Lower Triangle Watershed DEM to Prism Meshes using LaGriT

Tue Feb 13 14:47:58 2018
Project Directory: /scratch/sft/tam/IDEAS/East_River/Lower_Triangle

Steps for DEM to ATS Workflow:

INPUT DATA: Define and Process Input Data
SETUP: Define Spacing, Layers, and Boundaries
TOP SURFACE: Create Top surface triangulation and interpolate DEM
EXTRUDE INTO 3D: Generate Mesh Layers and stack into 3D Element mesh
MODEL SETUP: Write 3D Mesh and Boundary face sets to Exodus file.

2018 Mesh Versions (Using LaGriT Scripts)


All diretories include a compressed tar file with:
    prism_single_fs3.exo - single column with 3 facesets
    prism_fs6.exo - full mesh with 6 facesets (bottom,top,right,back,left,top layer outlet)
    prism_fs3.exo - full mesh with 3 facesets (bottom,top,sides)

Smooth 10m Triangulation

    Aug 13 lagrit_tri_10m_v1
    lagrit_tri_10m_v1/prism_fs6.exo nodes: 1309554 cells:  2171480   sm_10m_v1.tar.gz  (111M)  
    README file for V1 10m 

Smooth 25m Triangulation

    Aug 13 lagrit_tri_25m_v1
    lagrit_tri_25m_v1/prism_fs6.exo nodes: 284874  cells:  469935   sm_25m_v1.tar.gz  (23M)  
    README file for V1 25m 

Smooth 50m Triangulation

    Feb 12 lagrit_tri_50m_v1
    lagrit_tri_50m_v1/prism_fs6.exo nodes: 34596  cells:  55835  sm_50m_v1.tar.gz  (3.1M)  
    README file for V1 50m 

    Feb 12 lagrit_tri_50m_v2
    lagrit_tri_50m_v2/prism_fs6.exo nodes: 98022  cells:  178672  sm_50m_v2.tar.gz  (7.5M)  
    README file for V2 50m 

Gallery of All Mesh and DEM images

Input Data

Source Data From LBNL Zexuan Xu zexuanxu@lbl.gov
USGS 10 meter DEM product, not the Lidar DEM which has small differences
  USGS_DEM_LT10_XYZ.xyz     296173 points (original data)
  USGS_DEM_LT10_points.csv  148190 points (flip llcorner so tip is bottom and remove null values)

10m DEM connected into triangle surface cropped at boundary for interpolation of elevation values.
dem_tri_crop.inp 147920 nodes    294150 triangles

NAME     MIN               MAX              DIFFERENCE      
 xic     3.259128385E+05  3.311760044E+05   5.263165929E+03 
 yic     4.314867400E+06  4.320370711E+06   5.503310380E+03
 zic     2.759333252E+03  3.775072021E+03   1.015738770E+03

Lower Triangle DEM with NULLS removed
LaGriT Finite Element Mesh
Lines to define boundary regions
right, back, left

LaGriT Finite Element Mesh

V1 and V2 Vertical Spacing

V1 5 Layers single cell
LaGriT Finite Element Mesh
V2 5 Layers with multiple cells
LaGriT Finite Element Mesh
Material layers are ordered from top = 1 to bottom = 5.
Each layer is 1 cell thickness (thickness = dz).

Layer 1: dz = 0.1,  sublayers = 0
Layer 2: dz = 0.3,  sublayers = 0
Layer 3: dz = 0.6,  sublayers = 0
Layer 4: dz = 8.0,  sublayers = 0
Layer 5: dz = 21.0, sublayers = 0
Total depth = 30 meters
Material layers are ordered from top = 1 to bottom = 5.

Layer 1: dz = 0.1,  sublayers = 0, cells 1
Layer 2: dz = 0.1,  sublayers = 2, cells 3
Layer 3: dz = 0.6,  sublayers = 0, cells 1
Layer 4: dz = 1.0,  sublayers = 7, cells 8
Layer 5: dz = 7.0,  sublayers = 2, cells 3
Total depth = 30 meters

Method Smooth Triangulation of Top Surface

This part of the workflow is being developed in TINerator python software using GIS and LaGriT.
For these grids, LaGriT was used starting with a boundary polygon at uniform spacing.
LaGriT is used to triangulate and smooth to edge lengths near target lengths 50, 25, and 10m.
Quality measurements include aratio (1=all angles equal), min edges, max edges.

Boundary polygon points provided by Daniel Livingston scripts:

50m boundary polygon
LaGriT Finite Element Mesh
Triangulate Polygon
LaGriT Finite Element Mesh
Smooth and Interpolate DEM elevations
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh

Stacked Mesh

Use LaGriT to create layers from the top triangulation by translating to depth.
Stack layers and add sublayers as indicated and connect into a prism mesh.
Write Exodus Mesh file with boundary faces (side sets).
Sets include faces on bottom=1, and top=2
Sides are defined as 3 (default)
For 6 sets: right=3, back=4, left=5, River faces at outlet and top layer =6

LaGriT Finite Element Mesh
Find Elevations below 2771
LaGriT Finite Element Mesh
fs 6 at outlet and top layer
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh
LaGriT Finite Element Mesh