Moving Toward Consistency: Using NHDPlus to Delineate Texas Watersheds

Stephanie Painter - Tarleton State University, Texas Institute for Applied Environmental Research

Transcript

1. Moving Toward Consistency: Using NHDPlus to Delineate Texas Watersheds STEPHANIE PAINTER, SENIOR RESEARCH ASSOCIATE TEXAS INSTITUTE FOR APPLIED ENVIRONMENTAL RESEARCH (TIAER) TARLETON STATE UNIVERSITY, STEPHENVILLE, TX PAINTER@TARLETON.EDU DANIA GRUNDMANN, PROJECT MANAGER TEXAS COMMISSION ON ENVIRONMENTAL QUALITY (TCEQ), AUSTIN, TX DANIA.GRUNDMANN@TCEQ.TEXAS.GOV TEXAS GIS FORUM, 27 OCTOBER 2016 1
2. Financial support provided by the US Environmental ProtecZon Agency and the Texas Commission on Environmental Quality. 2
3. PresentaZon Goals q  What is the Texas Catchment Watersheds Geodatabase? q  Why was the geodatabase created? q  How was the geodatabase created? q  What kinds of improvements may be performed in the future? 3
4. PresentaZon Goals q  What is the Texas Catchment Watersheds Geodatabase? 4
5. As viewed in ArcCatalog 5
6. It’s a relaZonal database that connects two disZnct geographical datasets: Main Idea: To return a “catchment watershed” for each Assessment Unit TCEQ 1,928 AU Lines 479 AU Polys (reservoirs) USGS/EPA 123,735 Flowlines 113,794 Catchments TCEQ Assessment Units and NHDPlusV2 6
7. §  TCEQ Assessment Units (AUs) §  Represent hydrologically disZnct areas of streams and reservoirs §  Assigned unique idenZficaZon numbers §  Intended to be relaZvely homogeneous §  Basic unit for assessing water quality §  Segments contain one or more AUs Source: (TNRIS, 2016) AU 1205_02 (Poly) AU 1204_02 (Line) Segment 1205 Segment 1204 7
8. §  NHDPlusV2 §  NHD = NaZonal Hydrography Dataset §  Developed and refined by the USGS §  Contains Flowlines based on topographic maps §  Geometric network indicates flow direcZon and connecZvity Source: (McKay, et al. 2012) 8
9. §  NHDPlusV2 §  NHD = NaZonal Hydrography Dataset §  Developed and refined by the USGS §  Contains Flowlines based on topographic maps §  Geometric network indicates flow direcZon and connecZvity §  V2 = Version 2 (Released in 2012) §  Based on 2010 “snapshot” of the NHD-M (1:100,000-scale or bener) Source: (McKay, et al. 2012) 9
10. §  NHDPlusV2 §  NHD = NaZonal Hydrography Dataset §  Developed and refined by the USGS §  Contains Flowlines based on topographic maps §  Geometric network indicates flow direcZon and connecZvity §  V2 = Version 2 (Released in 2012) §  Based on 2010 “snapshot” of the NHDM (1:100,000-scale or bener) §  Plus = more data for GIS analysis §  Includes indexed Catchments §  1 Flowline COMID to 1 Catchment FEATUREID Source: (McKay, et al. 2012) 0 2 4 1 Miles 0 2 4 1 Miles 10
11. Querying a “catchment watershed” – a watershed composed of NHDPlus catchments 11
12. AUs and Catchments are linked via RelaZonship Classes File RelaZonships (for illustra,ve purposes only) Main Task: PopulaZng the relaZonship classes 12
13. ü  What is the Texas Catchment Watersheds Geodatabase? q  Why was the geodatabase created? PresentaZon Goals 13
14. Why was the Geodatabase created? §  Within Texas, using catchment watersheds provides a consistent method for developing water quality improvement project areas §  States regularly report water quality assessment decisions to the EPA §  EPA uses a Catchment Indexing Process (CIP) to assign status data geographically §  State of Texas has advocated a watershed approach that is more representaZve of water quality improvement efforts 14
15. ü  What is the Texas Catchment Watersheds Geodatabase? ü  Why was the geodatabase created? q  How was the geodatabase created? PresentaZon Goals 15
16. How was the geodatabase created? §  TCEQ Total Maximum Daily Load Program contracted with TIAER beginning FY 2015 §  ObjecZve: Create a tool that automates the delineaZon of catchment watersheds for Assessment Units in Texas §  Basic approach: §  Acquire Data §  TCEQ AUs §  NHD Flowlines and Catchments §  Determine project extent and projecZon §  Go through an IteraZve Process… Source: hnp://nhd.usgs.gov/data.html Source: hnp://www.horizon-systems.com/NHDPlus/NHDPlusV2_data.php 16
17. §  1st IteraZon §  Programming approach §  Visual C# and Map Window §  Program cycled through all the catchments looking for the associated AU §  Assumed that each catchment would only be associated with one AU §  Based on the NHD-H §  High-resoluZon §  Downloaded directly from USGS (!) §  Did not make use of flow direcZon §  Results were not encouraging 17
18. Downstream flag Upstream barrier Upstream barrier §  2nd IteraZon §  ArcGIS Model Builder using the Trace Geometric Network tool §  flags (downstream endpoints) and barriers (upstream endpoints) §  Converted AUs into points §  Snapped to the NHDFlowline network §  Disparate nature of the two datasets §  Required manual placement of points §  Three examples: 18
19. Example 1: Significant difference between AU and its flowline counterpart Swauano Creek 19
20. Example 2: No NHD Flowline Counterpart Comanche Springs 20
21. Example 3: MulZple channel situaZon Red River 21
22. §  2nd IteraZon §  ArcGIS Model Builder using the Trace Geometric Network tool §  flags (downstream endpoints) and barriers (upstream endpoints) §  Converted AUs into points §  Snapped to the NHDFlowline network §  Disparate nature of the two datasets §  Required manual placement of points §  Based on the NHD-M (medium resoluZon dataset) from USGS (!) §  Created the Catchment Watershed DelineaZon (CAWD) Tool in Model Builder §  IniZated a thorough QC process §  Pass Rate = 94% 22
23. §  3rd IteraZon §  MulZple refinements to the CAWD Methodology and the QC process §  Based on the NHDSnapshot from Horizon Systems CorporaZon (ü) §  Incorporated a modified linear-referencing approach §  AUs were converted to AU Reaches §  Allowed greater degree of control over the output §  Pass Rate = 99% §  Remaining challenges relate to complex overlapping catchments (generally in coastal areas) §  Deliverable includes custom database ediZng tools 23
24. FY 2016 CAWD Methodology 24
25. ü  What is the Texas Catchment Watersheds Geodatabase? ü  Why was the geodatabase created? ü  How was the geodatabase created? q  What kinds of improvements may be performed in the future? PresentaZon Goals 25
26. PotenZal Geodatabase Improvements §  Address areas with overlapping catchments §  Mostly in coastal areas §  Publish the Texas Catchments Watersheds Geodatabase as a webmap §  Improve usability and simplify maintenance §  Eventually transiZon database to High ResoluZon NHDPlus (HRNHDPlus) §  Expected to address missing AU counterparts and improve results 26
27. ü  What is the Texas Catchment Watersheds Geodatabase? ü  Why was the geodatabase created? ü  How was the geodatabase created? ü  What kinds of improvements may be performed in the future? PresentaZon Goals 27
28. Paluxy River near Glen Rose REFERENCES o  McKay, Lucinda, Timothy Bondelid, Tommy Dewald, Craig Johnston, Richard Moore, and Alan Rea. 2012. "NHDPlus Version 2 User Guide." Accessed Sep 22, 2016. hnp://www.horizon-systems.com/nhdplus/NHDPlusV2_documentaZon.php. o  TNRIS. 2016. "TCEQ Assessment Units." Texas Natural Resources Informa,on System. Sept 22. hnps://tnris.org/data-catalog/entry/tceq-assessment-units/. Thank you 28
29. Extra slides §  Example of a reservoir catchment watershed §  Example of overlapping catchment watersheds §  Example of holes resulZng from §  flowlines disconnected from the network, and §  sinks Source: (McKay, et al. 2012)
30. Reservoir Catchment Watershed Example
31. Overlapping Catchment Watersheds Example From the NHDPlus Version 2 User Guide – Horizon Systems CorporaZon Source: (McKay, et al. 2012) Divergent junc<on
32. Holes Example 1 No connec<on to the geometric network
33. Holes Example 2 No connec<on to the geometric network