Erosion Modeling Update for the West Valley PPA Model Neptune and - - PowerPoint PPT Presentation

▶
erosion modeling update for the west valley ppa model
SMART_READER_LITE
LIVE PREVIEW

Erosion Modeling Update for the West Valley PPA Model Neptune and - - PowerPoint PPT Presentation

Sep 20, 2023 433 likes •761 views

Erosion Modeling Update for the West Valley PPA Model Neptune and Company, Inc. 28 February 2018 West Valley Quarterly Public Meeting February 2018 Implementing Erosion in the West Valley PPA Model Two different sets of parameters in

slide-1
SLIDE 1

West Valley Quarterly Public Meeting • February 2018

Neptune and Company, Inc. 28 February 2018

Erosion Modeling Update for the West Valley PPA Model

slide-2
SLIDE 2

West Valley Quarterly Public Meeting • February 2018

Implementing Erosion in the West Valley PPA Model

  • Two different sets of parameters in the PPA Model:

➢Deterministic ➢Stochastic

  • Both will be informed by several lines of evidence,

including aerial imagery, the work of the EWG, erosion models beyond those evaluated by the EWG, and potentially other expert elicitation or literature review

  • The current presentation focuses only on the

evaluation of recent data obtained from processing aerial photography and LiDAR tomography

2

slide-3
SLIDE 3

West Valley Quarterly Public Meeting • February 2018

Implementing Erosion in the West Valley PPA Model

Deterministic

  • Length of each creek measured from its mouth (e.g.

the mouth of FC is at its confluence with BC)

  • Beginning and end points for reaches in the creeks
  • Initial distance from each Facility to the nearest

creek(s), with reach also identified Denote Franks Ck (FC), Erdman Bk (EB), Quarry Ck (QC), Buttermilk Ck (BC), and Cattaraugus Ck (CC)

3

slide-4
SLIDE 4

West Valley Quarterly Public Meeting • February 2018

Modeled Layout of WMAs

4

Each Waste Management Area (WMA) has one or more Facilities and Decision Units

slide-5
SLIDE 5

West Valley Quarterly Public Meeting • February 2018

Implementing Erosion in the West Valley PPA Model

Stochastic

  • Rate of gully migration from each adjacent creek

reach (one or two creeks) towards each associated Facility (length/time) (the rate distribution could be the same for all Facilities or could be varied in space by creek or by reach)

  • Rate of hillslope failure migration from creek reaches

towards each Facility (length/time) (the rate distribution could be the same for all Facilities or could be varied in space by creek or by reach)

5

slide-6
SLIDE 6

West Valley Quarterly Public Meeting • February 2018

Using Historical Imagery to Inform Erosion Model

Lidar Data

  • Two different sets of LIDAR data from 2015 and 2010
  • Orthorectified aerial photograph paired with the 2015

LIDAR data (i.e., a map of near-survey quality) Historical Aerial Photographs

  • Multiple historical aerial photographs from 1939,

1955, 1961, 1965, 1977, 1984, 1989

6

slide-7
SLIDE 7

West Valley Quarterly Public Meeting • February 2018

Overview of Approach

  • 1. Use LIDAR and the orthorectified image to pick control points

to compare to the historical images (e.g., fence line intersections, road intersections, buildings, railroad bridges, etc.)

  • 2. Use control points to relate the historical images to the 2015

LIDAR data – results in orthorectified historical images

  • 3. Review original aerial images under a stereoscope (pairs at a

time allow a 3D view)

  • 4. Record estimated locations of erosion impacts (gully heads,

stream valley edge, trace a flow path, drainage area)

  • 5. These features are mapped to the 2015 orthophoto and

LIDAR data for comparison

  • 6. Compute differences in feature locations from historical aerial

images to 2015 data

7

slide-8
SLIDE 8

West Valley Quarterly Public Meeting • February 2018 8

Lidar Data

Lidar Data

  • Information
  • n both the

vegetation structure and ground is

  • btained
slide-9
SLIDE 9

West Valley Quarterly Public Meeting • February 2018

LIDAR Analysis

  • The 2015 lidar data are used as a baseline

for all comparisons of historical imagery

  • Current state of hillslopes is characterized
  • Reaches are established; gully head

locations are identified

9

slide-10
SLIDE 10

West Valley Quarterly Public Meeting • February 2018

Lidar Data on Features in 2015

  • Plateau boundary

is characterized for 2015

  • Different reaches

have been named

  • Do data support

different rates for different reaches?

10

slide-11
SLIDE 11

West Valley Quarterly Public Meeting • February 2018

Example LIDAR Analysis

  • 2015 lidar data are used for comparison with

2010 lidar data (Only looks at changes after 2010)

  • High spatial resolution but short time period
  • Multiple sites have been selected as areas
  • f focus

11

slide-12
SLIDE 12

West Valley Quarterly Public Meeting • February 2018 12

slide-13
SLIDE 13

West Valley Quarterly Public Meeting • February 2018 13

slide-14
SLIDE 14

West Valley Quarterly Public Meeting • February 2018

Example LIDAR Analysis

  • We can examine changes in the “Bigslide”

area that have occurred between 2010 and 2015

  • Difference in the height maps show changes

in the plateau boundary

  • This type of analysis is done at many areas

14

slide-15
SLIDE 15

West Valley Quarterly Public Meeting • February 2018 15

slide-16
SLIDE 16

West Valley Quarterly Public Meeting • February 2018 16

LIDAR Analysis

  • Distributional

analysis of the height differences (2015-2010)

  • Areas of erosion are

shown in red

  • Areas of deposition

are shown in blue

slide-17
SLIDE 17

West Valley Quarterly Public Meeting • February 2018 17

LIDAR Analysis cont.

  • Recent slope

movement after the 2009 slide event

  • Gradations in

landslide and deposition are clearly visible demonstrating viability of the approach

slide-18
SLIDE 18

West Valley Quarterly Public Meeting • February 2018

Using Historical Imagery to Inform Erosion Model

Objectives

  • Inform components of the erosion process

(i.e. gully erosion and hillslope failure) within a PPA model of the site using historical information

  • Quantify uncertainty associated with

measurements to characterize observable “signal to noise” ratio

18

slide-19
SLIDE 19

West Valley Quarterly Public Meeting • February 2018 19

slide-20
SLIDE 20

West Valley Quarterly Public Meeting • February 2018 20

slide-21
SLIDE 21

West Valley Quarterly Public Meeting • February 2018 21

2015 Lidar

slide-22
SLIDE 22

West Valley Quarterly Public Meeting • February 2018

Historical Aerial Photo Analysis

  • Points along features of

interest are identified and recorded in a coordinate reference system

  • Control point sources

include Orthophotography, 2015 LiDAR, and historical 7.5’ topographic quad sheets

22

slide-23
SLIDE 23

West Valley Quarterly Public Meeting • February 2018

Observing Differences

1.Control points and erosive features are

identified on the historical imagery

2.They are mapped back to the 2015 image

and control points are used to estimate errors

3.Gully retreat and hillslope failure are

quantified to inform the PPA

23

slide-24
SLIDE 24

West Valley Quarterly Public Meeting • February 2018

Buttermilk Creek West

24

1939 Boundary Estimate 1955 Boundary Estimate

2015 Lidar Plateau Boundary

slide-25
SLIDE 25

West Valley Quarterly Public Meeting • February 2018

Uncertainty Propagation

25

  • Estimates of gully heads from 2015 lidar are

very accurate

  • Estimates of gully heads from historical

imagery have quantified uncertainty

  • Uncertainty is estimated using multiple

control points that exist in both the historical imagery and the 2015 lidar data

slide-26
SLIDE 26

West Valley Quarterly Public Meeting • February 2018

Uncertainty Propagation

26

2015 lidar estimate of gully head location 1939 photo estimate of gully head location 1939 photo point estimate uncertainty Estimate of distance between 2015 gully head location and 1939 gully head location

slide-27
SLIDE 27

West Valley Quarterly Public Meeting • February 2018

Uncertainty Propagation

27

Randomly selected angle Distance randomly sampled from the 1939 uncertainty distribution 2015 lidar estimate of gully head location 1939 photo estimate of gully head location

slide-28
SLIDE 28

West Valley Quarterly Public Meeting • February 2018

Uncertainty Propagation

28

Estimate of distance with uncertainty 2015 lidar estimate of gully head location 1939 photo estimate of gully head location 1939 photo point estimate uncertainty

slide-29
SLIDE 29

West Valley Quarterly Public Meeting • February 2018

Preliminary Results

29

  • A subset of gullies have been analyzed for linear

retreat rates using the 1939 and 1955 images with 2015 Lidar as a baseline

  • A different distribution of uncertainty is

developed for each image that is compared to 2015

  • This is done using the measurement error

associated with the control points

slide-30
SLIDE 30

West Valley Quarterly Public Meeting • February 2018

Uncertainty Propagation

30

*Based on the current analysis and work is

  • ngoing
slide-31
SLIDE 31

West Valley Quarterly Public Meeting • February 2018

Next Steps

31

  • Complete the analysis of available historical

imagery (just 1939 and 1955 images so far)

  • Gully retreat and hillslope failure features
  • Complete corresponding analysis of control points

to refine uncertainty distribution

  • Develop context for other lines of evidence

including erosion modeling, work of the EWG, expert elicitation, and literature reviews to provide a comprehensive evaluation of retreat rates for gullies and hillslopes