| Title |
Data-driven Model Prediction of Harmful Cyanobacterial Blooms in the Nakdong River in Response to Increased Temperatures Under Climate Change Scenarios |
| Authors |
장가연 ( Gayeon Jang ) ; 조민경 ( Minkyoung Jo ) ; 김자연 ( Jayun Kim ) ; 김상준 ( Sangjun Kim ) ; 박힘찬 ( Himchan Park ) ; 박준홍 ( Joonhong Park ) |
| DOI |
https://doi.org/10.15681/KSWE.2024.40.3.121 |
| Keywords |
Climate change scenarios; Cyanobacteria; Harmful algal bloom (HAB); Machine learning; Nakdong river |
| Abstract |
Harmful cyanobacterial blooms (HCBs) are caused by the rapid proliferation of cyanobacteria and are believed to be exacerbated by climate change. However, the extent to which HCBs will be stimulated in the future due to increased temperature remains uncertain. This study aims to predict the future occurrence of cyanobacteria in the Nakdong River, which has the highest incidence of HCBs in South Korea, based on temperature rise scenarios. Representative Concentration Pathways (RCPs) were used as the basis for these scenarios. Data-driven model simulations were conducted, and out of the four machine learning techniques tested (multiple linear regression, support vector regressor, decision tree, and random forest), the random forest model was selected for its relatively high prediction accuracy. The random forest model was used to predict the occurrence of cyanobacteria. The results of boxplot and time-series analyses showed that under the worst-case scenario (RCP8.5 (2100)), where temperature increases significantly, cyanobacterial abundance across all study areas was greatly stimulated. The study also found that the frequencies of HCB occurrences exceeding certain thresholds (100,000 and 1,000,000 cells/mL) increased under both the best-case scenario (RCP2.6 (2050)) and worst-case scenario (RCP8.5 (2100)). These findings suggest that the frequency of HCB occurrences surpassing a certain threshold level can serve as a useful diagnostic indicator of vulnerability to temperature increases caused by climate change. Additionally, this study highlights that water bodies currently susceptible to HCBs are likely to become even more vulnerable with climate change compared to those that are currently less susceptible. |