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Research Themes. Hydromorphology : Human-Nature Interactions #1. Interactions between hydrosphere and biosphere processes #2. Interactions of landscape processes within intensively managed watersheds Evolution, structure and function of hydrologic subsystems in hillslopes
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Research Themes Hydromorphology: Human-Nature Interactions #1. Interactions between hydrosphere and biosphere processes #2. Interactions of landscape processes within intensively managed watersheds Evolution, structure and function of hydrologic subsystems in hillslopes Stochastic transport in heterogeneous media Principal Investigators: MurugesuSivapalan, Praveen Kumar, Bruce Rhoads, Don Wuebbles Water Cycle Dynamics in a Changing EnvironmentAdvancing Hydrologic Science through Synthesis Objective to organize and employ synthesis activities to produce transformational outcomes that will be utilized to improve the predictability of water cycle dynamics in a changing Earth environment.
Unprecedented Types, Rates, Scales, and Magnitudes of Change
Limits to predictability • Prediction means making probabilistic • statements about future system states • given the current and past observed states • and our understanding of how nature works. • The four classical limits to predictability are • (NRC WSTB, 2002): • Type I – uncertainty in the characterization of initial states • Type II – uncertainty in the characterization of the dynamics at the interfaces • Type III – uncertainty in the characterization of model parameters • Type IV – uncertainty or inadequacy of characterization of critical processes, process interactions and feedbacks
Working Hypotheses: Patterns • Patterns help us to reduce the complexity through reduced dimensionality, and thus help to improve predictions • Patterns (both observed and so far unobserved) are emergent properties arising out of complex interactions and feedbacks between a multitude of processes. • Study of patterns (how to describe them, why they emerge, their impact on the overall response) yields new insights and lead to increased understanding. • Study of observed patterns (why they emerge) may give insights into unobservable or as yet unobserved patterns, and help to make improved predictions
Theme #1:Interactions between hydrosphere and biosphere processes Water balance partitioning at the catchment scale Peter Troch, Ciaran Harman and Sally Thompson
The Horton Index Proportion of available water that is vaporized Precip “Fast” runoff ET Wetting “Slow” runoff Annual Evapotranspiration HI = Annual Wetting
HortonIndex vs. Humidity Index Between years Between catchments Pattern that intrigues….. Annual Precipitation Humidity Index = Troch et al., 2009 (HP) Annual Potential Evaporation
Pattern that intrigues….. V : Growing-season vaporization (E+T) W : Growing-season wetting (P-S) “The natural vegetation of a region tends to develop to such an extent that it can utilize the largest possible proportion of the available soil moisture supplied by infiltration” (Horton, 1933, p.455) Horton, 1933 (AGU)
Rn VPD LAI U P T Models of landscapes as nonlinear filters Penman Monteith Model PPT Interception Model E Emax Infiltration Runoff Multiple Wetting Front Model T Root Water Uptake Model Drainage
Hypothesis ? ? ?
Theme #2: Interactions of landscape processes within intensively managed watersheds Sediment and Contaminant Dynamics Across Scales NanditaBasu, Ciaran Harman, Sally Thompson
Patterns that intrigue….. Why are they linear? Or, Why are watersheds chemostatic? At what scale are they chemostatic? And why? Nitrate load-discharge relationships across Mississippi Sediment load-discharge relationships
Filtering of solute variability across scales:Study sites Single Tile Drain Mississippi Basin Little Vermilion
Landscape and Network Filtering of Sediment Transport: Study Sites Goodwin Creek, Mississippi Rio Isabena, Spain
Hypothesis: Landscapes act as cascading,coupled filters Observed “patterns” are windows into this filtering Filtering of variable inputs by landscape structure and biogeochemical processes produces PATTERNS, as water and solutes cascade across spatial and temporal scales
Summary • Summer institute: grassroots type organization – team based, egalitarian, targeted and yet free to explore alternative ideas or approaches, trail blazing • Data based: recognize/extract patterns from data • Patterns needing a multitude of perspectives from different disciplines to explain or interpret • Interpretation of patterns using parsimonious models: a top-down approach • What are the minimum processes needed to describe strong physical, chemical and biological coupling over a wide range of spatial and temporal scales? • How do complex highly heterogeneous physical, chemical and biological systems respond to changes in forcing behavior and system structure? • Comparative hydrology: develop generalizable insights through comparisons and classification • Modeling of landscapes as nonlinear hierarchical filters – potentially transformative approach