Advanced geospatial technologies applied to gravel-bed river mapping and modeling

Mapping and modeling of river channels is essential in defining the Channel Migration Zone (CMZ). CMZ delineation is necessary to mitigate hazards, create opportunities to protect riparian habitat, predict channel response to changing land cover and disturbances, and design more environmentally-aligned engineering structures. This provides a compelling challenge to the GIScientist because of the need to understand fluvial process dynamics in space and time, and the narrow, elongated, and sinuous geometry of fluvial systems which complicates data collection, management and modeling of digital data describing these. This requires creation, management and correlation of a vast array of data of varying density and quality.; Research presented here develops and applies advanced geospatial data, technologies, and modeling to CMZ mapping of a dynamic gravel-bed river in the state of Washington, USA. Chapter 2 demonstrates how new, object-based image processing techniques enhance river mapping accuracies and data modeling opportunities by incorporating the spatial characteristics and relationships of hydrogeomorphic objects into the classification process, by fusing high resolution DEMs with image data, and by accounting for uncertainty.; In chapter 3, development and assimilation of a high resolution topographic LiDAR-based DEM with a one-dimensional hydraulic model enables the avulsion hazard of a reach of the Naches River in the state of Washington to be determined for multiple flow and channel-change scenarios. The DEM is used to optimize performance of the 1D hydraulic model HEC-RAS, post-processed output of which facilitates calculation of spatially explicit shear stress (tau0) and specific stream power per unit bed area (o).; In Chapter 4 a new data intensive GIS-based framework for delineating CMZs is implemented and assessed. The approach incorporates historical maps, field-survey data, and LiDAR derived data products as well as a system design that provides a flexible model for integrating GIS-based analyses into procedures for generating a comprehensive, detailed spatial understanding of fluvial processes and the potential for channel migration under likely scenario conditions.; Each of the chapters stand alone as individual research contributions, but collectively they emphasize the importance of CMZ mapping and modeling, and the increasingly important role emerging geospatial technologies play in improving our understanding of the fluvial geomorphic processes underlying river channel change.