Civil and Environmental Engineering Applications

Geospatial Database: a set of compatible data layers or themes

Relational Linkages

Spatial Attributes

Descriptive Attributes

Water RightLocations

Digital Elevation ModelDigital Elevation Model

Watershed DelineationWatershed Delineation

Raster-Vector Data Model

Raster

Vector

Real World

Map-Based Hydrology and Hydraulics

ArcViewInput Data

DEM

HEC-HMSFlood

discharge

HEC-RASWatersurfaceprofiles

ArcViewFlood

plain maps

CRWR-PrePro

Engineering Design

• Evaluate impact of building a dam– Determine elevation of spillway– Determine aerial extent of reservoir– Delineate contributing watershed– Generate 3D view of reservoir

• Givens– Approximate location of dam– Normal capacity of 50 Mm3 (40,500 acre-ft)– Flood capacity of 100 Mm3 (81,000 acre-ft)

Data Requirements

Elevation Data

1:24,000 DEM (Digital Elevation Model)

1:100,000 paper topographic map

DRG

1:24,000 DRG (Digital Raster Graphic)

Digital Elevation Model

Raster or grid data

Scale1:24,000 (30m)

Digital Raster Graphics

Raster dataScanned topographic map

Scale1:24,000 (30m)

Separate Up/Downgradient

Location of Dam

• Draw polygon to remove area downgradient of dam

• Limits volume calculation to reservoir area

Vector Data

• Used to represent discrete objects

• Point data - monuments, cities

• Line data - roads, rivers

• Vector data - boundaries, soil type

• Composed of distinct nodes & vertices

Generate TIN

TIN - Triangular Irregular Network

•Stores elevations, or other continuous

data, by creating triangles in 3D space

•More efficient data storage

•Estimate volume for cut and fill operations

Separate Up/Downgradient

• Creates two TINs

• Upgradient TIN can be used to determine dam elevation

Determine Dam Elevation

Surface - Area and Volume Statistics

• Elevation

• Area above or below

Dam Elevation

Elevation Volume Area ft m3 m2

224 50,656,491 12,117,735

227.1 100,777.495 18,487,230

Elevations determined by trial and error

Generate Reservoir Image

Map AlgebraAllows user to alter grid data using mathematical tools

1

2 4

35

4

6 5+ =

If ( > 5, 1, 0) = 0

0

1 05

4

6 4

Generate Reservoir Image

If (Elevation < 224, 1, 0)Boolean Image

Generate Reservoir Image

If (Elevation < 227.1, 1, 0)Boolean Image

Normal vs Flood Stage

Estimated reservoirs

can be compared

relative to each

other…..

Normal vs Flood Stage

… merged

with a DRG ...

Normal vs Flood Stage

… or compared

to the entire

watershed

Generating 3D Image

Surface Elevation2D View

3D Image

Vertical Exaggeration Factor = 5

3D Image

Vertical Exaggeration Factor = 5

3D Image

Vertical Exaggeration Factor = 5

GIS for Water QualityGIS for Water Quality

E. coliE. coli 394 cfu/100 mL394 cfu/100 mLNot-to-ExceedNot-to-Exceed

126 cfu/100 mL126 cfu/100 mLGeometric MeanGeometric Mean

400 cfu/100 mL400 cfu/100 mLNot-to-ExceedNot-to-Exceed

200 cfu/100 mL200 cfu/100 mLGeometric MeanGeometric MeanFecal Fecal coliform coliform

Buffalo and Whiteoak BayousBuffalo and Whiteoak Bayous

Landuse in Buffalo and Whiteoak Landuse in Buffalo and Whiteoak BayousBayous

WWTP SamplingWWTP Sampling

Sampled WWTPSampled WWTP

Storm Sewer SamplingStorm Sewer Sampling

EC (MPN/100 mL)0-394

> 394

““Computing is not about computers any more.Computing is not about computers any more.It is about livingIt is about living.”.”

Nicholas Negroponte, Founding Director of Nicholas Negroponte, Founding Director of MIT’s Media Lab. MIT’s Media Lab. Being DigitalBeing Digital (1995), p. 6. (1995), p. 6.