Latest Contributions by ChrisDonohue__GISP

Not sure if this will take you where you want to go, but I will throw it out there: If 0207 is the desired output of rasters with values of 02 + 07, try multiplying the first raster by 100 before adding the raster values together. Essentially:  (02*100) + 07 Chris Donohue, GISP ... View more

If I remember correctly, SetNull (Spatial Analyst) would be done like this to complete your task: The Input Conditional Raster:  dem_fa .  (your source raster to operate on) Expression (optional) would be:  VALUE > 849840 .  (values above 849840 are evaluated by the tool as True, so will become Null) Input File raster or constant value: 1 .  (constant value to set if False/Not Null, ie your streams will have a value of 1) Output raster:  (your output file name goes here) Note:  be sure to set the Environments (button at bottom of tool).  Also, I would avoid using the Default Geodatabase (Default.gdb) and instead set up a geodatabase specifically for this data and its processing. Chris Donohue, GISP ... View more

Less likely, but can sometimes be an issue -what can happen is the Value Field for the symbology gets defaulted to a field other than what you want for the layer file when the layer file is imported or applied to a feature class. When this happens the data will not display correctly as ArcMap is pulling from the wrong field. Check that the field in your data that you are displaying based on is listed correctly under the Value Field setting. Chris Donohue, GISP ... View more

As suggested by others, this can be done with the Create Fishnet (Data Management) tool Create Fishnet—Data Management toolbox | ArcGIS Desktop  Note that checking off the 'Create Label Points (optional) checkbox in the tool will provide a points layer of the centroids.  After that, it is just a question of culling down the points to just within your site and then adding whatever fields are needed. Chris Donohue, GISP ... View more

FYI - GISCI has published their position on this.  Note the suggested modifications to the legislation:   From the GIS Certification Institute: GISCI Establishes Position on the Geospatial Data Act of 2017   August 3, 2017 Dear Christopher,   You are receiving this email because you are an active GISP. You may have an interest in this current legislation, currently in the Committee on Commerce, Science, and Transportation, and scheduled to be taken up shortly by Congress for further discussion and action. We urge each GISP to review the bill and determine its impact on the geospatial community, and to consider contacting your representatives to advise them of your position. The GIS Certification Institute (GISCI) has crafted the following position statement in response to the Federal Geospatial Data Act of 2017 (S.1253). S.1253 is co-sponsored by Orrin Hatch (R-UT), Ron Wyden (D-OR), Dean Heller (R-NV) and Mark Warner (D-VA) has been a topic of much discussion within the GIS community. The American Association of Geographers (AAG) and the Urban Regional Information Systems Association (URISA) have expressed specific concerns about the bill as currently written.   Upon review of the Bill the GISCI Board of Directors has identified the following concerns.   Purpose Statement: The bill lacks a clear purpose statement. We believe this creates opportunities for misinterpretation of the Bill's intent. A well-crafted purpose statement would help "put a fence" around the Bill and minimize opportunities for misinterpretation.  Section 10 (Funding): We believe the language in this section is unnecessarily broad and could reduce or eliminate the availability of funds for research and other efforts not specific to the purpose of this Bill. A clear purpose statement along with some adjustments to Section 10 would help alleviate this concern. Section 11 (Use of Private Sector): This is the area of greatest concern given the conflation of "surveying and mapping" with "geospatial data" and the potential that federally funded geospatial data activities could be limited to architectural/engineering firms and licensed surveyors. We are specifically concerned about the wording in subsections b and c, which state:  Subsection (b) DEFINITION -- For purposes of selecting a firm for a contract under chapter 11 of title 40, United States Code, the term ''surveying and mapping'' shall have the meaning given the term ''geospatial data'' in section 2 of this Act. Subsection (c) MODIFICATION OF FEDERAL ACQUISITION REGULATION - Part 36 of the Federal Acquisition Regulation (48 C.F.R. 36.000 et seq.) shall be revised to specify that the definition of the term ''architectural and engineering services'' includes surveying and mapping services and the acquisition of geospatial data, to which the selection procedures of subpart 36.6 of such part 36 of the Federal Acquisition Regulation shall apply.   We believe these provisions could seriously impact the livelihood of Certified GIS Professionals (GISP®) and unnecessarily increase the cost of Federal geospatial data collection and management.   The GISCI Board of Directors is confident that these concerns can be addressed while maintaining the purpose and goals of the Federal Geospatial Data Act (S.1253).     If you have any questions about our position, please don't hesitate to contact me!   Thanks for your consideration!   Bill Hodge GISP Executive Director GIS Certification Institute 847 824-7768      [email protected]      GIS Certification Institute, 701 Lee St, Ste 680, Des Plaines, IL 60016   Chris Donohue, GISP ... View more

I believe the one you need it called "ESRI Shields Regular".  At least that is what it is called in ArcGIS 10.2.1 (not sure if it varies by software version). Chris Donohue, GISP ... View more

I ran across one of the county disclaimers today.       Source: Online Map, Sacramento County, California, USA California Government Code Section 6254.21 states that “No state or local agency shall post the home address or telephone number of any elected or appointed official on the internet without first obtaining the written permission of that individual.” As the cost to collect and continuously update that information is prohibitive, this website does not display the Assessee name. It may be obtained by calling (916) 875-0700, or by visiting the Assessor's Office at 3701 Power Inn Road, Suite 3000, in Sacramento. Chris Donohue, GISP ... View more

If the stream feature class is already dissolved and you have access to an Advanced ArcGIS license level, one option to re-split it only at those junctures is this: Run Intersect (Analysis) using only your stream feature class (no other inputs, yes only 1 input!) and for the "Output Type (Optional)" settting using "Points".  This will produce a point feature class of the stream intersections. Run Split Line at Point (Data Management) using the points from step 1 and the dissolved stream line feature class. Intersect—Help | ArcGIS for Desktop  How Intersect works—Help | ArcGIS for Desktop  Split Line at Point—Help | ArcGIS for Desktop  Chris Donohue, GISP ... View more

If you have access to the Spatial Analyst extension, typically, the next step would be to run a "Flow Accumulation", followed by a "Stream to Feature".  Note that the Flow Accumulation may require a few runs with different settings to come up with a usable output. Source:  Deriving runoff characteristics—Help | ArcGIS for Desktop  Flow Accumulation—Help | ArcGIS for Desktop  Stream to Feature—Help | ArcGIS for Desktop  The final part, finding the longest flow path from the many lines output in the "Stream to Feature" can be a challenge if you don't want manually go through the output linework and sum lengths.  See the below thread for some ideas on how to automate this.  Note - I have not tried it, but the python script posted by Luke Sturtevant  looks promising. using the Flow Length tool in Spatial Analyst's Hydrology Toolbox to find the Longest Flow Path  Chris Donohue, GISP ... View more

Assuming you have field data that represents the current conditions of the ditches, one way to do this would be to use the 3D Analyst extension, specifically the Cut/Fill tool.  Essentially one would create a surface of the existing condition and a surface of the desired (or previous) condition, then use Cut/Fill to find the change between the two. With the Cut Fill tool, you can do the following: Identify regions of sediment erosion and deposition in a river valley. Calculate the volumes and areas of surface material to be removed and areas to be filled to level a site for building construction. Identify areas that become frequently inundated with surface material during a mudslide in a study to locate safe areas of stable land for building homes. Cut Fill—Help | ArcGIS for Desktop  How Cut Fill works—Help | ArcGIS for Desktop  Chris Donohue, GISP ... View more

Can you provide some more background on what systems you have and what your processes are.  That will help folks in analyzing this: What version of SQL is being used? What version of ArcGIS is that tied to? Is the system set up to directly edit Default? Are there any nightly processes that run that would affect that dataset, like for example a scheduled Reconcile of all versions? Chris Donohue, GISP ... View more

 Tagging an expert:  Dan_Patterson Chris Donohue, GISP ... View more

I'm not entirely sure if this will work for what you need, but how about employing a Pivot Table? Pivot Table—Help | ArcGIS for Desktop  Note - it may also be easier to export the data to Excel and do a Pivot Table there (the Excel Pivot Table seems easier to use in some ways). Chris Donohue, GISP ... View more