CRWR-PrePro

Francisco “Paco” Olivera, Ph.D.Center for Research in Water Resources

University of Texas at Austin

Francisco Olivera1998 ESRI User ConferenceGIS Hydro 98 - Preconference SeminarCRWR-PreProJuly 26, 1998

The Team

Brian Adams Ximing Cai Aubrey Dugger Ferdinand Hellweger David Maidment Francisco Olivera Seann Reed

Overview

What is CRWR-PrePro?

Spatial Data

Input file fornon-GIS applications

CRWR-PrePro

What is CRWR-PrePro today?

Spatial Data

Basin file forHEC-HMS

Not all HMS optionsare included yet.

CRWR-PrePro

CRWR-PrePro Components

Watershed Characterization

Hydrologic Model Extraction

Model schematic andHEC-HMS basin file

What is HEC-HMS?

“It is a new generation software for precipitation-runoff simulation that supersedes the HEC-1 Flood Hydrograph Package.” HEC-HMS User’s Manual

It is a Windows version of HEC-1.

HEC-HMS Components

Control FileTime-related information

for a simulation

Precipitation File

Meteorological data

Basin FileParameter and

connectivity data for hydrologic elements

HEC-HMSSimulation

Previous Work

Watershed Delineator ArcView Extension

[ESRI-TNRCC]

Flood Flow Calculator

ArcView Extension[CRWR-TxDOT]

HECPREPRO ArcView Project

[CRWR-HEC]

CRWR-PreProArcView Project

[CRWR]

WatershedCharacterization

Watershed Characterization

Terrain Analysis

Stream-Watershed Delineation

Calculation of Hydrologic Parameters

WatershedCharacterization

Terrain Analysis

Terrain Analysis

Burn-In Streams[Grid]

Fill Sinks[Grid]

Flow Direction[Grid]

Flow Accumulation[Grid]

DEM[Grid]

DigitizedStream Network

[Line Coverage]

Hydrologic GIS Functions

Flow direction codes

1

248

16

32 64 128

71

56

445369

74

78 72 69 71

4768

58 55

21

31

67

58

49 46

37 38

64 22

61 16

Digital elevation model (DEM)

22

2 2 2

2

4 4

4 4

1 1 2 4 8

128

128 1 2 4

128 1 41

128

Flow direction grid

Stream NetworkFlow accumulation grid

0 0 0 0 0

0 1 1 2 1

0

0

0 0 0

3 8 5 2

1 1 20 0

1 24

Burn-In Streams

45

44

38

34

40

45

50

60

58

31

30

53

50

45

32

22

45

44

38

34

40

45

50

60

58

31

30

53

50

45

32

22

145

144

138

134

140

145

150

160

158

131

130

153

150

145

132

122

38

34

30

22

145

144

38

34

140

145

150

160

158

131

30

153

150

145

132

22

DEM creek Digitized creek

Digitized creek Raised DEM Burned-in DEM

DEM andDigitized Stream Network

Burned-In DEM

Elevation is increased by a fixed value in all DEM cells, except in those that coincide with the digitized stream network.

Flow Direction

Water flows to one of its neighbor cells according to the direction of the steepest descent.

Flow direction takes one out eight possible values.

Flow Accumulation

Flow accumulation is a measure of the drainage area in units of grid cells.

WatershedCharacterization

Stream-Watershed Delineation

Stream-Watershed Delineation

Stream NetworkDefinition

Watershed Delineation

Watershed OutletDefinition

Raster to VectorConversion

Stream Network Definition

AutomaticCells draining more area

than a user-defined threshold value.

InteractiveCells located downstream of

user-identified cells.

Stream Network[Grid]

Stream Network

All grid cells draining more than a user-defined threshold value (blue streams), or located downstream of user-defined cells (red streams) are part of the stream network.

Stream Segmentation

Stream segments (links) are the sections of a stream channel connecting two successive junctions, a junction and an outlet, or a junction and the drainage divide.

Watershed Outlet Definition

AutomaticMost downstream cells of

the stream segments

InteractiveUser-identified cells

[outlets, reservoirs, control points, etc.]

Watershed Outlets[Grid]

Watershed Outlets

The most downstream cells of the stream segments (brown cells), and the user-defined points (red dots) are the watershed outlets.

Modified Stream Segmentation

The interactively defined outlets modify the stream segmentation by subdividing the segment in which are located into two segments.

Watershed Delineation

Watershed Delineation

Watershed Outlets

Watershed Delineation

The drainage area of each watershed outlet (stream segment) is delineated.

Raster to Vector Conversion

WatershedVectorization

StreamVectorization

Merging of Watersheds

Dissolving SpuriousPolygons

Raster to Vector Conversion

Streams and watersheds are converted from raster to vector format.

Dissolving Spurious Polygons

Cells connected to the main watershed polygon through a corner are defined as a separate polygon (spurious polygon).

These polygons are dissolved into the main polygon.

Merging of Watersheds

Adjacent watershed polygons can be merged into a single polygon, if they share their outlet or one flows into the other.

Merging of Watersheds

The attribute tables are updated so that the watershed code (WshCode) of the streams is modified and the area of the new polygon is calculated.

WatershedCharacterization

Calculation of Hydrologic Parameters

Flow Length Downstreamto the Watershed Outlet

Flow Length Upstreamto the Watershed Divide

Longest Flow-Path

Watershed Lag-Time (SCS)

Flow length upstream and downstream

AverageCurve Number

Length and slope of the longest flow-

path

Identification of the longest flow-path

Lag-time

Watershed Lag-Time (SCS)

5.0

7.08.0w

p S67.31

]9)CN/1000[(Lt

tp: watershed lag-time (min)LW: length of longest flow-path (ft)CN: average Curve NumberS: slope of the longest flow-path (%)

Watershed Lag-Time (L/V)

Flow length upstream and downstream

Longest flow-path average velocity

Length of the longest flow-path

Lag-time

Watershed Lag-Time (L/V)

w

wp V60

L3048.06.0t

tp: watershed lag-time (min)Lw: length of longest flow-path (ft)Vw: longest flow-path average velocity (m/s)

Watershed Abstractions

Average Curve Number

SCS MethodInitial + Constant

Method

Initial Loss (mm)Constant Loss

(mm/hr)

Watershed Parameters

Stream Routing Method

Flow time (Ls/Vs)

Ls/Vs < t

MuskingumRouting

Ls/Vs > t

Pure LagRouting

Pure Lag Routing

s

slag V60

Lt

tlag: stream lag-time (min)Ls: length of longest flow-path (m)Vs: longest flow-path average velocity (m/s)

Muskingum Routing

s

s

V3600

LK

K: Muskingum K (hr)X: Muskingum XLs: length of longest flow-path (m)Vs: longest flow-path average velocity (m/s)n: number of sub-reaches

1t

V/LX2intn ss

Stream Parameters

Hydrologic Model Extraction

Hydrologic Model Extraction

Watersheds Polygons

Streams andsource streams

Shape Files of Watersheds and

Streams

Hydrologic Model Extraction

Hydrologic Model Extraction

Model Schematic and HEC-HMS

Basin File

Hydrologic Model

Connection to HEC-HMS

Model Schematic Parameter Transfer

HEC-HMS Basin File

ArcView Schematic

HEC-HMS Basin File (1)

HEC-HMS Basin File (2)

HEC-HMS Basin File (3)

HEC-HMS

Basin FileSystem Schematic

Basin FileWatershed Parameters

Basin FileWatershed Parameters

Basin FileStream Parameters

Precipitation File

Control File

Hydrograph Time Table

Hydrograph Summary

Hydrograph Plot

Where do we want to go?