Reservior Simulation

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

1.0 Introduction Waterflooding process is a secondary oil recovery effort that involves injection of water into an oil well reservoir to increase the underground pressure thereby increasing oil recovery (Grema and Cao, 2016). However, waterflooding processes are faced with constitutive recovery mechanism in terms of well placements, which determines the maximal recovery of oil at a given point in time. Well placements predominantly play a role as regards to production rates which serves as a consideration to which various oil companies identify in order to determine oil-water ratio (Grema and Cao, 2017). The placement of injection wells determines the oil and water production rates. It is for this reason that estimation of oil recovery in terms of well placements is considered. Reservoir models are expressed by nonlinear partial differential equations (PDEs) which constitute unsteady states and dimensions in the region of time and space (Grema and Cao, 2017). There are a lot of exor...

Experimentally, the research on the flow of liquid film of viscous liquid on vertically rotating flat disc partially immersed in a liquid bath has been investigated and modellelled by many researchers. The difference, in this research, the liquid being used is tap water. Meanwhile, the characteristic of disk surface chosen was hydrophobic one. The reason for this choice was due to the fact that the material being used to sell for public had hydrophobic characteristics. Therefore, for the disk material, the researcher used the material from acrylic and novotex that had hydrophobic characteristics on its surface. In addition to the disk material, also investigated the influence of surface topography, by doing three variations of topography. Furthermore, this research was conducted experimentally to see the flow characteristics of liquid film at the rotating vertically disk, especially at the low rotational speed around 1-20 rpm. The other parameter affected to the thickness characteri...

GSM Network in Nigeria in recent times has been epileptic due to drop in signal strength, which causes customer dissatisfaction with the quality of service delivery by network operators. University of Maiduguri has experience low signal quality in recent years due to frequent dropped calls, poor network interconnectivity, echoes and network congestion, therefore this work presents a detail analysis of the received GSM signal strength in university of Maiduguri. An android application program known as network cell info Lite was used for the measurement of signal strength for three different network in the university at random sampling points. The three network considered are: Network A, Network B and Network C, in three different locations; Academic area, student hostel and staff quarters within the university. The data collected were analyzed using SPSS Statistical tool. The mean value of the signal strength received using the software application shows that Network A with HSPA -91....

Growing demands of plastics deriving environmental and social concern on the plastics contained in municipal waste. Comprehending to this fact, this study emphasizes on minimization of plastic wastes during extrusion blow molding process by controlling the processing parameters including parison thickness, chiller temperature, melting temperature and extruder speed. L8 Taguchi orthogonal array (OA), signal to noise (S/N) ratio and analysis of variance (ANOVA) were conducted to investigate the influence of numerous blow moulding processing parameters on the plastic wastes.

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

GSM Network in Nigeria in recent times has been epileptic due to drop in signal strength, which causes customer dissatisfaction with the quality of service delivery by network operators. University of Maiduguri has experience low signal quality in recent years due to frequent dropped calls, poor network interconnectivity, echoes and network congestion, therefore this work presents a detail analysis of the received GSM signal strength in university of Maiduguri. An android application program known as network cell info Lite was used for the measurement of signal strength for three different network in the university at random sampling points. The three network considered are: Network A, Network B and Network C, in three different locations; Academic area, student hostel and staff quarters within the university. The data collected were analyzed using SPSS Statistical tool. The mean value of the signal strength received using the software application shows that Network A with HSPA -91....

Introduction An arc flash is an explosive burst of light and heat produced as part of an arc fault, a type of electrical explosion or discharge that results from a connection through air to ground or another voltage phase in an electrical system. The results are often violent and when a human is in close proximity to the arc flash, serious injury and even death can occur. Arc flash can be caused by many things including: dust, dropping tools, accidental touching, condensation, material failure, corrosion, faulty installation (Yadav and Harith, 2016). An Arc Flash study is a risk assessment of a workplace environment that determines Arc Flash hazards. It is important that an expert in electrical safety conducts an assessment to ensure that a company understands the risks their workplace poses to their personnel and how to protect them against it. The severity of an arc flash injury is caused by the temperature, fault current and time for circuit breaker to operate and closeness of the object to the danger zone. These zones are: flash protection limits, limited zone, restricted zone, prohibited zone. Arc Flash analysis requires the completion of a Short Circuit Study and a Coordination Study. The results of the Arc Flash calculations are based on the calculated values of fault current magnitudes found in the short circuit study and the associated clearing times of overcurrent protection devices as determined by the coordination study (Valdes and Floyd, 2021).

GSM Network in Nigeria in recent times has been epileptic due to drop in signal strength, which causes customer dissatisfaction with the quality of service delivery by network operators. University of Maiduguri has experience low signal quality in recent years due to frequent dropped calls, poor network interconnectivity, echoes and network congestion, therefore this work presents a detail analysis of the received GSM signal strength in university of Maiduguri. An android application program known as network cell info Lite was used for the measurement of signal strength for three different network in the university at random sampling points. The three network considered are: Network A, Network B and Network C, in three different locations; Academic area, student hostel and staff quarters within the university. The data collected were analyzed using SPSS Statistical tool. The mean value of the signal strength received using the software application shows that Network A with HSPA -91....

The Propellant Stimulation is applied to increase the permeability of rocks; a certain quantity of explosive material is donated at the bottom of the well opposite the producing layer, which causes many cracks in the near well area. A good Propellant Stimulation process must consider the explosive material quality and quantity, and the explosion should be prevented from vertically spread so all its energy will be used to crack the rocks. The first part of this chapter explains all the above in addition to the directed explosions and its calculation in an easy way. In the second part, I explained the Hydraulic Fracturing of the reservoir rocks in details, from principal elements of the process passing through cracking fluids, proppants, preparing the wells and ending with evaluating the effectiveness and discussing the methods of hydraulic fracturing. Hydraulic fracturing is the process of pumping fluid into a wellbore at an injection rate that is too high for the formation to accept without breaking. During injection the resistance to flow in the formation increases, the pressure in the wellbore increases to a value called the breakdown pressure, that is the sum of the in-situ compressive stress and the strength of the formation. Once the formation "breaks down," a fracture is formed, and the injected fluid flows through it.

Floods are the most common and destructive disasters around the globe, which becomes more challenging in coastal areas due to higher population density and catchment area relative to floods in an inland area. For effective coastal flood management to reduce flood adverse impacts it is necessary to investigate the flooding processes and their joint interaction in a coastal area. This paper selected the Brisbane River Estuary, Australia as an example and the MIKE 21 model is applied to investigate the effects of mesh resolution on the flood discharge and to explore compound flooding by computing variances in coastal flood assessments resulting from a separation of tidal and riverine processes. The statistical results showed that the Nash-Sutcliffe coefficient, E of water level are varied from 0.84 to 0.95 and the model simulated the 2011 flood extent results agreed with 90% accuracy with the observed flood extent. Five mesh resolutions cases were analyzed and the result found that the finer mesh resolution Case 5 was more appropriate for calculating the peak discharge with 2.7% with estimated discharge. Compound flood event simulation results emphasized that not considering the interaction of various flooding drivers caused 0.62 m and 0.12 m reduction in the flood levels at Jindalee and Brisbane city gauges, and uncertainties in flood extent. Simulated results of flood at Brisbane city gauge, showed that 2011 and 2013 floods with storm surge scenario 4 demonstrate, the increase in flood level to be 12% and 34% respectively. The results recommend flooding assessment by using mesh convergence with joint probability of compound flood under future storm surge for planning and management of coastal projects.

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD wi...

Mass movement is downslope movement of soil or rock debris due to gravitational pull or vertical sinking of the ground surface. Mass movements may occur for a considerably long duration or an extremely short period, such as landslides or rockfalls, and cause devastating consequences. Mass movement is a challenging subject because it cannot be explained by Mohr–Coulomb theorem. As such, an approach for predicting movement patterns must be developed. This research modeled a mass movement in Cihonje Hamlet in Parungponteng Village, Tasikmalaya District, West Java, Indonesia. The influence of viscosity and yield stress on the behavior of the mass movement was also investigated through back analysis. Results showed that viscosity and yield stress are inversely proportional to water content and both decrease as the water content approaches the liquid limit. Thus, low viscosity induces flow coverage.

Flood map nowadays is seen as an indispensable tool in urbanism, flood prevention and mitigation. For this reason, establishing flood map is mighty necessary for developing the socio economy of a river catchment. In recent years, creating this kind of map based on hydraulic models has been applied and proved good efficiencies in mitigating the consequences of flood catastrophes to human at many regions on the world. However, because of the lack of observed data in large catchments as well as developing countries, applying this work for these regions becomes a huge challenge for hydrologists. The insufficiency of meteo hydrological data, coarse resolution of topography, land cover data …brings many difficulties to choose a suitable model or decide a reasonable model structure for flood modelling in these catchments. This study via the flood modelling process at downstream of Vu Gia Thu Bon catchment, a coastal region in Viet Nam central will compare the differences between 1D model, 2D model, Quasi 2D model and 1D/2D coupling model for flood simulation. The study also presents the uncertainties of input data such as topography, land use, rainfall, and boundary condition when modelling flood events. These simulations are carried out on the modules of Mike by DHI software: Mike 11, Mike 21, Mike Flood. The results might show strong and weak points of each model. These could help modelers to get several judgments when selecting the model to build the flood map. This study is expected to give some usefulnesses for flood modeling in the coastal part of a big catchment.

The transient two-dimensional MHD boundary-layer stagnation point flow with heat and mass transfer in a saturated porous medium is presented here by taking into account the transient dispersion of a pollutant spewed by an external source in the presence of a uniform transverse magnetic field and stress (pressure) work. The laminar flow of viscous incompressible and electrically conducting fluid encompassing a convectively heated stationary permeable sheet is assumed to be described in terms of Darcian law. The nonlinear governing partial differential equations obtained are converted into ordinary differential equations by means of appropriate similarity transformations and consequently solved numerically using the forth order Runge-Kutta method with a shooting technique and depicted graphically for some pertinent values of the physical parameters embedded in the flow model. In addition, the skin-friction coefficient, the heat and pollution mass concentration rates are sorted out in tabular form, analyzed and discussed. We opine that findings of this present study will be found useful for environmental systems in pollution control and ventilation, and serve as complementary reference for researchers.

The development planning of a tidally-influenced fluvial zone poses a complex interaction between river discharge and its effect on the tidal patterns, especially in the dense population and high economic activity like Palembang located in South Sumatra Indonesia. Previous studies on numerical modelling in this area have focused on the flood; however, the hydrodynamic modelling described interaction between river discharge and tidal is not described in more detail. The present study aims to better understand the zone by using a combination of numerical modelling and qualitative assessment of in situ measurement data. Hence, the water level condition in the study area is a mix of tidal and river discharge. A 2D-hydrodynamic modeling has been successfully conducted to assess their interaction in this zone properly by using the commercial software, called MIKE21 FM. This study describes setting up the computational model, boundary location, type of forcing (tidal and non-tidal), bedfor...

In Canada, risk of flooding due to heavy rainfall has risen in recent decades; the most notable recent examples include the July 2013 storm in the Greater Toronto region and the May 2017 flood of the Toronto Islands. We investigate nonstationarity and trends in the short-duration precipitation extremes in selected urbanized locations in Southern Ontario, Canada, and evaluate the potential of nonstationary intensity-duration-frequency (IDF) curves, which form an input to civil infrastructural design. Despite apparent signals of nonstationarity in precipitation extremes in all locations, the stationary vs. nonstationary models do not exhibit any significant differences in the design storm intensity, especially for short recurrence intervals (up to 10 years). The signatures of nonstationarity in rainfall extremes do not necessarily imply the use of nonstationary IDFs for design considerations. When comparing the proposed IDFs with current design standards, for return periods (10 years or less) typical for urban drainage design, current design standards require an update of up to 7 %, whereas for longer recurrence intervals (50-100 years), ideal for critical civil infrastructural design, updates ranging between ∼ 2 and 44 % are suggested. We further emphasize that the above findings need re-evaluation in the light of climate change projections since the intensity and frequency of extreme precipitation are expected to intensify due to global warming. 1 Introduction Short-duration extreme rainfall events can have devastating consequences, damage to crops and infrastructures, leading to severe societal and economic losses in Canada (CCF, 2013; TRCA, 2013). In a warming climate, extreme precipitation events are expected to intensify due to moistening of the atmosphere (

1.0 Introduction Waterflooding process is a secondary oil recovery effort that involves injection of water into an oil well reservoir to increase the underground pressure thereby increasing oil recovery (Grema and Cao, 2016). However, waterflooding processes are faced with constitutive recovery mechanism in terms of well placements, which determines the maximal recovery of oil at a given point in time. Well placements predominantly play a role as regards to production rates which serves as a consideration to which various oil companies identify in order to determine oil-water ratio (Grema and Cao, 2017). The placement of injection wells determines the oil and water production rates. It is for this reason that estimation of oil recovery in terms of well placements is considered. Reservoir models are expressed by nonlinear partial differential equations (PDEs) which constitute unsteady states and dimensions in the region of time and space (Grema and Cao, 2017). There are a lot of exor...

The semiarid northeast of Brazil is one of the most densely populated dryland regions in the world and recurrently affected by severe droughts. Thus, reliable seasonal forecasts of streamflow and reservoir storage are of high value for water managers. Such forecasts can be generated by applying either hydrological models representing underlying processes or statistical relationships exploiting correlations among meteorological and hydrological variables. This work evaluates and compares the performances of seasonal reservoir storage forecasts derived by a process-based hydrological model and a statistical approach. Driven by observations, both models achieve similar simulation accuracies. In a hindcast experiment, however, the accuracy of estimating regional reservoir storages was considerably lower using the process-based hydrological model, whereas the resolution and reliability of drought event predictions were similar by both approaches. Further investigations regarding the deficiencies of the process-based model revealed a significant influence of antecedent wetness conditions and a higher sensitivity of model prediction performance to rainfall forecast quality. Within the scope of this study, the statistical model proved to be the more straightforward approach for predictions of reservoir level and drought events at regionally and monthly aggregated scales. However, for forecasts at finer scales of space and time or for the investigation of underlying processes, the costly initialisation and application of a processbased model can be worthwhile. Furthermore, the application of innovative data products, such as remote sensing data, and operational model correction methods, like data assimilation, may allow for an enhanced exploitation of the advanced capabilities of process-based hydrological models. 1 Introduction Drought is a type of natural hazard characterised by meteorological, hydrological, and water management conditions, affecting many regions around the globe. Generally, it arises due to a shortage of water availability. A general valid or comprehensive definition, however, is hardly achievable due to many different possible causes, complex relationships, and feedbacks among its determining factors and, consequently, different impacts on nature, society, and economy. As such, different categories can be distinguished ranging from meteorological (lack of rainfall) and hydrological (shortage of consumable water resources) to agricultural (water deficit for crops or husbandry) and socioeconomic droughts (not enough of income to pay water price). For the characterisation of droughts, different statistics can be computed describing duration, frequency, and severity based on various predictors and thresholds (Mishra and Singh, 2010). The semiarid northeast of Brazil (NEB) is one of the world's most densely populated dryland regions (Marengo et al., 2017). Its climate is characterised by a short rainy season with high interannual variability. As a consequence, already since the colonisation in the 16th century, regularly occurring severe droughts causing famine and mass exodus Published by Copernicus Publications on behalf of the European Geosciences Union.

In August 2017 Bangladesh faced one of its worst river flooding events in recent history. This paper presents for the first time an attribution of this precipitation-induced flooding from a combined meteorological and hydrological perspective. Experiments were conducted with three observational data sets and two climate models to estimate changes in extreme 10-day precipitation event frequency over the Brahmaputra basin. The precipitation fields were then used as meteorological input for four different hydrological models to estimate the corresponding changes in river discharge, allowing for comparison between approaches and for the robustness of the attribution results to be assessed. In all three observational precipitation data sets the climate change trends for extreme precipitation similar to observed in August 2017 are not significant, however in two out of three series, the sign of this insignificant trend is positive. One climate model shows a significant positive influence of anthropogenic climate change, whereas the other simulates a cancellation between the increase due to greenhouse gases and a decrease due to sulphate aerosols. Considering discharge rather than precipitation, the hydrological models show that attribution of the change in discharge towards higher values is somewhat less uncertain than for precipitation, but the 95% confidence interval still encompasses no change in risk. For the future, all models project an increase in probability of extreme events at 2 • C global heating since pre-industrial times, becoming more than 1.7 times more likely for high 10-day precipitation, and about a factor 1.5 more likely for discharge. Our best estimate on the trend in flooding events similar to the Brahmaputra event of August 2017 is derived by synthesizing the observational and model results: We find the change in risk to be greater than one and of similar order of magnitude (between 1 and 2) for both the meteorological and hydrological approach. This study shows that, for precipitation-induced flooding events, investigating changes in precipitation is useful, either as an alternative when hydrological models are not available, or as an additional measure to confirm qualitative conclusions. Besides, it highlights the importance of using multiple models in attribution studies,

In August 2017 Bangladesh faced one of its worst river flooding events in recent history. This paper presents for the first time an attribution of this precipitation-induced flooding from a combined meteorological and hydrological perspective. Experiments were conducted with three observational data sets and two climate models to estimate changes in extreme 10-day precipitation event frequency over the Brahmaputra basin. The precipitation fields were then used as meteorological input for four different hydrological models to estimate the corresponding changes in river discharge, allowing for comparison between approaches and for the robustness of the attribution results to be assessed. In all three observational precipitation data sets the climate change trends for extreme precipitation similar to observed in August 2017 are not significant, however in two out of three series, the sign of this insignificant trend is positive. One climate model shows a significant positive influence of anthropogenic climate change, whereas the other simulates a cancellation between the increase due to greenhouse gases and a decrease due to sulphate aerosols. Considering discharge rather than precipitation, the hydrological models show that attribution of the change in discharge towards higher values is somewhat less uncertain than for precipitation, but the 95% confidence interval still encompasses no change in risk. For the future, all models project an increase in probability of extreme events at 2 • C global heating since pre-industrial times, becoming more than 1.7 times more likely for high 10-day precipitation, and about a factor 1.5 more likely for discharge. Our best estimate on the trend in flooding events similar to the Brahmaputra event of August 2017 is derived by synthesizing the observational and model results: We find the change in risk to be greater than one and of similar order of magnitude (between 1 and 2) for both the meteorological and hydrological approach. This study shows that, for precipitation-induced flooding events, investigating changes in precipitation is useful, either as an alternative when hydrological models are not available, or as an additional measure to confirm qualitative conclusions. Besides, it highlights the importance of using multiple models in attribution studies,

The purpose of the paper is to explore the slip and cross diffusion impacts on unsteady MHD convective flow past an elongated surface which includes chemical reaction and stratification. The similarity transform is adopted to transfigure the nonlinear PDEs to nonlinear ODEs and then the solution is obtained by Runge-Kutta integration procedure with shooting method. Numerically determined solutions are presented through graphs. The analysis is made for local skin friction, local Nusselt number and local Sherwood number numerically. It is found that thermal slip and thermal stratification diminished the heat transfer rate for both suction/injection.

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (E ns) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD with an overall water level reduction below the maximum flood level. The results demonstrated that the innovative use of a CR could considerably decrease the overall flood peak and lessen flood severity in the coastal city of Brisbane.

In August 2017 Bangladesh faced one of its worst river flooding events in recent history. This paper presents for the first time an attribution of this precipitation-induced flooding from a combined meteorological and hydrological perspective.

This paper proposes the use of necessary storage to smooth out discharge variability to meet a discharge target as a signature of discharge variability in time. Such a signature has a distinct advantage over other statistical indicators such as standard deviation (SD) or coefficient of variation (CV) as it expresses hydrological variability in human terms, which directly indicates the difficulty and ease of managing discharge variation for water resource management. The signature is presented in the form of geographical distribution, in terms of both necessary storage (km 3) and normalized necessary storage (months), and is related to the basin characteristics of hydrological heterogeneity. The signature is analyzed in different basins considering the Hurst equation of range as a reference. The slope of such a relation and the scatter of departures from the average relation are analyzed in terms of their relationship with basin characteristics. As a method of calculating necessary storage, the flood duration curve (FDC) and drought duration curve (DDC) methods are employed in view of their relative advantage over other methods to repeat the analysis over many grid points. The Ganges–Brahmaputra–Meghna (GBM) basin is selected as the case study and the BTOPMC hydrological model with Water and Global Change (WATCH) Forcing Data (WFD) is used for estimating FDC and DDC. It is concluded that the necessary storage serves as a useful signature of discharge variability, and its analysis could be extended to the entire globe and in this way seek new insights into hydrological variability in the storage domain at a larger range of scales.

We analyze the simultaneous effects of thermal and concentrations on a mixed convection boundary layer flow over a permeable surface under convective surface boundary condition in the presence of heat generation and thermal radiation. Using a similarity variable, the governing nonlinear partial differential equations have been transformed into a set of coupled nonlinear ordinary differential equations, which are solved numerically using Maple 14 which uses a fifth-sixth order Runge–Kutta-Fehlberg algorithm together with shooting method. It is seen that as buoyancy force parameter N and the Biot number Bi increases, the skin-friction coefficient, heat transfer rate and the mass transfer rate also increases. It is also noticed that increasing the thermal radiation and the internal heat generation parameters, it enhances the skin-friction coefficient and the mass transfer rate while it decreases the heat transfer rate at the wall surface. The heat generation parameters γ enhances the skinfriction coefficient and the mass transfer rate. Similarly, the embedded flow parameters have significant influence on the double-diffusive convection and that heat generation and radiation parameters enhances the skin-friction coefficient and mass transfer while it reduces the heat transfer rate.

A well that penetrates the producing interval with a slant angle, ψ is called an inclined or slant well. If the well does not penetrate the entire formation thickness of the producing strata, it is called a partially penetrating or limited-entry well. For such cases, the slant angle, penetration length and penetration ratio significantly influence the characteristics of the pressure-transient responses. It is relevant the role of the ellipsoidal flow regime displayed at early time -before radial flow -which we recognized as a straight line exhibiting a -0.135 slope on the pressure derivative curve. Hence, this paper deals with the characterization of such flow regime and a methodology, using the pressure derivative, is introduced so the vertical and effective permeability is calculated. The proposed methodology was successfully applied to synthetic test data.

This study investigates a two-dimensional steady boundary layer stagnation laminar flow of heat and mass transfer due to a viscous, incompressible and first-order homogeneous chemically reacting fluid towards a heated stretching porous vertical plate embedded in a Newtonian fluid. The basic governing flow partial differential equations together with the boundary conditions are converted into a set of ordinary differential equations by means of existing similarity variables. The transformed set of equations were solved numerically by assigning realistic values to the basic flow parameters, using the classical Runge-Kutta fourth order integration method along with a shooting technique and implemented on Maple software. Important engineering dimensionless quantities of interest such as the wall shear stress, heat and mass transfer rates are analyzed, and discussed by means of graphs and tables. In other to ascertain the credibility of our computed results, comparisons were made with the existing, available and open literature works and have been found to be in extremely good agreement.

This paper investigates the combined effects of buoyancy force and fluid injection/suction on heat and mass transfer by a steady hydromagnetic boundary layer flow of a conducting incompressible fluid that is homogenously chemically reactive over a permeable surface in the presence of heat source and sink. The governing equations of momentum, energy and concentration balance were developed and transformed to a set of ordinary differential equations by method of similarity transformation and solved numerically. The influence of various pertinent parameters on the fluid velocity, temperature, concentration, skin friction coefficient, plate temperature, rate of heat and mass transfer are presented graphically and discussed quantitatively.

The transient two-dimensional MHD boundary-layer stagnation point flow with heat and mass transfer in a saturated porous medium is presented here by taking into account the transient dispersion of a pollutant spewed by an external source in the presence of a uniform transverse magnetic field and stress (pressure) work. The laminar flow of viscous incompressible and electrically conducting fluid encompassing a convectively heated stationary permeable sheet is assumed to be described in terms of Darcian law. The nonlinear governing partial differential equations obtained are converted into ordinary differential equations by means of appropriate similarity transformations and consequently solved numerically using the forth order Runge-Kutta method with a shooting technique and depicted graphically for some pertinent values of the physical parameters embedded in the flow model. In addition, the skin-friction coefficient, the heat and pollution mass concentration rates are sorted out in tabular form, analyzed and discussed. We opine that findings of this present study will be found useful for environmental systems in pollution control and ventilation, and serve as complementary reference for researchers.

The transient two-dimensional MHD boundary-layer stagnation point flow with heat and mass transfer in a
saturated porous medium is presented here by taking into account the transient dispersion of a pollutant spewed by an external
source in the presence of a uniform transverse magnetic field and stress (pressure) work. The laminar flow of viscous
incompressible and electrically conducting fluid encompassing a convectively heated stationary permeable sheet is assumed to
be described in terms of Darcian law. The nonlinear governing partial differential equations obtained are converted into
ordinary differential equations by means of appropriate similarity transformations and consequently solved numerically using
the forth order Runge-Kutta  method with a shooting technique and depicted graphically  for some pertinent values of the
physical parameters embedded in the flow model. In addition, the skin-friction coefficient, the heat and pollution mass
concentration rates are sorted out in tabular form, analyzed and discussed. We opine that findings of this present study will be
found useful for environmental systems in pollution control and ventilation, and serve as complementary reference for
researchers.

The transient two-dimensional MHD boundary-layer stagnation point flow with heat and mass transfer in a saturated porous medium is presented here by taking into account the transient dispersion of a pollutant spewed by an external source in the presence of a uniform transverse magnetic field and stress (pressure) work. The laminar flow of viscous incompressible and electrically conducting fluid encompassing a convectively heated stationary permeable sheet is assumed to be described in terms of Darcian law. The nonlinear governing partial differential equations obtained are converted into ordinary differential equations by means of appropriate similarity transformations and consequently solved numerically using the forth order Runge-Kutta method with a shooting technique and depicted graphically for some pertinent values of the physical parameters embedded in the flow model. In addition, the skin-friction coefficient, the heat and pollution mass concentration rates are sorted out in tabular form, analyzed and discussed. We opine that findings of this present study will be found useful for environmental systems in pollution control and ventilation, and serve as complementary reference for researchers.

Abstract Fresh water availability and demand is unequally distributed over time and space. Availability of fresh water has more or less remained constant despite natural temporal fluctuation (Gupta and Zaag, 2007); the demand for clean water is ever increasing. With increasing demand of water, surpassing the supply, an integrated water resource management approach is required to balance environmental, social and economic considerations in the decision making process.