Abstract
Water temperature is a key element of freshwater ecological systems and a critical element within natural resource monitoring programs. In the absence of in situ measurements, remote sensing platforms can indirectly measure water temperature over time and space. The Earth Resources Observation and Science (EROS) Center has processed archived Landsat imagery into analysis ready data (ARD), including Level-2 Provisional Surface Temperature (pST) estimates derived from the Landsat 4β5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Landsat 8 Thermal Infrared Sensor (TIRS). We compared in situ measurements of water temperature within the Yukon River in Alaska with 52 instances of pST estimates between June 2014 and September 2020. Agreement was good with an RMSE of 2.25 Β°C and only a slight negative bias in the estimated mean daily water temperature of β0.47 Β°C. For the 52 dates compared, the average daily water temperature measured by the USGS streamgage was 11.3 Β°C with a standard deviation of 5.7 Β°C. The average daily pST estimate was 10.8 Β°C with a standard deviation of 6.1 Β°C. At least in the case of large unstratified rivers in Alaska, ARD pST can be used to infer water temperature in the absence of or in tandem with ground-based water temperature monitoring campaigns.
Highlights
Water temperature is one of the key elements of freshwater ecological systems [1,2]
In comparing the daily U.S Geological Survey (USGS) streamgage measurement with the estimated mean Provisional Surface Temperature (pST) for the entire portion of the Yukon River captured within the analysis ready data (ARD) tile, we found good (r2 of 0.79) agreement (Figure 4b) with an overall root mean square error (RMSE) = 2.46 β¦C, variance ratio (VR) = 1.0, and a bias of β0.26 β¦C
The RMSE slightly increases, and the bias is slightly less negative compared to the Channel areas of interest (AOIs) (β0.22 β¦C compared to β0.26 β¦C, respectively)
Summary
Water temperature is one of the key elements of freshwater ecological systems [1,2]. In Arctic and sub-Arctic rivers, water temperature especially relates to the physical and thermal features of a river, as it affects how rivers interact with terrestrial portions of the landscape and governing river biotic communities [3]. Water temperature affects the timing and composition of the stream biotic community, influencing productivity [6] and habitat quantity and quality [7]. Water temperature plays a key role in the life cycle of salmonid species that are of significant ecological, cultural, and economic concern globally [8]; it can affect migration success, spawning location, incubation success, individual growth, competitive ability, and resistance to biotic and abiotic stresses including parasites, diseases, and pollutants [9,10].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call