Journal ArticleDOI
Indirect Environmental Effects of Dikes on Estuarine Tidal Channels: Thinking Outside of the Dike for Habitat Restoration and Monitoring
TLDR
In this article, the authors analyzed historical photos of the Skagit River delta marshes (Washington, U.S.) and compared changes in estuarine marsh and tidal channel surface area from 1956-2000 in the Wiley Slough area of the South Fork Skagits delta, and from 1937-2000 on the North Fork delta.Abstract:
While the most obvious effects of dike construction and marsh conversion are those affecting the con- verted land (direct or intended effects), less immediately apparent effects also occur seaward of dikes (indirect or unintended effects). I analyzed historical photos of the Skagit River delta marshes (Washington, U.S.) and compared changes in estuarine marsh and tidal channel surface area from 1956-2000 in the Wiley Slough area of the South Fork Skagit delta, and from 1937-2000 in the North Fork delta. Dike construction in the late 1950s caused the loss of 80 ha of estuarine marsh and 6.7 ha of tidal channel landward of the Wiley Slough dikes. A greater amount of tidal channel surface area, 9.6 ha, was lost seaward of the dikes. Similar losses were observed for two smaller North Fork tidal channel systems. Tidal channels far from dikes did not show comparable changes in channel surface area. These results are consistent with hydraulic geometry theory, which predicts that diking reduces tidal flushing in the undiked channel remnants and this results in sedimentation. Dikes may have significant seaward effects on plants and animals associated with tidal channel habitat. Another likely indirect dike effect is decreased sinuosity in a distributary channel of the South Fork Skagit River adjacent to and downstream of the Wiley Slough dikes, compared to distributary channels upstream or distant from the dikes. Loss of floodplain area to diking and marsh conversion prevents flood energy dissipation over the marsh surface. The distributary channel has responded to greater flood energy by increasing mean channel width and decreasing sinuosity. Restoration of diked areas should consider historic habitat loss seaward of dikes, as well as possible benefits to these areas from dike breaching or removal. Habitat restoration by breaching or removal of dikes should be monitored in areas directly affected by dikes, areas indirectly affected, and distinct reference areas.read more
Citations
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Journal ArticleDOI
Rapid response of tidal channel networks to sea-level variations (Venice Lagoon, Italy)
Federica Rizzetto,Luigi Tosi +1 more
TL;DR: In this article, the authors examined the effects of long and short-term sea-level fluctuations on the geomorphologic evolution of modern tidal channels through the joint interpretation of channel modifications, the 1938-2010 yearly time series of relative sea level rise, and the variations of strength and frequency of high tides which occurred in the same period.
Journal ArticleDOI
Identifying Major Stressors: The Essential Precursor to Restoring Cultural Ecosystem Services in a Degraded Estuary
Jennifer Ann Davis,Ian M. Kidd +1 more
TL;DR: In this paper, the authors highlighted the importance of identifying stressors as the basis for examining the potential to reduce the trade-offs between the multiple ecosystem services provided by an estuary and its tributaries, particularly between provisioning and cultural ecosystem services, within a rehabilitation context.
Journal ArticleDOI
Large Woody Debris Influences Vegetation Zonation in an Oligohaline Tidal Marsh
TL;DR: In this article, the authors investigated whether woody debris affects the distribution of estuarine shrubs, particularly nitrogen-fixingMyrica gale L. (sweetgale), which dominates the tidal shrub community of the Skagit River estuary, Washington, U.S.A.
Journal ArticleDOI
Changes in habitat availability for outmigrating juvenile salmon (Oncorhynchus spp.) following estuary restoration
Christopher S. Ellings,Melanie J. Davis,Eric E. Grossman,Isa Woo,Sayre Hodgson,Kelley L. Turner,Glynnis Nakai,Jean E. Takekawa,John Y. Takekawa +8 more
TL;DR: In this paper, the authors monitored a variety of physical parameters to measure changes in opportunity potential from historic, pre-restoration, and postrestoration habitat conditions at several sites across the Nisqually River Delta.
Journal ArticleDOI
Rethinking Conservation Practice in Light of Climate Change
Peter W. Dunwiddie,Sonia A. Hall,Molly W. Ingraham,Jonathan D. Bakker,Kara S. Nelson,Roger Fuller,Elizabeth Gray +6 more
TL;DR: In this article, the authors describe three general categories of strategies for restoring and managing natural systems in light of likely changes in future climate that collectively embrace many of the approaches that The Nature Conservancy is applying or considering in the state of Washington.
References
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Book
The Fractal Geometry of Nature
TL;DR: This book is a blend of erudition, popularization, and exposition, and the illustrations include many superb examples of computer graphics that are works of art in their own right.
Journal ArticleDOI
The Fractal Geometry of Nature
TL;DR: A blend of erudition (fascinating and sometimes obscure historical minutiae abound), popularization (mathematical rigor is relegated to appendices) and exposition (the reader need have little knowledge of the fields involved) is presented in this article.
Journal ArticleDOI
Fluvial Processes in Geomorphology
Book
Fluvial Processes in Geomorphology
TL;DR: Fluvial processes in geomorphology, Fluvial Processes in Geomorphology as discussed by the authors, fluvial processes and geomorphological processes in the field of geology.
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