Long-term spatial-temporal monitoring of eutrophication in Lake Burdur using remote sensing data

?ake eutrophication continues to be one of the major environmental challenges in lakes worldwide. This study is about using a remote sensing approach to monitor long-term chlorophyll-a (Chl-a) concentrations and the trophic state index (TSI) in ?ake Burdur, Turkiye. Surface reflectances from ?andsat 5, ?andsat 7, and ?andsat 8 satellite image collections were evaluated with an empirical equation to estimate a 38-year-long (1984-2021) time series of the lake's median Chl-a concentrations. Pixel quality masking is applied to retain only acceptable quality information and exclude images affected by cloud cover, icing, and other environmental factors from the analysis. The results were analyzed based on annual, seasonal, and monthly temporal averages. Over a period of 38 years, Chl-a concentrations were found to vary between 58.7 and 196.4 mg/m(3). Notably higher concentrations were recorded in 2010 and 2021, while lower concentrations were observed between 1991 and 1993. A substantial increase in Chl-a concentration was evident from 2002 to 2010. The maximum concentration of Chl-a during the first two decades of the analysis was 130 mg/m(3), which increased to 200 mg/m3 during the last two decades. ?andsatderived TSI values suggested that ?ake Burdur has been mostly hypertrophic for the entire study period.

Automated summary

This study applies remote sensing to monitor long-term chlorophyll-a (Chl-a) concentrations and the trophic state index (TSI) in Lake Burdur, Turkey. Surface reflectances from Landsat satellite images are analyzed to estimate a 38-year time series of Chl-a concentrations. The results show variations in Chl-a concentrations over time, with higher concentrations in 2010 and 2021 and lower concentrations between 1991 and 1993. The TSI values suggest Lake Burdur has been mostly hypertrophic throughout the study period.