Document Type : Research Article
Authors
1
M. SC. Student in Remote Sensing Engineering, Department of surveying Engineering, faculty of civil and Surveying Engineering, graduate university of advanced technology, Kerman
2
Department of Water Engineering, Faculty of Civil and Survey Engineering, Graduate University of Advanced Technology, Kerman
Abstract
An accurate estimation of temperature for surface streams plays a key role in assessing quality parameters and additionally their quality classification. To obtain this goal, there are a variety of field methods and laboratory tools for measuring water surface temperature (WST). However, it is not possible to continuously measure temperature in these sources, so it is recommended to use remote sensing data as a key solution in which it is possible to continuously measure temperature. In the current study, four images of Landsat-8 satellite imagery were used at four different times (07/March/2019، 26/May/2019، 14/August/2019, and 02/November/2019) to estimate the water surface temperature of the Karun River. Thus, after applying the necessary preconceptions to the images, the first Normalized Differential Water Index (NDWI) was used to separate the water areas from other areas. Then, the river boundary was carefully selected and extracted from the Landsat-8 satellite thermal band. The water surface temperature was calculated using the corresponding programming algorithm in the IDL environment of the ENVI software. Finally, to make a comparison between the results of Remote Sensing and recorded WST values, the Root-Mean-Squared-Error (RMSE) parameters for March, May, August, and November months were 0.34, 0.4, 0.33, and 0.36 (°C), respectively, indicating the satisfying accuracy level. The results showed that the Remote Sensing data is an accurate instrument for estimating WSTs.
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