HR: 14:10h
AN: H22F-03    [PDF]
TI: Ground Water Data Management Using the ArcObjects Library
AU: * Jones, N L
EM: njones@byu.edu
AF: Environmental Modeling Research Laboratory, 242 Clyde Building Brigham Young University, Provo, UT 84602 United States
AU: Gallup, D
EM: gallup@byu.edu
AF: Environmental Modeling Research Laboratory, 242 Clyde Building Brigham Young University, Provo, UT 84602 United States
AB: The principal advantage of utilizing GIS technology for regional ground water modeling is that it allows the model development to occur on the conceptual model level. The principal model features can be defined using points, arcs, and polygons. For example, production and observation wells can be input as points. Rivers, drains, and head-dependent boundary conditions can be defined using arcs. Lakes, recharge zones, seepage faces, and hydraulic conductivity zones can be represented using polygons. Once the conceptual model has been defined, the model can be discretized to the model grid. The feature objects are intersected with the model grid to determine which cells coincide with each model feature. The cell-by-cell model input can then be automatically extracted from the feature object data. This conceptual model approach has numerous advantages: 1. Model development much is more efficient since the tedious discretization process can be automated. 2. Since the conceptual model is defined independent of the model grid, the modeler can quickly test various grid resolutions. 3. Existing GIS data can be integrated into a modeling project with minimal effort. When building a GIS-based ground water modeling tool, one of two approaches is typically used: 1) the tools be built entirely within an existing GIS such as ArcGIS, or 2) the tools can be built in a stand-alone program that imports data provided by a GIS. There are several advantages/disadvantages to each of these methods. We have chosen to build our system in a stand-alone program called the Groundwater Modeling System (GMS). The Map Module in GMS provides an interface for building conceptual models and converting conceptual models to a variety of models including MODFLOW \& MT3DMS. One important component of a GIS-based modeling system is the capability to import GIS data. Traditionally, we have used the "shapefile" format for importing and exporting GIS data. The shapefile format is a fairly simple file format designed for exchanging GIS data. The main drawback of the shapefile approach is that not all GIS data are available in shapefile format. Recently, we have developed an entirely new method for importing GIS data for ground water modeling. This method is based on the new ArcObjects software library provided with the ArcGIS software. With ArcObjects, it is possible to embed a large portion of the ArcGIS functionality directly within your own application, provided that ArcGIS has been installed on the computer running the software. In GMS, we have developed a new "GIS Module" that incorporates the ArcObjects technology. With the ArcObjects tools, we can use the native ArcGIS "Add Data" dialog box to open virtually any GIS database supported by ArcGIS. We can then plot the imported database using the ArcObjects code, resulting in high quality map displays. In many cases, a GIS database contains substantially more information than is required by a modeling study. Using the ArcObjects code, we can select a subset of the database either by a graphical selection or by an SQL query. The selected data are then transformed to the format used by GMS for defining the conceptual models. When GIS data are initially developed, the format and naming conventions used are often non-standard. During this transformation process, the user is allowed to identify a filter for the attribute table that controls how the feature object attributes are to be mapped to the corresponding conceptual model attributes.
DE: 1829 Groundwater hydrology
SC: Hydrology [H]
MN: 2003 Fall Meeting