|Goodrich, David - Dave|
Submitted to: Hydrological Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2007
Publication Date: 3/14/2007
Citation: Bloschl, G., Ardoin, S., Bonell, M., Dorninger, M., Goodrich, D.C., Gutknecht, D., Matamoros, D., Merz, B., Shand, P., Szolgay, J. 2007. At what scales do climate variability and land cover change impact on flooding and low flows? Hydrological Processes. 21:1241-1247. Interpretive Summary: Land cover change and climatic variability can have profound effects on extreme hydrological events such as floods and low-flow during periods of drought. The United Nations UNESCO Division of Water Sciences has recognized the importance of these effects and has formed an expert working group to summarize the state of the science and develop key scientific challenges to identify the relative role of climatic variability and land cover change on floods and low flows as a function of watershed size. This paper summarizes a five-year research strategy and a series of workshops to test the approaches in selected basins.
Technical Abstract: Land cover, typically, is a local phenomenon, so its impact is likely to strongly decrease with catchment size. The position of the disturbance in the landscape will modulate the scale effects. In contrast, climate impacts may occur at larger scales so one would expect them to be apparent in both small and large catchments and be consistent in a region. The relative roles of land cover change and climatic variability is likely to vary from catchment to catchment as hydrology is a context dependent discipline, i.e. it matters where / when / how processes occur. For example, land cover effects in the tropics are fundamentally different from those in humid climates. In different hydrological settings the impacts will become important at different scales. However, very little is known on the scales of impact of the various controls that can be generalized to different environments. The UNESCO Division of Water Sciences has therefore initiated a working group on identifying the relative role of climatic variability and land cover change on floods and low flows as a function of spatial scale. The mandate of the working group is to summarise the state of the art of the subject, develop the key science questions, plan a five year research strategy for testing in HELP basins and other research experimental basins, and plan a series of workshops. This paper summarizes the findings of a working group meeting held in Vienna during November 28-30, 2005 to provide a road map of how to address these issues and act as a catalyst for motivating communication and targeted research.