A generalized Damköhler number for classifying material processing in hydrological systems
A generalized Damköhler number for classifying material processing in hydrological systems
复制标题
用于对水文系统中的物质处理进行分类的广义 Damköhler 数
DOI：
10.5194/hess-17-1133-2013
复制
发表时间：
2013
影响因子：
6.3
通讯作者：
S. Peiffer
中科院分区：
文献类型：
--
作者：
C. Oldham;D. Farrow;S. Peiffer
抽象。在不断变化的土地使用和气候条件下，评估污染物和养分跨流域转移的潜力至关重要。在过去的十年中，一个集水区的连通性/不连通性动态与其出口材料的潜力有关;然而，我们继续使用多种连通性定义，大多数都集中在物理（水文或水力）连通性上。与此相反，本文不断关注运输和物质转化之间的动态平衡，并将物质连通性定义为水文循环要素之间物质的有效转移。暴露时间尺度的概念被开发和使用来定义三个不同的制度：（一）这是水文连接和运输是由平流为主;（二）这是水文连接和运输是由扩散为主;和（三）这是实质上孤立的。暴露时间尺度与材料处理时间尺度的比率表示为无量纲数NE，其中NE是反应特异性的，并且允许估计感兴趣的反应发生的相关空间尺度。每个政权内的案例研究提供的例子，如何NE可以用来模拟系统，根据他们的敏感性，在水文变化和深入了解的地球化学过程，在指定的条件下是显着的。最后，我们探讨了NE框架对改善水资源管理的影响，以及在特定条件下对生物多样性、恢复力和化学竞争力的理解。
Abstract. Assessing the potential for transfer of pollutants and nutrients across catchments is of primary importance under changing land use and climate. Over the past decade the connectivity/disconnectivity dynamic of a catchment has been related to its potential to export material; however, we continue to use multiple definitions of connectivity, and most have focused strongly on physical (hydrological or hydraulic) connectivity. In contrast, this paper constantly focuses on the dynamic balance between transport and material transformation, and defines material connectivity as the effective transfer of material between elements of the hydrological cycle. The concept of exposure timescales is developed and used to define three distinct regimes: (i) which is hydrologically connected and transport is dominated by advection; (ii) which is hydrologically connected and transport is dominated by diffusion; and (iii) which is materially isolated. The ratio of exposure timescales to material processing timescales is presented as the non-dimensional number, NE, where NE is reaction-specific and allows estimation of relevant spatial scales over which the reactions of interest take place. Case studies within each regime provide examples of how NE can be used to characterise systems according to their sensitivity to shifts in hydrology and gain insight into the biogeochemical processes that are signficant under the specified conditions. Finally, we explore the implications of the NE framework for improved water management, and for our understanding of biodiversity, resilience and chemical competitiveness under specified conditions.