The Influence of Urban Development Density on Water

Pollution

The Influence of Urban Development Density on Water

Pollution

Kyushik Oh and Dong woo Lee

Department of Urban Planning

Hanyang University, Korea

IntroductionIntroduction

◈ Occurrence of many kinds of Environmental problems by urban developments

◈ Need for comprehensive water quality management approach such as Total Maximum Daily Load Program (TMDL)

◈ Need for Cumulative impacts for SEA (Strategic Environmental Assessment)

Analyzing the pattern of cumulative impacts

on water pollution caused by urban developments

Using in the decision making of urban planning

Assistance in the enforcement of SEA of EIA

Objective

Concept of cumulative impactsConcept of cumulative impacts

◈ Result of interactions between incremental developments projects in space and time periods

Exceeding an environmental carrying capacity

Occurrence of serious environmental problems

YongIn

BunDang

The study area and methodsThe study area and methods

◈ Study area■ The upper reaches of the Tancheon watershed area

◈ Remote sensed data on study area

Before development (1985) After development (2003)

Comparison of the increase of BOD intensity with the increase of urban developments

Identification of patterns of water pollution

Analysis of rainfall data

Rainfall data

Pollution intensity for seasons

Water qualitydata

◈ Methods

Urban developmentsincrease

Urban Developments Factor

Urban area Population

Employee

…

◈ Sub-basins and water quality observation points

Legend

0

20

40

60

80

100

120

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003(Year)

(%) WQOP1,2

WQOP3

ResultResult

The diffusion of a sewerage

Urban area Population

Employees

0

5

10

15

20

25

30

35

40

45

50

1900 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Urb

an a

rea(

)㎢

WQOP 1WQOP 2WQOP 3urbandevelop-ment

0

100

200

300

400

500

600

700

800

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

(Year)

(Per

son:

100

0)

WQOP1WQOP2WQOP3

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

1996 1997 1998 1999 2000 2001 2002 2003

(Year)

Em

ploy

ees

WQOP1WQOP2WQOP3

◈ Results of hierarchical cluster analysis on rainfall■ Dry season: January-May, October-December■ Wet season: June-September

◈ Changes of BOD intensity

Dry season

Wet season

0

5

10

15

20

25

30

35

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

(Year)

BO

D (

mg/

ℓ)

WQOP 1WQOP 2WQOP 3

0.00

5.00

10.00

15.00

20.00

25.00

30.00

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003(year)

BOD

(mg/

ℓ)

WQOP 1WQOP 2WQOP 3

Patterns of water pollutionPatterns of water pollution

0

5

10

15

20

25

30

2 5 8 11 14 17 20

Urban area ( )㎢

BO

D(m

g/ℓ

)

The increase ofBOD intensity

0

5

10

15

20

25

30

35

2 4 6 8 10 12

Urban area ( )㎢

BO

D(m

g/ℓ

)

The increase ofBOD intensity

0

5

10

15

20

25

30

35

0 50 100 150 200

Person(1000)

BO

D(m

g/L)

The increase ofBOD intensity

0

5

10

15

20

25

30

0 50 100 150 200 250

Person(1000)

BO

D(m

g/L)

The increase ofBOD intensity

WQOP1 WQOP2

Urbanarea

Popu-lation

0

5

10

15

20

25

30

35

1000 2000 3000 4000

Employees

BO

D(m

g/L)

The increase ofBOD intensity

0

5

10

15

20

25

30

1000 2000 3000 4000 5000 6000

Employees

BO

D(m

g/L)

The increase ofBOD intensity

WQOP1 WQOP2

Employee

Water pollution is getting more serious by urban developments

Variablelinear logic Exponential

Function

R2 Function

R2 Function

R2

Variation of urban

area

WQOP1

y = 3.606x - 15.186

 0.704y =

22.09Ln(x) - 31.434

0.5537y =

1.4681e0.2

576x

ExponentialR2 =

0.8381

WQOP2

y = 1.2839x -

3.64060.6927

y = 11.121Ln(

x) - 14.589

0.5476y =

2.6509e0.1

096x

 0.8254

Variation of

population

WQOP1

y = 0.2102x -

4.70310.9223

y = 16.608Ln(

x) - 58.873

0.8115y =

3.2312e0.0

146x

 0.9711

WQOP2

y = 0.1206x + 0.4958

0.9247y =

8.071Ln(x) - 22.762

0.7084y =

3.9593e0.0

098x

 0.9387

Variation of

business

WQOP1

y = 0.0125x -

19.0550.8228

y = 31.427Ln(

x) - 232.81

0.7682y =

1.205e0.000

9x

0.9105

WQOP2

y = 0.0075x -

12.5850.9421

y = 26.128Ln(

x) - 198.77

0.9178y =

1.7951e0.0

005x

0.9487

◈ Patterns of water pollution

ConclusionsConclusions

◈ Results■ Observing cumulative impacts occurred as a result of urban

developments■ Demonstrating the need for considering cumulative impacts for an

effective water quality management

◈ Limitations■ Insufficient water quality observation data■ Considering urban developments as only sources of cumulative impacts

Cumulative Impacts of Urban Developments on Water Pollution

Cumulative Impacts of Urban Developments on Water Pollution

Kyushik Oh and Dong woo Lee

Department of Urban Planning

Hanyang University, Korea