Caltrans District 4Andy Amacher510-622-8727

andrew.amacher@dot.ca.gov

Use of LIDAR in Project Scoping and Analysis

“LIDAR, which stands for Light Detection and Ranging, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth. These light pulses—combined with other data recorded by the airborne system— generate precise, three-dimensional information about the shape of the Earth and its surface characteristics.” [From NOAA]

LIDAR is publically available for many areas statewideUSGS, NOAA, and counties may have data available in your project area

USGS EarthExplorer (earthexplorer.usgs.gov) A search for all of California resulted in 203,340 LIDAR data tiles Data are “LAS” format (point clouds). In GIS convert to LAS Dataset, then convert to raster (.tif) format LIDAR metadata files (usually .xml) contain inputs needed such as projection and point spacing density County and other data sources may provide direct raster products based on area selections (Napa and Sonoma)

When analyzing data, you will most likely be interested in “last” or “ground returns” These are the final laser returns and often represent the ground surface Other returns may be useful for vegetation structure, maximum tree heights (first return), etc.

Project Details

area selection in EarthExplorer

An accurate ground surface can be used to scope:

Potential wetland areas (low points) Water flow directions Connections to water sources outside

of the project area OHWM contours based on ground-

truthed GPS mapping Actual surface distances to species

occurrences More, more, more

Figure 1 Identified low-points (wet areas) to

search for the federally endangered Sebastopol meadowfoam within R/W

Figure 2 Field GPS of OHWM used with LIDAR

derived 0.5 foot contours to determine an OHWM elevation (flat creek gradient system)

Note: LIDAR ground-level fails near bridge structure

ExamplesFigure 1

Figure 2

Figure 3 Use of LIDAR to determine

if culverts connected to Waters of the US. LIDAR ground surface was used to derive flow channels (Spatial Analyst GIS extension).

Figure 4 Use of ArcScene GIS to

display creek surface in 3D. Useful for examining creek channels for floodplains, constriction points, and potential fish passage barriers.

ExamplesFigure 3

Figure 4

Caveats Ground-truthing

Water is absorbed, dense vegetation may lack ground hits Ground is not always ground, urban areas are problematic Date of LIDAR can vary. Older LIDAR may not represent

current conditions Areas with recent projects or development may have been re-

contoured Creeks with scour or sedimentation issues can change bed

structure

Scoping and Analysis Tool Coupled with ground surveys and database results,

LIDAR can strengthen rationale, but should not be the main analysis

Fine Print Specifications

Need ArcInfo license with Spatial Analyst or 3D Analyst extension ArcInfo: : http://onramp.dot.ca.gov/dist05/gis/tools.html#ChangeLicense ArcScene requires 3D Analyst extension

Michael Galloway and Robert A. James

Caltrans, District 11 9/2/15

Large-scale Fairy Shrimp Mitigation at Lonestar West, San Diego

164-acre Caltrans-owned property on Otay Mesa, San Diego, abutting Brown Field Airport

Compensatory mitigation for SR-11 freeway and port of entry with Mexico Project designed by Caltrans biologists and landscape architects Property with agricultural history Fairy shrimp identified in 11 of 15 road rut pools and existing cattle stock

pond in 2010 before restoration work began 134 vernal pools restored/enhanced beginning in July 2012 as key

mitigation component Twenty-eight pools inoculated with salvaged soil containing fairy shrimp

cysts after first wet season Surveys by Caltrans District 11 biologists Pools depths and water quality (salinity, pH, TDS, temperature) measured Project integrated with mitigation for native grassland, Quino checkerspot

butterfly habitat, burrowing owls and other raptors, as well as listed/sensitive plant species

Property fenced and gated against unauthorized access Land proposed for transfer to USFWS Refuges

Lonestar West

After three wet seasons, 92 pools (~69%) documented to support federally endangered San Diego fairy shrimp (Branchinecta sandiegonensis; SDFS), with two of those pools also supporting federally endangered Riverside fairy shrimp (Streptocephalus wootoni; RFS)

Versatile fairy shrimp (B. lindahli; VFS) observed in two pools co-occurring with San Diego fairy shrimp, and will be monitored as a hybridization concern

Five pools with undetermined shrimp in 2014-15

Most pools support numbers estimated in 10’s (range 1’s-1,000’s); no observed trend

Water quality measures taken to demonstrate range of suitable parameters supporting fairy shrimp

Results

Continued Monitoring Two more wet seasons of fairy

shrimp surveys (total of five) following new USFWS protocol

Additional three annual dry season surveys of pool subset

Comparison of population numbers to reference site

Five year success criteria of at least 1.30 acres of basin area supporting SDFS and at least 0.22 acre of basin area supporting RFS; after three years, 2.84 acres of basin area supports SDFS and 0.22 acre of basin area supports RFS

Average to above average rainfall may further improve fairy shrimp occupancy and number

Training opportunity for Caltrans biologists seeking field experience for solo fairy shrimp permit

Lonestar West Future Directions

67P (cattle stock pond): SDFS & RFS 111P: SDFS & RFS

10P: SDFS 31P & 32P: SDFS 76P: SDFS 116P & 117P: SDFS