Latest Contributions by ChrisDonohue__GISP

I'd try Jayanta's idea.  However, if after trying it you find your data is not ending up where you expected it, check out this recent thread as there are many potential ways things can go awry in bringing in X,Y data: Importing GPS Coordinates from Excel into ArcMap One you get the data in correctly and it lines up with your expectations, you can use Jayanta's process to finish it out. Chris Donohue, GISP ... View more

(This topic popped up again today - so I'll post a reply in case others are looking for ideas besides the original poster) If you have access to both ArcGIS and the Spatial Analyst Extension, there are a variety of processes available.  Here's some topics to look at to help you get started: Overview of Hydrology Toolset ArcGIS Help 10.1 Understanding Drainage Systems ArcGIS Help 10.1 Hydrologic Analysis Sample Applications ArcGIS Help 10.1 Deriving Runoff Characteristics ArcGIS Help 10.1 Chris Donohue, GISP ... View more

Not exactly what you want but another option - If you have a more recent version of ArcGIS, you can also look into using the Alter Fields tool (Data Managment): ArcGIS Help (10.2, 10.2.1, and 10.2.2) Chris Donohue, GISP ... View more

You may want to consider changing your workflow so as to not edit the data while in Access if you intend to continue using it as a spatial file.  Note - if you want to edit it and then join it back to a spatial file, that is OK. Here's ESRI's advice on this: Similarly, you should only edit a personal geodatabase in ArcGIS. Although a personal geodatabase is stored as an Access .mdb, you should not open or modify the tables in a personal geodatabase inside Microsoft Access. This can corrupt the geodatabase and cause data loss. The limitation of Microsoft Access as an application to edit personal geodatabases is that Access was not designed to use or understand the ESRI functionality behind the personal geodatabase format. For example: The Access database format does not support geographic features. Personal geodatabases contain multiple underlying tables that provide information for a single feature class. When editing a feature class in ArcGIS, ArcGIS keeps track of changes in all the underlying tables. Editing the geodatabase in Access may cause those tables to become out of sync and corrupt the geodatabase. ArcGIS Help 10.1 This issue is reminiscent of issues people encounter with Shapefiles and Excel.  Can you look at a shapefile dbf in Excel?  Sure.  Can you edit a shapefile's attributes while in Excel.  Sure.  Is it a good idea?  No.  Even though the software will let you do it, you are just asking for trouble.  It will work for a while, then the file will get corrupted.  It's best to not even go that route, tempting though it is. Chris Donohue, GISP ... View more

This is an interesting concept.  I don't know the exact answer, but poked around and someone has written a book on the subject of Prominence.  Based on the excerpts of this book by Adam Helman posted online, there seems to be several flavors of Prominence and a variety of criteria that can be chosen for each: https://books.google.com/books?id=kr8AM-w8IFQC&pg=PT165&lpg=PT165&dq=prominence+island+parentage&source=bl&ots=kuZc6R7K9… Once a specific Prominence definition is chosen, it looks like it would be an interesting GIS challenge.  For starters, you would need a Digital Elevation Model (DEM) of the complete extent of the project area, which would likely cover a vast area.  For example, to derive the Prominence of Mount McKinley in Alaska, one typically would start with a DEM covering North, Central, and South America. The general solution process appears to be identifying the highest point in your project area (Peak 1), then looking at the next highest (Peak 2) and finding the highest point of land (the col or saddle) that connects each.  Then one checks the elevation distance between the col and Peak 2 to determine the Prominence of Peak 2, assuming the distance is more than your cutoff amount.  For example, if you determine your cutoff will be "for a peak to be distinctive, it must be at least 500 feet higher than the surrounding terrain connecting other peaks", then the distance of less than the cutoff makes that peak invalid for consideration of having any Prominence. Then repeat a comparison of Peak 2 to Peak 3, then Peak 3 to 4, etc.  Note that Peak 1 is a special situation - it does not normally get a Prominence, but if one is required it is typically its elevation compared to sea level. An article in Wikipedia offers some hints at the analytical process: Calculations and Mathematics: When the key col for a peak is close to the peak itself, prominence is easily computed by hand using a topographic map. However, when the key col is far away, or when one wants to calculate the prominence of many peaks at once, a computer is quite useful. Edward Earl has written a program called WinProm which can be used to make such calculations, based on a Digital Elevation Model. The underlying mathematical theory is called "Surface Network Modeling," and is closely related to Morse Theory. Topographic prominence - Wikipedia, the free encyclopedia However, most of the links are dead.  Chris Donohue, GISP ... View more

Almost forgot - one more use of Network Analyst that may fit what you need.  If you already have sites chosen, you could run Service Areas.  This could be useful to check your coverage. Chris Donohue, GISP ... View more

Sephe's suggestion of doing a Suitability Analysis is probably the best way to go. Another idea - If the primary access to these Emergency Health Services locations will be by driving, one potential analysis you could do would be to use the Network Analyst Extension to determine how accessible services would be by road.  You could do a Location-Allocation analysis. Network Analyst - Location/Allocation - See "Example 1:  Locating an ERS center" ArcGIS Help (10.2, 10.2.1, and 10.2.2) Network Analyst ArcGIS Help (10.2, 10.2.1, and 10.2.2) Network Analyst Tutorial ArcGIS Help (10.2, 10.2.1, and 10.2.2) Caveats/Considerations:  You will need to have a copy of Network Analyst.  Second you will need a good road layer that is set up for Network Analysis.  While road layers are fairly easily acquired, getting one that is clean and easily converted into a Network Dataset so it can be run in Network Analyst can be more problematic.  It can be a nightmare to try to clean up a road network - many road layers look great visually but have very small disconnects that cause the Network analysis to go awry.  Lastly, learning Network Analyst can take some time, as it is a bit different than other aspects of GIS, so take that into consideration if you haven't used it before.  Don't get me wrong - Network Analyst can be very powerful; but the level of effort required to get to the analysis stage can often easily be underestimated. Chris Donohue, GISP ... View more

Another thought - I've seen this issue crop up enough that I wonder if there is a third-party software out there that has been developed to help GIS Editors with communicating who is or isn't in a File Geodatabase.  Something that easily showed that a File Geodatabase was currently being accessed (instead of having to manually look at the folder with Windows Explorer and look in the File Geodatabase for the files with the "...sr.lock" in their names and then try to determine who the person accessing it is from the cryptic computer name that is part of the lock file name). All you Developers out there, here's a product awaiting development!  Chris Donohue, GISP ... View more

Is your question related to "Topographic Prominence"? Topographic prominence - Wikipedia, the free encyclopedia If so, have you determined which specifications will be used to determine Prominence?  It looks like there have historically been several different criteria used in determining a high points Prominence. Chris Donohue, GISP ... View more

Can you provide some context on what Prominence means in your case?  Is it a defined process, equation, analysis, etc?  How does one typically figure it out?  Knowing this will help in finding possible GIS solutions to derive it. Chris Donohue, GISP ... View more

If you want to digitize a line in a specific direction, this may be of help: ArcGIS Help (10.2, 10.2.1, and 10.2.2) Chris Donohue, GISP ... View more