Time-variable transit time distributions (TTDs) and StorAgeSelection (SAS) functions have been widely used to modelsystem scale hydrologic transport. However, these functions,TTD and SAS, are usually calibrated and not directlyobserved in unsteady systems. Also, the forms of thesefunctions are not well explained. In this dissertation, Idiscuss hydrologic processes and landscape structurecontrols on these functions as a tool to better understandand predict system scale hydrologic transport. Specifically,and throughout the dissertation, I provide directexperimental observations of these functions in unsteadysystems at two spatial scales (1 square meter sloping soil lysimeterand 330 square meter hillslopes) and explain process controls on theforms, time variabilities, and hysteresis of thesefunctions, with implications to the catchment scaledynamics. I also present hillslope scale low-orderprocess-based theories that provide direct links betweenthese functions and landscape hydraulic as well asgeomorphic structures. The theory considers subsurfacedynamics under steady state. We used it to examine specificstructure controls on the SAS function such as slopingimpermeable layer, saturated hydraulic conductivity that declineswith depth, and geomorphic structure of the hillslope.Subsequently, a theory to predict unsteady state SASfunction is developed that considers saturated zone dynamicsin a steep homogeneous hillslope. Finally, I present anapplication of the developed low-order theory-based model toa 6300 square meter till catchment that exemplifies a practical usageand potential advantage of the theory.
【 预 览 】
附件列表
Files
Size
Format
View
Processes and Landscape Structure Underlying System Scale Hydrologic Transport: Theory, Experiment, and Modeling
PDF
download
878987797
028-85220240
