Karst Identification and Assessment Using Lidar and Collector for Arcgis

Karst Identification and Assessment Using LiDAR and Collector For ArcGIS

• Karst? - Sinkholes, caves, and other features formed by the dissolution of carbonate rock • LiDAR? – Technology that can model surface and above-ground structure in high resolution • Collector? – Mobile app that permits users to collect, edit, and sync features from the field

Carl Beyerhelm – Resource Information Specialist – Coconino National Forest Karst Features Are Important

This karsty Swiss cheese landscape facilitates hydrologic recharge. Release of those waters support: • Perennial stream • Riparian vegetation • Recreation • Aquatic/terrestrial life Identification And Assessment – Why?

• Project – Thin veg and Rx burn on ~64,000 ac • Need – Protect structure and function of karst features • Task – Identify and assess karst features Typical Karst Features

Sinking (captured) stream Cave or opening Emerging stream or spring

Bedrock collapse (14 acres) Sinkhole or pit Prep – Geodatabase Schema

• Karst type (solution, pseudo, not karst, …) • Feature type (cave, sinkhole, pit, lava tube, …) • Surface and sub-surface geology • Opening, air flow, human-accessible, … • Hydrologic evidence, amount/location of debris • Micro-climate veg, vert/invert/cultural use • Hazards, proposed protections Prep – Pre-Identify 400+ Features Prep – Metrics From GIS Techniques

Footprint at pour point elev Depth profile Max depth and volume

Flow accumulation Contributing area Pour point location Prep – ArcGIS Online (AGOL)

• Publish hosted feature service from ArcMap • Enable edit, sync, and photo attachments • Develop web map in AGOL • Share with karst group Prep – Tile Packages

• Create bare earth and topo tile packages in ArcMap for side-load to mobile devices Field Procedure

• Two GeoCorps interns from the Geological Society of America, our “cave men” ;>)

• Navigate to karst features using a Garmin GPS with pre-loaded waypoints • Make assessment of karst features Field Procedure – Continued

• Use Collector for ArcGIS on a Samsung tablet to make assessment entries, and attach photos • Make additional hand sketches and notes Field Procedure - Tablet Screenshot Field Procedure – Continued

• Sync daily assessment entries with AGOL at the Verizon tower 6 miles from Ranger Station • Production was about 6 – 10 features per day Data Access – Mobile Device

• View, edit, sync, and attach photos using a mobile device Data Access – ArcGIS Online

View/edit in AGOL, including photo attachments

Export from AGOL to GDB with all photo attachments Data Access – ArcGIS

• View, edit, sync, and attach photos in ArcMap Results – Karst Types Results – Feature Types Sinking Stream Emerging Stream Cave Bedrock Collapse Sinkhole Duds – About 30% Technique Mostly Good, Some Issues

+ How do you get a summer job like that??!! + Data collection efficient, consistent, integrated - Features are not labelled in Collector - No out-of-the-box method to create dynamic, context sensitive, “smart” data entry forms - Attachment widget points only to “Camera” and “Gallery” - One instance of a hung sync - Read-only fields aren’t visible in edit mode Questions?