Estimation of Water Surface Temperature in Large Rivers Using Landsat 8 Thermal Infrared Imagery

Abstract:

River water temperature is an indicator of several freshwater properties including aquatic ecosystem health, species migration patterns, and rate of sedimentation. Water temperature also reflects the anthropogenic influence of urbanization and land use change on riparian environments. In all of these applications, water temperature can be used to study climatic trends and develop hypothesis for their cause based on the large rivers that traverse the landscape. Despite its importance, temperature measurements within large river systems is limited by sparse temperature gauging networks. Using thermal infrared (TIR) imagery captured by the TIRS instrument aboard Landsat 8, temperatures of large rivers can be estimated over large areas. Satellite remote sensing has long been used to estimate sea surface temperatures and the water surface temperatures of large lakes and reservoirs, but less work has been conducted to study the thermal regimes of rivers. Landsat 8 has TIR imagery available at 100-meter resolution, which easily allows for the thermal analysis of rivers wider than 300 meters. Here we document temporal variations in surface temperature of two large rivers in the United States using Landsat 8 imagery from 2012-2020. We validated the Landsat derived water surface temperatures with in situ temperature measurements collected by the United States Geological Survey. The methods developed by this study can be expanded to larger regions using the Google Earth Engine platform. The results of this study can also be used to inform decisions related to climate change mitigation, urban planning, and aquatic ecosystem management.