Q1: Why should I start using the BAGIS toolset instead of the GIS Weasel?
Q2: What is the best way to recover from a VBA error? (BAGIS)
Q3: How can I determine if ArcGIS VBA Resources for Developers was installed? (BAGIS)
Q4: Can I use GIS data with different projection systems?
Q5: What files are created by BAGIS when I define an AOI?
Q6: How big (or small) should my HRUs be? (BAGIS-H)
Q7: How many HRUs do I need? (BAGIS-H)
Q8: What shape should my HRUs be? (BAGIS-H)

Q1: Why should I start using the BAGIS toolset instead of the GIS Weasel?
A1:

• The graphic-based BAGIS user interface is more intuitive to use. An efficient design streamlines the workflow of basin analysis and improves processing times by a factor of 10.
• Data management is more efficient and flexible because BAGIS doesn't use the strict file structures required by Weasel. Instead BAGIS uses a file geodatabase.
• BAGIS adds new mapping and analysis capabilities to support basin analysis conducted at NWCC.
• HRU delineation is more efficient than Weasel and allows the use of new HRU parameters that are not available with the old tool.
• The BAGIS process log provides comprehensive documentation of the HRU delineation algorithms used.

Q2: What is the best way to recover from a VBA error? (BAGIS)
A2: Program errors might occur when unexpected situations or data are encountered during run-time. One of the goals in the development of BAGIS is to minimize the number of bugs in the model. However, it is unavoidable to have bugs in a computer program. When a VBA error is encountered, ArcMap will bring out the Visual Basic Editor interface and a debugging message. First, write down the error message and dismiss the message dialog window by clicking OK or Cancel. On the VBA Editor main menu, click Run and select Reset. Then, close the VBA Editor and return to ArcMap. If the Select Basin tool is disabled, just open the option (i.e., system settings) window and close it. This will reset the Select Basin tool and make it enabled.

Q3: How can I determine if ArcGIS VBA Resources for Developers was installed? (BAGIS)
A3:ArcGIS VBA Resources for Developers (VBA SDK) is a required component to run the BAGIS application. The SDK installer comes with the ArcGIS Desktop program regardless which license level (i.e., ArcInfo, ArcEditor, or ArcMap) of ArcGIS Desktop you have. To check if you have this kit installed, go to the ArcGIS Resource Center and search for a patchfinder program for the ArcGIS version you have (for example, it's patchfinder931.exe for ArcGIS 9.3.1). You'll need your ESRI global account to acces the resource center. Run the program and see if a product named "ArcGIS Desktop SDK for VBA" is on the list. If not, then you have to install the software using the ArcGIS Desktop installation media.

Q4: Can I use GIS data with different projection systems?
A4: No. It's a requirement that you reproject all you data into the USGS NAD83 Albers projection. BAGIS operates based on the condition that all data layers are in this projection coordinate system. This projection uses a linear unit in meters. Also, the DEM zunit (i.e., elevation unit) must be in meters. The only exceptions are the layers used as reference layers. They are only displayed for cartographic purpose and are not used in any analysis. The parameters of the USGS NAD83 Albers projection is listed below.

Q5: What files are created by BAGIS when I define an AOI?
A5:

Q6: How big (or small) should my HRUs be? (BAGIS-H)
A6: Not knowing anything about your specific application, HRUs should generally be between 0.1 and 500 square kilometers in size. If you make them outside of this range, you should probably re-examine your input parameters.

Q7: How many HRUs do I need? (BAGIS-H)
A7: Not knowing anything about your specific application, 100 is a good number for a PRMS model of a 1000 square kilometer watershed. Of course, there may be good reasons why you may want more or less.

Q8: What shape should my HRUs be? (BAGIS-H)
A8: HRUs can be any shape that makes sense for your application. MoWS generally uses irregularly shaped polygons, which correspond to overland flow or solar radiation planes associated with watershed stream segments. Some PRMS modelers prefer regular squares or rectangles which may correspond to gridded data sets or the spatial discretization scheme of other models.