Understanding and interpretation of catchment behaviour with a top down approach. Further development of flexible modul structures for hypothesis testing

了解大尺度的水文行为仍然是当代水文学尚未解决的挑战。已经提出了几种解决这一问题的方法，大致可分为“自上而下”和“自下而上”两种方法。这两种方法都面临着重大挑战和限制，人们越来越认识到，同时使用这两种方法对更好地了解水文过程具有重大影响。该项目涉及“研究股”和其他“工作包”，因为它采用“自上而下”的方法处理常见的研究问题，而其他分项目采用的方法主要是“自下而上”。“自上而下”的方法是一个从数据中学习的系统框架，它依赖于在分析的每一步对假设进行测试。认识到当前模型开发和测试方法的局限性，我们提出了灵活的模型方法作为深入假设检验的工具。该项目的主要目标是：(1)扩大现有灵活框架的能力；(2)利用灵活框架对集水行为进行系统调查。我们提出了一种基于通用元素的柔性模型方法，它提供了比现有柔性框架更细粒度和更大的灵活性。这一框架被应用于不同的案例研究，以调查(I)以实地调查为基础的以水文响应单元为基础的地貌表示与整个集水区响应之间的关系，以及(Ii)平均停留时间的估计及其与集水区特性的关系。

Understanding large scale hydrological behaviour remains an unresolved challenge of contemporary hydrology. Several avenues to address this problem have been proposed, which can be broadly classified in the ‘top-down’ and ‘bottom-up’ approaches. Both approaches face important challenges and limitations, and it is increasingly recognized that their simultaneous use makes a significant impact on better understanding hydrological processes. This project relates to the ‘Research Unit’ and the other ‘Work Packages’ as it addresses common research questions following a ‘top-down’ approach, while the approach adopted by the other sub-projects is mainly ‘bottom-up’. The ‘top-down’ approach is a systematic framework to learning from data, which relies on the testing of hypotheses at every step of analysis. Acknowledging the limitations of current approaches for model development and testing, we propose flexible model approaches as an instrument for incisive hypothesis testing. The main objectives of this project are (i) to extend the capabilities of current flexible frameworks, and (ii) to use flexible frameworks for a systematic investigation of catchment behaviour. We propose a flexible model approach based on generic elements which provide finer granularity and larger flexibility than existing flexible frameworks. This framework is applied to different case studies to investigate (i) the relation between fieldwork-based representation of the landscape in hydrological response units and the overall catchment response, and (ii) the estimation of mean residence time and its relation to catchment properties.