Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 84 for “"modflow"”.
-
Using MODFLOW to Predict Impacts of Groundwater Pumpage to Instream Flow: Upper Kittitas County, Washington
… UKC-GFM include: (1) using a newer version of MODFLOW (MODFLOW-NWT) with the new Newton Solver and the Upstream Weighting (UPW) package. The YRB-GFM used MODFLOW-2005, the PCG2 Solver, and the Hydrogeologic-Unit Flow (HUF) Package; (2) incorporating zone arrays with multiple hydraulic …
-
Quantifying climate change impacts on future water resources and salinity transport in a high semi-arid watershed using the APEX-MODFLOW-Salt model
… (GRW) (14,608 km2), Colorado, using the APEX-MODFLOW-Salt hydro-chemical watershed model and three different CMIP5 climate models output downscaled by Multivariate Adaptive Constructed Analogs (MACA), each for two climate scenarios, RCP4.5, and RCP8.5, for the period 2020–2099. The …
-
Evaluating least absolute deviation regression as an inverse model in groundwater flow calibration
… procedure built into the US Geological Survey MODFLOW groundwater model works well with single layer geologic systems; however, it does not work well with multi-layer systems. This dissertation provides the Least sum Absolute Deviation regression and Expectation Maximization procedures. These …
-
A Model for Simulating Soil-Zone Processes at the Regional Scale
… of watershed hydrologic processes. Currently MODFLOW does not simulate dynamic near-surface hydrologic processes such as, infiltration, hortonian runoff, dunnian runoff, and return flow. The Soil-Zone Flow Package (SZF) for MODFLOW is being developed to address these near-surface components …
-
Development of a model for simulation of solute transport in a stream aquifer system
… four primary models: The groundwater flow model, MODFLOW-96, the coupled groundwater surface water model, MODBRANCH 3.7, the aquifer solute transport model, MT3D 1.11, and a fourth model developed in this study referred to as Stream Solute Transport Model or SSTM 1.0. The flow interaction in a …
-
Impact of Phytoremediation System on Groundwater Flow in a Shallow Aquifer System
… with the groundwater modeling program MODFLOW. The trees are simulated using the Evapotranspiration Package within MODFLOW, within the GMS modeling platform, to produce a two-dimensional unconfined aquifer viewpoint groundwater model. Site characterization, setup, and rationale are …
-
Evaluating a Process-Based Mitigation Wetland Water Budget Model
… A second process-based model, utilizing MODFLOW-2005, was constructed to better predict water levels in mitigation wetlands. Modeled processes included groundwater movement and vegetative resistance to flow, which can be a significant factor in wetland water levels. The two versions of …
-
Groundwater Modeling and Hydrogeological Parameter Estimation: Potomac Aquifer System, SWIFT Research Center
… and middle Potomac aquifers were produced with MODFLOW. Parameter estimation using MODFLOW and PEST and the two sets of observation data resulted in hydrogeological parameters similar to those calculated using Theis and Cooper-Jacob methods. The change in the hydraulic conductivity and specific …
-
A study of the groundwater travel time distribution at a rural watershed in Iowa: A systems theory approach to groundwater flow analysis
… flow model of the aquifer was constructed using MODFLOW (Harbaugh et al., 2000). Hypothetical particles were then tracked through the simulated groundwater flow field using MODPATH (Pollock, 1994) to determine travel times associated with advective solute transport. The resultant distribution of …
-
In the Zone: the Effects of Soil Pipes and Dunes on Hyporheic and Riparian Zone Hydraulics and Biogeochemistry
… hydraulics. This research first employed MODFLOW and MT3D-USGS to model transient hyporheic hydraulics and nitrate transport in a length of riparian/riverbank soil to probe the effects of soil pipes on hydraulics and denitrification due to peak flow events in the channel. Findings showed …
-
Hydraulic Resistance due to Emergent Wetland Vegetation
… regression models developed from the flume data. MODFLOW was used to simulate a 4-hour flood event through the wetland. The vegetated open water surface was modeled as a highly conductive aquifer layer. On average, MODFLOW slightly underpredicted the water surface elevation. However, the model …
-
Estudio y modelización de la contaminación del acuífero del río Najerilla: aplicación de la microextracción en fase sólida para la determinación de los contaminantes
… samples. In this work a flow model using Visual Modflow was adjusted. The mathematical flow models reproduce successfully the behaviour of the polluted aquifer. Calculated levels by the mathematical model and observed head showed a good regression. The normalized root mean squared residual was …
-
Sequential Electron Acceptor Model of Intrinsic Bioremediation at a BTEX Contaminated LUST Site in Laurel Bay, South Carolina
… Using the field data, the groundwater flow model MODFLOW was used to develop and calibrate a flow model for the Laurel Bay site using GMS (Groundwater Modeling System) v2.1. MODFLOW was coupled with the SEAM3D contaminant transport model, and the available concentration levels were used to …
-
A spatial decision support system for basin scale assessment of improved management of water quantity and quality in stream-aquifer systems
… the ArcMap interface (ESRI, Inc.), and Geo-MODFLOW, a new MODFLOW-MT3DMS results analysis tool in the ArcMap interface. The modeling system is complemented with a new artificial neural networks (ANN) module for natural and irrigation return flow quantity and quality evaluation and salt …
-
Coupled Surface Water-Groundwater Model to Analyze Sustainability of the Atascadero Subbasin
… Subbasin was studied using HEC-HMS, and Visual MODFLOW was used to model the aquifer. Both HEC-HMS and Visual MODFLOW was calibrated to improve simulation accuracy. HEC-HMS was used to quantify natural recharge to the aquifer and to simulate streamflow and water level for the Salinas River. …
-
Modeling biotic and abiotic decay of trichloroethylene (TCE) using the Reactive Multi-Species Transport in 3-Dimensional Groundwater Aquifers (RT3D) code
… Aquifers (RT3D) code. RT3D is part of the MODFLOW family of codes that is commonly used in engineering practice. In addition, this thesis explores the mitigation of the effects of back diffusion by implementing these decay processes in a 2-Dimensional flow cell model. The flow cell is built …
-
A comparison of Wellhead Protection area delineation methods at Larimore, North Dakota
… changes in K, porosity, and recharge. </p><p>The MODFLOW/SURFER/GWPATH (MSG) method combines a numerical groundwater flow model (M), a contouring program (S), and a particle-tracking program (G). The hydraulic head distribution from a cone of depression generated by MODFLOW is combined with …
-
Estimation of leakage between the shallow and principal aquifers in the Las Vegas Valley Water District's main well field, Las Vegas, Nevada
… finite difference ground-water flow model (MODFLOW) was developed to estimate volume and velocity of potential leakage, and water quality samples were collected; Water levels collected in the shallow aquifer show a dependency on potentiometric head in the principal aquifer. A linear …
-
Hydrologic and hydraulic assessment of artificial recharge in the Sparta Aquifer of Union County, Arkansas
… of artificial recharge by well injection. A MODFLOW groundwater model was modified to simulate the aquifer's response. to artificial recharge. Results indicate that artificial recharge in this context is impractical. Injection increases hydraulic heads only locally, with the most improvement …
-
Transition to Novel Internet of Things Technology for Management of Groundwater Resources? Case of Cape Town, South Africa
… between the gateway and sensor. A combination of MODFLOW Software, Geographical Information System (GIS) and Analytic Hierarchy Process (AHP) techniques was then adopted to assess the groundwater processes related to Managed Aquifer Recharge (MAR) in the study area. This research investigates the …
Page 1 of 5