[Prev][Next][Index]

synthesis vol

PORTION OF CHAPTER I.4 BY CRAIG KOCHEL

----------------------------Original message----------------------------
Bob,

I'm going to try to cut and paste the outline here.  If this fails, let me
know and I will mail it surface mail.

Craig




Chapter I.4.A  Beaches and Dunes at the VCR -- Draft Outline (12/96)
R. Craig Kochel, Bucknell University

1. Introduction

        a. Mid-Atlantic Barrier Island Geomorphology  (general overview -
brief w/refs)
                1) Depositional environments, landforms, and ecosystems
                        a) Overview and spatial variation along the VCR
                2) Major sediment transport processes
                        a) Tidal inlets
                        b) Overwash
                        c) Longshore currents
                        d) Eolian

        b. Role of the active sand region - the beach and dunes (perspective)

2. Beaches at VCR

        a. Beach morphology
                1) Overview and spatial variation along the VCR
                2) Sand sources and supply - sand starved, linkages to the north

        b. Beach morphodynamics
                1) Wave, tide, and current climate overview (general
ranges, variations)
                2) Beach morphology (based primarily upon obs. at washover
sites)
                        a. Beach profile and features
                        b. States and form, stability, seasonality
                        c. Storm response
                3) Sedimentology

        c.  Washover areas
                1) Morphology and distribution
                2) Processes - hydrology, sand transport, storm response
                3) Interaction with beach and other barrier environments
                        - island profile fluctuation and response to storms
                4) Vegetation

3.  Dunes at VCR

        a. Dune variety and distribution (brief overview and classification)
                1) Berm and washover areas (ephemeral)
                2) Foredune areas
                3) Stable interior and maritime forest areas
                4) Beach-ridge and inlet margin areas
                5) Pimple areas

        b) Dune nucleation and evolution (summary of work on Parramore & Hog)
                1) Nucleation processes
                2) Sand supply
                3) Eolian sand transport - rates and controls
                3) Dune propagation

        c) Vegetation - ties with water table, salinity, overwash
disturbance stress
        d) Interaction between dunes and beach processes












Proposed Addition to Section II - Landscape Response to Disturbance Chapter
II.2 Barrier Islands  --- Overwash Areas
R. Craig Kochel, Bucknell University


Note:  VCR landscapes (and in large part, the vegetation that colonizes
these areas) are rather ephemeral and regulated by geomorphic processes
such as inlet currents and overwash, and to a lesser extent longshore
currents and eolian processes. Overwash is one of the major disturbance
processes that drive landscape evolution on the VCR barrier islands.  This
is especially dominant on low-profile reaches of the islands (northern 4/5
of Smith, all of Myrtle, Ship Shoal, and Wreck, most of Cobb, and
significant portions of Hog and Parramore.  If one factors in
hurricane-induced overwash disturbance, then all sectors of the islands are
subject to significant impact.  I suggest that we discuss washover areas
for low-profile island environments here.

Washover Areas on Low-Profile Island Segments

1. Washover environments at VCR
        a. Variety, distribution, and relationship to other barrier environments
        b. Characteristics
                1) Morphology
                2) Sedimentology

2.Storm overwash processes
        a. Storm tidal surge (brief, general)
        b. Storm waves (brief, general)
        c. Overwash hydraulics (brief, general, refs)
        d. Examples from recent events at VCR (focus on examples from w/o sites)
                - 1989 (offshore hurricance)
                - 1991 Halloween noreaster
                - offshore hurricanes - summers 1995, 1996

3. Disturbance - impact on barrier island landforms (focus on examples from
w/o sites)
        a. Beach-berm system (possibly include longshore bar system)
        b. Foredunes - landforms and vegetation
                - examples from VCR washover sites, pimples, etc.
                - erosion, sand transfer
                - water table - elevation, salinity
        c. Backbarrier marshes
                - burial/destruction (thresholds of survival - Parramore)
                - establishment of new sites for marsh colonization
        d. Island migration (shoreline erosion, rollover)
                - rates, general and specific storm events
                - cross-island profiles



(NOTE:  Somewhere, we probably need to have a section that presents an
overview of the nature and        variation of barrier island geomorphology
along the VCR because there is   considerable variation.
        It could be done in the intro here, or maybe we should do it in the
preceding section   - macrosite and barrier islands (Ch 1.3)




R. Craig Kochel
Professor and Chair
Department of Geology
Bucknell University
Lewisburg, PA  17837
717-524-3032