Palm Plantations: Simulating the Impact on Leaf Area Index and Eventual River Flow (..A Work in Progress)

Soil & Water SWAT Assessment Tool

From Large-Scale Rubber Plantations to Oil Palm Plantations: Simulating the Impact on Leaf Area Index and Eventual River Flow (..a work in progress)

M. Rafee Majid Centre of Innovation & Planning Development (CIPD) Faculty of Built Environment Universiti Teknologi Malaysia Noradila Rusli Faculty of Built Environment Universiti Teknologi Malaysia Muar River Watershed Johor, Malaysia

Northern part of Muar River watershed Total Area: 2982.83 km2

Malaysia STUDY AREA STUDY East

Malaysia

Muar River THE ISSUE ..and magnitudes too. Increased ofFlooding Incidences 1984 1937 - –

1984 (45 years):(45 1984 flood/yr 0.31 2007 (23 years):(23 2007 floods/yr 1.08 Figure Figure : Flood occurrences in

a Muar a Muar River

Floods occur during Northeast Monsoon (Nov. – March) ..lately with devastating effects types of plants with different physiologies. ..different landcovers hosting different THE SUSPECT Succession of vastSuccession LU/LC changes ..from original forest (upto 1960s) to (upto rubber late70s) to oilpalm(starting1980s).

Oil Palm Malaysia(x10 000 hectare) Hectare Oil Palm Price(US Dollar pertonne) US Dollar 3500 Linear (Oil Palm Price(US Dollar pertonne)) 800

3000 700

600 2500 500 2000 400 1500 300 1000 200

500 100

1982 1997 1974 1975 1976 1977 1978 1979 1980 1981 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1998 1999 2000 Oil palm area vs. Oil palm price

Rubber price (1960-2000) Production of Total export Contribution to crude palm (Million Malaysia's economy oil tonne) (RM Billion) 2000 10.84 10.84 14.85 million tonne 2002 11.748 10.16 11.33 million tonne 2003 13.35 12.25 22.14 million tonne 2009 17.56 17.56 49.60 million tonne FOREST’s INTERCEPTION of RAINFALL..

• Only 10% of the rainfall reaches a stream as runoff.

• Tree leaves, twigs, branches, trunks, and stems, along with the forest floor litter, create an extensive surface area that intercept rainwater and allow much of it to evaporate before reaching the soil

•Interception by forests and individual tree canopies is much greater than that by shrubs and other herbaceous plants (Pitman, 1989) HEVEA BRASILIENSIS (RUBBER) Canopy Leaf CHARACTERISTICS Stem •The plant, growing up to over 40 meters (m) in the wild, characteristically does not exceed 25 m in height when it is under cultivation

•During wintering (lasting for 4-6 weeks), the leaves of the tree die and fall off- create ‘sponge’ effect.

•LAI : LAI rubber < LAI forest

RAINFALL INTERCEPTION IN RUBBER TREES stemflow

interception& evaporation Litter throughfall net rainfallnet soilentering the

interception& evaporation Canopy interception& evaporation

Litter

stemflow

ELAEIS GUINEENSIS (PALM OIL) TREE CHARACTERISTIC

•Each tree can grow up to 18 meter and produces compact bunches

Bare floor RAINFALL INTERCEPTION IN ELAEIS GUINEENSIS (PALM OIL) Leaf : More throughfall Bare Floor : Higher water runoff, higher velocity– less infiltration LAI: LAI palm oil < LAI rubber <

Canopy LAI forest interception & evaporation

Rubber old growth Oil palm

Higher Higher runoff runoff Bare floor Bare floor Small net rainfall entering the soil 11

CLIMATE DATA

Rainfall

Year 2011 Year

Temperature - Relative humidity

Wind speed LAND USE (2002,2006,2008)

Solar Radiation 1970 Year FLOW DISCHARGE TOPOGRAPHY ASTER Digital Elevation Model (DEM) LANDUSE SOIL LEAF AREA INDEX (LAI)

MOD15A2: Level-4 MODIS global LAI

DATA INPUT DATA ASTER DEM DEM (30 Meter) ASTER LAI’s Value = MODIS LAI x scale factor (0.1) Mean LAI Value Land cover Type 2002 2006 2008 Forest 4.27 3.85 2.06 Oil Palm 2.54 2.83 1.05 Rubber 2.65 2.54 0.85 Overall LAI 3.54 3.30 2.50 Mean LAI value Forest

Oil Palm

Rubber RESULTS

Year 2008 Year 2002 Year 2006 40 Land cover 2002 2006 2008 35 Rubber 35.59% 27.84% 28.37% Oil Palm 25.54% 35.09% 35.31% 30 2002 Forest 24.48% 23.01% 22.64% Other 14.39% 14.06% 13.69%

25 2006

2008 20

(%) Mean LAI Value

Dominant Land Cover Changes Cover Land Dominant Land cover 2002 2006 2008 Oil Palm 15 Type Rubber 10 Forest 4.27 3.85 2.06 Forest Oil Palm 2.54 2.83 1.05 5 Rubber 2.65 2.54 0.85 Overall LAI 3.54 3.30 2.50 0 Oil Palm Rubber Forest Other Daily Simulated Flow using land cover year 2002 RESULTS Monthly 600 Warm-up – 1970 Obs Buloh Kasap SIM 2002

500 to 1983

400 NSE:0.78 300

Flow (cms) Flow 200 100

1/1/1990 1/1/2000 1/1/1984 1/1/1985 1/1/1986 1/1/1987 1/1/1988 1/1/1989 1/1/1991 1/1/1992 1/1/1993 1/1/1994 1/1/1995 1/1/1996 1/1/1997 1/1/1998 1/1/1999 1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 Daily 300 Warm-up – 1970 250 to 1983 Obs Buloh Kasap SIM 2002 200 NSE:0.71 150

Flow (cms) Flow 100

Jul-89 Jul-00 Jul-11

Jan-84 Jan-95 Jan-06

Jun-90 Jun-01

Oct-86 Oct-97 Oct-08

Apr-92 Apr-03

Feb-94 Sep-87 Sep-98 Feb-05 Sep-09

Dec-84 Dec-95 Dec-06

Aug-88 Aug-99 Aug-10

Nov-85 Nov-96 Nov-07

Mar-93 Mar-04

May-91 May-02 Month Daily Simulated Flow using land cover year 2006 RESULTS Monthly 600 Warm-up – 1970 to 1983 500 NSE: 0.77 Obs Buloh Kasap SIM 2006 400 300

Flow (cms) Flow 200 100

1/1/1985 1/1/1991 1/1/1984 1/1/1986 1/1/1987 1/1/1988 1/1/1989 1/1/1990 1/1/1992 1/1/1993 1/1/1994 1/1/1995 1/1/1996 1/1/1997 1/1/1998 1/1/1999 1/1/2000 1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 Daily 300 Warm-up – 1970 250 Obs Buloh Kasap SIM 2006

to 1983 200 NSE: 0.71 150

Flow (cms) Flow 100 50

Jul-89 Jul-00 Jul-11

Jan-84 Jan-95 Jan-06

Jun-90 Jun-01

Oct-86 Oct-97 Oct-08

Apr-92 Apr-03

Feb-94 Sep-87 Sep-98 Feb-05 Sep-09

Dec-84 Dec-95 Dec-06

Aug-88 Aug-99 Aug-10

Nov-85 Nov-96 Nov-07

Mar-93 Mar-04

May-91 May-02 Month Daily Simulated Flow using land cover year 2008 RESULTS Monthly 600 NSE: 0.8 Obs SIM 500 Warm-up – 1970

400 to 1983 300

Flow (cms) Flow 200 100

1/1/2010 1/1/1976 1/1/1977 1/1/1978 1/1/1979 1/1/1980 1/1/1981 1/1/1982 1/1/1983 1/1/1984 1/1/1985 1/1/1986 1/1/1987 1/1/1988 1/1/1989 1/1/1990 1/1/1991 1/1/1992 1/1/1993 1/1/1994 1/1/1995 1/1/1996 1/1/1997 1/1/1998 1/1/1999 1/1/2000 1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2011 Daily 300 250 FLOW Buloh Kasap SIM208mth2008 NSE: 0.72 200 Warm-up – 1970 150 to 1983

100 Flow (cms) Flow 50

Jul-79 Jul-86 Jul-93 Jul-00 Jul-07

Jan-83 Jan-76 Jan-90 Jan-97 Jan-04 Jan-11

Sep-80 Sep-87 Sep-94 Sep-01 Sep-08

Nov-81 Nov-88 Nov-95 Nov-02 Nov-09

Mar-84 Mar-77 Mar-91 Mar-98 Mar-05

May-78 May-85 May-92 May-99 May-06 Month Simulated Flow COMPARISONS for 2002, 2006 and RESULTS 2008 600

500 Obs Buloh Kasap SIM 2008 SIM 2006 SIM 2002

400

300

Flow (cms) Flow 200

100

1/1/1993 1/1/1984 1/1/1985 1/1/1986 1/1/1987 1/1/1988 1/1/1989 1/1/1990 1/1/1991 1/1/1992 1/1/1994 1/1/1995 1/1/1996 1/1/1997 1/1/1998 1/1/1999 1/1/2000 1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 300 Daily 250 Obs Buloh Kasap SIM 2008 SIM 2006 SIM 2002 200 150

Flow (cms) Flow 100 50

Jul-11 Jul-86 Jul-91 Jul-96 Jul-01 Jul-06

Jan-84 Jan-89 Jan-94 Jan-99 Jan-04 Jan-09

Sep-85 Sep-90 Sep-95 Sep-00 Sep-05 Sep-10

Nov-84 Nov-89 Nov-94 Nov-99 Nov-04 Nov-09

Mar-88 Mar-93 Mar-98 Mar-03 Mar-08

May-07 May-87 May-92 May-97 May-02 Monthly Simulated Annual Flow COMPARISONS for 2002, RESULTS 2006 and 2008

80 Flow Land use 2002 Flow Land use 2006 Flow Land use 2008 70

40 Flow (cms) Flow 30 20 10

1980 1993 2010 1976 1977 1978 1979 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2011 Year Conclusion..

• Vast replacement of rubber to oil palm seem to contribute to increase in frequency and magnitude of flooding.

• Still need to check against rainfall events & more detailed subwatershed comparisons needed.

• If proven the case, stormwater management plan is necessary for even the rural oil palm plantation to prevent monsoonal flooding.

• SWAT is capable of doing hydrology in heavy-rainfall tropical monoculture (rubber, oil palm) environment. Merci..