Using a Digital Terrain Model to Analyze a Watershed in Order to Match Inlets with their Respective Outfalls Aspen Navarro, Project Manager, GIS Analyst Michael Jones, Assistant Project Manager, GIS Analyst William Perry, Project Designer, GIS Analyst

Outline Purpose Scope Revised Timeline Challenges and Concerns Remaining Task Conclusion

Purpose New methodology Watershed analysis using a digital terrain model (DTM) -Identify where inlets fall within the watershed of specified outfall -narrows down where pollution is coming from Create a cartographic model for backup and reference DTM looks at the Earths surface, excluding any objects Why the network analysis didn’t work and what were doing now moving forward

Graph showing the scope of the project Graph showing the scope of the project. West of San Antonio in Bexar county

Showing the problems with the underground channel -why we changed our method

Revised Timeline Major delays included data processing issues and interoperability Issues, leading to a larger amount of time spent on pre-processing and a lower time spent on analysis. Four major dates; two meetings, a progress report, and a final project on Dec 7th. Activity Week Date 5-Sep 12-Sep 19-Sep 26-Sep 3-Oct 10-Oct 17-Oct 24-Oct 31-Oct 7-Nov 14-Nov 21-Nov 28-Nov 5-Dec Week Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Meeting with client ; research   Data collection; manipulation Preprocess data Analysis and integration Edit; finalize Final report Final presentation *Important dates *Meeting 1 *Meeting 2 *Progress Report *Final

Remaining Task Task 1: Organize data for analysis and delineate project area Minimize data Use data to delineate Westside Creeks Task 2: Watershed analysis Fill  Flow direction  Flow accumulation  Snap pour point  Watershed Task 3: Matching inlets with respective outfalls Identify inlets within each outfall watershed boundary

Watershed Analysis Challenges and Concerns Surface elevation will make results inaccurate Sewer pipes do not have curves Many of the outfalls are close together A digital terrain model (DTM) is required for an accurate watershed analysis Matching ALL inlets to outfalls within the timeline http://www.univ-st-etienne.fr/wikimastersig/doku.php/english:glossary:dtm

Screenshot showing the cluster of outfalls

Images comparing DEM to DTM Image on the left is the newest DEM nick provided us, image on the right is the DTM http://sandboxdocs.readthedocs.io/en/latest/tutorials/working-with-terrain/

Conclusion Increased accuracy of connecting inlets to outfalls Split up workload to catch up on lost time Moving forward with or without a DTM https://web.viu.ca/corrin/GIS/New_Folder/Export%20Graphic.jpg

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