3  Thermal Imagery Data

3.1 Introduction

To acquire and prepare thermal aerial infrared imagery, we worked with NV5 Geospatial1 (formerly Watershed Sciences, Inc), a contractor who has led prior efforts in the region to gather thermal aerial infrared data for aquatic habitat research (Watershed Sciences 2010). On July 5, 2020, NV5 collected thermal infrared imagery from a helicopter-mounted camera for the four steams on the Kenai Peninsula lowlands that were the focus of this study (Beaver Creek, Funny River, Moose River, and Crooked Creek). All streams were flown during the afternoon hours in order to maximize the thermal contrast between the river’s water and the banks.

The surveys extend for a total length of 59.1 km of the streams. Flight transects proceeded from the mouth of each stream in an upstream direction. The data were collected to aid the team in identifying the spatial variability in surface temperatures as well as thermal influence of point sources, tributaries, and surface springs.

Specific deliverables generated by NV5 Geospatial from the thermal imagery data include:

  • Rasters (map image files; .tif and .jpg formats)

  • Shapefiles (longitudinal temperature profiles, stream centerlines, others; .shp format)

  • Other supplemental items (coordinates of significant thermal features, maps and figures, and others)

The full technical report from NV5 Geospatial describes detailed methods and interpretation of aerial thermal infrared imagery. In the online version of this document2, the NV5 report can be downloaded at the below.