[1] The temporal and spatial pattern of seismicity associated with reservoir water level fluctuations, injection of high-pressure fluids in deep boreholes, and seasonal groundwater recharge provide a unique setting to study the hydrological properties of the seismogenic fractures. Pore pressure diffusion is primarily responsible for the build up of fluid pressures and the onset of seismicity. The hydrologic property controlling pore pressure diffusion is hydraulic diffusivity c, which is directly related to intrinsic permeability k. By analyzing more than 90 case histories of induced seismicity, we determined the hydraulic diffusivity value of fractures associated with seismicity to lie between 0.1 and 10 m2/s. This range of values of c corresponds to a range of intrinsic permeability values between 5 × 10−16 and 5 × 10−14 m2. We call this range the seismogenic permeability ks. Fractures with ks were found to be associated with Darcian flow. Fractures with permeability less than ks were aseismic, as the pore pressure increase was negligible. In fractures with permeability larger than ks, aseismic non-Darcian flow was observed. Seismicity was uniquely associated with fractures with seismogenic permeability. Thus seismogenic permeability is an intrinsic property of fractures where pore pressure diffusion is associated with seismicity.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2006JB004665

Seismogenic permeability, ks

Perception of drinking water in the Quebec City region (Canada): the influence of water quality and consumer location in the distribution system.

A CFD package was employed to simulate the steady state precipitation of barium sulphate in jet mixing devices (coaxial flow pipeline mixers and tee-junction mixers). Both 2D and 3D descriptions were employed. Solutions of the Navier-Stokes equations along with the standard two equation k-e turbulence model provide the velocity and energy fields while generation and development of the solid crystal phase were described by the moment equations of the population balance. Spatial distributions of species concentrations, supersaturation, total crystal number and magma density were calculated and the average size and coefficient of variation of the crystal product determined. Visualization of these distributions enables a rapid assessment of the effect of the actual flow pattern within a particular jet precipitator. The influence of the positions and orientation of the two inlet streams, as well as the length of the mixer on the mixing and the precipitation were investigated.

Application of CFD Modelling to Precipitation Systems

Incorporating ecological requirement into multipurpose reservoir operating rule curves for adaptation to climate change

In-pipe water quality monitoring in water supply systems under steady and unsteady state flow conditions: A quantitative assessment

Application of optimization techniques for determining the optimal operating policy of reservoirs is a major issue in water resources planning and management. As an optimization Genetic Algorithm, ruled by evolution techniques, have become popular in diversified fields of science. The main aim of this study is to explore the efficiency and effectiveness of genetic algorithm in optimization of multi-reservoirs. A computer code has been constructed for this purpose and verified by means of a reference problem with a known global optimum. Three reservoirs in the Colorado River Storage Project were optimized for maximization of energy production. Besides, a real-time approach utilizing a blend of online and a posteriori data was proposed. The results obtained were compared to the real operational data and genetic algorithm was found to be effective and can be utilized as an alternative technique to other traditional optimization techniques.

Optimization of Multireservoir Systems by Genetic Algorithm

A rectangular slit weir is designed for measurement of small ~,0.005 m 3 /s! discharges. The discharge coefficient is deter- mined experimentally using the measured discharges and the corresponding heads over the weir. The relationship between the discharge coefficient and all relevant dimensionless parameters is investigated. It is concluded that the discharge coefficient can be represented solely as a function of Reynolds number.

Measurement of Small Discharges in Open Channels by Slit Weir

Unsteady 2-D chlorine transport in water supply pipes

Realistic numerical simulation of chlorine decay in pipes

For applications such as using tracer techniques for discharge measurements in pipes or using a segment of a pipe as a mixing chamber, it is desirable to know the rate at which the concentration of injected material becomes mixed within the pipe cross section. The distance required to achieve a given degree of mixing depends on the injection system and the pipe flow characteristics. The mixing for three single-point injection systems is compared. The three systems are a center line source, a wall source, and a jet at the wall issuing perpendicularly to the pipe flow. A center line source can provide the most rapid mixing, but it is extremely difficult to maintain the symmetry necessary to achieve the rapid mixing. The wall source gives the slowest mixing. The mixing for a jet injection depends on M, the ratio of the jet momentum to the pipe momentum. For a jet injection, there is an optimum M which gives the most rapid mixing for given flow characteristics, and this mixing is more rapid than either a wall source or most practically achievable center line sources.

A. Metin Ger

Papers

Optimization of Multireservoir Systems by Genetic Algorithm

Measurement of Small Discharges in Open Channels by Slit Weir

Unsteady 2-D chlorine transport in water supply pipes

Realistic numerical simulation of chlorine decay in pipes

Comparison of Single-Point Injections in Pipe Flow