Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future
The water quality of Lake Erhai has deteriorated in recent decades due to socioeconomic development in the lake basin. After the massive implementation of water environmental protection measures in Lake Erhai in 2016, the trend of water quality deterioration has been curbed and the intensity and fre...
| Main Authors: | , , , , , |
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| Format: | Article |
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MDPI AG
2024-03-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/16/7/972 |
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| author | Tianbao Xu Wei Ma Jun Chen Lizeng Duan Huayu Li Hucai Zhang |
| author_facet | Tianbao Xu Wei Ma Jun Chen Lizeng Duan Huayu Li Hucai Zhang |
| author_sort | Tianbao Xu |
| collection | DOAJ |
| description | The water quality of Lake Erhai has deteriorated in recent decades due to socioeconomic development in the lake basin. After the massive implementation of water environmental protection measures in Lake Erhai in 2016, the trend of water quality deterioration has been curbed and the intensity and frequency of algal blooms has decreased. However, water quality monitoring data show that pollutant concentrations in Lake Erhai still exceed acceptable values, and there is a risk of water quality standard limits being further exceeded in the future. Therefore, it is urgent to systematically study the variability characteristics of water quality in Lake Erhai to provide practical methods to predict the future evolution of water quality. Based on water quality monitoring data from 2009 to 2019, the current water quality characteristics of Lake Erhai were analyzed, and a two-dimensional hydrodynamic and water quality mathematical model was built to predict the water quality in 2025. The results showed that the total phosphorus (TP) concentration declined after 2016, mainly due to the significant reduction of TP entering the lake due to pollution interception. However, the concentrations of the potassium permanganate index (COD<sub>Mn</sub>) and total nitrogen (TN) increased after 2016, demonstrating that the pollution control measures have had little effect on the improvement of COD<sub>Mn</sub> and TN. The spatial and temporal distribution of pollutants showed that the water quality in winter and spring was better than in summer and autumn, and the water quality in the southern lake was better than in the northern lake. This analysis indicates that non-point source pollution remains the main source of pollution in Lake Erhai, and that rainfall is the main driving force of pollutants exceeding the water quality standard. According to the water quality predictions, without additional pollution control measures, pollutant concentrations in Lake Erhai will exceed the Class II water quality standard by 2025. This study analyzes the water quality characteristics, predicts the direction of future water quality changes, and provides a theoretical basis for the future water quality protection of Lake Erhai. |
| first_indexed | 2024-04-24T10:33:32Z |
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| id | doaj.art-6ac9c36132b745bb9b9f521214d0f8cd |
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| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-04-24T10:33:32Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-6ac9c36132b745bb9b9f521214d0f8cd2024-04-12T13:27:05ZengMDPI AGWater2073-44412024-03-0116797210.3390/w16070972Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near FutureTianbao Xu0Wei Ma1Jun Chen2Lizeng Duan3Huayu Li4Hucai Zhang5Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650500, ChinaChina Institute of Water Resources and Hydropower Research, Beijing 100038, ChinaPower China Kunming Engineering Corporation Limited, Kunming 650051, ChinaInstitute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, ChinaInstitute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, ChinaInstitute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming 650500, ChinaThe water quality of Lake Erhai has deteriorated in recent decades due to socioeconomic development in the lake basin. After the massive implementation of water environmental protection measures in Lake Erhai in 2016, the trend of water quality deterioration has been curbed and the intensity and frequency of algal blooms has decreased. However, water quality monitoring data show that pollutant concentrations in Lake Erhai still exceed acceptable values, and there is a risk of water quality standard limits being further exceeded in the future. Therefore, it is urgent to systematically study the variability characteristics of water quality in Lake Erhai to provide practical methods to predict the future evolution of water quality. Based on water quality monitoring data from 2009 to 2019, the current water quality characteristics of Lake Erhai were analyzed, and a two-dimensional hydrodynamic and water quality mathematical model was built to predict the water quality in 2025. The results showed that the total phosphorus (TP) concentration declined after 2016, mainly due to the significant reduction of TP entering the lake due to pollution interception. However, the concentrations of the potassium permanganate index (COD<sub>Mn</sub>) and total nitrogen (TN) increased after 2016, demonstrating that the pollution control measures have had little effect on the improvement of COD<sub>Mn</sub> and TN. The spatial and temporal distribution of pollutants showed that the water quality in winter and spring was better than in summer and autumn, and the water quality in the southern lake was better than in the northern lake. This analysis indicates that non-point source pollution remains the main source of pollution in Lake Erhai, and that rainfall is the main driving force of pollutants exceeding the water quality standard. According to the water quality predictions, without additional pollution control measures, pollutant concentrations in Lake Erhai will exceed the Class II water quality standard by 2025. This study analyzes the water quality characteristics, predicts the direction of future water quality changes, and provides a theoretical basis for the future water quality protection of Lake Erhai.https://www.mdpi.com/2073-4441/16/7/972Lake Erhaiwater qualitywater quality characteristicswater quality prediction |
| spellingShingle | Tianbao Xu Wei Ma Jun Chen Lizeng Duan Huayu Li Hucai Zhang Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future Water Lake Erhai water quality water quality characteristics water quality prediction |
| title | Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future |
| title_full | Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future |
| title_fullStr | Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future |
| title_full_unstemmed | Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future |
| title_short | Water Quality of Lake Erhai in Southwest China and Its Projected Status in the near Future |
| title_sort | water quality of lake erhai in southwest china and its projected status in the near future |
| topic | Lake Erhai water quality water quality characteristics water quality prediction |
| url | https://www.mdpi.com/2073-4441/16/7/972 |
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