Please use this identifier to cite or link to this item:
Title: Restoring vertical connectivity in rivers: geomorphic, hydrologic and biogeochemical responses to log sills in the Williams and Hunter Rivers, NSW, Australia
Contributor(s): Mika, Sarah Jessie (author); Boulton, Andrew  (supervisor); Ryder, Darren  (supervisor)
Conferred Date: 2013
Copyright Date: 2013
Open Access: Yes
Handle Link:
Abstract: In alluvial rivers, groundwater and stream water are intimately connected via the saturated sediments lying below and beside the river channel, termed the 'hyporheic zone'. This zone is a spatially and temporally dynamic mosaic of biogeochemically distinct patches that are connected by multiple, hierarchical hydrological flowpaths that also vary in space and time. Active and diverse hyporheic zones promote resilience and resistance in rivers through thermal buffering, retention of water, solutes and organic matter, biogeochemical filtration, nutrient cycling, and biological production that occur within these ecotones between alluvial rivers and true groundwaters. However, alluvial river systems are among the most endangered ecosystems in the world, and in many the spatial and temporal configuration of hyporheic exchange has been impaired by human activities. Efforts to restore hyporheic zones are increasingly common. Typically, these projects have sought to reinstate geomorphic complexity through augmenting coarse sediment or installing wooden structures such as log sills. Most of these attempts have been on low-order reaches and focused at fine-scales (e.g. a single riffle). This thesis describes the first large-scale field experiment to assess the restoration outcomes and ecological success of large, engineered, multi-log structures such as those typically deployed by catchment managers. My study derived a conceptual model from the literature that hypothesized the mechanisms by which a log sill anchored within a riffle would increase hyporheic exchange and influence nutrient processing. I then tested these hypotheses using two log sills placed in each of two gravel-bed rivers, the Hunter River and the Williams River, New South Wales, Australia.
Publication Type: Thesis Doctoral
Fields of Research (FoR) 2008: 060204 Freshwater Ecology
040310 Sedimentology
040601 Geomorphology and Regolith and Landscape Evolution
Fields of Research (FoR) 2020: 310304 Freshwater ecology
370509 Sedimentology
370906 Regolith and landscape evolution
Socio-Economic Objective (SEO) 2008: 960904 Farmland, Arable Cropland and Permanent Cropland Land Management
Socio-Economic Objective (SEO) 2020: 180607 Terrestrial erosion
180603 Evaluation, allocation, and impacts of land use
Rights Statement: Copyright 2013 - Sarah Jessie Mika
HERDC Category Description: T2 Thesis - Doctorate by Research
Publisher/associated links:
Appears in Collections:School of Environmental and Rural Science
Thesis Doctoral

Files in This Item:
13 files
File Description SizeFormat 
open/MARCXML.xmlMARCXML.xml3.67 kBUnknownView/Open
open/SOURCE05.pdfhidden4.81 MBAdobe PDF
Download Adobe
open/SOURCE06.pdfhidden700.14 kBAdobe PDF
Download Adobe
open/SOURCE03.pdfhidden617.16 kBAdobe PDF
Download Adobe
open/SOURCE04.pdfhidden5.44 MBAdobe PDF
Download Adobe
1 2 Next
Show full item record

Page view(s)

checked on Jun 11, 2023


checked on Jun 11, 2023
Google Media

Google ScholarTM


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.