Spring Reservoir Research Articles

Use of recession-curve analysis for estimation of karstification degree and its application in assessing overflow/underflow conditions in closely spaced karstic springs

In the southern part of the Slovenský Kras Mountains, located on the Hungarian–Slovakian border, a transboundary karstic aquifer Dolný vrch/Alsohegy underlies the structure and discharges groundwater flow to 15 major karst springs around its margin. Hydrograph recession curves from nine-gauged springs on the Slovak part of the aquifer were analysed, and for each individual spring, depletion hydrograph equations were classified into different categories based on recessional parameters quantitatively describing individual groundwater flow sub–regimes. Discharge depletion was used to create recessional equations, and these were linked to karstification degree, a qualitative scale ranging from 1 to 10. A new application of hydrograph separation was based on examining and combining pairs of springs that likely fit into the category of overflow/underflow springs for a single groundwater reservoir. Recession-curve analysis performed on coupled discharges of two pairs of neighbouring springs was conducted to examine their possible linkage as a single groundwater reservoir, with an overflow outlet and underflow outlet. In the process of discharge coupling, discharges of the springs, hypothesized to be branches of the same source and observed at the same time were simply added together. By analyzing the resulting new time series, a new classification of sub-regimes could be generated. Surprisingly, new facts were revealed about the overflow/underflow springs, which primarily were not recognized previously as being connected components of a single groundwater reservoir. Summations of combined overflow/underflow discharge volumes of a single spring reservoir led to discovery of apparent presence of turbulent flow sub-regimes on the coupled recession curve. Presence of possible overflow/underflow springs of a single groundwater basin should be considered during hydrograph analyses if the springs have attributes that suggest they may be part of a combined flow system. Treating these springs as separate entities as a result can produce significant misinterpretation of drainage parameters. Furthermore, identification of overflow branches facilitates the generation of new research ideas for further speleological investigations nearby, and for assessing the system in a more effective manner.

Single step purification and characterization of a thermostable and calcium independent α-amylase from Bacillus amyloliquifaciens TSWK1-1 isolated from Tulsi Shyam hot spring reservoir, Gujarat (India)

A thermophilic bacteria, identified and designated as Bacillus amyloliquifaciens TSWK1-1 (16S rRNA gene sequence, GenBank: GQ121033), was isolated from a hot water reservoir located at Tulsi Shyam, Gujarat, India. The optimum temperature and pH for amylase production were 50°C and 7.0, respectively. The crude enzyme was partially purified by ammonium sulphate fractionation followed by dialysis. However, single step purification was achieved on Phenyl Sepharose 6FF affinity column with 45.71% yield, 8000U/mg specific activity and 13.33 fold purification. The molecular weight of the purified α-amylase was 43kD. The optimal temperature and pH for amylase activity were 70°C and 7.0, respectively; however, the purified amylase was stable at broad temperature and pH range. The purified amylase did not require Ca++ and K+; however, it was moderately affected by Mg++ and Cu++ and significantly inhibited by Na+ and Fe++. The amylase was highly thermostable and remained active for 24h at 60°C, for 12h at 70°C and up to 3h even at 90°C. Other unique features of the enzyme were calcium independent nature and resistance against chemical denaturation by Urea and Guanidine–HCl. The data on the enzymatic stability at different levels of purity would add significantly to the knowledge of amylases.

Drinking water quality and protection of resources

Abstract The structure of public water supply in Germany and the water resources used are briefly described. An overview over the legal requirements for drinking water is given, and the sources for contaminants are outlined. Then the multiple-barrier approach is discussed with respect to the resources groundwater and spring water, lake and reservoir water, and river water. Examples for treatment schemes are given and the principle of subsurface transport of river water as a first treatment step is described.

Probable regional geothermal field reconnaissance in the Aegean region from modern multi-temporal night LST imagery

The Hellenic Peninsula and the adjacent Aegean and Ionian seas are segmented into regions on the basis of Terra satellite-MODIS instrument derived land surface temperatures (LST) to test if they can be used in the field reconnaissance for potential geothermal targets, each region representing a different thermal signature. The method has been used successfully to identify hot spot and geothermal activity in the Afar Triangle and in the Red Sea. Night monthly average LST values per pixel, since 2001, are used in this work for geothermal field identification. Average LST seasonal variability is expressed by a common centroid curve of pixel cluster. Clusters were subsequently ranked in increasing LST according to their centroids. Cluster-2 represents by far the Aegean volcanic arc (AVA) which comprises the high enthalpy (320 and 350°C, respectively) geothermal fields of Milos and Nisyros. The interpretation of LST terrain segmentation into sub-clusters of Cluster-2 is consistent with thermal anomalies related to the volcano-islands of the AVA, the occurrence of thermal anomalies related to granodiorite plutons in the Cyclades and to the volcano-related anomalies of the Dodecanese Province. We conclude that the identification of such thermal anomalies obtained by a combination of remote sensing (LST), regional geology and field data (borehole, thermal spring and subsurface hydrothermal reservoir temperatures) can be a particularly useful exploration tool for localizing geothermal anomalies.

Forecasting Spring Reservoir Inflows in Churchill Falls Basin in Québec, Canada

The performance of different models and procedures for forecasting aggregated May–July streamflow for the Churchill Falls basin on the Québec-Labrador peninsula is compared. The models compared have different lead times and include an autoregressive model using only past streamflow data, an autoregressive with exogenous input model utilizing both past streamflow and precipitation, and a linear regression model using the principal components of exogenous measures of atmospheric circulation inferred from the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis project. The forecast skills of the different approaches are compared using a variety of measures of performance. The results indicate that relatively accurate forecasts using only measures of atmospheric circulation can be issued as early as in December of the prior year. A multimodel combination approach is found to be more effective than the use of a single forecast model. In addition, it is concluded that forecasting models utilizing atmospheric circulation data are useful, especially for basins where hydroclimatic observations are scarce and for basins where flows and other hydroclimatic variables are not strongly autocorrelated (do not depend on their past).

BALD EAGLE FORAGING AND RESERVOIR MANAGEMENT IN NORTHERN CALIFORNIA

We studied food habits, mechanisms of prey acquisition, and the effects of reservoir drawdown and fisheries management in a population of Bald Eagles (Haliaeetus leucocephalus) nesting on Shasta (Lake) Reservoir, a large impoundment in northern California used intensively for irrigation and recreation. Prey deliveries at seven nests were mostly bass (Micropterus sp., 55% of total prey biomass) and salmonids (14%), and all principal fish prey species were either introduced or regularly stocked. Carrion and moribund fish, mostly bass, accounted for >75% of successful foraging attempts. Fish mortality was related to spawning stress, disease, and catch-and-release angling; fish fatalities associated with bass fishing provided carrion throughout the breeding season. The proportions of fish species in the eagles' diet, as measured by prey deliveries to the nest, were positively correlated with those found in live-fish sampling and carrion surveys; all were predominantly bass. Benefits associated with seasonal and long-term reservoir drawdown included exposing spawning and foraging fish to eagle predation, and the likely release of nutrients and food for rapid fish growth upon re-inundation. Probable disadvantages of extended drawdown included loss of eagle foraging habitat and reductions in the standing crop of fish, likely resulting in competition among eagle pairs. Bald Eagle productivity was at or above average during the 2-yr study, a relatively wet period following a long drought and associated low pool levels, and we found a positive relationship between historic spring reservoir levels and Bald Eagle productivity from 1979–1999. Effects of fish introductions on trophic relationships and species composition warrant careful examination of eagle foraging requirements; however, past and present fisheries management appears to be currently benefiting the opportunistic eagles.

Modelling the impact and potential mitigation of cold water pollution on Murray cod populations downstream of Hume Dam, Australia

AbstractA one‐dimensional hydrodynamic reservoir model is coupled with a stochastic fish population model to examine the impacts of cold water pollution (CWP) on the Australian freshwater fish, Murray cod, downstream of Hume Dam, Australia. Mitigation of CWP through the introduction of selective withdrawal capabilities to access near‐surface water is predicted to increase discharge temperatures during the crucial spring‐early summer post‐spawning period by 4–6°C for normal operating conditions, that is, a full reservoir in early spring. No improvement in discharge temperature was predicted for drought conditions characterized by relatively low storage levels in early spring. The predicted temperature increase using selective withdrawal increased the predicted average minimum female population abundance by 30–300% depending on the assumed spawning behaviour. Increased discharge temperatures appear to be achievable and are expected to reduce the stress currently impacting Murray cod populations due to CWP during crucial post‐spawning periods. This provides evidence that mitigation of this problem may assist in rehabilitating Murray cod populations in the Murray River downstream of Hume Dam. Copyright © 2007 John Wiley & Sons, Ltd.

Regulation of Rotifer Community by Predation of Cyclops vicinus (Copepoda) in the Římov Reservoir in Spring

AbstractThe structuring role and predation impact of Cyclops vicinus on the rotifer community was studied using in situ enclosure experiments in Římov Reservoir during the spring of 2000. Seasonal changes in abundance and birth rates of the rotifer species Synchaeta lakowitziana , Polyarthra spp., Keratella cochlearis and Kellicottia longispina were related to predation pressure, i.e. selectivity and cropping rates of C. vicinus . All four rotifer species were found to be consumed by C. vicinus whose predation rates showed a marked succession through the spring period and corresponded to changes in the relative abundance of the pelagic species. The highest predation rates exhibited by C. vicinus were on Synchaeta lakowitziana and Polyarthra spp., being 11.3 and 6.4 ind Cyclops –1 day–1 respectively. The activity of the predator switched among three types of preferred food during the spring period. The most preferred, Synchaeta, was replaced by Polyarthra after Synchaeta became extinct and these species were replaced by Keratella when both soft‐bodied forms were not available in sufficient quantities. Loricated species (K. cochlearis and K. longispina) were consumed at a slower rate. We calculated the proportion of rotifer production cropped day–1 in order to estimate the predation impact of C. vicinus , which ranged from 11.6 to more than 100% over time and rotifer species. This shows that relative predation impact can be high not only on species most strongly selected, but also on species which are not selected. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Inflight straylight analysis for ASTER thermal infrared bands

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument was launched into Earth orbit on the Terra platform in late 1999. ASTER produces images of the Earth in 14 spectral bands including five bands in the thermal infrared (TIR) part of the electromagnetic spectrum (8-12 /spl mu/m). On one occasion ASTER was used to image the Moon as part of the long-term calibration strategy for instruments on the Terra platform. Analysis of the imagery revealed that the TIR band had noticeable straylight effects (ghosting), and an algorithm was developed to correct for these effects. The algorithm was applied to ASTER/TIR images acquired over a vicarious calibration (VC) site at Cold Springs Reservoir (CSR), NV. Data from CSR had been evaluated in three previous VC experiments and showed large unexplained differences between the ASTER image radiance and vicarious predicted radiance not observed in other larger, more laterally homogenous sites. After straylight correction the vicarious and image radiances were in good agreement. A further comparison with nearly simultaneous airborne TIR data acquired with the MODIS/ASTER (MASTER) sensor indicated that the ASTER straylight corrected data also agreed with the airborne data. Finally, the algorithm was applied to artificially created models. The results indicated that a radiance change caused by straylight reached 6% to 8% of a radiance contrast for a smaller square target than 10/spl times/10 pixels or a narrower line target than five pixels. Straylight in ASTER/TIR imagery may not be very large for most targets, but may become an error factor for high-radiance-contrast targets.

Impact of meteorological predictions on real‐time spring flow forecasting

AbstractMeteorological predictions, such as precipitation and temperature, are commonly used to improve real‐time hydrologic forecasting, despite their inherent uncertainty and their absence in the model calibration stage. In this study, we quantify the effect of meteorological prediction errors on the accuracy of daily spring reservoir inflow forecasts using weather predictions in both the model calibration and testing phases. Different modelling experiments are compared using an operational conceptual model and nonlinear empirical models to assess the effects of using daily numerical weather predictions as opposed to the use of historical observations. It is found that, even with large prediction errors, meteorological forecasts can provide significant improvement of spring flow forecast for up to 7 days lead time, particularly for low flows. Spring flow prediction errors associated with the type of hydrological model used are significantly larger than those related to the meteorological predictions, particularly for 1 to 4 days ahead forecasts. The experimental results also indicate that multiple model‐based forecasting using an iterative prediction approach appears to be the most effective method for an adequate use of weather predictions. Copyright © 2003 John Wiley & Sons, Ltd.

Stream-Channel Position of Adult Rainbow Trout Downstream of Navajo Reservoir, New Mexico, Following Changes inReservoir Release

Because of potential conflicts between management of reservoir releases for endangered native fishes and tailwater trout fisheries, we used radiotelemetry to monitor channel position of rainbow trout Oncorhynchus mykiss during elevated spring reservoir releases designed to benefit native fishes. Fish were monitored at two sites downstream of Navajo Dam, New Mexico: a site with braided channels 0.6 km downstream of the dam and a less complex site 6 km downstream of the dam. Fish were also radio-tagged and monitored during the winter at the upstream site to study movement patterns during low-flow conditions. Of 17 fish monitored during elevated spring discharge, transmitter signals from 5 fish were lost during increased flows; the other 12 fish remained near the point of capture and moved laterally into shoreline and side channel habitats during increased flows. Comparisons between the upstream and downstream sites were confounded by our inability to locate four fish at the downstream site. Fish monitored during winter, low-flow conditions showed little overall movement and no preference for shoreline habitats. Our observations suggest that elevated spring discharge from Navajo Reservoir does not cause long-distance displacement of adult rainbow trout.

Phytoplankton composition, dominance and abundance as indicators of environmental compartmentalization in Jurumirim Reservoir (Paranapanema River), Sao Paulo, Brazil

Patterns in the spatial and temporal composition, dominance and abundance of the phytoplankton community of the Jurumirim Reservoir (Brazil) were studied during one year at ten different sampling stations. The main phytoplankton associations were characterized by diatoms and blue-green algae, in distinctive patterns of dominance. The main species were Microcystis aeruginosa Kuetz, Anabaena circinalis Rabenhorst, A. spiroides Kleb., A. solitaria Kleb., Aulacoseira cf. italica Grunow and A. granulata (Ehr.) Simon. A high growth of Aulacoseira was observed in the upstream zones of the reservoir in spring, at the beginning of the seasonal rainy period. This growth was a response to increased flow rates and input of fresh nutrients by the main feeder rivers. A high concentration of blue-green algae, especially Anabaena circinalis and A. spiroides, was observed in winter (dry season) in the lacustrine part of the reservoir, towards the dam. These algae benefitted from the longer water retention times and greater internal circulation of nutrients in the absence of a thermocline at this time of the year. Among the Cyanophyceae, there was an alternation between M. aeruginosa, more abundant in summer, and Anabaena, dominant in autumn and winter. A conspicuous growth of Anabaena occurred in a diverticle of the reservoir, sheltered from the main advective processes that predominate in the central channel. Higher phytoplankton diversity was associated with the contact zone between riverine and lacustrine systems.

Paleoseismic studies of the San Francisco Peninsula segment of the San Andreas Fault zone near Woodside, California

A late Holocene slip rate is proposed for the San Francisco Peninsula segment of the San Andreas fault zone at the Filoli Center, located between the town of Woodside and Upper Crystal Springs Reservoir, California. At this site the primary trace of the San Andreas fault zone traverses N35°W across the head of a large alluvial fan, offsetting buried stream channel deposits. One deposit, with a minimum calibrated accelerator mass spectrometry (AMS) radiocarbon age of 2070±120 years B.P., is offset 30±2 m, yielding an average geologic slip rate of 17±4 mm yr−1 for the late Holocene. A stratigraphically lower channel sequence, with a minimum calibrated AMS radiocarbon age of 330±200 years B.P., is offset 4.1±0.5 m. We interpret that this older sequence records both the penultimate earthquake on the peninsula segment, accompanied by 1.6±0.7 m of dextral slip, and the ∼2.5 m of slip that occurred in 1906. On the basis of radiocarbon analyses and historical descriptions we propose that the pre‐1906 earthquake occurred in June 1838. Our interpretations suggest that the San Francisco Peninsula segment of the San Andreas fault zone may rupture in earthquakes of at least two magnitudes: (1) a large‐magnitude (≈Mw 8) event with a recurrence of ∼250–320 years that involves the North Coast, San Francisco Peninsula, and Santa Cruz Mountains segments, as occurred in 1906 and (2) a Mw 7.0–7.4, 1838‐type event that ruptures only the San Francisco Peninsula segment. The apparent difference in slip rate of 7 ± 7 mm ‐yr−1 between the North Coast segment (24±3 mm yr−1) and the peninsula segment (17±4 mm yr−1) suggests a possible slip rate gradient on the northern California section of the San Andreas fault.

Commentary: senior-serve: an ethical case study

A small but growing number of watershed investment programs in the western United States focus on wildfire risk reduction to municipal water supplies. This paper used return on investment (ROI) analysis to quantify how the amounts and placement of fuel treatment interventions would reduce sediment loading to the Strontia Springs Reservoir in the Upper South Platte River watershed southwest of Denver, Colorado following an extreme fire event. We simulated various extents of fuel mitigation activities under two placement strategies: (a) a strategic treatment prioritization map and (b) accessibility. Potential fire behavior was modeled under each extent and scenario to determine the impact on fire severity, and this was used to estimate expected change in post-fire erosion due to treatments. We found a positive ROI after large storm events when fire mitigation treatments were placed in priority areas with diminishing marginal returns after treating >50–80% of the forested area. While our ROI results should not be used prescriptively they do show that, conditional on severe fire occurrence and precipitation, investments in the Upper South Platte could feasibly lead to positive financial returns based on the reduced costs of dredging sediment from the reservoir. While our analysis showed positive ROI focusing only on post-fire erosion mitigation, it is important to consider multiple benefits in future ROI calculations and increase monitoring and evaluation of these benefits of wildfire fuel reduction investments for different site conditions and climates.

Length-Dependent Winter Survival and Lipid Composition of Age-0 Largemouth Bass in Bay Springs Reservoir, Mississippi

Age-0 largemouth bass Micropterus salmoides were studied in Bay Springs Reservoir, Mississippi, to determine if the larger young had greater survival through their first winter and if this survival was influenced by levels of energy reserves. Abundance decreased from 542 young/ hectare in June, when fish averaged 37 mm total length, to 12/hectare in March, when lengths averaged 149 mm. The length-frequency distribution of this year–class was positively skewed during June–August, became bimodal during September–January, and lost most of the smaller mode by March. During September–January, fish in the smaller mode decreased in abundance from 176 to 9/hectare and their mean length remained near 60 mm; fish in the larger mode decreased in abundance from 76 to 27/hectare and increased in length from 108 to 154 mm. Whole-body lipid content increased from 3.5% of dry body weight in fall to 5.9% in December and decreased to 3.3% in March. All young had equal amounts of stored lipid by late fall, but by March the surviving small young had less lipid than large young, suggesting that during winter smaller fish spent their reserves at a faster rate. Protein content averaged 74.6% of the dry body weight and neither differed among months nor changed with fish length. Mortality of the smallest young was accelerated in late fall and winter, coinciding with decreases in lipid stores and rapid drops in water temperature.

Denying the Desert

The home of Disneyland and Universal Studios, Hearst Castle and the San Diego Chargers, California has nurtured a variety of fantasies and dreams. For a century and a half, hope and denial concocted an intoxicating brew, luring millions of Americans to this remarkable place. California, as Norris Hundley reminds us, not only ranks first within the United States in population (30 million), agriculture, and industry but, if listed among the nations of the world, it is the fourth most significant economic entity. At the close of World War II California seemed to be a land of unlimited promise. For individuals such as my father, a Norwegian immigrant's son who had grown up on the icy shore of Lake Erie and graduated to a teaching job in Detroit, it offered not only a new winter but a new chance. He and my mother bought their one and only home, a well-built but modest three-bedroom ranch-style house, for perhaps 3 percent of its current value. Constructed a few miles from the San Andreas fault and the Crystal Springs reservoir, that home symbolizes a postwar California prosperity that recently has become more fragile with each passing year. To most outsiders the fragility appears to lie with the fault; to most Californians the Great Thirst may be more perilous than the Big One. Of course many citizens would just as soon refocus the discussion entirely. For example, many see the state as an environmental haven-more schools, parks, and public places have been named after John Muir than any other person. But Muir died in 1914, a broken-hearted man, after the decision had been made to flood his beloved Hetch Hetchy. The waters from the valley flowed westward to their storage facility south of San Francisco -to quiet, pristine Crystal Springs. Growing up in California I learned early on to appreciate Carey McWilliams's observation that water was the key that unlocked the riches of the arid West. In The Great Thirst Norris Hundley provides us with an illuminating

Feeding of Predaceous Fishes on Out-Migrating Juvenile Salmonids in John Day Reservoir, Columbia River

Diets of northern squawfish Ptychocheilus oregonensis, smallmouth bass Micropterus dolomieu, walleye Stizostedion vitreum, and channel catfish Ictalurus punctatus from John Day Reservoir were examined to determine the extent of predation on juvenile salmonids during seaward migrations of the salmonids during April–August 1983–1986. Juvenile Pacific salmon Oncorhynchus spp. and steelhead O. mykiss were the most important food group (by weight) of northern squawfish – about 67% – but made up smaller proportions of the food of the other predators: channel catfish, 33%; walleyes, 14%; smallmouth bass, 4%. Seasonal changes in diets indicated that northern squawfish preferred juvenile salmonids in May and August (generally the peak period of salmonid out-migration), and switched to prickly sculpin Cottus asper when numbers of juvenile salmonids declined; walleyes and smallmouth bass showed a preference only for prickly sculpin among the prey fishes analyzed. As judged by dietary composition and prey selectivity, the northern squawfish was the major fish predator on juvenile salmonids in the reservoir; channel catfish also were important predators in the upper reservoir in spring. Walleyes and smallmouth bass were much less important predators on salmonids, and appeared to select subyearling chinook salmon only in August when the distribution of this prey overlapped with that of the predators. Size-selective predation by northern squawfish may also play an important role in reducing survival of the smaller individuals within each run of out-migrating juvenile salmonids.

Seismic evaluation of lifeline systems--case studies

This book contains the papers presented at the technical session titled Seismic Evaluation of Lifeline Systems—Case Studies at the ASCE Fall Convention in Boston, October 27-31, 1986. The session was a follow-up to an early effort on presenting the current research results on lifeline earthquake engineering around the world. Three papers from the United States deal with case studies in Boston, the Crystal Springs Reservoir outlet system in San Francisco, and the risk analysis for the Molelumne Aqueduct in California. Three papers from China deal with seismic damage analysis and its aseismic measures of sewer pipelines, seismic evaluation of several lifeline systems including above and below ground lifelines, and retaining structures in liquified regions.

Production of the chironomid Procladius bellus in an annual drawdown reservoir

SUMMARY. 1. In Laurel Creek Reservoir. Ontario, a small, eutrophic annual drawdown reservoir, some individuals of the chironomid Procladius bellus survive the winter drawdown.2. With refilling of the reservoir in spring, colonization by P. bellus is continuous and there were three generations a year.3. Production estimated by the size‐frequency method was 117.12 kg (175 mg m−2) in 1980 and 70.14 kg (105 mg m‐2) in 1981. Annual P:B was about 13 in both years.4. Substantial slation‐to‐station variations in production occurred and overall production was lower than in shallow habitats.

Holocene history of the San Andreas fault between Crystal Springs Reservoir and San Andreas Dam, San Mateo county, California

Abstract The geologic part of a seismic safety investigation of San Andreas Dam focused on a two mile reach of the fault between the dam and Crystal Springs Reservoir. Historical documents and detailed mapping revealed that the 1906 faulting caused 7 to 9 ft of right shear in the left (eastern) abutment and occurred on nearly straight traces that experienced a maximum of 9 ft of slip, 90 per cent of which was concentrated within a zone 100 ft wide. Radiocarbon dates on detrital charcoal from two sites of ponded alluvium established that the 1906 traces have been active for at least the last 3,000 yr. Deflected stream channels further indicate that the 1906 traces have been the locus of right slip for the last 6500 yr and perhaps for all of Holocene time. Detailed geomorphic and stratigraphic analyses of one site showed that five 1906 magnitude slip events have occurred within the last 1130 ± 160 radiocarbon years from which a minimum strain rate of 1.2 cm/yr and an average recurrence frequence of 224 ± 25 yr can be calculated. Trenches excavated across the 1906 traces of the San Andreas fault revealed that the zone of active faulting is marked by a slow upwelling of highly sheared rock materials. This apparent vertical movement of fault gouge, when coupled with right shear and differential stream erosion, has produced most of the distinctive landforms of the rift valley.