Collaborative Research: Cross-Scale Interactions Among Climate, Land-Use, and River-Water Quality

水质是世界上最宝贵的自然资源之一。鉴于最近和预测的气候变化(一些地区干旱更加频繁和严重)和土地利用(与全球对肉类、乳制品和林业产品需求增加相关的农业集约化)，重要的是了解气候和土地利用的同时变化如何影响水质。例如，干旱期间的农业集约化是否会增加进入河流的泥沙径流，以及这些影响发生在多大尺度上？该项目将使用遥感和计算机可视化工具，分析气候变化和土地利用之间的相互作用如何在多个相互作用的尺度上影响河流水质：从几分钟到几十年，从小流域到区域流域。拟议的研究将展示这些跨尺度的相互作用如何影响具有多维社会相关性的自然资源：水处理、娱乐、安全、旅游和生态系统健康。这项研究的结果将为美国新兴的数据监测网络提供信息，说明应该在哪个空间和时间尺度上进行水采样，以捕捉气候和土地利用的相互作用。项目成果和数据将通过各种方式向公众传播，包括开放获取的期刊、公共网站和大学/高中讲习班。该项目将研究的一个基本问题是，气候和土地利用的同时变化是否会导致正反馈和级联事件，从而导致河流水质发生戏剧性和广泛的变化。以前的研究未能在多个时空尺度上同时评估气候-土地利用相互作用对河流水质的影响，原因是：(1)没有能够同时分析多个维度和时空尺度的工具包；(2)缺乏资源(即高分辨率的长期和一致的水质数据集)；(3)缺乏技术(即以高空间和时间分辨率捕捉土地覆盖的变化的能力)。该项目克服了这些限制，它使用(1)一套复杂的可视化工具进行组合分析；(2)世界上最全面和最广泛的水质数据集之一(25年以来有相应的气候数据)；(3)为新西兰全国开发的融合的8天时间分辨率和30米空间分辨率的土地覆盖数据集。因此，这项研究将是第一次在多个时空尺度上同时评估气候和土地利用变化对一套水质变量的交互影响。此外，应用复杂的视觉分析工具同时研究多个尺度上的景观动态可能会推动地理学和空间科学的新范式。

Water quality is one of the world's most valued natural resources. Given recent and predicted changes in both climate (more frequent and intense droughts in some regions) and land use (agricultural intensification associated with increasing global demand for meat, dairy, and forestry products), it is important to understand how simultaneous changes in climate and land use affect water quality. For example, does agricultural intensification during a drought increase sediment runoff into rivers, and at what scales do these effects take place? This project will use remote sensing and computer visualization tools to analyze how interactions between shifting climate and land use affect river water quality across multiple interacting scales: from minutes to decades, and from small catchments to regional drainage basins. The proposed research will demonstrate how these cross-scale interactions affect a natural resource with multidimensional societal relevance: water treatment, recreation, safety, tourism, and ecosystem health. Findings from this research will inform emerging US data monitoring networks as to at which spatial and temporal scales water sampling should be conducted to capture interactions from climate and land use. Project results and data will be communicated to the public through various means, including open-access journals, a public website, and college/high school workshops. A fundamental question that this project will investigate is whether simultaneous shifts in climate and land use result in positive feedbacks and cascading events that lead to dramatic and widespread changes in river water quality. Previous studies have not been able to assess the effects of climate-land use interactions on river water quality over multiple spatial and temporal scales simultaneously due to (1) not having a toolkit that can analyze multiple dimensions and spatial-temporal scales simultaneously; (2) lack of resources (i.e., long-term and consistent water quality datasets with fine resolution); and (3) lack of technology (i.e., ability to capture land cover changes with fine spatial and temporal resolution). This project overcomes these limitations by using (1) a sophisticated set of visualization tools to analyze in combination; (2) one of the world's most comprehensive and extensive water quality datasets (25 years with corresponding climate data); and (3) a fused 8-day temporal resolution and 30-meter spatial resolution land cover dataset that has been developed for the entire country of New Zealand. Thus, this research will be the first time that the interactive effects of climate and land use changes on a suite of water quality variables will be assessed over multiple spatial-temporal scales simultaneously. Further, the application of sophisticated visual analysis tools to investigate landscape dynamics across multiple scales simultaneously could be the impetus for a new paradigm in Geography and Spatial Sciences.