Surface flow and connectivity under changing land uses

Introduction

The aim of this project is to assess the effects of human induced changes in the system and increase the knowledge of spatial and temporal scale relationships within the catchment using the understanding of flow and sediment dynamics in the Don catchment.

As part of the CatSci EST Programme, this project aims also, in conjunction with the projects of the other CatSci members, to provide a deeper understanding for integrated catchment management.

Approach

This project will assess the effects of human induced changes in the catchment, in this case specifically changes in land use or non-natural alterations of the flow, by trying to answer questions such as how anthropogenic impacts affect connectivity and how the effects of those impacts propagate within and beyond single and adjacent landscape fragments and within and beyond the time of the study. The transfer of water and sediments through the system, which strongly conditions physical habitats, will be used as a tool to address these issues, which should assist also in obtaining more realistic estimations of sediment yield risk from hillslopes to streams.

For that purpose, it will be necessary to recognize causal relationships and feedbacks. Thus, the project will consider hillslope-channel coupling and its relation to the catchment and assess the significance of different systems components under variable conditions. In addition, temporal and spatial relationships will be identified to assess the relevance of scale in catchment processes.

A nested framework will be adopted to try to couple specific cases with the big picture at the catchment scale by using areas of the catchment as a natural laboratory. Field studies include plot experiments, sediment coring and analysis, flow and sediment load measurements, qualitative surveys and channel cross-sections at different locations. The analysis of the cores and study of historical material will provide information to integrate the temporal factor more comprehensively. Simultaneously, beyond the specific case study, a geomorphological characterization of the Don Catchment will be conducted and finally, a modelling approach will be used to analyse the processes from the specific case to the larger scale.