Piloting High-Resolution NHDPlus for Minnesota Susanne Maeder Minnesota Geospatial Information...
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Transcript of Piloting High-Resolution NHDPlus for Minnesota Susanne Maeder Minnesota Geospatial Information...
Piloting High-Resolution NHDPlus for Minnesota
Susanne MaederMinnesota Geospatial
Information Office
American Water Resources Association
GIS Specialty Conference
New Orleans, LA
March 27, 2012
Project Goals
• EPA NHDPlus v2 Design Document (EPA, USGS): – Quick to run – can
refresh Med-Res frequently
– Ability to distribute functions so that other users can create data
– Ability to build from scratch with higher-res source data
• Minnesota’s Project Goals: – Test Build of High-Res
NHDPlus v. 2 Data for Minnesota
– Understanding Data Inputs
– Understanding NHDPlus Build/Refresh v. 2 Tool
– Evaluating Results
Area of Interest
All drainage upstream of Lake Pepin, beginning
with 070101
Input Data Sets
Core Inputs: NHD, WBD, NED• High-Res NHD – rigorous editing required• WBD – 8/25/2011 version based on MN DNR
‘catchments’ layer• NED – USGS statewide 10-m DEM
Ancillary Data: Stream gages, diversions, additions, removals• Stream Gages (flow benchmarks)
– USGS NHDPointEvents/NWIS data; DNR-PCA HYDSTRA
• Large-Scale Diversions • Additions/removals (DNR Water Appropriation
Permits); consumptive use
NHDPlus v. 2 Creation Steps
Source: Horizon Systems
High-Res NHD Data Preparation
• NHDGeoEdit QA/QC Process
• NHDPlus Build/Refresh QA/QC Process
NHDUpdate/NHD GeoEditor Version 4.0- Released March 13, 2012- Full NHDPlus Build/Refresh QA/QC Tools? - Only runs on NHD Model 2.1(ComID issue)
NHD Data Preparation Issues
• NHDPlus Build/Refresh QA/QC– Need to be able to unequivocally identify the
main flow path and construct a traversable flow network
– GNIS names are very important– Ensure calculation of VAA values– Potential severe errors:
• Flow table entry never navigated; improper network end; invalid or duplicate flow table entry; potential loop; incomplete divergence
– Warnings/ informational errors:• Isolated network; circular named path,
possible inflowing connection
NHD Data Preparation – Selecting Main Path
• PlusFlowlineVAA
• DivFracMP
NHD Data Preparation – Selecting Main Path
Questions?
Lake Itasca State Park – Headwaters of the Mississippi
Photo Source: Minnesota Department of Natural Resources