How does climate change contribute to lake warming and alterations in water quality?

气候变化对水质的影响已被确定为人类面临的最重要挑战之一。特别是，了解湖泊变暖的机制及其对水质的影响至关重要。湖泊变暖增加了有害藻华的风险，这可能对饮用水、家庭用水、食品生产和娱乐活动产生负面影响。湖冰物候学（定义为冰破裂和冻结的时间）是气候变暖的一个敏感指标，由于它对交通、冬季娱乐和宗教的重要性，在世界各地已经记录了几个世纪。我的长期研究目标是预测未来全球环境变化对湖泊的影响。我的短期目标是了解气候变化对湖泊冰盖、水温和水质的模式、趋势和驱动因素的影响。例如，不冻结事件的驱动因素是什么，它们在时空上是否一致？早期的融冰会导致水温升高吗？气候、景观特征和湖泊形态如何相互作用，影响全球水质的空间格局？哪些湖泊最容易受到水质退化的影响？我们将利用从北半球数百个湖泊收集的长期气候和生态时间序列来解决我们的研究问题，并量化气候变化对湖泊冰物候、湖泊变暖和水质的影响。我们正在开发和更新三个数据库：1)全球湖泊和河流冰物候数据库，该数据库可追溯到公元853年，代表了北半球湖泊的520多个时间序列；2)全球湖泊温度协作数据库，汇总了1985 - 2009年全球291个湖泊的地表温度、气候和地貌特征；3)全球水质数据库，汇总了91个国家26000个湖泊的叶绿素、水的清晰度和营养物浓度。我们将使用尖端的统计分析来确定早期的冰破裂和减少的冰盖是否会导致水温升高和水质下降。在项目期间，我将培养2名博士后，2名博士，3名硕士，5名理学士。所有HQP将获得先进的数据管理和统计技能知识，同时量化天气，气候和湖泊形态之间的复杂关系，以了解气候变化对湖泊变暖和世界各地湖泊水质的影响。最终，我们有能力确定哪些湖泊易受气候变化变暖和水质退化的影响，从而制定脆弱性评估和重点适应计划，以减轻气候变化对淡水质量的影响。

The impact of climate change on water quality has been identified as one of the most important challenges facing humankind. In particular, it is vital to understand the mechanisms involved in lake warming and its consequences on water quality. Lake warming increases the risk of nuisance algal blooms, which can negatively affect drinking water, domestic household water use, food production, and recreational activities. Lake ice phenology (defined as the timing of ice breakup and freeze) is a sensitive indicator of climate warming and has been recorded for centuries around the world because of its importance to transportation, winter recreation, and religion. My long-term research objectives are to predict the future impacts of global environmental change on lakes. My short-term objectives are to understand the impacts of climate change on the patterns, trends, and drivers of lake ice cover, water temperatures, and water quality. For example, what are the drivers of no-freeze events and are they coherent spatio-temporally?; Is earlier ice break-up contributing to warmer water temperatures?; How do climate, landscape characteristics, and lake morphology interact to inform spatial patterns in water quality worldwide?; and Which lakes are most vulnerable to degraded water quality? We will capitalize on long-term climatic and ecological time series collected from hundreds of lakes around the Northern Hemisphere to address our research questions and quantify the impacts of climate change on lake ice phenology, lake warming, and water quality. We are developing and updating three databases: 1) Global Lake and River Ice Phenology database, which dates back to 853 AD and represents over 520 time-series from lakes around the Northern Hemisphere; 2) Global Lake Temperature Collaboration database summarizing lake surface water temperatures, climate, and geomorphological characteristics between 1985 and 2009 for 291 lakes located around the world; and 3) Global Water Quality Database summarizing chlorophyll, water clarity, and nutrient concentrations from 26,000 lakes found in 91 countries. We will use cutting-edge statistical analysis to identify whether earlier ice break-up and reduced ice cover will lead to warmer water temperatures and degraded water quality. Over the duration of the proposal, I will train 2 Post-doctoral Researchers, 2 PhD students, 3 MSc students, and 5 BSc students. All HQP will gain knowledge in advanced data management and statistical skills while quantifying complex relationships between weather, climate, and lake morphology, to understand the impacts of climate change on lake warming and water quality of lakes around the world. Ultimately, our ability to identify which lakes are vulnerable to warming and degraded water quality in response to climate change will permit the development of vulnerability assessments and focused adaptation plans to mitigate climate change impacts on fresh water quality.