[PDF] Coastal Sand Dunes Of Oregon And Washington eBook

Author : Alfred M. Wiedemann
Publisher :
Page : 132 pages
File Size : 39,18 MB
Release : 1999
Category : Nature
ISBN :

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Plants of the Oregon Coastal Dunes offers a useful, informative guide for visitors to the Oregon Dunes National Recreation Area or anyone spending time on the state's remarkable beaches. The standard reference on the Oregon dunes for thirty years, this handy guide identifies those plants most likely encountered and serves as a general introduction to the ecology of dune areas. The first two sections explain the natural history of dunes and describe plant communities associated with dunes and how they change over time. The final section provides an easy-to-use key to ninety common dune plants. Each species profile includes a photograph, a detailed description, and information on habitat and range.

Author : Willard Thomas McLaughlin
Publisher : Forgotten Books
Page : 54 pages
File Size : 49,19 MB
Release : 2016-06-24
Category : Business & Economics
ISBN : 9781332891597

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Excerpt from Controlling Coastal Sand Dunes in the Pacific Northwest Six years ago the advancing sand dunes on the Clatsop Plains of Oregon, at the mouth of the Columbia River, were menacing forts, military reservations, roads, and private property valued at Worse, they were also threatening to impede the ow of nearly of ocean-going commerce moving in and out of the entrance to the Columbia River, which lay directly in the path of the oncoming dunes. Today the sand movement on the Clatsop Plains has been arrested, and what was once a dangerous expanse of wind blown sand 20 miles long and at places miles wide has been transformed into a mantle of planted grass. In wartime this work is especially vital, much more important than the money values that were protected by this 6-year job of the Soil Conservation Service. Similar conditions are found at the mouths of other navigable rivers on the Pacific coast and on other coastal areas. The methods and techniques of dune control de scribed in this publication, as applied to the Pacific North west coast, can be adopted as well to other threatened points. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works."

Author : Jeremy M. Mull
Publisher :
Page : 120 pages
File Size : 26,67 MB
Release : 2011
Category : Beach erosion
ISBN :

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Coastal foredunes protect lives, infrastructure, and ecosystems during severe winter storms. In the U.S. Pacific Northwest (PNW), coastal foredune geomorphology is determined by both physical and ecological mechanisms. Before the 1900's, the native plant Elymus mollis was the dominant dune grass and dune morphology was largely determined by sediment supply and other physical factors. The introduction of two different invasive beach grasses in the first half of the 20th century resulted in significant changes to PNW foredune geomorphology. Recent work has shown that the invasive beach grass Ammophila arenaria is associated with taller, narrower foredunes while the grass Ammophila breviligulata is associated with shorter, broader foredunes. We hypothesize that this may impact coastal vulnerability as the taller, narrower foredunes may be more resistant to overtopping, but less resistant to erosion, while the shorter, broader foredunes may be more resistant to erosion, but less resistant to overtopping. The work presented in this thesis is part of a larger, interdisciplinary effort to determine the relative importance of physical and ecological mechanisms in controlling coastal foredune geomorphology and vulnerability in the PNW. Airborne topographic lidar data is used to characterize the regional variability in foredune geomorphology within several littoral cells, subcells, and beaches of the PNW. We present and discuss techniques to automatically and accurately extract foredune morphometric parameters from a lidar elevation data set of the coasts of Oregon and Washington. If the different grass species do affect foredune geomorphology, it is important to understand how managing them might impact coastal vulnerability. Therefore, we use the geomorphological parameters and measured hydrodynamic parameters during a major winter storm to estimate vulnerability to overtopping and erosion at beaches with distinctly different foredunes. Estimates of overtopping and erosion are normalized by the foredune heights and widths to elucidate how the different foredune types, and possibly the associated beach grasses, affect vulnerability. A series of simple foredune erosion models including a geometric model, an equilibrium profile model, and a wave impact model are evaluated for applicability to the PNW coast.