Cavity balancing is the process of altering the flow front within a cavity through thickness and design changes such that the desired fill pattern is achieved. The 2 dimensional (2D) cavity-balancing algorithm, developed by Lam and Seow [1] can only handle 2D geometry. This represents a major drawback as most, if not all of the practical injected parts are not 2D parts. To overcome this difficulty, the present investigation has developed a 2.5 dimensional (2.5D) cavity balancing optimization routine implemented within a 2.5 D finite elements domain. The aim of the automated cavity balancing routine is to reduce product development time and to improve product quality. This will lower the level of prerequisite expert knowledge necessary for successful mold and part design. The automated cavity balancing routine has been developed using the concept of flow paths. The hill-climbing algorithm of Lam and Seow is utilized but modified for the generation of flow paths for 2.5D parts. The algorithm has been implemented in a computer program running as an external loop to the MOLDFLOW software. Case studies are provided to demonstrate the efficiency of this routine. / Singapore-MIT Alliance (SMA)

Hyporheic water is thought to infiltrate at the head of a riffle which in turn is complemented by upwelling back to the stream at the tail of the riffle in a pool-riffle-pool (PRP) sequence. Heat tracing is a potentially useful method to characterize these hyporheic flow paths and quantify associated fluxes. Temperature was monitored within a PRP sequence for several days. Temperature in the hyporheic zone reflected the diel temperature change in the river but not uniformly. The observed thermal pattern exhibited deeper penetration of thermal oscillations below the head pool and shallower penetration below the tail pool. This pattern is consistent with the conceptual model of hyporheic exchange over a PRP sequence. One-dimensional analytical heat transport models were used at different points below the PRP sequence to estimate distributed vertical fluid fluxes. The calculated fluxes exhibit a trend that follows the expected distribution for a PRP sequence but modified for a losing stream. Deviation of both magnitude and distribution of fluxes from the conceptual ‘downwelling-to-upwelling’ model is partly due to the dominantly losing conditions at the study site but the trends are consistent with a losing stream undergoing hyporheic exchange. Violation of the assumptions in the analytical models most likely adds error to flux estimates. For this study, flux estimation methods using a temperature time series amplitude analysis more closely matched field measurements than phase methods. / text

Meltwater reaching the base of the snowpack may either infiltrate the underlying stratum, run off, or refreeze, forming a basal ice layer. Frozen ground underneath a melting snowpack constrains infiltration promoting runoff and refreezing. Compositional changes in chemistry take place for each of these flowpaths as a result of phase change, contact between meltwater and soil, and mixing between meltwater and soil water. Meltwater ion concentrations and infiltration rate into frozen soils both decline rapidly as snowmelt progresses. Their temporal association is highly non-linear and the covariance must be compensated for in order to use time-averaged values to calculate chemical infiltration over a melt event. This temporal covariance is termed �enhanced infiltration� and represents the additional ion load that infiltrates due to the timing of high meltwater ion concentration and infiltration rate. Both theoretical and experimental assessments of the impact of enhanced infiltration showed that it causes a greater ion load to infiltrate leading to relative dilute runoff water. Sensitivity analysis showed that the magnitude of enhanced infiltration is governed by initial snow water equivalent, average melt rate, and meltwater ion concentration factor. Based on alterations in water chemistry due to various effects, including enhanced infiltration, three major flowpaths could be distinguished: overland flow, organic interflow, and mineral interflow. Laboratory experiments were carried out in a temperature-controlled environment to identify compositional changes in water from these flowpaths. Samples of meltwater, runoff, and interflow were filtered and analyzed for major anions and cations. Chemical signatures for each flowpath were determined by normalizing runoff and interflow concentrations using meltwater concentrations. Results showed that changes in ion concentrations were most significant for H⁺, NO₃^�, NH₄⁺, Mg²⁺, and Ca²⁺. Repeated flushes of meltwater through each interflowpath caused a washout of ions. In the field, samples of soil water and ponding water were collected daily from a Rocky Mountain hillslope during snowmelt. Their normalized chemical compositions were compared to the laboratory-identified signatures to evaluate the flowpath. The majority of the flowpaths sampled had chemical signatures, which indicated mineral interflow, only 10% showed unmixed organic interflow.

Meltwater reaching the base of the snowpack may either infiltrate the underlying stratum, run off, or refreeze, forming a basal ice layer. Frozen ground underneath a melting snowpack constrains infiltration promoting runoff and refreezing. Compositional changes in chemistry take place for each of these flowpaths as a result of phase change, contact between meltwater and soil, and mixing between meltwater and soil water. Meltwater ion concentrations and infiltration rate into frozen soils both decline rapidly as snowmelt progresses. Their temporal association is highly non-linear and the covariance must be compensated for in order to use time-averaged values to calculate chemical infiltration over a melt event. This temporal covariance is termed �enhanced infiltration� and represents the additional ion load that infiltrates due to the timing of high meltwater ion concentration and infiltration rate. Both theoretical and experimental assessments of the impact of enhanced infiltration showed that it causes a greater ion load to infiltrate leading to relative dilute runoff water. Sensitivity analysis showed that the magnitude of enhanced infiltration is governed by initial snow water equivalent, average melt rate, and meltwater ion concentration factor. Based on alterations in water chemistry due to various effects, including enhanced infiltration, three major flowpaths could be distinguished: overland flow, organic interflow, and mineral interflow. Laboratory experiments were carried out in a temperature-controlled environment to identify compositional changes in water from these flowpaths. Samples of meltwater, runoff, and interflow were filtered and analyzed for major anions and cations. Chemical signatures for each flowpath were determined by normalizing runoff and interflow concentrations using meltwater concentrations. Results showed that changes in ion concentrations were most significant for H⁺, NO₃^�, NH₄⁺, Mg²⁺, and Ca²⁺. Repeated flushes of meltwater through each interflowpath caused a washout of ions. In the field, samples of soil water and ponding water were collected daily from a Rocky Mountain hillslope during snowmelt. Their normalized chemical compositions were compared to the laboratory-identified signatures to evaluate the flowpath. The majority of the flowpaths sampled had chemical signatures, which indicated mineral interflow, only 10% showed unmixed organic interflow.

Every year, many wells are subject to well intervention operations for a variety of different reasons, such as Plug and Abandon (P&A) operations or well control situations. Wells that are not properly plugged, in addition becoming an inherent blowout threat, can act as a preferential pathway for surface contaminants to reach and impair ground water quality, and could cause injury to livestock, wildlife, or humans. Hence, federal code (or state code if in state waters) states that the wells must be plugged according to regulations. If attempts with a surface intervention operation fail, a relief type subsurface intervention project is deemed appropriate. A relief well type of intersection into each target wellbore will create a hydraulic flow path suitable for plugging operations. The plugging operation will require the placement of permanent plugging fluids into the Target Well (TW) to meet Mineral Management Services (MMS), or other regulatory agency, approved plugging criteria. Evidently, there is a need to design a method to insure that the scenarios are accurately defined, analyzed and the results can be effectively implemented to complete the plug and abandonment operations. A software package, coupled with the skill of a hydraulic modeling specialist, could provide final resolution to and better understanding of the problem. However, considering uncertainties in some input information, there is a need to develop a multi-purpose package which enables the user to manipulate dynamically a wide range of input data in order to obtain the best fit. Therefore, the decision was made to develop a software package specifically built and designed to address the common problems encountered during well intervention projects. The well intervention toolkit will be used to investigate the plugging and abandonment scenarios. The well intervention toolkit not only provides the critical input parameters to other commercial software but would also be a means to analyze and simulate the well intervention hydraulics

Meltwater reaching the base of the snowpack may either infiltrate the underlying stratum, run off, or refreeze, forming a basal ice layer. Frozen ground underneath a melting snowpack constrains infiltration promoting runoff and refreezing. Compositional changes in chemistry take place for each of these flowpaths as a result of phase change, contact between meltwater and soil, and mixing between meltwater and soil water. Meltwater ion concentrations and infiltration rate into frozen soils both decline rapidly as snowmelt progresses. Their temporal association is highly non-linear and the covariance must be compensated for in order to use time-averaged values to calculate chemical infiltration over a melt event. This temporal covariance is termed �enhanced infiltration� and represents the additional ion load that infiltrates due to the timing of high meltwater ion concentration and infiltration rate. Both theoretical and experimental assessments of the impact of enhanced infiltration showed that it causes a greater ion load to infiltrate leading to relative dilute runoff water. Sensitivity analysis showed that the magnitude of enhanced infiltration is governed by initial snow water equivalent, average melt rate, and meltwater ion concentration factor. Based on alterations in water chemistry due to various effects, including enhanced infiltration, three major flowpaths could be distinguished: overland flow, organic interflow, and mineral interflow. Laboratory experiments were carried out in a temperature-controlled environment to identify compositional changes in water from these flowpaths. Samples of meltwater, runoff, and interflow were filtered and analyzed for major anions and cations. Chemical signatures for each flowpath were determined by normalizing runoff and interflow concentrations using meltwater concentrations. Results showed that changes in ion concentrations were most significant for H+, NO3�, NH4+, Mg2+, and Ca2+. Repeated flushes of meltwater through each interflowpath caused a washout of ions. In the field, samples of soil water and ponding water were collected daily from a Rocky Mountain hillslope during snowmelt. Their normalized chemical compositions were compared to the laboratory-identified signatures to evaluate the flowpath. The majority of the flowpaths sampled had chemical signatures, which indicated mineral interflow, only 10% showed unmixed organic interflow.

The thesis deals with analysis of factors contributing to the development of ephemeral gully erosion on area of the Czech Republic. Method used to direct measurements of ephemeral gully erosion was developed. The statistical sample of gullies was measured to describe the characteristics of ephemeral gullies. Statistical methods were used to compute simple and multiple linear regression models. The models describe relationships between ephemeral gully parameters or factors contributing to development of ephemeral gully. The thesis is concentrated with the development of methodology for prediction the occurrence and prediction of parameters of ephemeral gullies. The methodology can be used to design the optimal erosion control measures in the conditions of the Czech Republic.

No description available.

Despite being one of the most productive ecosystems on earth, wetland areas have been heavily affected by human activities. The Cienaga Grande de Santa Marta (CGSM) in Colombia is one of these wetlands, where the inadequate construction of roads modified the hydrology and connectivity of this water body, generating massive mangrove mortality episodes. The lack of knowledge on the hydrological processes and connectivity of the CGSM has impaired mangrove restoration plans. Here we use wetland interferometry technique to remotely monitor the wetland and understand the flow of water in/out and across the CGSM wetland complex. A close collaboration with Miami University allowed us to access CGSM’s interferograms created with ALOS Palsar satellite data (from 2007 until 2011). The interferograms resulting from the analysis were correlated with daily hydrological data (precipitation, runoff in the main inflow of freshwater to the wetland, tide charts) to finally identify two main paths of inflow of water that are still active and are continuously feeding freshwater into the Cienaga. The most persistent was identified in the south-west part of the CGSM; a water flow coming directly from the Magdalena River and entering the main lagoon in its south-west corner. The second was located in the north-west area, where most of the mangroves have died. In this case, different interferograms showed different potential water flow paths depending on the season (dry / wet season), the Magdalena River’s discharge and the rainfall. These results reflect the complex hydrology of the CGSM . Furthermore, a coherence analysis was conducted to assess the quality of the remote sensing data and to better understand the different responses of the features within the Cienaga. The results showed that the coherence analysis could also be potentially used to identify areas of dead mangrove. This study confirms that despite the blockage of the connectivity of the wetlands, there are still important freshwater flow paths feeding the CGSM. Additional hydrological studies are needed to ensure the further understanding of the hydrology of the CGSM and confirm the results of this study.

Les milieux aquifères karstiques représentent des ressources en eau importantes, particulièrement sur le pourtour méditerranéen où ils constituent la majorité des réservoirs d'eau douce souterraine. La demande en eau ayant littéralement explosée au cours de ces dernières années, ces ressources en eau constituent un facteur limitant du développement, à l'origine de conflits d'aménagements et d'usages. Il est donc nécessaire d'avoir une meilleure connaissance de ces milieux afin de proposer une exploitation appropriée, répondant aux besoins régionaux. Toutefois, ces milieux restent encore mal connus, notamment à cause de la difficulté à caractériser leur fonctionnement inhérent à l'hétérogénéité organisée de leurs écoulements. Afin d'améliorer la connaissance de ces milieux, nous avons réalisé une étude détaillée des propriétés hydrologiques de l'aquifère karstique du Lez situé en région Nord Montpelliéraine. La source du Lez alimente en eau potable la région par des pompages dans le conduit principal du réseau de drainage. Le bassin (d'une superficie d'environ 200 km²) est équipé d'un réseau dense de piézomètres, ainsi que d'un site expérimental, situé à 4.5 km au nord de la source du Lez concentrant une vingtaine de forage sur une superficie d'environ 1500 m². Ce travail porte à la fois sur 1) une caractérisation multi-échelle de l'hétérogénéité des propriétés hydrodynamiques du système, et 2) une étude du transfert de masse au sein du réservoir via analyse de traçages artificiels réalisés à l'échelle régionale et à l'échelle du site expérimental. Dans un premier temps, les essais en puits seul ont permis caractériser les différents éléments du karst et d'identifier les structures les plus transmissives. A l'échelle du site expérimental, l'analyse de l'essai de pompage a mis en évidence une connectivité globale liée à l'interface stratigraphique et une hiérarchisation des écoulements dépendante de la fracturation verticale. Enfin, l'étude des interférences des pompages du Lez à l'échelle régionale indique une compartimentation hydraulique du système. Les propriétés hydrodynamiques estimées dépendent de l'hétérogénéité structurale et des conditions hydrologiques du bassin. Le recoupement de ces différentes analyses permet une discrétisation des paramètres hydrauliques des composantes structurant les écoulements au sein d'un massif karstique. L'étude du transfert de masse à l'échelle locale et régionale complète cette caractérisation et renseigne les propriétés de transport du réseau karstique. Les essais de traçage à l'échelle du site mettent en évidence la forte hétérogénéité du milieu avec des chemins d'écoulement multiples induisant un gradient de vitesse. Tandis qu'à l'échelle régionale une corrélation des vitesses d'écoulement est observée au sein du réseau de drainage principal.L'ensemble de ces résultats fournit une meilleure connaissance à différentes échelles des propriétés et de la vulnérabilité de ces milieux complexes, constituant une base essentielle pour une modélisation hydrodynamique multi-échelle de ce type d'aquifères. / Characterizing groundwater flows in karst aquifers at different scales of space and time, is not an easy task due to the high level of heterogeneity of these aquifers. Because the limited testing radius of classical hydraulic methods (slug tests, pumping tests), the regional hydraulic parameters of karst systems are generally estimated using the flow recession analysis method. But this integrative method generally does not give a differentiation into regionally varying parameters. Also, it is generally difficult to gather enough data to characterize aquifer heterogeneities at regional scale. For this reason, most of studies about hydrodynamic characterization of karst aquifer focus on local scales, i.e experimental field site scale or borehole scale; measurements at small scale could then be upscaled to obtain hydrodynamic parameters at regional scale. Consequently, understanding scale dependence of groundwater flows organization in such a context is of prime importance for the development of regional scale model.In this study, the monitoring of groundwater flow and transport is performed at several scales of time and space, within a single Mediterranean karstic carbonate aquifer, the Lez karst aquifer, located South of France. Groundwater is intensely pumped in a karst conduit upstream of the main karst outlet (Lez spring), for regional water supply. At regional scale, the relatively dense groundwater monitoring network permits to determine the hydrodynamic properties of the aquifer inferred from the hydrodynamic response to pumping at the Lez spring. At the scale of the experimental field site (Terrieu site), that comprises 22 boreholes, several experiments (i.e. pumping tests, packer tests, slug and injection tests) were performed to determine the hydrodynamic properties at experimental field site scale and borehole scale. Tracer experiments were also performed to provide an estimation of transport properties both at the scale of the experimental field site and at regional scale.The hydrodynamic properties estimated at different scale of space and time (for different hydrological conditions) were compared with flow paths organization linked to the geological structure of the reservoir. At regional scale both the hydrological conditions (i.e. high or low water level) and geological compartmentalization that impact the hydraulic connectivity, control the hydrodynamic properties. Tracer experiments revealed short time transfer and high connectivity between injection points and the spring. At the experimental field site scale, pumping and tracer test highlighted heterogeneous flow pattern that can be linked to the position of boreholes and the main geological features. At borehole scale, hydraulic tests revealed a high range of hydrodynamic properties (transmissivity from 10-11 m²/s to 10-2 m²/s) depending on the investigated part of the aquifer (matrix, fracture or drain).Depending on the water level conditions, the aquifer presents variable organization of flows that modify the hydrodynamic parameters. As expected, variability of hydrodynamic parameters depends on the scale of investigation: a difference of 10 to 105 has been quantified for a same parameter characterized at borehole scale and at regional scale. This hydrogeological parameters quantification of karst system provides important constrain about multiscale modeling using conceptual models to represent the characteristics of the main flow paths.