Investigating Ugandan crater lake water quality and hydrology using novel monitoring data sets.

NERC：罗拉：NE/L002604/1热带湖泊为其社区提供了重要的水资源和生态系统服务，但人们对其对气候和环境变化的反应知之甚少。在乌干达西部，80多个火山口湖为农村社区提供了重要的资源。这些包括家庭用水、作物和牲畜资源，以及为个体渔业和生态旅游提供机会。先前的工作（例如，米尔斯，2009年; Saulnier-Talbot等人，2014年）表明，这些火山口湖及其集水区受到人类影响的压力越来越大，如森林砍伐和气候变化。通过了解火山口湖对过去不同时间尺度的环境变化的反应，可以预测其水平衡和水质的未来变化，从而有助于为地表水供应的可持续管理提供信息（米尔斯等人，2017年）。来自热带湖泊的长期监测数据很少，即使存在，也往往是不连续的，覆盖的时间相对较短（<20年），但Kibale鱼类项目（由加拿大麦吉尔大学的Lauren Chapman教授领导）自1991年以来一直定期监测恩库鲁巴湖，使这个乌干达小湖泊成为非洲监测最好的湖泊之一。该研究项目将整理、组织和数字化该项目收集的湖泊pH值、电导率和降雨量数据，创造东非最长的水质测量记录。与该地区的许多其他湖泊相比，恩库鲁巴湖的集水区经历了低水平的人类干扰，因此提供了一个难得的机会来了解气候变化对湖泊系统及其功能的影响，以及对水量和水质的影响，而没有人的显著影响。除了长期监测外，古湖沼学，即对湖泊沉积物的研究，可用于提取关于过去环境和气候变化的信息，但时间要长得多。湖泊沉积物记录了湖泊系统的许多组成部分（包括生物和地球化学组成部分），这些组成部分可以作为湖泊及其流域的历史书，并可以通过分析来推断环境变化及其驱动因素。沉积物可以用放射性技术测定年代，这样就可以了解变化的时间，并与其他已知的环境变化相关联。对恩库鲁巴湖沉积物中保存的环境指标的研究（Saulnier-Talbot等人，2014年，2018年）和其他一些乌干达火山口湖（例如米尔斯等人，2014;米尔斯等人，2018; Ryves等人，2011年），已经表明，随着时间的推移，火山口湖的水平衡有显着波动。我们将从这项研究中获得对恩库鲁巴湖水文系统的更好理解，这将有助于解释从湖泊沉积物中获得的关于过去湖泊状况的记录，并有助于了解气候变化对这些社会的潜在影响，经济和环境未来重要湖泊的水质。

NERC: Laura Hunt: NE/L002604/1Tropical lakes provide important water resources and ecosystem services to their communities, but their response to climate and environmental change is poorly understood. In western Uganda more than 80 crater lakes provide critical resources to rural communities. These include household water use, and resource for crops and livestock, in addition to provision of opportunities for artisanal fisheries and ecotourism. Previous work (e.g. Mills, 2009; Saulnier-Talbot et al., 2014) has shown that these crater lakes and their catchments are under increasing pressure from human impacts, such as deforestation, and climate change. By understanding the response of the crater lakes to past environmental changes across various timescales, it is possible to predict future changes in their water balance and water quality, thus helping inform sustainable management of surface water supplies (Mills et al., 2017). Long-term monitoring data from tropical lakes is sparse, and where they do exist, they tend to be discontinuous and cover relatively short time periods (<20 years), however the Kibale Fish Project (led by Prof. Lauren Chapman from McGill University in Canada) has routinely monitored Lake Nkuruba since 1991, making this small Ugandan lake one of the best-monitored lakes in Africa. The proposed research project will collate, organise, and digitise lake pH, conductivity and rainfall data collected by this project, creating the longest record of water quality measurements from eastern Africa. Compared to many other lakes in the region, the catchment of Lake Nkuruba has experienced a low level of human disturbance and so offers a rare opportunity to understand the impact of climate change on a lake system and its function, and upon water quantity and quality, without the significant added impact of people. In addition to long-term monitoring, palaeolimnology, the study of lake sediments, can be used to extract information about past environmental and climatic changes, but over a much longer time frame. Many components of a lake system (including biological and geochemical components) are recorded in the lake sediments, which act as a history book for the lake and its catchment, and can be analyzed to infer environmental change and its drivers. The sediments can be dated using radiometric techniques, so that timing of changes can be understood and correlated with other known environmental changes. Studies of the environmental indicators preserved in lake sediments from Lake Nkuruba (Saulnier-Talbot et al., 2014, 2018) and a number of the other Ugandan crater lakes (e.g. Mills et al., 2014; Mills et al., 2018; Ryves et al., 2011), have shown there have been significant fluctuations of the crater lake water balance over time. The improved understanding of Lake Nkuruba's hydrological system that we will get from this research will improve understanding of these Ugandan lake systems in general, which will help interpretation of the records obtained from lake sediments about past lake conditions as well as helping to understand the potential impact of climatic change on the water quality of these socially, economically, and environmentally important lakes in the future.