Runoff generation processes in headwater catchments: the role of storage and release

加拿大的河流系统是由排干源头集水区的溪流提供的。这些源头承担了我们大河一半以上的流量。它们很少被测量，关于它们如何存储和传输降雨和融雪的信息也很少。由于源头与景观过程和下游水域有着内在的联系，它们影响着流域中水和溶质的供应、运输和命运。我们目前的降水-径流模型在表示水源的方式上缺乏过程现实性。因此，流域系统将如何应对土地利用和气候变化存在很大的不确定性。因此，对加拿大和其他地方未来水质和水量变化的预测充满了不确定性。 我工作的长期目标是发展对源头流域径流产生过程的新理解，特别是关注这些流域如何在不同的时间和空间尺度上储存和释放水。拟议的工作重点是四个相互关联的工作包，它们解决了在这一研究领域取得进展的最重要和最根本的障碍--衡量、理解、建模和理论。这项工作的预期意义是，它将有助于开发合理的流域径流模型，并减少流域对气候和土地利用变化的反应预测的不确定性。

River systems in Canada are fed by streams draining headwater catchments. These headwaters are responsible for more than half of the flow in our large rivers. They are rarely gauged and little information exists on how they store and transmit rainfall and snowmelt. Since headwaters are connected intrinsically to landscape processes and downstream waters they influence the supply, transport, and fate of water and solutes in watersheds. Our current models of precipitation-runoff lack process realism for the way that headwaters are represented. Therefore large uncertainties exist on how watershed systems will respond to landuse- and climate-change. As a result, prediction of future changes in water quality and quantity in Canada and elsewhere is fraught with uncertainty. The long term objective of my work is to develop new understanding of runoff generation processes in headwater catchments, focused especially on how these store and release water at different time and space scales. The proposed work focuses on four inter-related work packages that address the most important and fundamental impediments for moving forward in this research area—for measurement, understanding, modeling and theory. The anticipated significance of this work is that it will aid the development of watershed runoff models that work for the right reason and reduce uncertainty in projections of watershed response to changing climate and landuse.