JDS International Seminar Evaluation of the Best Management

JDS International Seminar 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 1

Outlines Introduction Objectives Methodology Results & Discussions Conclusion 2

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

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

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

Study Area Ø Located in southern part of Myanmar Ø Catchment Area　 -　5004. 46 km 2　 Ø Climate - Tropical monsoon climate (3000 mm Annual Rainfall) Ø Main River - Bago River Location map of Bago River Basin. Ø Livelihood – fishing and seasonal farming * Department of Meteorology and Hydrology * Irrigation and Water Utilization Management Department

Objectives 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 7

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

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

The Modified Universal Soil Loss Equation (MUSLE) (William and Berndt 1977) Sed = 11. 8(Qsurf. qpeak. Ahru)0. 56 Kusle. Cusle. Pusle. LSusle. CFRG Where; Sed = the sediment yield (metric tons per day) Sediment yield of the watershed Qsurf = the surface runoff volume (mm. H 2 O /ha) qpeak = the peak runoff rate ( m 3/s) Ahru = the area of HRU (ha) Sub-basin HRU Reach HRU = Hydrological Response Units Many Products Water yield Sediment yield Chemical Nutrients (NO 2) Evapotranspiration +++ 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 10

Input Data processing Soil map of Myanmar 2015 Global Land cover map 1. Precipitation 2. Maximum & Minimum Temperature 3. Relative Humidity (1991 -2016) SRTM -1, USGS (U. S Geological Survey Data Explore) website, http: //earthexplorer. usgs. gov/ European Space Agency, (https: //www. esa-landcovercci. org/? q=node/175) Department of Meteorology and Hydrology, Myanmar Food and Agriculture Organization (FAO) Digitized Soil Map of the World, version 3. 6 Rice & Forest (main land cover) Digital Elevation Model (DEM) (2 stations, Bago and Zaungtu) 11

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

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

Calibration & Validation No. Parameter Description and Units Interval Fitted Parameter 1 ALPHA_BF. gw Base flow alpha factor (1/days) 0 -1 0. 115 2 CN 2. 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 (mm. H 2 O) 0 -5000 875 5 EPCO. hru Plant uptake compensation factor 0 -1 0. 495 6 CH_N 2. rte Manning’s n value for the main channel 0 -0. 3 0. 0465 7 CH_K 2. 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 H 2 O) 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 (mm. H 2 O) 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 (mm. H 2 O/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 14

Results & Discussions Sediment yield 14 12 10 8 6 4 2 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 0 2000 8. 384722678 4. 848934426 8. 247730874 6. 70379235 8. 557360656 6. 805459016 5. 621961749 10. 87304781 6. 756239071 6. 883251366 10. 0919877 8. 566083333 5. 87813388 7. 331092896 9. 2625 11. 68987842 11. 20312705 9. 119821038 9. 830241803 7. 703681694 1999 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 1998 Year 11 ton/ha/year 1997 Primary Results Average Sediment yield (ton/ha/year) Cannot be applied until the model is calibrated 15

Calibration & Validation Current Results Calibration at Bago Station (1997 -2006) observed Discharge simulated discharge 800 Validation at Bago Station (2007 -2016) 600 500 400 300 200 100 0 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Over estimation – 2 years Under estimation – 6 years 700 Discharge (m 3/s) Over estimation – 2 years Under estimation – 2 years Year 800 600 500 No Parameter 1 Coefficient of determination 0. 78 (R 2) 0. 65 2 Nuff-Suttcliffe Effiency (NSE) 0. 71 0. 56 3 Percent Bias (PBIAS) -30. 2 -28 400 300 200 100 0 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Discharge (m 3/s) 700 Year observed discharge simulated discharge Calibration Validation Some values are not satisfactory 16 (Moriasi et al. , 2007; Setegn et al. , 2010; Yan et al. , 2012).

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

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/s 11269 -0089333 -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/s 11707 -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/s 10666 -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. 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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