Modeling water and pollutant connectivity in pristine and human-impacted landscapes

生态水文学家试图更好地了解、预测和缓解各种具有社会和经济意义的环境问题，包括洪水、干旱和水污染。虽然这些问题是由不同的过程造成的，但它们都可以通过互联互通的镜头进行检查。事实上，“连通性”指的是一个特定的景观位置“A”将水和其他物质(例如污染物或生物群)传输到另一个位置“B”的能力，它是陆地和水生生态系统健康的关键指标。鉴于在连通性衡量标准上缺乏科学共识，模型被视为估计和测试关于连通性的假设的实用工具。然而，尽管现有的降水-径流模型用于连通性估计，但很少有人明确地考虑到这一目标，这引发了人们对他们预测的可靠性的质疑。现有的大多数模型依赖于隐式连通性模拟方法，即只通过空间聚集的代理度量来考虑与连通性相关的部分景观属性。相反，显式的连通性模拟方法很少见：它们应该考虑大量的景观属性，并允许它们对连通性的影响在空间和时间上变化，要么是通过基于方程的建模(EBM)，要么是通过从复杂系统理论引入的方法，如基于主体的建模(ABM)。后者在生态学上比较常见，但在水文学上比较稀少。因此，拟议研究方案的目标是四个方面：1)比较现有降雨-径流模型在连通性隐式模拟方面的性能；2)按照水文学中的典型做法，使用基于方程的建模原则创建水和水中介污染物连通性的空间显式模型；3)使用借用生态学的基于主体的建模工具创建空间显式连通性模型；以及4)评估混合连通性建模方法在不同空间和时间尺度上的价值。重点将放在加拿大和世界其他地区森林、农业和城市地区从小流域到大流域的各种地点：这将确保考虑到各种景观，并评估与模型数据要求和计算效率有关的空间可变问题。鉴于其对原始和受人类影响的地貌的数据模型集成的高度重视，拟议的研究计划将为未来的生态水文学家提供独特和重要的培训机会。

Ecohydrologists seek to better understand, predict and mitigate various environmental issues of societal and economic significance, including floods, droughts and water pollution. While those issues are created by different processes, they can all be examined through the lens of connectivity. Indeed, "connectivity" refers to the ability of a given landscape location "A" to transmit water and other materials (e.g., pollutants or biota) to another location "B", and it is a key indicator of terrestrial and aquatic ecosystem health. Given the lack of scientific consensus on connectivity measures, models are seen as pragmatic tools for estimating and testing hypotheses about connectivity. However, while existing precipitation-runoff models are used for connectivity estimation, few were explicitly designed with this goal in mind, raising questions about the reliability of their predictions. Most existing models rely on implicit connectivity simulation approaches, whereby only some of the landscape properties relevant to connectivity are considered through spatially aggregated proxy measures. Conversely, explicit connectivity simulation approaches are rare: they should account for a large number of landscape properties and allow their influence on connectivity to vary in space and time, either via equation-based modelling (EBM) or through methods imported from complex systems theory, such as agent-based modelling (ABM). The latter are relatively common in ecology but scarce in hydrology. The goal of the proposed research program is, therefore, four-fold: 1) compare the performance of existing precipitation-runoff models in their implicit simulation of connectivity; 2) create spatially explicit models of water and water-mediated pollutant connectivity using equation-based modelling principles, as is typical in hydrology; 3) create spatially explicit models of connectivity using agent-based modelling tools borrowed from ecology; and 4) assess the value of hybrid connectivity modelling approaches at different spatial and temporal scales. The focus will be on sites ranging from small catchments to large watersheds located in forested, agricultural and urban regions of Canada and other parts of the world: this will ensure that a good variety of landscapes is considered and spatially variable issues related to model data requirements and computational efficiency are appraised. Given its strong emphasis on data-model integration in pristine and human-impacted landscapes, the proposed research program will provide unique and vital training opportunities for future ecohydrologists.