Large-scale water quality modeling to screen for risks in Canadian and global freshwater bodies using a high-resolution river routing approach

保护我们的地表水资源的质量对于维护依赖这些资源的人类和水生生态系统的健康和安全至关重要。为了成功地维持河流和湖泊的生态系统服务，包括饮用水的供应，我们需要能够监测和预测维持水生栖息地和生物多样性的关键水质特征，如水温和沉积物浓度；我们需要了解影响它们的潜在有害物质的来源、去向和分布。通过提名提供清洁水作为可持续发展的核心目标，这一重要性得到了国际社会的承认。由于河流系统中的水质对气候变化和人类活动都很敏感，而且影响可以沿着河流网络长距离累积或传播，因此迫切需要更好地了解地表水和人类干扰之间的大范围关系，即整个流域、国家和世界。我提出的未来5年的研究计划旨在加强全球水文模拟方案，以便分析将加拿大和全球淡水资源置于危险境地的当前和未来水质趋势。我将专注于三个具体的研究前沿：(A)我将创建一种建模方法，以高空间分辨率估计全球所有河流和湖泊的水温状况，该方法基于将全球气温与流动路线方案相结合，并考虑到冰川、雪和地下水。(B)我将制定一个全球模拟框架，以高空间分辨率估计泥沙运移及其可能的变化。以及(C)我将完成一个化学命运模型的开发，该模型能够估计我们水道中新出现的污染物的浓度，如下水道中的家用化学品、药品、工业污染物、微塑料或纳米颗粒，覆盖整个加拿大，并最终覆盖世界。在拟议的研究计划中，我的学生将融合地理信息科学(GIS)和遥感技术的最新方法。过去十年里，我在我的研究实验室里制作了无缝的全球数据，包括850万条河流和140万个湖泊的高分辨率地图，再加上新的建模技术，将使首次在泛加拿大和全球范围内进行研究成为可能，这是以前无法实现的。其主要目标是制定一个模型和情景框架，能够筛查有风险的区域，特别是在饮用水摄入量等关键地点。我预计我的成果将广泛适用于战略淡水规划和流域综合管理，包括评估生活或工业用水、农业用地做法、水库调度和气候变化对下游水质的影响。

Protecting the quality of our surface water resources is of paramount importance to preserve the health and safety of humans and aquatic ecosystems that depend on them. To successfully maintain the ecosystem services of rivers and lakes, including the supply of drinking water, we need to be able to monitor and predict critical water quality characteristics that sustain aquatic habitats and biodiversity, such as water temperature and sediment concentrations; and we need to understand the sources, fate and distribution of potentially harmful substances affecting them. This importance has been internationally recognized by nominating the provision of clean water as a central Sustainable Development Goal. Since water quality in the river system is sensitive to both climate change and anthropogenic activities, and effects can accumulate or propagate over long distances along the river network, there is an urgent need to better understand relationships between surface water and human perturbations at large scales, i.e. for entire basins, countries, and the world. My proposed research program over the next 5 years aims to enhance global hydrological modeling schemes in order to analyze current and future water quality trends that put Canadian and global freshwater resources at risk. I will focus on three specific research frontiers: (a) I will create a modeling approach to estimate water temperature regimes for all rivers and lakes globally at high spatial resolution, based on combining global air temperature with a flow routing scheme, taking glaciers, snow, and groundwater into account. (b) I will develop a global modeling framework to estimate sediment transport and its possible changes at high spatial resolution. And (c) I will complete the development of a chemical fate model that is capable of estimating concentrations of emerging contaminants in our waterways, such as down-the-drain household chemicals, pharmaceuticals, industrial pollutants, microplastics, or nanoparticals, covering all of Canada and ultimately the world. For the proposed research program, my students will blend state-of-the-art methodologies from Geographic Information Science (GIS) and Remote Sensing. The seamless global data that I have produced over the last decade in my research lab, including high-resolution maps of 8.5 million river reaches and 1.4 million lakes, combined with new modeling techniques will allow for first-time studies at pan-Canadian and global scales that have previously been unachievable. The main goal is to develop a model and scenario framework capable of screening for regions at risk, in particular at critical locations such as drinking water intakes. I anticipate broad applicability of my results for strategic freshwater planning and integrated river basin management, including assessments of the effects of domestic or industrial water use, agricultural land use practices, reservoir operation, and climate change on downstream water quality.