Last post by maryramirez - November 07, 2017, 02:30:27 PM
I am running SLAMM without a dikes raster layer. When I check 'include dikes' on the execute screen, the results for Time 0 are very different than when I don't check 'include dikes'. Checking 'include dikes' results in a T=0 that is nearly identical to initial conditions, which is good (not the case when 'include dikes' is not checked). However, I don't see certain conversions that I would expect over time and that do occur when 'dikes' are not checked (specifically reg. flooded marsh converting to tidal flat). Neither run actually includes a dike layer, so I'm wondering what is causing the difference. Thanks!
I think the problem is that the ASCII DEM is treating 1.17e-38 as its NODATA value. The GIS software is then not recognizing this NODATA value. Try specifying a NODATA value of -9999 prior to conversion and this may solve the problem.
Also, look at the header in the first lines of the ASCII DEM to see if that helps understand the problem (the NODATA value is defined there.) The best way to do this is convert the file type to a TXT file and look at it in the Windows Explorer Preview pane (not Internet Explorer, just the Windows Explorer file manager).
Last post by Hartney - October 20, 2017, 03:29:43 PM
I am having an issue when I convert my study area dem to ascii. The elevation range/values are different following the conversion (see image You cannot see attachments on this board.). dem_censustract is my original dem while dem_asc is the new file after conversion. I found one person mention a similar issue on another gis forum but the question was unanswered. Has anyone else encountered this issue? Is there a work around?
It may depend on which SLAMM version you are using. However, in general you click edit cells, make your edits using draw/fill cells, and when done you may simply close the window and you will be asked if you want to overwrite the raster (the raster will have same name as the original one but with the edits) or click "Save As ..." and save the raster and project with different names. Hope this solves your problems.
Last post by pse1999 - October 05, 2017, 02:29:49 PM
I am having trouble, once finishing the editing of the nwi within the "set map attributes" program getting the saved copy to be the new NWI layer with the now filled in blank cells. Is there a sequence in which things should be saved? I have tried closing the program and reopening with the new nwi ASCII file, and it keeps reverting to the unedited. Thank you for your time.
On November 3rd, at 10:30 AM EST, Warren Pinnacle Consulting Inc. will present the results of a multi-year sea-level rise modeling project supported by the New York State Energy Research and Development Authority (NYSERDA). This project has produced a new decision-support tool designed to help decisionmakers understand the benefits of different adaptation strategies for wetland management under uncertain future conditions. The presentation will focus on background of the project and results from three New York county case studies, as well as presenting a tutorial for users interested in learning how to use the tool.
SLAMM Marsh-Management Tool Friday, November 3, 2017
10:30 am | Eastern Daylight Time (New York, GMT-04:00) | 1 hr 30 mins Register After your request has been approved, you'll receive instructions for joining the meeting.
Prioritization of marsh-management strategies can be a difficult undertaking. Ideally, a manager could evaluate the relative benefits of adaptation strategies and maximize wetland benefits while considering uncertainty both in future sea-level rise and dynamic marsh response. Warren Pinnacle has developed a modeling framework to evaluate the costs and benefits of management strategies while accounting for these uncertainties using the SLAMM marsh migration model. Model results are combined with ecosystem-valuation assessments from stakeholders that define a set of relative "wetland benefits" (e.g., habitat preservation, flood protection), and each site's wetland benefits can then be projected into the future and compared to the estimated costs for each adaptation strategy. By calculating the "wetland benefits per estimated cost" ratio, one can identify the most effective marsh management strategies.
To understand these curves and parameters, please see the spreadsheet:
Which is installed along with SLAMM.
You will see that the equations describe a third order polynomial which then can be scaled to the min and max accretion values. That allows you to play games keeping the shape of the feedback curve intact but increasing or decreasing the minimum and maximum accretion values as part of a sensitivity or uncertainty analysis.
Let me know if you can't find the spreadsheet or have additional questions.