The document summarizes a study evaluating best management practices (BMPs) for soil erosion in the Bago River Basin in Myanmar using the Soil and Water Assessment Tool (SWAT) model. The study aimed to assess sediment yield, identify critical soil erosion areas, and determine the most effective BMPs. The SWAT model was set up, calibrated using discharge and sediment data from 1997-2006, and validated from 2007-2016. Preliminary results found average annual sediment yield of 11 ton/ha/year and acceptable but imperfect calibration and validation performance. Improved modeling is needed to fully evaluate BMP scenarios to reduce soil erosion in the basin.

1. Evaluation of the Best Management
Practices for Soil Erosion at Bago River
Basin, Myanmar
Presenter : Pa Pa Shwe Sin Kyaw
Student ID : 201626062
Supervisor : Prof. Kenlo Nishida Nasahara
Date : 16/1/2018
JDS International Seminar
1

2. Introduction
Objectives
Results & Discussions
Outlines
Conclusion
Methodology
2

3. Introduction
Background
Soil Erosion
the removal of top soil
layer by erosive agents
Rainfall (main erosive agent)
Sediment
Sediment
Solid matter eroded, transported or
deposited by flowing water
3
Google images
Soil detachment and deposition process
(Wikipedia)
Type of soil erosion from water
Source: USDA NRCS, 2002 (http://iowacedarbasin.org/runoff/erosion.htm)

4. Selection of best method to
reduce soil erosion & sediment
yield
Best Management Practices (BMPS)
Venting
Farming practices
New Reservoirs & Hill Lakes
4
(Mitiba et al. 2016)

5. Problem Statements
 Lack of systematic study on soil erosion
 No proper planning of sediment and erosion control
 Need to evaluate structural and non structural measures
Sedimentation problems in irrigation
canals and structures (IWUMD*)
Severe floods in 2011 and 2015
(facebook)
http://kawasakilab.blogspot.jp/2015/11/myanmar-stay-for-student-exchange_23.html
Forest degradation & Climate change Soil erosion
(Hlaing K. 2008).
High sediments in Bago River
Bago River Basin
5
(Hlaing et al. 2008)

6.  Located in southern part of
Myanmar
 Catchment Area - 5004.46
km2
 Climate - Tropical monsoon
climate (3000 mm Annual
Rainfall)
 Main River - Bago River
 Livelihood – fishing and
seasonal farming
Study Area
* Irrigation and Water Utilization Management Department
* Department of Meteorology and Hydrology
Location map of Bago River Basin.

7. Overall Objective
To apply SWAT Model for investigation of the best management practices (BMPs) for soil
conservation and sustainable water resources management in Bago River Basin
Specific Objectives
1. To assess the amount of sediment yield for Bago River Basin
2. To identity and prioritize critical source areas regarding Soil Erosion
3. To find out the best management practices (BMPS) for soil conservation in the basin
Objectives
7

8. Land
Cover
Map
Soil
Map
Climate
Data
Sediment Yield
(first Objective)
Evaluation of the Best
Management Practices
(BMPs)
(third objective)
Calibration &
Validation
SWAT Model
Set up
Observed
Discharge &
Sediment Data
Methodology
Digital
Elevation
Model
(DEM)
Critical Sources Area
(second objective)
Calibrated SWAT
Model
8

9. • Soil and Water Assessment Tool (SWAT)
• Developed by United States Department of Agriculture
(USDA)- Agriculture Research Service (ARS)
SWt = SWo + Σt
i (Rday - Qsurf - ETi - Wseep - Qgw)
water balance equation
Penmam-Monteith method,
Priestly-Taylor method
Hargreaves method
SWAT Model Overview
http://swat.tamu.edu/
Processed based empirical model
Qsurf
Rday
ETi
Qgw
Wseep
Water yield of the watershed
9
(Neitsch, Arnold, Kiniry, Williams, & King, 2005).

10. Where; Sed = the sediment yield (metric tons per day)
Qsurf = the surface runoff volume (mmH2O /ha)
qpeak = the peak runoff rate ( m3/s)
Ahru = the area of HRU (ha)
Kusle = soil erodibility factor of USLE
Cusle = cover and management factor of USLE
Pusle = support practice factor of USLE
LSusle = topographic factor of USLE
CFRG = coarse fragment factor
Sediment yield of the watershed
The Modified Universal Soil Loss Equation (MUSLE) (William
and Berndt 1977)
Sed = 11.8(Qsurf . qpeak . Ahru)0.56 Kusle . Cusle .Pusle .LSusle .CFRG
10
Many Products
Water yield
Sediment yield
Chemical
Nutrients (NO2)
Evapotranspiration
+++
Sub-basin
HRU
Reach
HRU = Hydrological Response Units

11. Input Data processing
Digital Elevation Model (DEM)
SRTM -1, USGS (U.S Geological
Survey Data Explore) website,
http://earthexplorer.usgs.gov/
2015 Global Land cover map
European Space Agency,
(https://www.esa-landcover-
cci.org/?q=node/175)
Rice & Forest (main land cover)
Food and Agriculture Organization
(FAO)
Digitized Soil Map of the World, version
3.6
Soil map of Myanmar 1. Precipitation
2. Maximum & Minimum
Temperature
3. Relative Humidity
(1991-2016)
Department of Meteorology
and Hydrology, Myanmar
(2 stations, Bago and Zaungtu)
11

12. SWAT Model Set up
Subbasins
Watershed
Delineation
Hydrological Response
Units Analysis Create HRUs
Weather Data
Run SWAT
Model
61
1190
Simulate (1992 - 2016)
Write Weather Input
tables
12
Warm up periods 5 yeras

13. Calibration & Validation
SWAT-CUP - Calibration and Uncertainty Programs
SUFI2 – Sequential Uncertainty Fitting version 2
Calibration – adjusting the parameters
Validation – using the adjusted parameters
Observed
Discharge Data
Observed
Sediment Data
Department of Meteorology
and Hydrology, Myanmar
Bago Station & Zaungtu Station
Calibration Periods – 1997 – 2006 (10 years)
Validation Periods – 2007 – 2016 (10 years)
Calibration &
Validation
13

14. No. Parameter Description and Units Interval Fitted Parameter
1 ALPHA_BF.gw Base flow alpha factor (1/days) 0-1 0.115
2 CN2.mgt Initial SCS runoff Curve number II 35-98 36.57
3 GW_DELAY.gw Groundwater delay from soil to channel (days) 0-50 30.25
4 GWQMN.gw Threshold depth of water in the shallow aquifer required for return flow to occur (mmH2O) 0-5000 875
5 EPCO .hru Plant uptake compensation factor 0-1 0.495
6 CH_N2.rte Manning’s n value for the main channel 0-0.3 0.0465
7 CH_K2.rte Hydraulic conductivity of the main channel (mm/h) 0-500 47.5
8 REVAPMN.gw Threshold depth of water in the shallow aquifer for “revap” (mm H2O) 0-500 497.5
9 GW_REVAP .gw Groundwater ‘revap’ coefficient 0.02-0.2 0.195
10 SHALLST Initial depth of water in the shallow aquifer (mmH2O) 0-50000 38750
11 ESCO .hru Soil evaporation compensation factor 0-1 0.755
12 LAT_TIME .hru Lateral flow travel time (days) 0-180 65.69
13 SOL_AWC .sol Available water capacity of soil layer (mmH2O/mm soil) 0-1 0.635
14 SOL_K .sol Saturated hydraulic conductivity (mm/h) 0-2000 830
15 RCHRG_DP .gw Deep aquifer percolation fraction 0-1 0.395
Calibration & Validation
14

15. Year
Average Sediment yield
(ton/ha/year)
1997 8.384722678
1998 4.848934426
1999 8.247730874
2000 6.70379235
2001 8.557360656
2002 6.805459016
2003 5.621961749
2004 10.87304781
2005 6.756239071
2006 6.883251366
2007 10.0919877
2008 8.566083333
2009 5.87813388
2010 7.331092896
2011 9.2625
2012 11.68987842
2013 11.20312705
2014 9.119821038
2015 9.830241803
2016 7.703681694
0
2
4
6
8
10
12
14
Sediment yield
Primary Results
Results & Discussions
Cannot be applied until the model is
calibrated
15
11 ton/ha/year

16. 0
100
200
300
400
500
600
700
800
1997
1997
1997
1998
1998
1998
1999
1999
1999
2000
2000
2000
2001
2001
2001
2002
2002
2002
2003
2003
2003
2004
2004
2004
2005
2005
2005
2006
2006
2006
Discharge
(m3/s)
Year
Calibration at Bago Station (1997-2006)
observed Discharge simulated discharge
0
100
200
300
400
500
600
700
800
2007
2007
2007
2008
2008
2008
2009
2009
2009
2010
2010
2010
2011
2011
2011
2012
2012
2012
2013
2013
2013
2014
2014
2014
2015
2015
2015
2016
2016
2016
Discharge
(m3/s)
Year
Validation at Bago Station (2007-2016)
observed discharge simulated discharge
Calibration & Validation Current Results
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No Parameter Calibration Validation
1 Coefficient of determination
(R2)
0.78 0.65
2 Nuff-Suttcliffe Effiency
(NSE)
0.71 0.56
3 Percent Bias (PBIAS) -30.2 -28
Some values are not satisfactory
Over estimation – 2 years
Under estimation – 2 years
Over estimation – 2 years
Under estimation – 6 years
(Moriasi et al.,2007; Setegn et al., 2010; Yan et al., 2012).

17. Conclusion
 Successfully run SWAT model for my study area
 Calibration and validation Results show that the model performance is acceptable
 Need to improve results to reach satisfactory level
 Have to improve SWAT model to calibrated model and carry on the research
 Applied the proposed BMPs to SWAT and the suitable BMPs for the basin will be
figured out by means of different scenarios simulations
 Evaluate the most efficient BMPs for the basin by technical and financial aspect
17

18. References
1. Record from 1991 to 2016, Department of Meteorology and Hydrology, Ministry of Transport, Myanmar.
2. Koch, H., & Grünewald, U. (2009). A comparison of modelling systems for the development and revision of water
resources management plans. Water Resources Management, 23(7), 1403–1422. http://doi.org/10.1007/s11269-008-
9333-x
3. Gassman, P., Reyes, M., Green, C., & Arnold, J. (2007). The soil and water assessment tool: historical development,
applications, and future research directions. Transactions of the ASABE, 50(4), 1211–1250.
http://doi.org/10.13031/2013.23637
4. Hlaing, K. T., Haruyama, S., & Aye, M. M. (2008). Using GIS-based distributed soil loss modeling and
morphometric analysis to prioritize watershed for soil conservation in Bago river basin of Lower Myanmar.
Frontiers of Earth Science in China, 2(4), 465–478. http://doi.org/10.1007/s11707-008-0048-3
5. Shrestha, S., & Htut, A. Y. (2016). Land Use and Climate Change Impacts on the Hydrology of the Bago River
Basin, Myanmar. Envionemental Modeling and Assessment, 819–833. http://doi.org/10.1007/s10666-016-9511-9
6. Strauch, M., Lima, J. E. F. W., Volk, M., Lorz, C., & Makeschin, F. (2013). The impact of Best Management
Practices on simulated streamflow and sediment load in a Central Brazilian catchment. Journal of Environmental
Management, 127. http://doi.org/10.1016/j.jenvman.2013.01.014
7. Khaing Aung Myo (2014), Mapping Flood Inundation in the Bago River Basin, Myanmar. Master Thesis, Asian
Institute of Technology (AIT), Thailand.
8. Maw, Hsu Myat (2015), Impact of Climate and Land Use Change on Soil Erosion and Stream Flow in the Bago
River Basin. Master Thesis, Asian Institute of Technology (AIT), Thailand. 18

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