Looking at catchments as closely coupled hydro-geo-ecosystems reveals an organized architecture that is characterized by typical patterns of topography, soil and vegetation and self-similar flow networks at many different scales. As catchments evolve in response to changes in climate, management, development, and natural geomorphic processes, these patterns and networks are a result of processes that occur over a large range of time scales and with different degree of persistence, and they can organize storage of water, nutrients and energy exchange as well as mass export (water, sediments) across large-scale gradients. Understanding similarity is also fundamental for building more realistic dynamic catchment models that balance the necessary complexity with the greatest possible simplicity and to address the problem of transient hydro-geo-ecosystems. Comparative hydrology across catchments through the lens of catchment organization and evolution can be used to increase our understanding of catchment process and behavior across regional, continental and global scales.
Specifically, the linkages between catchment organization, similarity, and evolution could provide further insight towards addressing a range of hydrologic research questions including, but not limited to:
- the degree of model complexity needed to characterize catchment processes and response,
- the relative effects of hydroclimatology and physical properties on catchment response,
- the uncertainties involved in identification of dominating processes and hydrologic response behavior,
- the underlying organizing principles that shape the catchments,
- the impacts of human-induced change on catchment response behaviour and similarity, and
- the resilience of catchments to change.
This session welcomes a combined discussion on ideas and studies that synthesize and (or) further our understanding of catchment organization, similarity, and evolution.