PaMAGIC Newsletter


Hydrography or lidar – Is that the Choice?

PA Topographic and Geologic Survey Office
Middletown, PA 
January 31, 2017

Purpose – To assess the relative value and utility of Pennsylvania’s existing Quality Level 3 (QL3) statewide lidar and/or a new lidar dataset collected to today’s QL2 standards and specifications. The assessment will focus primarily on the tolerances, cost and timeliness for updating statewide hydrography, including flowlines, watershed boundaries, wetlands, and stormwater control structures.

This workshop supports PaMAGIC’s Integrated Water Data Initiative. Reports from earlier workshops and projects can be found at: 
Workshop Design – The entire group will first receive detailed briefings on technical aspects of lidar specifications, collection, and utilization. Attendees will break into teams of 4-5 individuals and work independently to develop a recommended methodology and timeline for the development of a modern, authoritative surface water basemap for PA. All teams will begin with the same set of base information and results from past and current projects upon which to base their designs. Extrapolation, interpolation, documented assumptions, and sophisticated guesswork will be required to create defensible work products.

10:00    Welcome, Introductions, Workshop Overview and Expectations
10:15    Technical Background Presentations
•    Technical directions in hydrography– “Elehydro” concepts
•    Basic Lidar Specifications and Terminology
•    Expected costs and time requirements for data collection
•    Data richness comparisons – QL2 vs. QL3
•    Data management considerations
Hydrography derivation from lidar – local and national experiences
•    Lancaster NHD Support Pilot – 2016
•    Chiques Creek – Topographic Wetness Index
•    Rapid automated flowline extraction for the Chesapeake Bay Watershed
•    NJ QL2 vs QL3 comparison
•    Indiana Statewide  Local Res NHD from lidar
Supporting Data in PA
•    County hydrography
•    MS4 – Municipal and DOT
•    Wetlands/NAIP derivatives
•    FEMA floodplains
12:45      Lunch and Group Tasking
1:15        Collaboration Sessions
•    Small Groups – Scenario 1
•    Small Groups -  Scenario 2
2:15        Team Presentations 
3:00        Adjourn (tentative)