Groundwater Management in Asian Coastal Cities: A proposal for climate change impact and adaptation study 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
Presentation Outline � Introduction � Coastal aquifer issues � Research studies at AIT � Other studies in Asia � Potential impacts of climate change on coastal aquifers � Proposed research � Next steps 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): 2 nd richest GW reservoir � Coastal water supplies dependent on interaction between fresh and saltwater 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 Mukand S. Babel AIT. March 2008
Introduction Asian Cities Role of Groundwater Problems Groundwater (selected) 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, Major source Sal. Intrusion, Pollution (urban) Philippines 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. 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) 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) Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � 10,300 km 2 total area � 10.6 million people (2003) 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: Aquife r Aquife r Code Code Zone Zone 1 Bangkok Aq uife r 1 Bangkok Aq uife r BK BK 50-m zone 50-m zone one of the most 2 Phra Pra da e ng Aq uife r 2 Phra Pra da e ng Aq uife r PD PD 100-m zone 100-m zone productive, yielding up to uang Aq uife r uang Aq uife r 3 Nakhon L 3 Nakhon L NL NL 150-m zone 150-m zone 200 m 3 /hr of excellent 4 Nonthaburi Aq uife r 4 Nonthaburi Aq uife r NB NB 200-m zone 200-m zone 5 Sam Khok Aq uife r 5 Sam Khok Aq uife r SK SK 300-m zone 300-m zone quality water hai Aq uife r hai Aq uife r 6 Phaya T 6 Phaya T PT PT 350-m zone 350-m zone � Deeper aquifers seldom honburi Aq uife r honburi Aq uife r 7 T 7 T T T B B 450-m zone 450-m zone used by domestic wells 8 Pak Nam Aq uife r 8 Pak Nam Aq uife r PN PN 550-m zone 550-m zone Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Mid-1950’s: extensive use of GW started Gr oundwater P umpage in Bangkok and Sur r ounding Ar eas 2,500,000 � Continuous increase T otal Pumpage MWA Pumpage (Various Studies) MWA Pumpage (c olle c ted from MWA in 2004) in GW use until 1997 MWA Pumpage (DMR, 1998) 2,000,000 E stimated Private Pumpage (Various Studies) E stimated Private Pumpage (DMR, 1998) � According to DGR, in E stimated Private Pumpage (K asetsart U niv., 2004) 3 / d) E stimated Public Pumpage (K asetsart U niv., 2004) 1,500,000 Pumpage (m T otal Pumpage (K asetsart U niv., 2004) 2004: � Total GW use = 1,000,000 2.2 MCM/d 500,000 � Private Pumpage = 1.8 MCM/d 0 1954 1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 Year � Private Users: largest groundwater users Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Decline of piezometric level P hr a P r adaeng Aquifer Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 Dec -91 Sep-94 Jun-97 Mar-00 Dec -02 0 PD0055 B ang B authong, Nonthaburi PD0002 Muang, Samut Prakan PD0040 Minburi, B angkok 5 PD0068 B ang Sai, Ayutthaya PD0059 L at L umkaew, Pathm T hani .) PD0053 Nakhon Chaisiri, Nakhon Pathom e ve l (m be low G.L 10 PD0018 K ra T humbaen, Samut Sakhon 15 20 25 L Wate r 30 35 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Decline of piezometric level Nakhon L uang Aquife r Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 De c -91 Se p-94 Jun-97 Mar-00 De c -02 0 10 .) 20 e ve l (m be low G.L 30 40 50 NL 0005 Bang Bautho ng , No nthaburi L 60 NL 0055 Muang , Samut Prakan Wate r NL 0016 Minburi, Bang ko k NL 0012 Bang Sai, Ayutthaya 70 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 80 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Decline of piezometric level Nonthabur i Aquife r Apr-78 Jan-81 Oc t-83 Jul-86 Apr-89 De c -91 Se p-94 Jun-97 Mar-00 De c -02 0 10 .) e ve l (m be low G.L 20 30 40 50 NB0004 Bang Bautho ng , No nthaburi Bang ko k NB0049 Muang , Samut Prakan L NB0046 Minburi, Bang ko k 60 Wate r NB0069 Bang Sai, Ayutthaya NB0015 L at L umkae w, Pathum T hani 70 NB0020 Nakho n Chaisiri, Nakho n Patho m Samut Sakho n NB0025 K ra T humbae n, Samut Sakho n 80 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Land subsidence � Land subsidence still occurring (~1.0 cm/yr in most parts) � Since 1978: Max. subsidence= ~1.0 m observed � 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) Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Land subsidence Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Groundwater contamination N W E S Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 N D 20 0 20 40 Kilometers Chloride levels (mg/L) in PD aquifer, 1990 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Groundwater contamination N W E S Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 N D 20 0 20 40 Kilometers Chloride levels (mg/L) in PD aquifer, 1995 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer � Groundwater contamination N W E S Chloride levels (mg/L) 0-250 250-600 600-1000 1000-3000 3000-5000 5000-10000 10000-20000 20 0 20 40 Kilometers N D Chloride levels (mg/L) in PD aquifer, 2005 Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer Measures undertaken by the Government � 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/m 3 imposed (6 provinces) � 1992: Groundwater Act amended � 1994: Tariff increased to 3.5 Bt/m 3 (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/m 3 (in Critical Zone) � 2003: Groundwater Act amended � 2004: Tariff increased to 8.5 Bt/m 3 (Critical Zone); Groundwater Preservation Charge imposed in Critical Zone Mukand S. Babel AIT. March 2008
AIT Research in Bangkok Aquifer 18 T HB 17.00 17 T o tal Gro undwate r Charg e 16 Gro undwate r Pre se rvatio n Charg e 15 T OT AL CHARGE 14 Gro undwate r U se Charge 13 3 ) 12 Charge (Bt/ m 11 10 T HB 8.50 T HB 8.50 9 8 7 6 5 4 T HB 3.50 3 2 T HB 1.00 1 0 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 Mukand S. Babel AIT. March 2008
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