Southern Dunes. Sustainability issues along the coast due to intense development. Jim Randall Paolo Weatherbee INTRODUCTION

Transcription

1 Southern Dunes Sustainability issues along the coast due to intense development Jim Randall Paolo Weatherbee INTRODUCTION Reconnaissance mapping of 25 west coast dune sheets to establish; landward extent of Pleistocene dunes Transition from Holocene to Pleistocene dunes Morphostratographic development of coastal plain dune sheet deposits 1

2 All data points now visually represented Oregon We realized that the only usable data were in the Bandon area rn lifo Ca ia FOCUS: BANDON AREA Attributes critical to regional mapping of dunal properties for: Drainage Slope stability Wetlands Aquifer potential 2

3 ORIGIN AND HYDROGEOLOGIC PROPERTIES OF GLEYED PALEOSOLS IN SEA CLIFF EXPOSURES OF PLEISTOCENE DUNE SHEETS, CENTRAL OREGON COAST By: Peterson, Curt D., Hofgren, Chris J., Bourret, Carrie L., Browning Craig, Hilary, Burkett, Sarah P., Fetters, Samuel V., Halley, Rebecca J., Johnson, Matthew E. Lutz, William E., Marshall, Michael S., Moore, Amberlee, Ordway, Gayle A., Parenteau, Mary N., Peasley, Carl A., Romey, Adam W., Smith, Lesley A., Stephan, James R., Timmons, Angela M., Urbanczyk, Molly R., Wyatt, Tara L., Youngberg, Timothy L. Geology Department, Portland State University, Portland, Oregon Submitted February, 2003 To: Greg Pettit and Larry Caton Oregon Department of Environmental Quality 1721 SW 11th Street Portland, Oregon Rae Benedict Dept of Human Services ESC 800 NE Oregon St, Ste 608 Portland, OR Work involved Manipulation of original excell files Importation into ArcMap Joins, Relates Select by attributes Interpolation 3

4 METHODS Data in its original format before being Given to us Data was modified for ease and imported into ArcGIS Set up coordinate system using display XY data menu Set to UTM Zone 10 N 4

5 5 Tables as they appear in ArcMap after: Projected coordinate System was defined We then turned this into a feature class as seen in the next slide Most work involved: Relate Joins Select by attributes Manipulation of tables Interpolation Bandon All dune points in the Bandon area Via Select by Attributes

6 6 Pleistocene Dune points Holocene Dune points Select by Attributes units Like *PD* units Like *HD* Thin Thick Pleistocene 11, MY BP Holocene < 11,000 years ago Extent of the Pleistocene in the Bandon Area Digitized, note that the extent conforms to crests of coastal high points

7 7 Extent of the Holocene A clear distinction between extents Digitized the thick Holocene Sediments for visualization 6.10 M 10.0 M 3.40 M 5.50 M

8 8 Digitized the thin Holocene Sediments for visualization 0.05 M 2.00 M 2.15 M 3.00 M Bandon Bg points A reduced grayish sedimentary Layer that is highly impermeable and has Implications for the environment and construction Had to interpolate and create a surface.

9 Given: 63 M 85.5 M Created new field Spline: Bg 2 F requency Histogram Transformation: None Count Min Max Mean Std. Dev. : 7 : 21.7 : : : Skewnes s Kurtosis 1 st Quartile M edian 3 rd Quartile : : : : : Spline_Bando B6 B2 Bg 6 Bg 9 Bg B9 Bandon B Data 10 1 Data Source: Bandon_Attributes_Bg Events Attribute: PDBg_A KRIGING IDW Bg 27 Bg 32 Given ALT Depth to BG ALT of Bg Bg 2 = 86 M 0.72 M = M Bg 6 = 46 M M = M Bg 9 = 33 M 3.40 M = M Bg 10 = 60 M 3.50 M = M Bg 27 = 23 M 1.30 M = M Bg 32 = 90 M 6.55 M = M 9

10 We also interpolated the surface at the apparent bottom of the pleistocene Pleistocene IDW H isto gra m Tra ns fo rm at io n : N o n e Fr eque ncy Idw_pleistoc1 1 Co unt M in Max Mean S t d. D ev : 48 : : : : S k e wn e s s Ku rt o s is 1 s t Q u a rt ile M e d ia n 3 r d Q u a rt ile : : : : : Da ta Spline 1.06 D at a S o urce : ple ist oc en e_c o x A ttrib u te: A LT _C o x Kriging

11 Closing Remarks We were given the southern portion of the study area. Not many points south of Bandon likely because of the funding Oregon funding) With respect to limited amount of data, we found extents of Holocene and Pleistocene more extensive). Found depths of the gleyed layer Bg Bg) ) in the Bandon area Depths for the Pleistocene Need more data points and info in the area that we concentrated on. For example: surface breaks? 11