scenario that we have defined.

[Ecological risk assessment of dam construction for terrestrial plant species in middle reach of Lancangjiang River, Southwest China].

PubMed

Li, Xiao-Yan; Dong, Shi-Kui; Liu, Shi-Liang; Peng, Ming-Chun; Li, Jin-Peng; Zhao, Qing-He; Zhang, Zhao-Ling

2012-08-01

Taking the surrounding areas of Xiaowan Reservoir in the middle reach of Lancangjiang River as study area, and based on the vegetation investigation at three sites including electricity transmission area (site 1), electricity-transfer substation and roadsides to the substation (site 2), and emigration area (site 3) in 1997 (before dam construction), another investigation was conducted on the vegetation composition, plant coverage, and dominant species at the same sites in 2010 (after dam construction), aimed to evaluate the ecological risk of the dam construction for the terrestrial plant species in middle reach of Lancangjiang River. There was an obvious difference in the summed dominance ratio of dominant species at the three sites before and after the dam construction. According the types of species (dominant and non-dominant species) and the changes of plant dominance, the ecological risk (ER) for the plant species was categorized into 0 to IV, i.e., no or extremely low ecological risk (0), low ecological risk (I), medium ecological risk (II), high ecological risk (III), and extremely high ecological risk (IV). As affected by the dam construction, the majority of the species were at ER III, and a few species were at ER IV. The percentage of the plant species at ER III and ER IV at site 3 was higher than that at sites 1 and 2. The decrease or loss of native plants and the increase of alien or invasive plants were the major ecological risks caused by the dam construction. Effective protection strategies should be adopted to mitigate the ecological risk of the dam construction for the terrestrial plants at species level.

Techniques for computing discharge at four Navigation Dams on the Illinois and Des Plaines Rivers in Illinois

USGS Publications Warehouse

Mades, Dean M.; Weiss, Linda S.; Gray, John R.

1991-01-01

Techniques for computing discharge are developed for Brandon Road Dam on the Des Plaines River and for Dresden Island, Marseilles, and Starved Rock Dams on the Illinois River. At Brandon Road Dam, streamflow is regulated by the operation of Tainter gates and headgates. At Dresden Island, Marseilles, and Starved Rock Dams, only Tainter gates are operated to regulate streamflow. The locks at all dams are equipped with culvert valves that are used to fill and empty the lock. The techniques facilitate determination of discharge at locations along the upper Illinois Waterway where no streamflow-gaging stations exist. The techniques are also useful for computing low flows when the water-surface slope between control structures on the river approaches zero and traditional methods of determining discharge based on slope are unsatisfactory. Two techniques can be used to compute discharge at the dams--gate ratings and tailwater ratings . A gate ratingdescribes the relation between discharge, gate opening, tailwater stage, and headwater stage. A tailwater rating describes the relation between tailwater stage and discharge. Gate ratings for Tainter gates at Dresden Island, Marseilles, and Starved Rock Dams are based on a total of 78 measurements of discharge that range from 569 to 86,400 cubic feet per second. Flood hydrographs developed from the gate ratings and Lockmaster records of gate opening and stage compare closely with streamflow records published for nearby streamflow-gaging stations. Additional measurements are needed to verify gate ratings for Tainter gates and headgates at Brandon Road Dam after the dam rehabilitation is completed. Extensive leakage past deteriorated headgates and sluice gates contributed to uncertainty in the ratings developed for this dam. A useful tailwater rating is developed for Marseilles Dam. Tailwater ratings for Dresden Island Dam and Starved Rock Dam are of limited use because of varying downstream channel-storage conditions. A tailwater rating could not be developed for Brandon Road Dam because its tailwater pool is substantially affected by the headwater pool of Dresden Island Dam.

Environmental Risk Assessment System for Phosphogypsum Tailing Dams

PubMed Central

Sun, Xin; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

2013-01-01

This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams. PMID:24382947

Environmental risk assessment system for phosphogypsum tailing dams.

PubMed

Sun, Xin; Ning, Ping; Tang, Xiaolong; Yi, Honghong; Li, Kai; Zhou, Lianbi; Xu, Xianmang

2013-01-01

This paper may be of particular interest to the readers as it provides a new environmental risk assessment system for phosphogypsum tailing dams. In this paper, we studied the phosphogypsum tailing dams which include characteristics of the pollution source, environmental risk characteristics and evaluation requirements to identify the applicable environmental risk assessment methods. Two analytical methods, that is, the analytic hierarchy process (AHP) and fuzzy logic, were used to handle the complexity of the environmental and nonquantitative data. Using our assessment method, different risk factors can be ranked according to their contributions to the environmental risk, thereby allowing the calculation of their relative priorities during decision making. Thus, environmental decision-makers can use this approach to develop alternative management strategies for proposed, ongoing, and completed PG tailing dams.

The Characterization of Chlorophyll-A and Microalgae Isolation Process of Wastewater Collected at Sembrong Dam

NASA Astrophysics Data System (ADS)

Wellson, R.; Othman, N.; Matias-Peralta, H. M.

2016-07-01

Recently, there has been an increasing number of river water quality deterioration that has brought into water quality disruptions that entering dams including in Johor and one of them is occurred in Sembrong Dam in Johor. Sembrong Dam is a major water source for some 120,000 people in the districts of Kluang and parts of Batu Pahat. The quality of water in Sembrong should be well-monitored in ensuring the continuous distribution of clean and safe water supply to peoples. Based on the news reported by The Star news dated on 11 May 2015, the water bodies in Sembrong Dam are polluted by the algae blooms which has started to cause problems in treating water phase by clogging up the filters and causing the production to be reduced and finally resulting in frequent water disruptions to residents. Therefore, there is a need to study the water quality of the dam water prior to further water treatment. One of important characterizations is by measuring chlorophyll-a and the isolation of the dominant microalgae species in the water body in which they are able to indicate the level of water pollution. This paper presents the determination of chlorophyll-a and the isolation of microalgae strains collected from Sembrong Dam. Chlorophyll-a is a photosynthetic pigment present in all species of phytoplankton, including algae and in some photosynthetic bacteria, known as cyanobacteria. The method used in measuring the chlorophyll-a is based on the standard method of IS0 10 260. The average chlorophyll-a concentration measured at Sembrong Dam is 175.9 µg L-1 and it is responsible for the appearance of green color in the sample and it is categorized into hypereutrophic state which is highly polluted. The technique used for isolation of microalgae strains is traditional method which is by spreading the sample on agar. The pure isolate indicated that the genus Botryococcus is the dominant algae species which is characterized morphologically. Both chlorophyll-a and microalgae isolation are good biological indicator that indicate the pollution of Sembrong Dam. The pure culture is very important that it can be used for further studies with series of different tests to understand its properties and character for sustainability approach towards environmentally friendly as well as for microalgae removal formula.

The design of the intelligent monitoring system for dam safety

NASA Astrophysics Data System (ADS)

Yuan, Chun-qiao; Jiang, Chen-guang; Wang, Guo-hui

2008-12-01

Being a vital manmade water-control structure, a dam plays a very important role in the living and production of human being. To make a dam run safely, the best design and the superior construction quality are paramount; moreover, with working periods increasing, various dynamic, alternative and bad loads generate little by little various distortions on the dam structure inevitably, which shall lead to potential safety problems or further a disaster (dam burst). There are many signs before the occurrence of a dam accident, so the timely and effective surveying on the distortion of a dam is important. On the basis of the cause supra, two intelligent (automatic) monitoring systems about the dam's safety based on the RTK-GPS technology and the measuring robot has been developed. The basic principle, monitoring method and monitoring process of these two intelligent (automatic) monitoring systems are introduced. It presents examples of monitor and puts forward the basic rule of dam warning based on data of actual monitor.

A Video Method to Study Drosophila Sleep

PubMed Central

Zimmerman, John E.; Raizen, David M.; Maycock, Matthew H.; Maislin, Greg; Pack, Allan I.

2008-01-01

Study Objectives: To use video to determine the accuracy of the infrared beam-splitting method for measuring sleep in Drosophila and to determine the effect of time of day, sex, genotype, and age on sleep measurements. Design: A digital image analysis method based on frame subtraction principle was developed to distinguish a quiescent from a moving fly. Data obtained using this method were compared with data obtained using the Drosophila Activity Monitoring System (DAMS). The location of the fly was identified based on its centroid location in the subtracted images. Measurements and Results: The error associated with the identification of total sleep using DAMS ranged from 7% to 95% and depended on genotype, sex, age, and time of day. The degree of the total sleep error was dependent on genotype during the daytime (P < 0.001) and was dependent on age during both the daytime and the nighttime (P < 0.001 for both). The DAMS method overestimated sleep bout duration during both the day and night, and the degree of these errors was genotype dependent (P < 0.001). Brief movements that occur during sleep bouts can be accurately identified using video. Both video and DAMS detected a homeostatic response to sleep deprivation. Conclusions: Video digital analysis is more accurate than DAMS in fly sleep measurements. In particular, conclusions drawn from DAMS measurements regarding daytime sleep and sleep architecture should be made with caution. Video analysis also permits the assessment of fly position and brief movements during sleep. Citation: Zimmerman JE; Raizen DM; Maycock MH; Maislin G; Pack AI. A video method to study drosophila sleep. SLEEP 2008;31(11):1587–1598. PMID:19014079

Systemic exposure of vinpocetine in pregnant Sprague Dawley rats following repeated oral exposure: An investigation of fetal transfer.

PubMed

Waidyanatha, Suramya; Toy, Heather; South, Natalie; Gibbs, Seth; Mutlu, Esra; Burback, Brian; McIntyre, Barry S; Catlin, Natasha

2018-01-01

Vinpocetine is being used worldwide by people of all ages, including pregnant women, for its purported multiple health benefits. However, limited data is available addressing the safety/toxicity of vinpocetine. The National Toxicology Program conducted studies to examine potential effects of vinpocetine on the developing rat. Disposition data is helpful to put the fetal findings into context and provide information on the potential risk for humans. The current study reports the systemic exposure and toxicokinetic (TK) parameters of vinpocetine and metabolite, apovincaminic acid (AVA), in pregnant Harlan Sprague Dawley rats, fetuses and amniotic fluid following oral gavage exposure of dams to 5 and 20mg/kg vinpocetine from gestational day 6 to 18. Vinpocetine was absorbed rapidly in dams with a maximum plasma concentration (C max ) reaching ≤1.37h. Predicted C max and area under the concentration versus time curve (AUC) increased less than proportionally to the dose. Vinpocetine was rapidly distributed to the peripheral compartment. More importantly, significant transfer of vinpocetine from dam to fetuses was observed with fetal C max and AUC≥55% of dams. Vinpocetine was cleared rapidly from dam plasma with an elimination half-life of ≤4.02h with no apparent dose-related effect. Vinpocetine was rapidly and highly metabolized to AVA with AVA plasma levels in dams ≥2.7-fold higher than vinpocetine, although in the fetuses, AVA levels were much lower than vinpocetine. Comparison of current rat data with literature human data demonstrates that systemic exposure to vinpocetine in rats following repeated exposure to 5mg/kg is similar to that following a single human relevant dose of 10mg suggesting that the findings from the toxicology study may be relevant to humans. Published by Elsevier Inc.

Knockout maternal adiponectin increases fetal growth in mice: potential role for trophoblast IGFBP-1

PubMed Central

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Guo, Zhuyu; Schaack, Jerome; Hay, William W.; Moretto Zita, Matteo; Parast, Mana; Shao, Jianhua

2016-01-01

Aims/hypothesis The main objective of this study was to investigate whether maternal adiponectin regulates fetal growth through the endocrine system in the fetal compartment. Methods Adiponectin knockout (Adipoq−/−) mice and in vivo adenovirus-mediated reconstitution were used to study the regulatory effect of maternal adiponectin on fetal growth. Primary human trophoblast cells were treated with adiponectin and a specific peroxisome proliferator-activated receptor α (PPARα) agonist or antagonist to study the underlying mechanism through which adiponectin regulates fetal growth. Results The body weight of fetuses from Adipoq−/− dams was significantly greater than that of wild-type dams at both embryonic day (E)14.5 and E18.5. Adenoviral vector-mediated maternal adiponectin reconstitution attenuated the increased fetal body weight induced by maternal adiponectin deficiency. Significantly increased blood glucose, triacylglycerol and NEFA levels were observed in Adipoq−/− dams, suggesting that nutrient supply contributes to maternal adiponectin-regulated fetal growth. Although fetal blood IGF-1 concentrations were comparable in fetuses from Adipoq−/− and wild-type dams, remarkably low levels of IGF-binding protein 1 (IGFBP-1) were observed in the serum of fetuses from Adipoq−/− dams. IGFBP-1 was identified in the trophoblast cells of human and mouse placentas. Maternal fasting robustly increased IGFBP-1 levels in mouse placentas, while reducing fetal weight. Significantly low IGFBP-1 levels were found in placentas of Adipoq−/− dams. Adiponectin treatment increased IGFBP-1 levels in primary cultured human trophoblast cells, while the PPARα antagonist, MK886, abolished this stimulatory effect. Conclusions/interpretation These results indicate that, in addition to nutrient supply, maternal adiponectin inhibits fetal growth by increasing IGFBP-1 expression in trophoblast cells. PMID:27495989

Coal-mining seismicity and ground-shaking hazard: A case study in the Trail Mountain area, Emery County, Utah

USGS Publications Warehouse

Arabasz, W.J.; Nava, S.J.; McCarter, M.K.; Pankow, K.L.; Pechmann, J.C.; Ake, J.; McGarr, A.

2005-01-01

We describe a multipart study to quantify the potential ground-shaking hazard to Joes Valley Dam, a 58-m-high earthfill dam, posed by mining-induced seismicity (MIS) from future underground coal mining, which could approach as close as ???1 km to the dam. To characterize future MIS close to the dam, we studied MIS located ???3-7 km from the dam at the Trail Mountain coal mine. A 12-station local seismic network (11 stations above ground, one below, combining eight triaxial accelerometers and varied velocity sensors) was operated in the Trail Mountain area from late 2000 through mid-2001 for the dual purpose of (1) continuously monitoring and locating MIS associated with longwall mining at a depth of 0.5-0.6 km and (2) recording high-quality data to develop ground-motion prediction equations for the shallow MIS. (Ground-motion attenuation relationships and moment-tensor results are reported in companion articles.) Utilizing a data set of 1913 earthquakes (M ??? 2.2), we describe space-time-magnitude distributions of the observed MIS and source-mechanism information. The MIS was highly correlated with mining activity both in space and time. Most of the better-located events have depths constrained within ??0.6 km of mine level. For the preponderance (98%) of the 1913 located events, only dilatational P-wave first motions were observed, consistent with other evidence for implosive or collapse-type mechanisms associated with coal mining in this region. We assess a probable maximum magnitude of M 3.9 (84th percentile of a cumulative distribution) for potential MIS close to Joes Valley Dam based on both the worldwide and regional record of coal-mining-related MIS and the local geology and future mining scenarios.

Comparative phylogenetic analysis and transcriptional profiling of MADS-box gene family identified DAM and FLC-like genes in apple (Malusx domestica)

PubMed Central

Kumar, Gulshan; Arya, Preeti; Gupta, Khushboo; Randhawa, Vinay; Acharya, Vishal; Singh, Anil Kumar

2016-01-01

The MADS-box transcription factors play essential roles in various processes of plant growth and development. In the present study, phylogenetic analysis of 142 apple MADS-box proteins with that of other dicotyledonous species identified six putative Dormancy-Associated MADS-box (DAM) and four putative Flowering Locus C-like (FLC-like) proteins. In order to study the expression of apple MADS-box genes, RNA-seq analysis of 3 apical and 5 spur bud stages during dormancy, 6 flower stages and 7 fruit development stages was performed. The dramatic reduction in expression of two MdDAMs, MdMADS063 and MdMADS125 and two MdFLC-like genes, MdMADS135 and MdMADS136 during dormancy release suggests their role as flowering-repressors in apple. Apple orthologs of Arabidopsis genes, FLOWERING LOCUS T, FRIGIDA, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 and LEAFY exhibit similar expression patterns as reported in Arabidopsis, suggesting functional conservation in floral signal integration and meristem determination pathways. Gene ontology enrichment analysis of predicted targets of DAM revealed their involvement in regulation of reproductive processes and meristematic activities, indicating functional conservation of SVP orthologs (DAM) in apple. This study provides valuable insights into the functions of MADS-box proteins during apple phenology, which may help in devising strategies to improve important traits in apple. PMID:26856238

Model analysis of check dam impacts on long-term sediment and water budgets in southeast Arizona, USA

USGS Publications Warehouse

Norman, Laura M.; Niraula, Rewati

2016-01-01

The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.

Comparative phylogenetic analysis and transcriptional profiling of MADS-box gene family identified DAM and FLC-like genes in apple (Malusx domestica).

PubMed

Kumar, Gulshan; Arya, Preeti; Gupta, Khushboo; Randhawa, Vinay; Acharya, Vishal; Singh, Anil Kumar

2016-02-09

The MADS-box transcription factors play essential roles in various processes of plant growth and development. In the present study, phylogenetic analysis of 142 apple MADS-box proteins with that of other dicotyledonous species identified six putative Dormancy-Associated MADS-box (DAM) and four putative Flowering Locus C-like (FLC-like) proteins. In order to study the expression of apple MADS-box genes, RNA-seq analysis of 3 apical and 5 spur bud stages during dormancy, 6 flower stages and 7 fruit development stages was performed. The dramatic reduction in expression of two MdDAMs, MdMADS063 and MdMADS125 and two MdFLC-like genes, MdMADS135 and MdMADS136 during dormancy release suggests their role as flowering-repressors in apple. Apple orthologs of Arabidopsis genes, FLOWERING LOCUS T, FRIGIDA, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 and LEAFY exhibit similar expression patterns as reported in Arabidopsis, suggesting functional conservation in floral signal integration and meristem determination pathways. Gene ontology enrichment analysis of predicted targets of DAM revealed their involvement in regulation of reproductive processes and meristematic activities, indicating functional conservation of SVP orthologs (DAM) in apple. This study provides valuable insights into the functions of MADS-box proteins during apple phenology, which may help in devising strategies to improve important traits in apple.

Novel Synergistic Protective Efficacy of Atovaquone and Diclazuril on Fetal-Maternal Toxoplasmosis

PubMed Central

Oz, Helieh S.

2014-01-01

Over 1 billion people globally are estimated to be infected with Toxoplasma gondii with severe or unknown consequences and no safe and effective therapies are available against congenital or persistent chronic infection. We propose that atovaquone and diclazuril synergistically protect against fetal-maternal toxoplasmosis. Methods Programmed pregnant mice were treated with atovaquone and diclazuril monotherapy, or combined (atovaquone + diclazuril) therapy and infected with tachyzoites (0, 300, 600) and the course of infection was studied. Results Infected dams with low dose (300) developed moderate toxoplasmosis complications and treatments were similarly effective with minor differences between monotherapies. In contrast, major differences were observed amongst varied treatments during high-dose (600) infection and severe related- toxoplasmosis complications as follows. Dams developed hydrothorax, ascities and excess weight gain. Combined therapy (P < 0.01) and to a lesser extent diclazuril monotherapy (P < 0.05) protected dams from excess weight, hydrothorax, and ascities. Infected dams exhibited splenomegaly, hepatomegaly and severe hepatitis. Combined therapy synergistically normalized pathology (P < 0.001) and to a lesser degree monotherapy (diclazuril P < 0.01, and atovaquone P < 0.05) protected dams from hepatitis and splemomegaly. Additionally, behavioral response to pain stimuli and fetal weight and fetal numbers were significantly preserved in treated dams Conclusions This is the first report describing combined atovaquone and diclazuril therapy (a) to be safe in pregnancy, (b) to exert novel synergistic effects, and (c) to protect dams and their nested fetuses against adverse effects of severe toxoplasmosis. PMID:25210646

The Social, Historical, and Institutional Contingencies of Dam Removal

NASA Astrophysics Data System (ADS)

Magilligan, F. J.; Sneddon, C. S.; Fox, C. A.

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

Assessing changes in failure probability of dams in a changing climate

NASA Astrophysics Data System (ADS)

Mallakpour, I.; AghaKouchak, A.; Moftakhari, H.; Ragno, E.

2017-12-01

Dams are crucial infrastructures and provide resilience against hydrometeorological extremes (e.g., droughts and floods). In 2017, California experienced series of flooding events terminating a 5-year drought, and leading to incidents such as structural failure of Oroville Dam's spillway. Because of large socioeconomic repercussions of such incidents, it is of paramount importance to evaluate dam failure risks associated with projected shifts in the streamflow regime. This becomes even more important as the current procedures for design of hydraulic structures (e.g., dams, bridges, spillways) are based on the so-called stationary assumption. Yet, changes in climate are anticipated to result in changes in statistics of river flow (e.g., more extreme floods) and possibly increasing the failure probability of already aging dams. Here, we examine changes in discharge under two representative concentration pathways (RCPs): RCP4.5 and RCP8.5. In this study, we used routed daily streamflow data from ten global climate models (GCMs) in order to investigate possible climate-induced changes in streamflow in northern California. Our results show that while the average flow does not show a significant change, extreme floods are projected to increase in the future. Using the extreme value theory, we estimate changes in the return periods of 50-year and 100-year floods in the current and future climates. Finally, we use the historical and future return periods to quantify changes in failure probability of dams in a warming climate.

The Social, Historical, and Institutional Contingencies of Dam Removal.

PubMed

Magilligan, F J; Sneddon, C S; Fox, C A

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

Damming the Brahmaputra: Impacts on the Resilience of Local Communities to Floods and Climate Change

NASA Astrophysics Data System (ADS)

Rampini, C.

2016-12-01

Recurrent destructive floods along the Brahmaputra river basin are a major challenge for the people and state governments of Northeast India. Climate change is expected to further exacerbate this challenge, as melting Himalayan glaciers and changes in the South Asian monsoon lead to an increase in the frequency of severe floods. At the same time, the Brahmaputra has become the focus of India's hydropower development efforts, with 140 new dams planned along its main stem and tributaries. Though these dams could provide flood protection for downstream communities, political and economic factors have led dam builders to prioritize hydroelectricity generation over flood control. Using the Ranganadi Hydroelectric Project in Arunachal Pradesh as a case study, this research investigates the effects of dam building on the resilience of downstream communities to floods that are becoming increasingly severe as a result of climate change. Findings suggest that dams in Northeast are eroding downstream communities' resilience to floods by increasing their vulnerability and reducing their adaptive capacity to these natural hazards. The risk is that, as dams and climate change jointly make the floodplains of Northeast India increasingly hazardous, uninhabitable and unproductive, they will push local communities away from these landscapes and agricultural livelihoods and towards more carbon-intensive livelihoods. More broadly this research highlights the danger of pursuing climate change mitigation and renewable energy development projects without considering their impacts on the vulnerability and adaptability of affected communities to climate change.

Survival Estimates for the Passage of Juvenile Salmonids through Snake River Dams and Reservoirs, 1994 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muir, William D.

1995-02-01

In 1994, the National Marine Fisheries Service and the University of Washington completed the second year of a multi-year study to estimate survival of juvenile salmonids (Oncorhynchus spp.) passing through the dams and reservoirs of the Snake River. Actively migrating smolts were collected at selected locations above, at, and below Lower Granite Dam, tagged with passive integrated transponder (PIT) tags, and released to continue their downstream migration. Survival estimates were calculated using the Single-Release, Modified Single-Release, and Paired-Release Models.

Lower San Fernando corrugated metal pipe failure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bardet, J.P.; Davis, C.A.

1995-12-31

During the January 17, 1994, Northridge earthquake, a 2.4 m diameter corrugated metal pipe was subjected to 90 m of extensive lateral crushing failure at the Lower San Fernando Dam. The dam and outlet works were reconstructed after the 1971 San Fernando Earthquake. In 1994, the dam underwent liquefaction upstream of the reconstructed berm. The pipe collapsed on the west side of the liquefied zone and a large sinkhole formed over the drain line. The failure of this drain line provides a unique opportunity to study the seismic response of buried drains and culverts.

JPRS Report, Science & Technology Europe

DTIC Science & Technology

1988-11-30

Study of a Dam The dam for a reservoir is made by filling on the original soil, so it can be modeled with two types of material. The ... the structural and load symmetries it was enough to study a half model . Within the framework of the static study we determined the nodal movements...two symmetrical axes it was enough to study a quarter model of the dome. JPRS-EST-88-012 30

Fall Chinook Salmon Survival and Supplementation Studies in the Snake River and Lower Snake River Reservoirs, 1995 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, John G.; Bjomn

1997-03-01

In 1994, the National Marine Fisheries Service and the US Fish and Wildlife Service began a cooperative study to investigate migrational characteristics of subyearling fall chinook salmon in the Snake River. The primary study objectives were to (1) determine the feasibility of estimating detection and passage survival probabilities of natural and hatchery subyearling fall chinook salmon released in the Snake River (Chapter 1), (2) investigate relationships between detection and passage survival probabilities and travel time of subyearling fall chinook salmon and environmental influences such as flow volume and water temperature (Chapter 1), (3) monitor and evaluate dispersal of hatchery subyearlingmore » chinook salmon into nearshore rearing areas used by natural fish (Chapter 2), and (4) monitor and evaluate travel time to Lower Granite Dam, growth from release in the Snake River to recapture at Lower Granite Dam, ATPase levels of fish recaptured at Lower Granite Dam, and survival from release in the free-flowing Snake River to the tailrace of Lower Granite Dam (Chapter 2).« less

The use of seismic tomograms for the identification of internal problems with earthen dams and levees

USDA-ARS?s Scientific Manuscript database

According to the National Inventory of dams (NID, 2009), out of the 84,134 dams in the US, more than 87% (73,423) are earthen dams. The majority of these earthen dams are past or approaching their design life expectancy of 50 years. According to the National committee on Levee Safety (NCLS, 2009),...

5 CFR 532.269 - Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam employees.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Engineers, U.S. Army navigation lock and dam employees. 532.269 Section 532.269 Administrative Personnel... Determinations § 532.269 Special wage schedules for Corps of Engineers, U.S. Army navigation lock and dam... and dam equipment or who repair and maintain navigation lock and dam operating machinery and equipment...

33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General...

33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Marshall Ford Dam and Reservoir... Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex. The Secretary of the... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General...

46. Photocopy of photograph, c. 1933. VIEW OF DAM AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

46. Photocopy of photograph, c. 1933. VIEW OF DAM AND FOREBAY. NOTE ALL WATER FLOWING THROUGH FOREBAY AND OUT EITHER TAILRACE OR SLUICE GATE (INSTEAD OF OVER DAM) BECAUSE OF LOW WATER FLOW. (Courtesy of the Potomac Edison Company Library (Hagerstown, MD), Historical Data Files, Dam No. 5 listing - Dam No. 5 Hydroelectric Plant, On Potomac River, Hedgesville, Berkeley County, WV

Structures of Escherichia coli DNA adenine methyltransferase (Dam) in complex with a non-GATC sequence: Potential implications for methylation-independent transcriptional repression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horton, John R.; Zhang, Xing; Blumenthal, Robert M.

DNA adenine methyltransferase (Dam) is widespread and conserved among the γ-proteobacteria. Methylation of the Ade in GATC sequences regulates diverse bacterial cell functions, including gene expression, mismatch repair and chromosome replication. Dam also controls virulence in many pathogenic Gram-negative bacteria. An unexplained and perplexing observation about Escherichia coli Dam (EcoDam) is that there is no obvious relationship between the genes that are transcriptionally responsive to Dam and the promoter-proximal presence of GATC sequences. Here, we demonstrate that EcoDam interacts with a 5-base pair non-cognate sequence distinct from GATC. The crystal structure of a non-cognate complex allowed us to identify amore » DNA binding element, GTYTA/TARAC (where Y = C/T and R = A/G). This element immediately flanks GATC sites in some Dam-regulated promoters, including the Pap operon which specifies pyelonephritis-associated pili. In addition, Dam interacts with near-cognate GATC sequences (i.e. 3/4-site ATC and GAT). All together, these results imply that Dam, in addition to being responsible for GATC methylation, could also function as a methylation-independent transcriptional repressor.« less

Structures of Escherichia coli DNA adenine methyltransferase (Dam) in complex with a non-GATC sequence: Potential implications for methylation-independent transcriptional repression

DOE PAGES

Horton, John R.; Zhang, Xing; Blumenthal, Robert M.; ...

2015-04-06

DNA adenine methyltransferase (Dam) is widespread and conserved among the γ-proteobacteria. Methylation of the Ade in GATC sequences regulates diverse bacterial cell functions, including gene expression, mismatch repair and chromosome replication. Dam also controls virulence in many pathogenic Gram-negative bacteria. An unexplained and perplexing observation about Escherichia coli Dam (EcoDam) is that there is no obvious relationship between the genes that are transcriptionally responsive to Dam and the promoter-proximal presence of GATC sequences. Here, we demonstrate that EcoDam interacts with a 5-base pair non-cognate sequence distinct from GATC. The crystal structure of a non-cognate complex allowed us to identify amore » DNA binding element, GTYTA/TARAC (where Y = C/T and R = A/G). This element immediately flanks GATC sites in some Dam-regulated promoters, including the Pap operon which specifies pyelonephritis-associated pili. In addition, Dam interacts with near-cognate GATC sequences (i.e. 3/4-site ATC and GAT). All together, these results imply that Dam, in addition to being responsible for GATC methylation, could also function as a methylation-independent transcriptional repressor.« less

Adiponectin Deficiency Impairs Maternal Metabolic Adaptation to Pregnancy in Mice.

PubMed

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Nguyen, Amanda; Schaack, Jerome; Hay, William W; Shao, Jianhua

2017-05-01

Hypoadiponectinemia has been widely observed in patients with gestational diabetes mellitus (GDM). To investigate the causal role of hypoadiponectinemia in GDM, adiponectin gene knockout ( Adipoq -/- ) and wild-type (WT) mice were crossed to produce pregnant mouse models with or without adiponectin deficiency. Adenoviral vector-mediated in vivo transduction was used to reconstitute adiponectin during late pregnancy. Results showed that Adipoq -/- dams developed glucose intolerance and hyperlipidemia in late pregnancy. Increased fetal body weight was detected in Adipoq -/- dams. Adiponectin reconstitution abolished these metabolic defects in Adipoq -/- dams. Hepatic glucose and triglyceride production rates of Adipoq -/- dams were significantly higher than those of WT dams. Robustly enhanced lipolysis was found in gonadal fat of Adipoq -/- dams. Interestingly, similar levels of insulin-induced glucose disposal and insulin signaling in metabolically active tissues in Adipoq -/- and WT dams indicated that maternal adiponectin deficiency does not reduce insulin sensitivity. However, remarkably decreased serum insulin concentrations were observed in Adipoq -/- dams. Furthermore, β-cell mass, but not glucose-stimulated insulin release, in Adipoq -/- dams was significantly reduced compared with WT dams. Together, these results demonstrate that adiponectin plays an important role in controlling maternal metabolic adaptation to pregnancy. © 2017 by the American Diabetes Association.

Adiponectin Deficiency Impairs Maternal Metabolic Adaptation to Pregnancy in Mice

PubMed Central

Qiao, Liping; Wattez, Jean-Sebastien; Lee, Samuel; Nguyen, Amanda; Schaack, Jerome; Hay, William W.

2017-01-01

Hypoadiponectinemia has been widely observed in patients with gestational diabetes mellitus (GDM). To investigate the causal role of hypoadiponectinemia in GDM, adiponectin gene knockout (Adipoq−/−) and wild-type (WT) mice were crossed to produce pregnant mouse models with or without adiponectin deficiency. Adenoviral vector–mediated in vivo transduction was used to reconstitute adiponectin during late pregnancy. Results showed that Adipoq−/− dams developed glucose intolerance and hyperlipidemia in late pregnancy. Increased fetal body weight was detected in Adipoq−/− dams. Adiponectin reconstitution abolished these metabolic defects in Adipoq−/− dams. Hepatic glucose and triglyceride production rates of Adipoq−/− dams were significantly higher than those of WT dams. Robustly enhanced lipolysis was found in gonadal fat of Adipoq−/− dams. Interestingly, similar levels of insulin-induced glucose disposal and insulin signaling in metabolically active tissues in Adipoq−/− and WT dams indicated that maternal adiponectin deficiency does not reduce insulin sensitivity. However, remarkably decreased serum insulin concentrations were observed in Adipoq−/− dams. Furthermore, β-cell mass, but not glucose-stimulated insulin release, in Adipoq−/− dams was significantly reduced compared with WT dams. Together, these results demonstrate that adiponectin plays an important role in controlling maternal metabolic adaptation to pregnancy. PMID:28073830

Applying the World Water and Agriculture Model to Filling Scenarios for the Grand Ethiopian Renaissance Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villa, Daniel L.; Tidwell, Vincent C.; Passell, Howard D.

The World Water and Agriculture Model has been used to simulate water, hydropower, and food sector effects in Egypt, Sudan, and Ethiopia during the filling of the Grand Ethiopian Renaissance Dam reservoir. This unique capability allows tradeoffs to be made between filling policies for the Grand Ethiopian Renaissance Dam reservoir. This Nile River Basin study is presented to illustrate the capacity to use the World Water and Agriculture Model to simulate regional food security issues while keeping a global perspective. The study uses runoff data from the Intergovernmental Panel for Climate Change Coupled Model Inter-comparison Project Phase 5 and informationmore » from the literature in order to establish a reasonable set of hydrological initial conditions. Gross Domestic Product and population growth are modelled exogenously based on a composite projection of United Nations and World Bank data. The effects of the Grand Ethiopian Renaissance Dam under various percentages of water withheld are presented.« less

New evidence of Yangtze delta recession after closing of the Three Gorges Dam

PubMed Central

Luo, X. X.; Yang, S. L.; Wang, R. S.; Zhang, C. Y.; Li, P.

2017-01-01

Many deltas are likely undergoing net erosion because of rapid decreases in riverine sediment supply and rising global sea levels. However, detecting erosion in subaqueous deltas is usually difficult because of the lack of bathymetric data. In this study, by comparing bathymetric data between 1981 and 2012 and surficial sediment grain sizes from the Yangtze subaqueous delta front over the last three decades, we found severe erosion and significant sediment coarsening in recent years since the construction of Three Gorges Dam (TGD), the largest dam in the world. We attributed these morphological and sedimentary variations mainly to the human-induced drastic decline of river sediment discharge. Combined with previous studies based on bathymetric data from different areas of the same delta, we theorize that the Yangtze subaqueous delta is experiencing overall (net) erosion, although local accumulation was also noted. We expect that the Yangtze sediment discharge will further decrease in the near future because of construction of new dams and delta recession will continue to occur. PMID:28145520

Egypt: after the Aswan Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walton, S.

1981-05-01

Ten years after its completion, the controversial Aswan High Dam's hydrologic and human consequences are clearer because of a joint US-Egyptian interdisciplinary study. Water supply and distribution is emerging as a major world resource problem with the recognition that unsafe drinking water and inadequate sanitation contribute to health problems. Dams provide water supplies, but they also create conditions favorable to the spread of water-borne diseases. The Aswan Dam solved problems of flooding and drought by opening 2.5 million acres to year-round irrigation, although some of the reclaimed land has been lost to urban expansion and shoreline erosion, and provides hydroelectricmore » power. The negative effects include increasing soil salinity, changes in the water table, excessive downstream water plant growth, and diseases such as schistosomiasis and other intestinal parasites, and the social impact on the Nubians, whose homeland was flooded. Planners must use the information gathered in this study to see that the benefits outweigh the human costs. 22 references, 7 figures.« less

An environmental streamflow assessment for the Santiam River basin, Oregon

USGS Publications Warehouse

Risley, John C.; Wallick, J. Rose; Mangano, Joseph F.; Jones, Krista L.

2012-01-01

The Santiam River is a tributary of the Willamette River in northwestern Oregon and drains an area of 1,810 square miles. The U.S. Army Corps of Engineers (USACE) operates four dams in the basin, which are used primarily for flood control, hydropower production, recreation, and water-quality improvement. The Detroit and Big Cliff Dams were constructed in 1953 on the North Santiam River. The Green Peter and Foster Dams were completed in 1967 on the South Santiam River. The impacts of the structures have included a decrease in the frequency and magnitude of floods and an increase in low flows. For three North Santiam River reaches, the median of annual 1-day maximum streamflows decreased 42–50 percent because of regulated streamflow conditions. Likewise, for three reaches in the South Santiam River basin, the median of annual 1-day maximum streamflows decreased 39–52 percent because of regulation. In contrast to their effect on high flows, the dams increased low flows. The median of annual 7-day minimum flows in six of the seven study reaches increased under regulated streamflow conditions between 60 and 334 percent. On a seasonal basis, median monthly streamflows decreased from February to May and increased from September to January in all the reaches. However, the magnitude of these impacts usually decreased farther downstream from dams because of cumulative inflow from unregulated tributaries and groundwater entering the North, South, and main-stem Santiam Rivers below the dams. A Wilcox rank-sum test of monthly precipitation data from Salem, Oregon, and Waterloo, Oregon, found no significant difference between the pre-and post-dam periods, which suggests that the construction and operation of the dams since the 1950s and 1960s are a primary cause of alterations to the Santiam River basin streamflow regime. In addition to the streamflow analysis, this report provides a geomorphic characterization of the Santiam River basin and the associated conceptual framework for assessing possible geomorphic and ecological changes in response to river-flow modifications. Suggestions for future biomonitoring and investigations are also provided. This study was one in a series of similar tributary streamflow and geomorphic studies conducted for the Willamette Sustainable Rivers Project. The Sustainable Rivers Project is a national effort by the USACE and The Nature Conservancy to develop environmental flow requirements in regulated river systems.