A Conceptual Framework for Integration Development of GSFLOW Model: Concerns and Issues Identified and Addressed for Model Development Efficiency

In Coupled Groundwater and Surface-Water Flow (GSFLOW) model, the three-dimensional finite-difference groundwater model (MODFLOW) plays a critical role of groundwater flow simulation, together with which the Precipitation-Runoff Modeling System (PRMS) simulates the surface hydrologic processes. While the model development of each individual PRMS and MODFLOW model requires tremendous time and efforts, further integration development of these two models exerts additional concerns and issues due to different simulation realm, data communication, and computation algorithms. To address these concerns and issues in GSFLOW, the present paper proposes a conceptual framework from perspectives of: Model Conceptualization, Data Linkages and Transference, Model Calibration, and Sensitivity Analysis. As a demonstration, a MODFLOW groundwater flow system was developed and coupled with the PRMS model in the Lehman Creek watershed, eastern Nevada, resulting in a smooth and efficient integration as the hydrogeologic features were well captured and represented. The proposed conceptual integration framework with techniques and concerns identified substantially improves GSFLOW model development efficiency and help better model result interpretations. This may also find applications in other integrated hydrologic modelings

A Conceptualized Groundwater Flow Model Development for Integration with Surface Hydrology Model

A groundwater system model was developed and calibrated in the study area of Lehman Creek watershed, eastern Nevada. The model development aims for integrating the surface hydrologic model - precipitation runoff modeling system (PRMS) model - with the three-dimensional (3D) finite-difference model MODFLOW. A two-layer groundwater model was developed with spatial discretization of 100 x 100 m grid. The water balance was estimated with inflows of gravity drainage and initial streamflow estimated from a calibrated PRMS model, and with outflows of spring discharges, boundary fluxes, and stream base flow. A steady-state model calibration was performed to estimate the hydraulic properties. The modeling results were able to represent the geographic relieves, simulate water balance components, and capture the hydrogeologic features. The preliminary results presented in this study provide insights into the local groundwater flow system and lay groundwork for future study of interactive influences of surface hydrologic variation

Simulation Analysis of 3D Seepage Groundwater Flow and Making of 3D Geological Structure Model in Multilayered Ground(Post-Print version)

In the management and a usage of a groundwater resource, we need to work on an accurate grasp of the current situation and to make a future vision in the region where the groundwater exploitation is active. In this research, we aim at the creation of the three-dimensional geological structure model in multilayered ground and the three-dimensional seepage flow analysis of groundwater by using the model. The area in this research exist many multi-layers which are alternately stratified gravel layers and clay layers. Firstly, based on bowling log and an altitude distribution map, we grasped the topography and the geological structure of a target area. Secondly, based on boring log, we interpolated the layer thickness of every layer in a model by using the Kriging method. The outline of the three-dimensional geological structure is completed by piling them up. Thirdly, considering of the position of pumping wells and the layer thickness distribution, we divided mesh. Finally, we reproduced groundwater flow by conducting groundwater analysis, and created the figure which visualized the groundwater flow.EIT-JSCE Joint International Symposium on International Human Resource Development for Disaster-Resilient Countries 201

Impacts of Three-Dimensional Non-Uniform Groundwater Flows for Quantifying Groundwater-Surface Water Interactions Using Heat as a Tracer

Heat-as-a-tracer has become a common method to quantify surface water-groundwater interactions (SW/GW). However, the method relies on a number of assumptions that are likely violated in natural systems. Numerical studies have explored the effects of violating these fundamental assumptions to various degrees, such as heterogeneous streambed properties, two-dimensional groundwater flow fields and uncertainty in thermal parameters for the 1-dimensional heat-as-a-tracer method. No work to date has addressed the impacts of non-uniform, three-dimensional groundwater flows on the use of heat-as-a-tracer to quantify SW/GW interactions. Synthetic temperature time series were generated using COMSOL Multiphysics for a three-dimensional cube designed to represent a laboratory setup of homogeneous, isotropic sand with a sinusoidal temperature variation applied to the top. We compare temperature-derived fluxes to model-generated fluxes to assess the performance of methods using temperature to quantify 1D vertical fluxes in response to multi-dimensional groundwater flows. Both increasingly non-uniform and non-vertical groundwater flow fields result in increasing errors for both amplitude-ratio-derived groundwater flux and temperature-derived effective thermal diffusivity. For losing flow geometries, errors in temperature-derived effective thermal diffusivity are highly correlated with errors in temperature-derived flux and can be used to identify if underlying assumptions necessary for heat-as-a-tracer for quantifying groundwater flows have been violated. For this model set-up, when groundwater flows are non-uniform, the thermal method generally calculates fluxes outside the range occurring between temperature sensor pairs. When errors are low (15% of flux calculations), temperature derived fluxes more closely match the minimum magnitude flow occurring between the sensors

Numerical modelling of multiple standing column wells for heating and cooling buildings

A model for simulating clusters of standing column wells (SCWs) for use in geothermal heating and cooling systems is described in this paper. The model is three-dimensional, dynamic and solves the governing equations using a finite volume discretisation scheme with a fully implicit algorithm. The slower-acting field equations are solved using a wider time interval than that used for the faster-acting well equations and the two sets of equations are coupled through the field equation source terms. A groundwater bleed feature is incorporated. The model is applied to two evaluative test cases the first of which involves heating only and the second, heating and cooling. Results of the applications suggest that SCWs can deliver substantially higher rates of heat transfer than conventional closed loop borehole heat exchanger arrays especially when groundwater bleed is operational. An important practical consequence of this is that far less geotechnical drilling is needed when using SCWs than is the case with closed loop arrays

The development and validation of the object-oriented quasi three-dimensional regional groundwater model ZOOMQ3D

This report documents the modifications made to the object-oriented regional groundwater model ZOOM2D (The University of Birmingham, 2001). Additional mechanisms are introduced to this model to satisfy the generally-accepted functional requirements of a commonly-applied regional groundwater flow model. The modified model, ZOOMQ3D, is quasi three-dimensional and is validated through comparison with analytical solutions and with instructional problems formulated for MODFLOW (McDonald and Harbaugh, 1988) by Anderson (1993)

Groundwater transfer and injection pilot project: construction of a three dimensional groundwater flow model

The Mississippi River Valley Alluvial Aquifer has experienced substantial groundwater declines in eastern Arkansas and northwest Mississippi due largely to irrigation for rice corn soybeans and other water intensive crops. To alleviate groundwater decline and ensure future sustainability of water resources the U.S. Department of Agriculture has in conjunction with the U.S. Geological Survey and the University of Mississippi initiated studies to determine potential avenues of remediation. Options include improved irrigation efficiency installation of surface weirs inter-basin transfers and groundwater transfer and injection. This study develops a three-dimensional groundwater flow model of a withdrawal well adjacent to a river for a groundwater transfer and injection project. The numerical model is developed using Modflow Flex Visual 5.0 and utilized to assess the effect of varying hydrologic and geologic parameters on the local potentiometric surface. Assessing the potential for drawdown of the potentiometric surface and reduction of storage in the aquifer surrounding the withdrawal well is of particular importance. According to the model results drawdown and reduction of storage are minimal in all cases. Changes in the river conductance and aquifer conductivity are the most substantial factors affecting the water table and resulting changes in storage

Dressing the Emperor: The Role of Three-Dimensional Information Visualization Software in the Development of Three-Dimensional Hydrogeologic Models

This poster was presented at the 2006 Annual Meeting of the Geological Society of America, October 22-25, 2006, Philadelphia, Pa.The goal of this research is to develop a model that describes the saturated and unsaturated groundwater flow in Berrien County, Michigan (1,350 km2), an area containing a complex sequence of glacio-lacustrine deposits. Stone and others (2001) mapped the morphosequences in Berrien County at a scale of 1:24,000, which includes georeferenced structure contours for 20 individual units. We have developed a methodology to translate this detailed morphostratigraphy into a solid three-dimensional geologic model, and then into a three-dimensional block of data that can be used as input to a finite-difference groundwater-flow model. Letsinger and others (2006) describe the process of using geographic information system software to convert the structure contours into georeferenced raster layers that describe each unit. At this stage of the reconstruction, only the bounding surfaces between the units are defined. In order to stack the units in vertical space using customized computer code, a “virtual well field” (regularized two-dimensional array of points) samples each x-y location in each of the 20 rasterized data layers. Units that are intersected from the top bounding surface (surface topography) to the bottom bounding surface (bedrock surface) are then identified. The result of this step is a vector (one-dimensional array) at each virtual well location that describes the elevation of each morphostratigraphic unit boundary intersected at that location. However, at this stage, the model is essentially a regularized three-dimensional point cloud, and three-dimensional information visualization software (3DIVS) is then utilized to generate a solid geologic model by interpolating the vertical geologic “samples” throughout the model domain. A finite-difference grid (“brickpile”) at the chosen resolution of the groundwater-flow model is then generated from the solid geologic model using data-processing functions of the 3DIVS

Dressing the Emperor: The Role of Three-Dimensional Information Visualization Software in the Development of Three-Dimensional Hydrogeologic Models

This poster was presented at the 2006 Annual Meeting of the Geological Society of America, October 22-25, 2006, Philadelphia, Pa.The goal of this research is to develop a model that describes the saturated and unsaturated groundwater flow in Berrien County, Michigan (1,350 km2), an area containing a complex sequence of glacio-lacustrine deposits. Stone and others (2001) mapped the morphosequences in Berrien County at a scale of 1:24,000, which includes georeferenced structure contours for 20 individual units. We have developed a methodology to translate this detailed morphostratigraphy into a solid three-dimensional geologic model, and then into a three-dimensional block of data that can be used as input to a finite-difference groundwater-flow model. Letsinger and others (2006) describe the process of using geographic information system software to convert the structure contours into georeferenced raster layers that describe each unit. At this stage of the reconstruction, only the bounding surfaces between the units are defined. In order to stack the units in vertical space using customized computer code, a “virtual well field” (regularized two-dimensional array of points) samples each x-y location in each of the 20 rasterized data layers. Units that are intersected from the top bounding surface (surface topography) to the bottom bounding surface (bedrock surface) are then identified. The result of this step is a vector (one-dimensional array) at each virtual well location that describes the elevation of each morphostratigraphic unit boundary intersected at that location. However, at this stage, the model is essentially a regularized three-dimensional point cloud, and three-dimensional information visualization software (3DIVS) is then utilized to generate a solid geologic model by interpolating the vertical geologic “samples” throughout the model domain. A finite-difference grid (“brickpile”) at the chosen resolution of the groundwater-flow model is then generated from the solid geologic model using data-processing functions of the 3DIVS

Simulation of Groundwater Flow, Denpasar-Tabanan Groundwater Basin, Bali Province

DOI: 10.17014/ijog.v6i3.123Due to the complex structure of the aquifer systems and its hydrogeological units related with the space in which groundwater occurs, groundwater flows were calculated in three-dimensional method (3D Calculation). The geometrical descritization and iteration procedures were based on an integrated finite difference method. In this paper, all figures and graphs represent the results of the calibrated model. Hence, the model results were simulated by using the actual input data which were calibrated during the simulation runs. Groundwater flow simulation of the model area of the Denpasar-Tabanan Groundwater Basin (Denpasar-Tabanan GB) comprises steady state run, transient runs using groundwater abstraction in the period of 1989 (Qabs-1989) and period of 2009 (Qabs-2009), and prognosis run as well. Simulation results show, in general, the differences of calculated groundwater heads and observed groundwater heads at steady and transient states (Qabs-1989 and Qabs-2009) are relatively small. So, the groundwater heads situation simulated by the prognosis run (scenario Qabs-2012) are considerably valid and can properly be used for controlling the plan of groundwater utilization in Denpasar-Tabanan GB