Maximum Stream Research Articles

Influence of Variable Streamside Management Zone Configurations on Water Quality after Forest Harvest

Streamside management zones (SMZs) are a common best management practice (BMP) used to reduce water quality impacts from logging. The objective of this research was to evaluate the impact of varying SMZ configurations on water quality. Treatments (T1, T2, and T3) that varied in SMZ width, canopy retention within the SMZ, and BMP utilization were applied at the watershed scale to two watersheds each. Watersheds with wider SMZs (T3: 110 ft, 100% canopy retention) and improved crossings were not significantly different from unharvested control (C) watersheds for all parameters except nitrate and diurnal stream temperatures. Changes in total suspended solids, turbidity, nitrate, dissolved oxygen, and maximum stream temperature were detected for watersheds treated with the current recommended minimum SMZ configurations (T1: 55 ft, 50% canopy retention) and watersheds with unharvested SMZs (T2: 55 ft, 100% canopy retention) and improved crossings.

Effective Analysis by Arrangement of Multi-Baffle at Weir Downstream

The purpose of the study is to analyze the reduction effects of multi-baffle installed for improving the scour issue of weir downstream and the study reviewed the flow reduction effect for the location of the battle and the reduction effect associated with the baffle installation. We carried out nine cases of experiments and analyzed reduction effects through the flow rate comparison for the arrangement type of the cases. As the result of the experiment, the maximum flow rate in the weir downstream of the case 1, which has no baffle installation, is measured at 2.068 m/s due to multidirectional flow and crossing waves, and channel walls had whirlpool generation on the left and right with fast discharge flow. The maximum water level showed lower water level than when the battle was installed as there is no flow resistance. The maximum stream velocity in the weir downstream from cases 2 to 9 installed with a baffle demonstrated reduction in the maximum stream velocity than before the battle was installed and showed an increased tendency than before the baffle was installed as the maximum water level is affected by flow resistance. As the result of the comparison of the reduction effect by installing the baffle, the V type of the case 6 demonstrated the best reduction effect.

Constructal allocation of heat transfer area in Flue Gas Desulfurization equipment for coal-firing power plants

In this paper, we report opportunities to maximize the overall heat transfer rate of a cooler and reheater by appropriately shaping the flue gas desulfurization equipment of a thermal power plant driven by coal-firing combustion. The hottest combustion gas experiences a temperature drop through the cooler, which heats the water that circulates through the cooler and reheater. Constructal design is implemented in order to determine flow configurations that are superior. The overall heat transfer area is constrained (finite). We show that the most effective allocation of the heat transfer area can be pursued so that the maximum heat transfer density (or, compactness, as watts per volume) is achievable. The paper also documents two design candidates at the cooler outlet (with and without a maximum allowable gas stream temperature) and considers the balanced and unbalanced counter flows. The performance is superior when more degrees of freedom are allowed in the design. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of Environmental Water Transfers on Stream Temperatures

Low streamflows and warm stream temperatures currently limit habitat and productivity of trout, including native Lahontan cutthroat trout in Nevada's Walker Basin. Environmental water transfers, which market water from willing sellers to instream uses, are evaluated to improve instream habitat. We use River Modelling System, an hourly, one-dimensional hydrodynamic and water quality model, to estimate current and potential environmental water transfer effects on stream temperatures. Model runs simulate a range of environmental water transfers, from 0.14 to 1.41 cms, at diversions and reservoirs for wet year 2011 and dry year 2012. Results indicate that critically warm stream temperatures generally coincide with low flows, and thermal refugia exist in East Walker River, a tributary of the Walker River. Environmental water transfers reduce maximum stream temperatures by up to 3 °C in dry years and are more effective in dry years than wet years. This research suggests that environmental water transfers can enhance instream habitat by improving water quality as well as increasing instream flow. Copyright © 2015 John Wiley & Sons, Ltd.

Numerical study of magnetic field on mixed convection and entropy generation of nanofluid in a trapezoidal enclosure

The flow under influence of magnetic field is experienced in cooling electronic devices and voltage transformers, nuclear reactors, biochemistry and in physical phenomenon like geology. In this study, the effects of magnetic field on the flow field, heat transfer and entropy generation of Cu–water nanofluid mixed convection in a trapezoidal enclosure have been investigated. The top lid is cold and moving toward right or left, the bottom wall is hot and the side walls are insulated and their angle from the horizon are 15°, 30°, 45° and 60°. Simulations have been carried out for constant Grashof number of 104, Reynolds numbers of 30, 100, 300 and 1000, Hartmann numbers of 25, 50, 75 and 100 and nanoparticles volume fractions of zero up to 0.04. The finite volume method and SIMPLER algorithm have been utilized to solve the governing equations numerically. The results showed that with imposing the magnetic field and enhancing it, the nanofluid convection and the strength of flow decrease and the flow tends toward natural convection and finally toward pure conduction. For this reason, for all of the considered Reynolds numbers and volume fractions, by increasing the Hartmann number the average Nusselt number decreases. Furthermore, for any case with constant Reynolds and Hartmann numbers by increasing the volume fraction of nanoparticles the maximum stream function decreases. For all of the studied cases, entropy generation due to friction is negligible and the total entropy generation is mainly due to irreversibility associated with heat transfer and variation of the total entropy generation with Hartmann number is similar to that of the average Nusselt number. With change in lid movement direction at Reynolds number of 30 the average Nusselt number and total entropy generation are changed, but at Reynolds number of 1000 it has a negligible effect.

Effect of Perpendicular Magnetic Field on Free Convection in a Rectangular Cavity

The steady free convective flow of a viscous incompressible and electrically conducting fluid in a two-dimensional cavity in the presence of a magnetic field applied normal to the plane of the cavity is investigated. The side vertical walls of the cavity are heated differentially while the horizontal walls are assumed to be insulated. The governing equations are re-formulated in terms of vorticity and stream function. The resulting boundary value problem is solved numerically using an alternating direction implicit (ADI) method. A number of plots illustrating the influence of Hartmann number and Rayleigh number on the streamlines and isotherms as well as the velocity and temperature profiles are shown. Furthermore, results for the average Nusselt number and the maximum absolute stream function have been obtained, and these are compared with the corresponding results in the literature when the magnetic field is applied along the cavity in the horizontal direction.

Modelling temperature change downstream of forest harvest using Newton's law of cooling

We adapted Newton's law of cooling to model downstream water temperature change in response to stream-adjacent forest harvest on small and medium streams (average 327 ha in size) throughout the Oregon Coast Range, USA. The model requires measured stream gradient, width, depth and upstream control reach temperatures as inputs and contains two free parameters, which were determined by fitting the model to measured stream temperature data. This model reproduces the measured downstream temperature responses to within 0.4 °C for 15 of the 16 streams studied and provides insight into the physical sources of site-to-site variation among those responses. We also use the model to examine how the pre-harvest to post-harvest change in daily maximum stream temperature depends on distance from the harvest reach. The model suggests that the pre-harvest to post-harvest temperature change approximately 300 m downstream of the harvest will range from roughly 82% to less than 1% of that temperature change that occurred within the harvest reach, depending primarily on the downstream width, depth and gradient. Using study-averaged values for these channel characteristics, the model suggests that for a stream representative of those in the study, the temperature change approximately 300 m downstream of the harvest will be 56% of the temperature change that occurred within the harvest reach. This adapted Newton's law of cooling procedure represents a highly practical means for predicting stream temperature behaviour downstream of timber harvests relative to conventional heat budget approaches and is informative of the dominant processes affecting stream temperature. Copyright © 2015 John Wiley & Sons, Ltd.

Hierarchical Bayesian clustering for nonstationary flood frequency analysis: Application to trends of annual maximum flow in Germany

AbstractEspecially for extreme precipitation or floods, there is considerable spatial and temporal variability in long term trends or in the response of station time series to large‐scale climate indices. Consequently, identifying trends or sensitivity of these extremes to climate parameters can be marked by high uncertainty. When one develops a nonstationary frequency analysis model, a key step is the identification of potential trends or effects of climate indices on the station series. An automatic clustering procedure that effectively pools stations where there are similar responses is desirable to reduce the estimation variance, thus improving the identification of trends or responses, and accounting for spatial dependence. This paper presents a new hierarchical Bayesian approach for exploring homogeneity of response in large area data sets, through a multicomponent mixture model. The approach allows the reduction of uncertainties through both full pooling and partial pooling of stations across automatically chosen subsets of the data. We apply the model to study the trends in annual maximum daily stream flow at 68 gauges over Germany. The effects of changing the number of clusters and the parameters used for clustering are demonstrated. The results show that there are large, mainly upward trends in the gauges of the River Rhine Basin in Western Germany and along the main stream of the Danube River in the south, while there are also some small upward trends at gauges in Central and Northern Germany.

Urbanização e Impactos no Ciclo Hidrológico na Bacia do Mineirinho

Este trabalho teve como objetivo comparar cenários de ocupação urbana e seus efeitos no ciclo hidrológico da Bacia do Mineirinho. Buscou-se avaliar os riscos de enchentes causados pelo aumento das áreas de impermeabilização que tem ocorrido com a implantação do novo Campus da USP, São Carlos, SP. Foram estabelecidos quatro cenários de ocupação urbana: cenário pré-urbanização (1972); cenário 2000, cenário 2025 com Plano Diretor (CPD); e cenário 2025 sem Plano Diretor (SPD). Para comparação dos diferentes cenários realizaram-se simulações hidrológicas com modelo hidrológico IPH II. Pode-se observar que no cenário 2025 SPD a vazão máxima aumentou 388,0% quando comparada ao cenário 1972 e 319,4% quando comparada ao cenário 2000. Entre os cenários 2025 CPD e 2025 SPD há diminuição de 22,3% na vazão máxima e aumento no tempo de pico é de 50 minutos. Mesmo com aplicação de diretrizes do PD os riscos de inundações continuam altos.

Regression Analysis of Annual Maximum Daily Rainfall and Stream Flow for Flood Forecasting in Vellar River Basin

Flood is a natural demolishing phenomenon, forecast of which is of high importance, to reduce its impact. On the other hand, it also serves as a major source of water when conserved through proper means. For this purpose, estimation of flood is of at utmost importance. The present study employed regression analysis between weighted maximum rainfall and maximum stream flow for the flood events of respective catchments of Vellar river basin. Regression equation was framed between Annual Maximum Daily Rainfall, Stream Flow and area for each catchment. Based on the equation, flood prioritization rank was given to each of the catchment. Thereby, Lower Vellar is prioritized as first rank and Upper Vellar is prioritized as last rank respectively. This study reveals that the Lower Vellar is the most vulnerable catchment and which needs flood control measures.

Seasonal river flow variability of the Middle and Lower Danube and its tributaries

The seasonality of stream flow variability indicates special feature of local cycle of precipitations, evaporation and the timing of snow melt. This study presents seasonal occurrence of maximal and minimal annual flows and spatial variability of seasonal index (Is) in the Middle and Lower Danube basin. The analysis is based on 47 time series of monthly runoff (12 for the Danube and 35 for its tributaries), which are collected from public database. The results show that the maximum annual stream flow appears during all months, but with highest frequency in April for 68% from watersheds. It varies between one and 60% (Danube – Baziaz). The monthly flow is concentrated in summer–autumn hydrological season, except for the Jalomita, Siret and Prut river basins, where it is in the winter. The highest frequency of minimum monthly runoff for the Danube and the Tisza is in October and November and for the Sava and Velika Morava – in August and September. The lowest and highest monthly discharge of the given month in the entire period were recorded in different years. Seasonal index (Is) is between 0.98 and 3.18. It is about 1.00 for the Danube and more than 2.00 for the Tisza, Ialomita, Siret and Prut watersheds. Is is stability – coefficient of variation is up to 0.30 with the exception of several river basins. Stream flow variability of the Middle and Lower Danube can provide valuable information for scientific studies and integrated management of water resources.

Lattice Boltzmann simulation of magnetohydrodynamic natural convection heat transfer of Al 2 O 3 –water nanofluid in a horizontal cylindrical enclosure with an inner triangular cylinder

Abstract In this study the lattice Boltzmann method is applied to investigate the effect of magnetic field on natural convection heat transfer of Al 2 O 3 –water nanofluid in a two-dimensional horizontal annulus. In this model, the effect of Brownian motion on the effective thermal conductivity is also considered. The effective thermal conductivity and the effective viscosity of nanofluid are calculated by KKL (Koo–Kleinstreuer–Li) correlation. The effect of nanoparticle volume fraction for the enhancement of heat transfer was examined for several sets of values of Rayleigh and Hartmann numbers. Also, a correlation of the Nusselt number with physical parameters is presented. The obtained results indicate that the value of the maximum stream function decreases with increasing Hartmann number. Furthermore, we notice that the Nusselt number has a direct relationship with the Rayleigh number; but quite the opposite is true with the Hartmann number. The obtained results indicate that the Lattice Boltzmann method with double-population is a powerful approach for the simulation of natural convection heat transfer in nanofluids in regions with curved boundaries.

Instream Habitat Restoration and Stream Temperature Reduction in a Whirling Disease‐Positive Spring Creek in the Blackfoot River Basin, Montana

AbstractAnthropogenic warming of stream temperature and the presence of exotic diseases such as whirling disease are both contemporary threats to coldwater salmonids across western North America. We examined stream temperature reduction over a 15‐year prerestoration and postrestoration period and the severity of Myxobolus cerebralis infection (agent of whirling disease) over a 7‐year prerestoration and postrestoration period in Kleinschmidt Creek, a fully reconstructed spring creek in the Blackfoot River basin of western Montana. Stream restoration increased channel length by 36% and reduced the wetted surface area by 69% by narrowing and renaturalizing the channel. Following channel restoration, average maximum daily summer stream temperatures decreased from 15.7°C to 12.5°C, average daily temperature decreased from 11.2°C to 10.0°C, and the range of daily temperatures narrowed by 3.3°C. Despite large changes in channel morphology and reductions in summer stream temperature, the prevalence and severity of M. cerebralis infection for hatchery Rainbow Trout Oncorhynchus mykiss remained high (98–100% test fish with grade > 3 infection) versus minimal for hatchery Brown Trout Salmo trutta (2% of test fish with grade‐1 infection). This study shows channel renaturalization can reduce summer stream temperatures in small low‐elevation, groundwater‐dominated streams in the Blackfoot basin to levels more suitable to native trout. However, because of continuous high infections associated with groundwater‐dominated systems, the restoration of Kleinschmidt Creek favors brown trout Salmo trutta given their innate resistance to the parasite and the higher relative susceptibility of other salmonids.Received February 3, 2014; accepted May 3, 2014

Morphometric analysis of Upper Tons basin from Northern Foreland of Peninsular India using CARTOSAT satellite and GIS

The morphometric analysis of river basin helps to explore the interrelationship between hydraulic parameters and geomorphologic characteristics. The study has been conducted in the Upper Tons basin of Northern Foreland of Peninsular India. The river basin has been characterized using the topographical maps, CARTOSAT satellite image integrated using the GIS techniques. The drainage density analysis indicates lower values in the north-eastern regions and thus these regions can be categorized as better ground water potential zone. There are in total 10 sub-watersheds which have been delineated; SW-4 has maximum drainage density (4.75), stream frequency (5.61) and drainage texture (26.64) followed by SW-6–10. The prioritized sub-watershed numbers SW-4 and SW-6–10 need conservation practices because of their high erodibility and run-off. SW-1–3 and SW-5 regions have better permeable bed rocks and hence good for water harvesting. The areal parameter indicates elongated shape of basin and moderate to steeper ground slope. The results are supported by extensive field survey. This study can be applied for soil and water management, as well as disaster prevention from similar type of drainage basins.

L-moments approach for flood frequency analysis of river Okhuwan in Benin-Owena River basin in Nigeria

The flood frequency analysis of River Okhuwan at Ugonoba site in Benin Owena River Basin in Nigeria was carried out using annual maximum stream flow series for 20 years (1989-2008). The objective of the study was to determine the best fit probability distribution model applicable to the site from amongst three selected 3-parameter distribution models namely: Generalized Extreme Value distribution (GEV), Generalized Logistic distribution (GLO) and generalized Pareto distribution (GPA) whose parameters were estimated by the method of L-moments. The best fit distribution was selected based on result of four goodness-of-fit tests applied to the candidate distributions. The results indicate that GPA is the best fit distribution model for analyzing the annual maximum flood series at the study site for return period less than or equal to 25 years but for return periods between 25years and 200 years, GLO or GEV is recommended in that order.Keywords: Flood frequency Analysis,L-moments, Probability distribution, Return period, Parameter estimation

Geographic Variability in Elevation and Topographic Constraints on the Distribution of Native and Nonnative Trout in the Great Basin

AbstractUnderstanding local and geographic factors influencing species distributions is a prerequisite for conservation planning. Our objective in this study was to model local and geographic variability in elevations occupied by native and nonnative trout in the northwestern Great Basin, USA. To this end, we analyzed a large existing data set of trout presence (5,156 observations) to evaluate two fundamental factors influencing occupied elevations: climate‐related gradients in geography and local constraints imposed by topography. We applied quantile regression to model upstream and downstream distribution elevation limits for each trout species commonly found in the region (two native and two nonnative species). With these models in hand, we simulated an upstream shift in elevation limits of trout distributions to evaluate potential consequences of habitat loss. Downstream elevation limits were inversely associated with latitude, reflecting regional gradients in temperature. Upstream limits were positively related to maximum stream elevation as expected. Downstream elevation limits were constrained topographically by valley bottom elevations in northern streams but not in southern streams, where limits began well above valley bottoms. Elevation limits were similar among species. Upstream shifts in elevation limits for trout would lead to more habitat loss in the north than in the south, a result attributable to differences in topography. Because downstream distributions of trout in the north extend into valley bottoms with reduced topographic relief, trout in more northerly latitudes are more likely to experience habitat loss associated with an upstream shift in lower elevation limits. By applying quantile regression to relatively simple information (species presence, elevation, geography, topography), we were able to identify elevation limits for trout in the Great Basin and explore the effects of potential shifts in these limits that could occur in response to changing climate conditions that alter streams directly (e.g., through changes in temperature and precipitation) or indirectly (e.g., through changing water use).

Influence of streamside buffers on stream temperature response following clear-cut harvesting in western Oregon

Determining the effectiveness of different riparian buffers for mitigating forest-harvesting impacts on stream temperatures continues to be of interest throughout the world. Four small, low or medium elevation streams in managed western Oregon forests were studied to determine how the arrangement and amount of streamside retention strips (buffers) in clear-cut units influenced stream temperatures. Buffers included (i) no tree, (ii) predominantly sun-sided 12 m wide partial, and (iii) two-sided (Best Management Practice, (BMP)) 15–30 m wide buffers. Harvested units alternated with uncut units along 1800–2600 m study reaches. Impacts of harvesting on stream temperatures were determined by time series comparisons of postharvest and preharvest regressions. Trends for daily maximum and mean stream temperature significantly increased after harvest in no tree buffer units. Partial buffers led to slight (<2 °C) or no increased warming. BMP units led to significantly increased warming, slight, or no increased warming. Temperature responses in uncut units appeared to be linked to responses in upstream harvested units. In many instances, when harvested units exhibited significantly higher postharvest trends, lower trends were observed in the uncut units downstream. Stream temperature trends of 7 day moving maxima indicated warming through the no tree buffer units and some of the BMP units. Peaks in maxima were not maintained in downstream units. Stream temperature responses were related to buffer implementation and stream features, relating to cooling and warming.

Convection of a stratified colloidal suspension

The convection of a colloidal suspension, which is a binary mixture of a carrier medium with an admixture of nanoparticles having a large positive thermal diffusion parameter, has been studied for the case of the heating of a horizontal cell from below and periodic conditions at the vertical boundaries corresponding to the experimental situation of ring channels. Bifurcation diagrams have been constructed for vibrational and monotonic regimes of the convection of the colloidal mixture. The time dependences of the maximum stream function and the stream function at a fixed point of the cell, as well as the spatial distributions of the concentration field of the colloid admixture, have been obtained. It has been shown that a stable regime of traveling waves exists in a certain region of the parameters of the problem (Boltzmann and Rayleigh numbers characterizing the gravitational stratification and intensity of the thermal effect, respectively).

Effect of contemporary forest harvesting practices on headwater stream temperatures: Initial response of the Hinkle Creek catchment, Pacific Northwest, USA

We investigated the effect of contemporary forest harvesting practices on warm-season thermal regimes of headwater streams using a Before-After-Control-Intervention (BACI) design within a nested, paired watershed study. We applied harvesting treatments to four headwater tributaries of Hinkle Creek, designed in accordance with the Oregon Forest Practices Act. Therefore, fixed-width buffer strips containing overstory merchantable trees were not left adjacent to the four non-fish-bearing streams. The summer following harvesting, we observed a variable temperature response across the four harvested streams. Mean maximum daily stream temperatures ranged from 1.5°C cooler to 1.0°C warmer relative to pre-harvest years. We also observed significantly lower minimum and mean daily stream temperatures, and recorded particularly low temperatures in treatment streams on days that minimum stream temperatures in reference streams were high. At the watershed scale, we did not observe cumulative stream temperature effects related to harvesting 14% of the watershed area in multiple, spatially-distributed harvest units across four headwater catchments. At the watershed outlet, we observed no change to maximum, mean, or minimum daily stream temperatures. We attribute the lack of consistent temperature increases in headwater streams to shading provided by a layer of logging slash that deposited over the streams during harvesting, and to increased summer baseflows. Comparisons of canopy cover before and after harvesting indicate little change in canopy cover when logging slash is considered, indicating that logging slash affected energy balances within the streams. However, other ecosystem-level effects of logging slash in forest streams are difficult to predict. In order to devise optimum practices related to in-stream slash management, forest scientists and policymakers should continue to study and consider the potential impacts of logging slash to stream ecosystems.

Assessment of Adequacy of Available Streams in Okada/Environs for Viable Source of Sustainable Water Supply

The study area comprises of Okada Town and its environs (having combined base population estimate of 78,000) are located in the South Western part of Edo State in Nigeria. The study area is primarily an agricultural and commercial area with prospects of becoming a big town with attendant water supply problems. This study assessed the adequacy of available streams as possible viable sources of water supply with the objective to assess the existing water facilities, capacity and production levels. And further, to carry out comparative analysis of projected target water demand and minimum stream flow. The study area falls under urban water schemes, although in terms of economic and commercial activities, it has the character of rural and semi-urban composition. The 20-year projected population of target water consumers is 124,800 using arithmetic growth rate pattern and 140,877 persons using geometric pattern, both with growth rate of 3%. The 20-projected ultimate water supply is 23,250 m3/day. The existing water schemes have total capacity of 7,600 m3 and effective capacity of 2,512 m3.The present water supply of 1,618 m3/day is very grossly inadequate when compared totarget water demand. Okada; Iguedo and Okhai Streams are the three source streams. The combined and reliable stream yields is226,534m3/day and 103,886m3/day respectively. The maximum stream abstraction is 81,455m3/day. Analysis of water demand, stream yield and projected water demands showed adequacy of the source streams as possible viable sources of water supply.