[PPT] - Groundwater Management in Asian Coastal Cities: A proposal for PowerPoint Presentation

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Asian Science and Technology Seminar (ASTS) in Thailand March 11, 2008, Swisshotel Nai Lert Park, Bangkok

Dr. Mukand S. Babel

Water Engineering and Management, AIT

Groundwater Management in Asian Coastal Cities: A proposal for climate change impact and adaptation study

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Mukand S. Babel

AIT. March 2008

Presentation Outline

Introduction Coastal aquifer issues

Research studies at AIT Other studies in Asia

Potential impacts of climate change

n coastal aquifers

Proposed research Next steps

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Mukand S. Babel

AIT. March 2008

Introduction

Globally, groundwater provides

about 50% of current potable water supplies (serving nearly 2 billion people) 40% of self-supplied industries 20% of water use in irrigation

Asia and the Pacific: groundwater provides drinking water to nearly 32% of population Coastal aquifers: important source of water in coastal zones

Indian coast (7,000km): 2nd richest GW reservoir Coastal water supplies dependent on interaction between fresh and saltwater

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Mukand S. Babel

AIT. March 2008

Introduction

Urbanization, increase in population and water demand due to economic development put immense pressure on groundwater resources leading to undesirable consequences Groundwater use trends in Asia

Philippines: industrial and domestic use increase annually by 14% and 11.5%, resp. (1988-2001) HCMC, Vietnam: GW use steadily increases, 34% of total demand (2005) Tianjin, China: exploitation (1991-2002) has exceeded available in most districts

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Mukand S. Babel

AIT. March 2008

Introduction

Asian Cities (selected) Role of Groundwater Groundwater Problems Dhaka, Bangladesh Sole source Falling groundwater levels Tianjin, China Major source Land subsidence Nagpur, India Major source Pollution from urban area Jakarta, Indonesia Minor source Salinity intrusion Cebu City, Philippines Major source

Sal. Intrusion, Pollution (urban)

Jaffna, Sri Lanka Sole source

Sal. Intrusion, Pollution (urban)

Bangkok, Thailand Major source

Sal. Int., Poll. (urb), subsidence

Hat Yai, Thailand Minor source

Sal. Intrusion, Pollution (urban)

Hanoi, Vietnam Major source Pollution from urban area

Source: World Bank (1998). Groundwater in urban development.

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Mukand S. Babel

AIT. March 2008

Coastal Aquifer Issues

Major groundwater management issues in coastal aquifers

Decline of piezometric level Land subsidence Groundwater contamination (more especially salinity intrusion)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Past studies (selected)

1978-1981: Investigation of Land Subsidence 1978-1982: Groundwater Resources Development and Management Study 1987-1992: Simulation Study of the Bangkok Aquifer System

Most recent studies (selected)

2004-2007: Sustainable Groundwater Management in Bangkok (IGES) 2006-2007: Estimation of Safe Yield for the Bangkok Aquifer System

Current studies

2007-2008: Groundwater Quality Management Policy Research in Bangkok and Vicinity (IGES)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

10,300 km2 total area 10.6 million people (2003)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

8 aquifer layers Most of extraction from 3 aquifers at depths 100- 250 m (PD, NL, and NB Aquifers) Nonthaburi (NB) Aquifer:

ne of the most

productive, yielding up to 200 m3/hr of excellent quality water Deeper aquifers seldom used by domestic wells

550-m zone PN 8 Pak Nam Aq uife r 450-m zone T B 7 T honburi Aq uife r 350-m zone PT 6 Phaya T hai Aq uife r 300-m zone SK 5 Sam Khok Aq uife r 200-m zone NB 4 Nonthaburi Aq uife r 150-m zone NL 3 Nakhon L uang Aq uife r 100-m zone PD 2 Phra Pra da e ng Aq uife r 50-m zone BK 1 Bangkok Aq uife r Zone Code Aquife r 550-m zone PN 8 Pak Nam Aq uife r 450-m zone T B 7 T honburi Aq uife r 350-m zone PT 6 Phaya T hai Aq uife r 300-m zone SK 5 Sam Khok Aq uife r 200-m zone NB 4 Nonthaburi Aq uife r 150-m zone NL 3 Nakhon L uang Aq uife r 100-m zone PD 2 Phra Pra da e ng Aq uife r 50-m zone BK 1 Bangkok Aq uife r Zone Code Aquife r

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Gr

undwater

P umpage in Bangkok and Sur r

unding Ar

eas

500,000 1,000,000 1,500,000 2,000,000 2,500,000 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002

Year Pumpage (m

3/ d)

T

tal Pumpage

MWA Pumpage (Various Studies) MWA Pumpage (c olle c ted from MWA in 2004) MWA Pumpage (DMR, 1998) E stimated Private Pumpage (Various Studies) E stimated Private Pumpage (DMR, 1998) E stimated Private Pumpage (K asetsart U niv., 2004) E stimated Public Pumpage (K asetsart U niv., 2004) T

tal Pumpage (K

asetsart U niv., 2004)

Mid-1950’s: extensive use of GW started Continuous increase in GW use until 1997 According to DGR, in 2004: Total GW use = 2.2 MCM/d Private Pumpage = 1.8 MCM/d Private Users: largest groundwater users

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Decline of piezometric level

P hr a P r adaeng Aquifer

5 10 15 20 25 30 35

Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 Dec -91 Sep-94 Jun-97 Mar-00 Dec -02

Wate r L e ve l (m be low G.L .)

PD0055 B ang B authong, Nonthaburi PD0002 Muang, Samut Prakan PD0040 Minburi, B angkok PD0068 B ang Sai, Ayutthaya PD0059 L at L umkaew, Pathm T hani PD0053 Nakhon Chaisiri, Nakhon Pathom PD0018 K ra T humbaen, Samut Sakhon

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Decline of piezometric level

Nakhon L uang Aquife r

10 20 30 40 50 60 70 80

Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 De c -91 Se p-94 Jun-97 Mar-00 De c -02

Wate r L e ve l (m be low G.L .)

NL 0005 Bang Bautho ng , No nthaburi NL 0055 Muang , Samut Prakan NL 0016 Minburi, Bang ko k NL 0012 Bang Sai, Ayutthaya NL 0071 L at L umkae w, Pathum T hani NL 0068 Nakho n Chaisiri, Nakho n Patho m NL 0032 K ra T humbae n, Samut Sakho n

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Decline of piezometric level

Nonthabur i Aquife r

10 20 30 40 50 60 70 80

Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 De c -91 Se p-94 Jun-97 Mar-00 De c -02

Wate r L e ve l (m be low G.L .)

NB0004 Bang Bautho ng , No nthaburi NB0049 Muang , Samut Prakan NB0046 Minburi, Bang ko k NB0069 Bang Sai, Ayutthaya NB0015 L at L umkae w, Pathum T hani NB0020 Nakho n Chaisiri, Nakho n Patho m NB0025 K ra T humbae n, Samut Sakho n Samut Sakho n Bang ko k

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Land subsidence

Land subsidence still

ccurring (~1.0 cm/yr in

most parts) Since 1978: Max. subsidence= ~1.0 m

bserved

1979-1981: Reached 5- 10 cm/yr in some areas Subsiding areas coincide with GW depression zones Surrounding areas at risk

L and Subside nc e in 2003 (So urc e : DGR)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Land subsidence

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Groundwater contamination

20 20 40 Kilometers

N E W S

Chloride levels (mg/L) in PD aquifer, 1990

Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 N D

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Mukand S. Babel

AIT. March 2008

20 20 40 Kilometers

N E W S

Chloride levels (mg/L) in PD aquifer, 1995

AIT Research in Bangkok Aquifer

Groundwater contamination

Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 N D

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Mukand S. Babel

AIT. March 2008

20 20 40 Kilometers

N E W S

Chloride levels (mg/L) in PD aquifer, 2005

AIT Research in Bangkok Aquifer

Groundwater contamination

Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 N D

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

1969: Land subsidence given public attention 1978: Enforced Groundwater Act, B.E. 2520 (1977); Start licensing for groundwater activities 1983: Critical Zone identified (4 provinces) 1984: Groundwater tariff of 1 Bt/m3 imposed (6 provinces) 1992: Groundwater Act amended 1994: Tariff increased to 3.5 Bt/m3 (6 provinces) 1995: All provinces must pay groundwater charge; Critical Zone expanded (7 provinces) 2000-’03: Tariff increased from 3.5 to 8.25 Bt/m3 (in Critical Zone) 2003: Groundwater Act amended 2004: Tariff increased to 8.5 Bt/m3 (Critical Zone); Groundwater Preservation Charge imposed in Critical Zone

Measures undertaken by the Government

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

T HB 17.00 T HB 8.50 T HB 8.50 T HB 3.50 T HB 1.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Jan-84 Jan-85 Jan-86 Jan-87 Jan-88 Jan-89 Jan-90 Jan-91 Jan-92 Jan-93 Jan-94 Jan-95 Jan-96 Jan-97 Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06

Date Charge (Bt/ m

3)

T

tal Gro undwate r Charg e

Gro undwate r Pre se rvatio n Charg e Gro undwate r U se Charge

T OT AL CHARGE

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

1. Lack of institutional thrust (Resulting in ineffective laws and

regulations)

Illegal wells still exist; Not all wells metered despite regulations
2. Inadequate inspection and budgetary constraints
3. Groundwater Database and Monitoring System not updated

and maintained

Monitoring well system does not cover all aquifers
4. Lack of alternative sources of water
Limits control of groundwater use and effectiveness of charges
5. Groundwater Development Fund
Difficult to use Fund by other stakeholders especially by academic

institutions, and even by DGR

6. Groundwater Preservation Charge
Imposed at a flat rate

Major Deficiencies Identified (2004-07 study)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Regulatory or Direct Control

Controlling illegal users of groundwater Controlling the use of water in industries Relocation of large groundwater users (ex. Industries) Allow some authority (existing or new) to extract groundwater and supply to customers

Economic Measures

Also charge agro-wells for groundwater use Modification of Groundwater Preservation Charge rates Further increase of groundwater use charges

Proposed Policy Options/Improvements (2004-07 study)

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Technical Measures

Conduct artificial recharge (ASR) Provision of alternative water sources

Supporting Measures

Updating/redefining the Critical Zones Improved monitoring of groundwater activities Demand-side management in domestic and industrial sectors, such as leakage management in pipe networks Amendment of the Groundwater Act or relevant regulations regarding the procedural changes in the use of the Groundwater Development Fund (GDF) Promote the sustainable use of groundwater instead of complete stoppage as well as the conjunctive use of groundwater and surface water Promotion of knowledge and public awareness on groundwater Establish regulations at national and local levels Build local capacities in managing groundwater

Proposed Policy Options / Improvements

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Mukand S. Babel

AIT. March 2008

AIT Research in Bangkok Aquifer

Objectives of the current study on GW quality

(2007-2008)

Collect background data and assess the extent of groundwater pollution (more particularly chloride contamination) in Bangkok aquifer system focusing

n the three aquifers: PD, NL, NB;

Collect and analyze the existing policies on groundwater quality management to determine their effectiveness and identifying gaps with respect to the current situation; Suggest options and/or policy measures to address the flaws in existing groundwater quality management

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Mukand S. Babel

AIT. March 2008

Other Studies in Asia

Decline of piezometric level

Manila, Philippines: groundwater abstraction has lowered the piezometric level by 2.4m per year HCMC, Vietnam: groundwater table declines down to 1.95m annually (1994-2003) Tianjin, China: water level has continually dropped in saltwater regions

Source: Agenda for Water Sector Strategy for North China. Ministry of Water Resources, World Bank and AUSAID, 2001 Difference between deep groundwater levels in 1958 and 1998 in the Hai Basin Plains in northern China

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Mukand S. Babel

AIT. March 2008

Other Studies in Asia

Land subsidence

Metro Manila, Philippines: subsidence ranges from 0.12 to 1.20 cm Tianjin, China: 7,300 km2 is affected, max subsidence at 3m (1959-1994)

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Mukand S. Babel

AIT. March 2008

Other Studies in Asia

Salinity intrusion

Andhra Pradesh, India: brackish groundwater have been observed Manila, Philippines: intrusion in aquifers reaching 5km inland, upconing of saline connate water; Cl levels in some parts exceeded 17,000mg/L HCMC, Vietnam: 2,359 damaged wells due to saltwater intrusion

S. Korea (west): 5% of wells

within 10km from coast with Chloride levels above standards

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Mukand S. Babel

AIT. March 2008

SEVERITY OF ISSUES WERE MAINLY DUE TO INCREASE IN GROUNDWATER EXTRACTION….

WHAT ABOUT THE IMPACTS OF CLIMATE CHANGE???

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Mukand S. Babel

AIT. March 2008

Climate Change Impacts

1. Potential impacts by changes in

temperature and precipitation

Changes in precipitation and evaporation

will influence recharge, including temporal changes

Increased evapotranspiration in semi-arid

and arid regions may lead to salinization

f shallow aquifers
Droughts result to declining water levels,

while increased rainfall intensity may lead to more runoff and less recharge

Reduced groundwater head caused by

lower rainfall will exacerbate the impacts

f sea level rise

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Mukand S. Babel

AIT. March 2008

Climate Change Impacts

1. Potential impacts by changes in temperature

and precipitation

Coastal aquifers in Peninsular India is expected to

lose 0.075-0.078% of fresh groundwater per year from 2000-2099 due to increased salinity

Increased extraction of groundwater (more

particularly in deep aquifers) as surface water becomes more unreliable

BUT, overexploitation of the deep aquifers will cause arsenic contamination in deep aquifers, e.g. in western Bangladesh

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Mukand S. Babel

AIT. March 2008

Climate Change Impacts

2. Potential impacts due to sea level rise

(globally, 2 to 3 mm/yr in the early 21st century)

Sea level rise leads to intrusion of saltwater into

fresh groundwater in coastal aquifers (India, China and Bangladesh are especially susceptible)

In two small, flat coral islands off the coast of India,

the thickness of freshwater lens was computed to decrease from 25m to 10m and from 36m to 28m for a sea level rise of only 0.1m

In Ho Chi Minh City, saltwater intrusion has been
bserved and is escalating
Tidal inflow into the Pasig River

(Philippines) contributes to high salinity of groundwater

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Mukand S. Babel

AIT. March 2008

Climate Change Impacts

AIT. March 2008

AIT. March 2008

Next Steps

Development of research partnership Development of concept paper and full proposal to be initiated by AIT (with inputs from this forum) Funding by donor agencies?? Research implementation (3-5 years)

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