hong-tea kim 2015. 9. 16. review for rainfall-runoff model in watershed building data for watershed...

Open Source GIS-based Geomorphohydrological Water-shed Model and it`s Application to Flash Flood Prediction in

Ungaged Basins

Hong-Tea Kim

2015. 9. 16

CONTENTS

1.Overview

2.Development of Geomorpho-hydrological Watershed

Model and Flash Flood Prediction Model

3.Development Directions Using GIS in the Future

03

01. Overview

Background

Advance of Geomorpho-hydrological aspects ⇒ Runoff characteristics analysis through analyzed topographical data by GIS technique

In many studies the runoff characteristics with geomorpho-hydrological unit hydrograph method had been analyzed, but the rainfall-runoff simulation system that developed using geomorpho-hydrological method lacks

Characteristics of flash flood at the mountain river basin : Causes a lot of damages of human life in a short amount of time

⇒ Needs to be linked to the flood prediction and warning system of large river or build up flash flood prediction model of mountain river and prediction and warning system

In order to predict the flash flood at the mountain river, an automatic rain gauge and waring device are installed and being operated, but enough grounds for warning criteria for watersheds is no

04

01. Overview

Objective

GCUH is the one of the well known geomorpho-hydrological unit hydrograph methods. This method had been applied to sub-basin and mid-basin in order to figure out the characteristics of the rainfall-runoff ⇒ Try to apply geomorph-hydrological unit hydrograph method on the ungauged

mountain basin through a system development (Development of G2WMS model)

By using G2WMS model and GCUH formula, flash flood prediction model and prediction-warning system apply and build up at the mountain basin ⇒ Trying to suggest a proper estimate method for the ungauged mountain basin

(Development of F2PUB model)

Develop K-GCUH formula through a topography similarity process of the Korea mountain basin ⇒ By excluding the complicated GCUH parameters , a geomorph-hydrological unit

hydrograph can be estimated only using watershed area and river length data

05

01. Overview

Procedures for research

Review for rainfall-runoff model in watershedBuilding data for

watershed and hydrological data

Review of unit hydrograph method

Whether or not of flood routing method- hydrological data: B1,B2

Runoff review by flood event types- hydrological data: B2

Examples of applied GCUH theory

Fractal analysis and K-GCUH formula

Flash flood prediction and warning system construction for mountain basin

Design flood estimation and analysis

Existing report, Matrix method

Study area: Andong-DamHydrological data(B1): data for actual unit hydrographHydrological data(B2): long and short-term rainfall data for rainfall-runoff simulation

Channel: Muskingum-Cunge, reservoir: modified-Puls method

Topography and fractal analysisfor mountain basin

K-GCUH formula derivation

The basin mean precipitation : using kriging method The basin mean precipitation : using kriging method

GCUH, Clark, Snyder, SCS method

Actual unit hydrographhydrological data: B1, B2

Unit hydrological method, Flood routing method

Unit hydrological method: Clark, linear GCUH, non-linear GCUH

Flood routing method: Clark, linear GCUH, non-linear GCUH

Unit hydrological method: rainfall+Clark, linear GCUH, non-linear GCUH

Flood routing: rainfall+ Clark, linear GCUH,non-linear GCUH+flood routing

case-1

obs-1

case-2

case-3

app-1

app-2

app-3

Case-2.1

Case-2.2

Case-3.1

Case-3.2

Building GIS and watershed data of study area

Hydrological data collection and arrangement

06

01. Overview

Research trend

Hydrological model research for Flash Flood Carry out an improvement research of the rainfall-runoff model about the sub-basin and mid-basin

Research on the geomorph-hydrological unit hydrograph method and flood routing about the ungauged

mountain basin is insufficient

Geomorph-hydrology related research Perform part of the feature analysis of the geomorphological hydrological factors

Insufficient review on the interrelationship between the geomorphological characteristic and geomor-

phological hydrological factors of the mountain basin of Korea

Insufficient development of geomorpho-hydrological unit hydrograph which can be applied to the

mountain basin of Korea

Flash flood related research Research result of Carpenter etc.(1999) had been applied for the standard calculation of the flash flood

warning trigger rainfall

Research result of the unit hydrograph method is usually applied to calculate the flood discharge of the

flash flood event

07

01. Overview

Background utilizing an open source GIS

Usability Cost reduction by using free offer

Can be used in various operating system(OS)

Programs can be revised easily

New and various functions can be used through continuous updats

Use of the this study Estimation of topographical factors

- dividing watershed map, DEM, stream-network, Horton order etc.

Estimation of hydrologic variables

- branching ratio, extension ratio, area ratio, channel slope, channel length etc.

Version QGIS 2.10 ‘Pisa’

08

OutlineData collection

(weather, topography, hydrology etc.)

Development of geomorpho-hydrological wathershed model and flash

flood prediction model(G2WMS and F2PUB)

Flash flood prediction of ungauged watershed

F2PUB development

Development of G2WMS model

K-GCUH formula derivation

Review and application for G2WMS and F2PUB

K-GCUH

G2WMS

F2PUB

Model development Develop GIS based geomorpho-hydrological watershed model in order to use the geomorpho-hydrolog-

ical unit hydrograph to the ungauged mountain basin(G2WMS)

Developement of Korea geomorpho-hydrological unit hydrograph reflected Korea geomorphological

characteristic(K-GCUH)

Development of the flash flood prediction-warning system of the ungauged watershed linked K-GCUH

and G2WMS(F2PUB)

02. Development of Geomorpho-hydrological Watershed Model and Flash Flood Prediction Model

09

Study area and data collection

Study area K-GCUH & G2WMS : Andong-Dam watershed

F2PUB : Sogeum-stream watershed in Odae mountain

Data of Andong-Dam watershed (Hydrological data) Data status of rain gauge stations

Division No. Station name Data period

Rainfall

1 Poongsan 1987~2003

2 Euichon 1987~2003

3 Gosun 1987~2003

4 Yeongyang 1987~2003

5 Andong 1983~2003

6 Bonghwa 1988~2003

Water-level(Discharge)

7 Andong-Dam 1995~2003

8 Dosan 1984~2003

9 Socheon 1985~2003

Flood events for unit hydrograph and rainfall-runoffFlood event Period

Duration day

Runoff ra-tio Note

e1 89/07/22~08/08 18 0.72

e2 90/09/08~09/17 10 0.88

e3 99/07/31~08/15 16 0.88

e4 00/09/06~09/24 19 0.75

e5 02/08/30~08/16 18 0.75 Long-term multiplex rainfall

e6 02/08/30~09/04 6 0.85 Short-term single rainfall

e7 03/09/11~09/16 6 0.79 Short-term double rainfall

< e1 > < e2 > < e3 > < e4 >

< e7 >< e6 >< e5 >


010


Generation of topographical data using QGIS (Andong-Dam watershed)

DEM & Rainfall·Water-level Station Subbasin classify

Soilmap Land-use


011


Data of Andong-Dam watershed (topographical data)

w1

w2

w3

R1

R2

DEM Sub-basin

Soilmap Landuse Mimic

Sub-basin No.

Area(km2)

RiverLength(km)

Ave.slope(m/m)

Altitude Diff.(m)

Lca

(km)

CNBranching

ratio(RB)

Extensionratio(RL)

Arearatio(RA)

Main ch.length

(LΩ,km)

Main ch.slope

(SΩ, m/m)

Area for main ch.(AΩ, km2)

Rough-ness(n)

Ave. width of main ch.(bΩ, m)AMC-Ⅱ AMC-Ⅲ

w1 649.05 65.1 0.020 1304 - 65 81 4.204 2.647 4.754 46.790 0.005 634.16 0.04 241

w2 508.90 47.7 0.024 1157 - 64 80 3.501 2.073 3.942 20.670 0.003 511.16 0.03 205

w3 423.59 51.1 0.014 726 - 65 81 3.373 1.932 3.731 22.229 0.002 430.29 0.025 180

Sum 1590.85 171.6 0.0085 1453 71.961 65 81 4.116 2.511 4.526 66.880 0.070 1590.85 0.027 481

Watershed characteristics and GCUH parameters

SeparationFlood wave Velocity ratio

(Vw/V)

Ave. width(B, m)

Channel length(L, m)

Channel slope(S, m/m)

Roughness(n)

Side gradient(xH:1V)

Cross section shape

R1 1.6 180 121642 0.001 0.04 0 1 1: rectangle2: trapezoid3: triangleR2 1.4 600 49946 0.0014 0.03 0 1

Input data for Muskingum-Cunge routing


012


Data of Sogeum-stream in Odae mountain

RiverLength(km)

CNBranching

ratio(RB)

Extensionratio(RL)

Arearatio(RA)

Main ch.length

(LΩ,km)

Main ch.slope

(SΩ, m/m)


Rough-ness(n)

Ave. width of main ch.(bΩ, m)AMC-Ⅱ AMC-Ⅲ

8.8 85 93 4.487 2.091 3.201 3.164 0.112 24.871 0.078 24

Basin Area(A, km2)

Length(L, m)

Altitude Diff.(H, m)

Ave. slope(S, H/L)

Sogeumgang 24.871 8800 1114 0.127

Watershed characteristics

Station nameTM coordinate Longitude and latitude coordinate

X coordinate Y coordinate Longitude Latitude

No. 1 rain gauge 344409.810 476710.240 128˚38´33˝ 37˚46´40˝

No. 2 rain gauge 348594.470 475819.060 128˚42´14˝ 37˚46´04˝

Installation coordinate of automatic rain gauge

K-GCUH parameters


013

Korea geomorpho-hydrological unit hydrograph development

Derivation procedures of geomorpho-hydrological unit hydrograph

K-GIUH derivation

Watershed area is less than 50km2

Watershed area is more than 50km2

𝑄𝑃=1.101

𝐿Ω0.769 𝑉 𝑡𝑃=

0.47𝐿Ω0.796

𝑉𝐴Ω0.0011 𝑉

𝑄𝑃=0.968 𝐴Ω

0.138

𝐿Ω 𝑉 𝑡𝑃=

0.535𝐿Ω

𝑉𝐴Ω0.122 𝑉

K-GCIUH derivation

Watershed area is less than 50km2

Watershed area is more than 50km2

𝑄𝑃=0.195𝑖𝑟 𝐴Ω

0.38𝑆Ω0.75

𝑛1.5 𝐿Ω1.962 𝑉 3.519

𝑄𝑃=0.145𝑖𝑟 𝐴Ω

0.702𝑆Ω0.75

𝑛1.5 𝐿Ω2.5 𝑉 𝑡𝑃=2.608

𝑛1.5 𝐿Ω1.962

𝑖𝑟 𝐴Ω0.38𝑆0.75

Existing geomorpho-hydrological unit hy-

drograph

GIUHGCIUH

GCUH

Horton order interaction formula

Watershed area, A ＜ 50 km2 ⇒

Horton order(RB, RL, RA) = f (A,L)

Watershed area, A ≥ 50 km2 ⇒

Horton order(RB, RL, RA) = f (A,L)

Average width(bΩ) equation

bΩ = 2.9772 × A0.620

K-GIUH, K-GCIUH, K-GCUH (50KM2under, 50KM2 over)

K-GCIUH 유도

Watershed area is less than 50km2 Watershed area is more than 50km2

𝑄𝑃=1.734𝑖𝑟

1.4 𝐴Ω0.575𝑆Ω

0.2 𝑡𝑟𝑛𝐿Ω

0.785 (1− 0.121𝑖𝑟

0.4 𝐴Ω0.07 𝑆Ω

0.2 𝑡𝑟𝑛𝐿Ω

0.785 )+0.75

𝑄𝑃=1.538𝑖𝑟

1.4 𝐴Ω0.575𝑆Ω

0.2𝑡 𝑟𝑛𝐿Ω

0.872 (1− 0.121𝑖𝑟

0.4 𝐴Ω0.07𝑆Ω

0.2𝑡 𝑟𝑛𝐿Ω

0.872 )+0.75


014

GIS-based geomorpho-hydrological watershed model(G2WMS) development

G2WMS model structure

w1

w4

w3

w2

J 1

J 2

RS

J 3

R1

R2

RS1RS

w1

w2

w3

w4

하도

하도

저수지

category Estimation method Note

GCUH parameter andTopographical variables Using GIS program w1, w2, w3, w4

Watershed runoff K-GCUH, GCUH, Clark, Snyder, SCS method w1, w2, w3, w4

Floodrouting

Channelrouting

Muskingum, Muskingum-cunge R1, R2

Reservoir rout-ing Puls, Modified-Puls RS1

Estimation method for categories

Flow chart of G2WMS modelStart

Simulation condition

Topographical variables data entry

Estimation of GCUH parameters

Rainfall data entry

Estimation of effective discharge

Runoff hydrographs for watersheds

GCUH K-GCUH Clark Snyder SCS

Synthesis of runoff hydrograph and base-flow

Base-flow estimation

Input data for G2WMS simulation

Runoff hydrograph estimation in outlet

For i=1:niter if SS=CRChannel routing (Muskingum, Muskingum-Cunge) Elseif SS=RR Reservoir routing(Puls, modified-Puls) Elseif SS=HM Synthesis of runoff hydrograph EndEnd

End

- Result derivation- Save a file

channel

channel

reservoir

< G2WMS mimic >


015


Unit hydrograph compararison by durations

< GCUH > < Clark > < Snyder > < SCS >

Comparison of actual representative unit hydrograph

Actual representa-tive unit hydrograph

GCUH unit hydro-graph

Clark unit hydro-graph

Snyder unit hydro-graph

SCS unit hydro-graph

Timd of concen-tration(TP, hr)

Peakdis-

charge(QP)

m3/sec


Peakdis-

charge(QP)

m3/sec


Peakdis-

charge(QP)

m3/sec


Peakdis-

charge(QP)

m3/sec


Peakdis-

charge(QP)

m3/sec

12.0 20.5 11.5 20.8 13.0 21.4 15.3 20.5 15.9 20.8

Peak discharge and time of concentration for unit hydrographs

< Comparison of unit hydrographs >


Actual unit hydrograph

Non-dimension unit hydro-

graph

GCUH

Clark

Snyder

SCS

016


Comparison result of the unit hydrograph Estimation method of input variables of GCUH are intricate than other unit hydrograph methods and

has many topographical variables

But it can be simplified through the GIS technique and programmings

Peak discharge and time of concentration of the ungauged mountain basin can be efficiently calculated

Estimation methodsAssessment category GCUH Clark Snyder SCS

Ungauged mountain basin appli-cability good good common common

GIS technique applicability good common common common

Optimization process simple complexity common common

Rainfall proportion non-linear linear linear linear

Estimation method ofinput variables complexity simple simple simple

Hydrograph type triangle time-area curve curve SCS dimensionless curve

Considering of topographical vari-ables lot common few few

Adjustment parameter - Storage coefficient Watershed characteristic and storage coefficient Lag time

< Strength and weakness of unit hydrographs >


017

GIS-based geomorpho-hydrological watershed model(G2WMS) application

Actual flood event Rainfall-runoff simulation using actual precipitation data at singe and divide watershed

Single watershed : comparison of Clark, linear GCUH, non-linear GCUH unit hydrograph result

Divide watershed : comparison of Clark, linear GCUH, non-linear GCUH unit hydrograph and Muskingum-Cunge routing result

< e1 >

Clark (single watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >

Correlation : 0.81 Correlation : 0.69 Correlation : 0.76 Correlation : 0.76

Correlation : 0.79 Correlation : 0.79 Correlation : 0.78


018


< e1 >

GCUH linear (single watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >




019


< e1 >

GCUH non-linear (single watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >




020


< e1 >

Clark (divide watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >




021


< e1 >

GCUH linear (divide watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >




022


< e1 >

GCUH non-linear (divide watershed)

< e2 > < e3 > < e4 >

< e5 > < e6 > < e7 >




023

Design flood estimation

Input data and mimic of study area

w1

w2

w3

R1

R2

Mimic

< G2WMS mimic of Andong-dam watershed>

Sub-basin

RiverLengt

h(km)

Main ch.

length(LΩ,km)

Main ch.slope

(SΩ, m/m)


Rough-ness(n)

Ave. width of main ch.(bΩ, m)

CN

W1 65.1 46.79 0.005 634.16 0.04 241 85

W2 47.7 20.67 0.003 511.16 0.03 205 85

W3 51.1 22.229 0.002 430.29 0.025 180 85

< Input data of K-GCUH unit hydrograph for Estimation of Runoff in Watershed >

5HC 1 0 0 0 0KK H1CR H1Muskingum-Cunge 1.6 180 121642 0.001 0.04 0 1KK C1HM C1 NaN NaN NaN NaN 2 0 0 0 0KK H12CR H12Muskingum-Cunge 1.4 600 49946 0.0014 0.03 0.1KK C12HM C12 NaN NaN NaN NaN 3 0 0 0 0KK H123ZZ

< Input data of G2WMS model >


024

Design flood estimation procedure and result comparison

< Design flood estimation procedure >

Classify LocationArea of

watershed(km2)

Flood discharge frequency (m3/sec)

Note50 yr. 80 yr. 100

yr.200 yr.

Nakdong-river flood

plan(2004)

Before joining Banbyeoncheon 1628 2350 2562 2713 3014 HEC-

HMS

Result of this study Andong-dam 1591 2420 2752 2879 3379 G2WMS

< Compare of design flood discharge frequencies for Andong-dam watershed (48 hours) >

Collection of geomorphological and hydrological data

Probability precipitation estimation for duration-frequencies in rainfall point

Mean areal rainfall estimation

Time distribution of rainfall data

Initial and base-flow estimation

Base flood discharge estimation using rainfall-runoff model

Design flood discharge estimation

Critical duration decision

Design flood decision 결정


025

Flash flood prediction model(F2PUB) development

Flash flood prediction-warning system of the ungauged watershed was develop by linking to G2WMS

Flash flood warning trigger rainfall of the watershed can be calculated Flash flood warning trigger rainfall estimation procedure

CN calculation by landuse and soilmap

Construction of Kriging System

Grid weights calculation for each point

Areal average rainfall calculation of rainfall

data by durations

Watershed division

Design of Thiessen polygon

Thiessen rates calculation for each point

Areal average rainfall calculation of rainfall

data by durations

Watershed division

Decision of duration

Critical depth decision(Yb) of outlet cross-section

Critical discharge(Qd) of outlet cross-section

Calculation of effective rainfall using K-GCUH (QP= Qd)

Calculation of total rainfall(Rt) by SCS method

Decision of rainfall duration

Decision of warning criteriaAreal average rainfall(Ravg) > warning

criteria rainfall(Rt)

Warning

Duration : 10, 20, 30,…,120 min

0.5, 0.7, 1.0 m

- Assuming a rectangular section- Manning’s formula

𝑅𝑒=(𝑅𝑡− 𝐼𝑎)

2

(𝑅𝑡− 𝐼𝑎)+𝑆

Kriging System

Thiessen Polygon method

Warning criteria system


026

Flash flood prediction model(F2PUB) application

Calculation result of the flash flood warning trigger rainfall

When an initial loss(Ia) is 0, critical depth(d) of 0.5m’s critical discharge(Qd) is 17.07m3/sec

Time(min)

Effective dischargeReffective

(mm)

Critical rainfallRT(mm), d=0.5m



Ia=0.2S Ia=0.1S Ia=0 Ia=0 Ia=0

10 2.47 12.17 10.22 8.27 8.74 9.26

20 3.07 13.32 11.37 9.42 9.97 10.58

30 3.52 14.12 12.17 10.22 10.82 11.51

40 3.89 14.76 12.81 10.87 11.52 12.26

50 4.22 15.32 13.37 11.42 12.12 12.91

60 4.53 15.82 13.87 11.92 12.66 13.50

70 4.81 16.28 14.33 12.39 13.16 14.05

80 5.09 16.72 14.77 12.82 13.64 14.58

90 5.36 17.14 15.19 13.24 14.10 15.08

100 5.62 17.54 15.59 13.64 14.54 15.58

110 5.88 17.94 15.99 14.04 14.98 16.06

120 6.14 18.33 16.38 14.43 15.41 16.55

Qd

(m3/sec)17.07 19.40 22.22

Note Warning Evacuation warning 1 Evacuation warning 2

< Dangerous flow rate based on duration time at the Sogeum-stream watershed >


027

Flash flood prediction model(F2PUB) application

Flash flood prediction-warning procedure

Watershed division Warning Existing plan

Improvement plan Content Note

Sogeum-stream basin

warning 4mm/10mim 9mm/20mimDuration 20 min, rainfall

causing water-depth of 0.5m 9.42

Evacuation warning

16mm/10mim 10mm/20mim

Duration 20 min, rainfall causing water-depth of 0.7m 9.97

Evacuation warning

28mm/10mim 11mm/20mim

Duration 20 min, rainfall causing water-depth of

1.0m10.58

reset 2mm/10mim -

< Warning criteria plan in Sogeum-stream basin (duration 20min) >

< Flash flood warning criteria and warning procedure >

RT=(0.32XP1+0.68XP2)

-RT : Total rainfall of duration 20 min

-P1 : Rainfall of duration 20 min in first rainfall gauge station

-P2 : Rainfall of duration 20 min in second rainfall gauge station

Total rainfall estima-tion

Warning(RT>9mm)

Warning : 9mm/20minEvacuation warning 1 : 10mm/20minEvacuation warning 2 : 11mm/20min

<1st warning station>

: warning

<2nd , 3rd warning> station: warning


028

Conclusion

Development of Korean geomorpho-hydrological unit hydrograph(K-GCUH)

Applicability review through comparison of peak discharge and actual hydrograph review

Build up GIS based watershed hydrological simulation system(G2WMS)

This system can be runoff simulation for divided watershed including the geomorphological watershed

runoff method that use K-GCUH, geomorpho-hydrological unit hydrograph, flood routing

Development of flash flood prediction system(F2PUB) Suggest warning criteria for flash flood about the ungauged watershed

Availability of three models By developing K-GCUH, simplify calculation progress from the preexisting complicated GCUH parame-

ters

Development of G2WMS : flood discharge can be calculate by applying geomorpho-hydrological unit hy-

drograph to the rainfall-runoff model

Development of F2PUB : can be a useful material for the flash flood prediction of the ungauged water-

shed


029

03. Development Directions using GIS in the Future

Through the plug-in development is

need for a easy and convenient use in other aspects

Definition and conversion automation for coordinate system

The automatic creation of river order such as Horton`s order etc.

The automation for a start point and end point information of river

The automation of watershed divide etc

Thank you!

hong-tea kim 2015. 9. 16. review for rainfall-runoff model in watershed building data for watershed...

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