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| 引用本文: | 贺诗文,张运林,李娜,罗菊花.中营养湖泊(四川邛海)偶发性藻类水华遥感提取及原因初探.湖泊科学,2025,37(2):389-400. DOI:10.18307/2025.0213 |
| He Shiwen,Zhang Yunlin,Li Na,Luo Juhua.Occasional algal blooms in Lake Qionghai (Sichuan), a mesotrophic lake: Remote sensing extraction and preliminary investigation of their causes. J. Lake Sci.2025,37(2):389-400. DOI:10.18307/2025.0213 |
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| 中营养湖泊(四川邛海)偶发性藻类水华遥感提取及原因初探 |
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贺诗文1，2，3，张运林1，2，3，李娜1，3，罗菊花2，3，4
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1.中国科学院南京地理与湖泊研究所，湖泊与流域水安全全国重点实验室, 南京 211135 ；2.中国科学院大学, 北京 100049 ；3.中国科学院大学南京学院, 南京 211135 ；4.中国科学院南京地理与湖泊研究所, 中国科学院流域地理学重点实验室, 南京 211135
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| 摘要: |
| 本研究结合卫星遥感影像和机器学习的分类方法，监测到四川邛海在2022年2—3月发生了罕见的大面积藻类水华，初步从气温、风速、营养盐和水生植被分布等角度探究了此次藻类水华大范围暴发的可能原因。遥感监测显示，2022年2月18日，邛海开始出现水华，随后水华覆盖面积逐渐增大，到3月10日，水华面积达到最大（13.67 km2），占总水面面积的50.63%，此后水华面积逐渐降低，3月19日开始没有监测到明显的水华。基于模拟数据发现邛海在1985—2022年间，湖泊水温每十年增加0.14 ℃，并且水温与水生植被的面积呈现明显负相关。相比于2000s，2010—2020年邛海氮磷营养盐浓度没有明显上升且波动幅度变小。但水生植被（尤其是沉水植被）面积退化严重，水生植被面积每十年约减少0.19 km2，沉水植被面积每十年约减少0.10 km2。分析表明，从宏观来看，在气候变化、水位上升的多重胁迫下，水生植被加剧退化，浮游植物更容易取得优势地位。2022年2—3月气温快速上升，风速较低且缺乏降雨等气象条件也有利于藻类水华的形成，水温持续性上升促进了水体分层，为浮游植物生长提供了有利条件。但邛海偶发性的大面积藻类水华形成的深层次原因还需进一步探究。在未来气候变化情景下，对于邛海这类相对清洁的水体，藻类水华风险也将持续存在并值得高度关注。 |
| 关键词: 邛海 藻类水华 沉水植被 遥感提取 |
| DOI：10.18307/2025.0213 |
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| 基金项目:国家重点研发计划项目（2022YFC3204100）；中国科学院国际交流计划“国际杰出团队”（2024PG0017）；江苏省“333”工程领军型人才团队项目联合资助 |
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| Occasional algal blooms in Lake Qionghai (Sichuan), a mesotrophic lake: Remote sensing extraction and preliminary investigation of their causes |
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He Shiwen1，2，3，Zhang Yunlin1，2，3，Li Na1，3，Luo Juhua2，3，4
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1.State Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 211135 , P.R.China ；2.University of Chinese Academy of Sciences, Beijing 100049 , P.R.China ；3.University of Chinese Academy of Sciences, Nanjing, Nanjing 211135 , P.R.China ；4.Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 211135 , P.R.China
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| Abstract: |
| This study utilized a combination of satellite remote sensing imagery and machine learning classification methods to monitor a rare large-scale algal bloom event in Lake Qionghai(Sichuan) from February to March, 2022. Preliminary investigation into the possible causes of this widespread algal bloom event was conducted from the perspectives of temperature, wind speed, nutrient levels, and aquatic vegetation distribution. Remote sensing monitoring revealed that on February 18, 2022, algal blooms began to appear, with the bloom area gradually increasing in the lake. By March 10, the bloom reached a maximum area of 13.67 km2 (accounting for 50.63% of the total water surface area), after which the bloom area gradually decreased, and disappeared since March 19. Based on simulated data, it was found that Lake Qionghai experienced a warming rate of 0.14 ℃ per decade between 1985 and 2022. Furthermore, there was a significant negative correlation between water temperature and the area of aquatic vegetation. In comparison to the 2000s, the nitrogen and phosphorus nutrient concentrations in Lake Qionghai did not show a significant increase and exhibited reduced fluctuations from 2010 to 2020. However, extensive degradation of aquatic vegetation was observed with aquatic vegetation coverage decreasing by 0.19 km2 every decade, 0.10 km2 among which are submerged vegetation. Our analysis suggested that from a macro perspective, under the multiple stressors of climate change and rising water levels, the degradation of aquatic vegetation exacerbated, favoring the dominance of phytoplankton in Lake Qionghai ecosystem. The rapid increase in temperature, low wind speeds, and lack of rainfall from February to March, 2022 also facilitated the algal bloom formation. The sustained increase in water temperature promoted stratification of the water column, which also provided favorable conditions for the growth of phytoplankton. However, the causes of the occasional widespread algal bloom formation in Lake Qionghai require further investigation. Under future climate change scenarios, algal bloom risks will still exist in a relatively clean water like Lake Qionghai and this warrants continued attention. |
| Key words: Lake Qionghai algal bloom submerged vegetation remote sensing extraction |
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