Survey Modular Finite-difference Ground-water Flow Research Articles

Providing decision support system in groundwater resources management for the purpose of sustainable development

Decision support system (DSS) for sustainable development is an efficient tool in managing aquifers, since an aquifer as a complex system is not a structural issue due to varied components. In this article, software entitled DSS-SMGW-01 is developed based on the so-called DSS to realize sustainable management of groundwater. This system includes a database, a simulation model, and a decision-making model controlled through a graphical user interface. This software controls exploitation of groundwater in managing subunits and integrated management of water resources and consumptions. Furthermore, management options are evaluated by the software according to aquifer sustainability and socio-economic indicators. In this system, WEAP-MODFLOW linked model (Water Evaluation And Planning system dynamically linked to the United States Geological Survey modular finite-difference groundwater flow model), Analytic Hierarchy method, and Simple Additive Weighting method are utilized for simulation of groundwater resources system, weighting indicators and prioritizing options, respectively. In order to evaluate efficiency of the exerted system, Qazvin plain data was used and 68 experts from different parts of water industry in Iran were consulted to have the best analysis on weighting the indicators. Consequently, the prepared system was found to be successful in designing and prioritizing the seven managing indices.

GEOSSAV: a simulation tool for subsurface applications

Geostatistical Environment fOr Subsurface Simulation And Visualization (GEOSSAV) is a tool for the integration of hard and soft data into stochastic simulation and visualization of distributions of geological structures and hydrogeological properties in the subsurface. GEOSSAV, as an interface to selected geostatistical modules (bicalib, gamv, vargplt, and sisim) from the Geostatistical Software LIBrary, GSLIB (GSLIB: Geostatistical Software Library and User's Guide, 2nd Edition, Oxford University Press, Oxford, 1998, 369pp), can be used for data analysis, variogram computation of regularly or irregularly spaced data, and sequential indicator simulation of subsurface heterogeneities. Sequential indicator simulation, based on various kriging techniques (simple, ordinary, and Bayesian), is suitable for the simulation of continuous variables such as hydraulic conductivity of an aquifer or chemical concentrations at a contaminated site, and categorical variables which indicate the presence or absence of a particular lithofacies. The software integration platform and development environment of GEOSSAV is Tool command language (Tcl) with its graphical user interface, Toolkit (Tk), and a number of Tcl/Tk extensions. The standard Open Graphics Library application programming interface is used for rendering three-dimensional (3D) data distributions and for slicing perpendicular to the main coordinate axis. Export options for finite-difference groundwater models allow either files that characterize single model layers (which are saved in ASCII matrix format) or files that characterize the complete 3D flow model setup for MODFLOW-based groundwater simulation systems (which are saved in block-centered flow package files (User's documentation for MODFLOW-96, an update to the US Geological Survey modular finite-difference ground-water flow model, Geological Survey Open-File Report 96-485, Reston, VA, 1996, 56pp)). GEOSSAV can be used whenever stochastic solutions are preferred to solve site-specific heterogeneity problems, e.g., in the field of hydrology, groundwater, groundwater and/or soil contamination, site remediation, air pollution, and ecology. An example from the Rhine/Wiese aquifer near Basel demonstrates the application of GEOSSAV on geostatistical data analysis and subsurface visualization. GEOSSAV has been successfully tested on Microsoft Windows NT 4.0/2000/XP and on SuSE Linux 7.3. The current version is available at http://www.unibas.ch/earth/pract.

Simulation of cylindrical flow to a well using the U.S. geological survey modular finite-difference ground-water flow model. Computer note : Reilly, T E; Harbaugh, A W Ground WaterV31, N3, May–June 1993, P489–494

Simulation of cylindrical flow to a well using the U.S. geological survey modular finite-difference ground-water flow model. Computer note : Reilly, T E; Harbaugh, A W Ground WaterV31, N3, May–June 1993, P489–494

Simulation of vertical compaction in models of regional ground-water flow : Leake, S A Proc 4th International Conference on Land Subsidence, Houston, 12–17 May 1991P565–574. Publ Wallingford: IAHS Press, 1991

A new computer program was developed to simulate vertical compaction in models of regional ground-water flow. The program accounts for ground-water storage changes and compaction in discontinuous interbeds or in extensive confining beds. The new program is a package for the U.S. Geological Survey modular finite-difference ground-water flow model. Several features of the program make it useful for application in shallow unconfined flow systems. Geostatic load can be treated as a function of watertable elevation, and compaction is a function of computed changes in effective stress at the center of a model layer. Thickness of compressible sediments in an unconfined model layer can vary in proportion to saturated thickness. The new package was tested by comparison with an existing model of onedimensional compaction.