Digital Shoreline Analysis System Version 2.2.1 28 September 2004 Installation: Copy the the DSAS extension (.avx file) to your ArcView extensions directory (typically EXT32 or EXT16). Then open an ArcView project that you want to use the DSAS extension with and add the extension to the project using "File -> Extensions" menu. More information: Official DSAS website is http://woodshole.er.usgs.gov/project-pages/dsas/ Known issues for the DSAS extension: 1. DSAS extension can not be used as a default extension for ArcView. Doing so will cause Arcview to generate an error during startup. Instead, make it a default extension for your project. For example, load the extension after a new project has been created. Once saved, DSAS will load automatically every time that project is opened. 2. DSAS adds required fields to shoreline/baseline shapefiles. If any of those fields was created external to DSAS and does not match the expected field type or if its size is less than expected, DSAS will complain. To work around this issue, you can try converting fields to the types and sizes suggested by DSAS. 3. DSAS assumes a default accuracy value of +/- 6 meters. Because ArcView is unable to differentiate between a null value and a zero value in a numeric field, it is not currently possible to use an accuracy value of +/- 0 meters. 4. DSAS will create three new, but empty themes if the user attempts to cast transects with only the baseline theme active (highlighted). Make sure both the shoreline and baseline files are active before casting transects. 5. Once themes are generated by DSAS (transect, intersect, and changes), it is highly recommended that the changes theme be copied to a new shapefile (Theme -> Convert to Shapefile). If the changes theme is removed from the view without saving to a new shapefile, it will fail to load when added back to the view, giving the error message: "Number of shapes does not match number of table records." 6. To avoid getting errors when manually adding additional transects to an existing theme, select an existing transect while in an edit session, then go to Edit -> Copy Feature, Edit -> Paste. You can then move the duplicate transect (using the pointer and vertex edit arrows) to the desired location. You must save and recalculate after each newly created transect in order to get the changes theme to update. If multiple transects are added during a single edit session, the changes theme will only update for the last transect added (both the transect and intersect themes and associated attribute fields update without errors). NOTE: this only applies to newly created transects, not to automatically generated transects modified by the user. Change log: Version 2.2.1: - Changes theme fields are now updated after a recalculate (HOWEVER see #6 above). Version 2.2: - Incorporated LRR calculation scripts from Emily Himmelstoss. - Added back "DSAS.Intersect.RemoveFromTransect" script that was not included in the distribution. Version 2.1.1: - Removed some debugging messages that were inadvertently left in the released code. Version 2.1: - "Changes" theme was added that contains individual shoreline change data. This theme complements "transect" theme and provides shoreline change information on the basis of an era. - Users can now opt to pick closest or furthest intersection points when transects are cast independent of whether the baselines are on-shore or off-shore. - Users can now turn on/off log file generation which is useful only for debugging purposes. The log file used to contain era-based change information also which now have been moved to "changes" theme. - A bug was identified and fixed that could potentially cause ArcView crashes under specific circumstances. Version 2.0 Final: - Off-shore baselines are supported now in addition to on-shore (landwards) baselines. - Default settings can now be changed through "Default Parameters" dialog box accessible with a view button. Default parameters are saved with the project automatically. - Attribute Editor now operates on the first active theme only, in the spirit of ArcView. - Smarter intersection algorithm that now takes into account the date and accuracy of each shoreline involved in the intersection. - Attribute Editor follows selection in view allowing the user to bring up a feature in the Attribute Editor without having to click their way to it. - New fields are introduced introduced to transect and intersect shapefiles. Now both shapefiles feature a timestamp field that helps keeping trac of when cast operations were performed. The transect shapefile also features a "PointCnt" field that specifies the number of shoreline intersection points involved in the rate calculations. - Miscellaneous user interface and stability improvements should make DSAS easier to use and less prone to crashing under unexpected circumstances. Version 2.0 Beta 3: - DSAS now performs checks to avoid a number of situations where it may run into an error. - DSAS now forces the user to use different transect and intersect themes in each view rather than defaulting to "transect" and "intersect" respectively. Manipulation of the same theme(s) from different views was a potential source of conflicts. - DSAS now uses the standard ID field generated by ArcView if it exists. If it doesn't exist, DSAS will create one that is compatible with ArcView. - DSAS is now more lenient about fields required in baseline/shoreline shapefiles. As long as a field matches the expected type and its size is equal or larger than expected, DSAS will not generate any warnings. If the field type does not match, DSAS will display a warning and stop. If the field type matches but field size is smaller than expected, DSAS will display a warning and attempt to proceed. It will be the user's responsibility to make sure values that are input can fit in the provided field. - The error "Variable pts has not been initialized" while trying to cast transects has been fixed. This error occured when the start of a baseline was not within transect distance from any shoreline. Now DSAS detects this situation and proceeds to the next transect location on the baseline until it can determine which direction to cast transects to. - Miscellenaous changes in naming, labelling, etc. based on user feedback. Version 2.0 Intermediary Release Oct. 4, 2002: - Trivial problems that prevented DSAS V2.0 Beta 2 from working at al were fixed. Version 2.0 Beta 2: [change log not available at the time of writing] Version 2.0 Beta 1: - Initial beta release for testing.