Regional Seminar on SWAT, SANREM Book Launch and SWAT Workshop, Bogor, Indonesia (SWAT School of Bogor) June 27-29, 2012

Transcription

1 Regional Seminar on SWAT, SANREM Book Launch and SWAT Workshop, Bogor, Indonesia (SWAT School of Bogor) June 27-29, 2012

2 Introduction Objectives SWAT application Results Acknowledgements 2

3 Bi Doup - Núi Bà Jan-16 Đà Lạt Landsat-5 Thematic Mapper Hồ Dầu Tiếng Hồ Trị An Dec-30 TPHCM) Biên Hoà Bình Thuận Cần Giờ Jan-16 Cần Thơ Vĩnh Long Jan-07 UTM, Zone 48 North, WGS 84

4 Núi Bà Đà Lạt SRTM Digital Elevation Hồ Dầu Tiếng Hồ Trị An TP HCM ) Biên Hoà Bình Thuận Cấn Giờ Cần Thơ Vĩnh Long UTM, Zone 48 North, WGS 84

5 Song Be River basin Problem Identification - Emerging water problems threaten the livelihood of local people - Coffee growers in Western Highlands exhaustedly water in In the historical flood of 1999, 2000, Relation of water problem - The development approach and the failure of trade-off between conservation and development in watershed area C A M B O D I A - High growth of population - Social complex - Agricultural activities - Land use planning

6 Vietnam C A M B O D I A Area: 7,650 km² Cambodia Elevation: 80 1,000 m Mean precipitation: 2,200 2,600 mm Mean temperature: C 6

7 To simulate stream flow from Digital Elevation Model (DEM), land use, soil and weather data using SWAT model. To assess fluctuations and find out the rule of water discharge in Be river basin. 7

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9 DEM ASTER GDEM Resolution: 30 m Range: m Legend Elevation (m) 9

10 Legend Land use type Land use Data SIWRP (Southern Institute for Water Resources Planning) 14 land use types Grasslands/ shrublands (28.18 %), Mixed closed natural forest (15.16 %) 10

11 Legend Soil class Soil map Department of Soil Science in HCM City (1995) 5 soil classes Rhodic Ferralsols (63.85 %), Ferric Acrisols (29.95 %) 11

12 Weather Southern Institute for Water Resources Planning (SIWRP) 8 meteorological stations: Bu Nho, Chon Thanh, Dac Nong, Dong Phu, Loc Ninh (Song Be), Phuoc Hoa, Phuoc Long and So Sao Temporal resolution: Daily Period:

13 Discharge Southern Institute for Water Resources Planning (SIWRP) 2 flow gages: Phuoc Long, Phuoc Hoa Temporal resolution: Monthly Period:

14 Coefficient of determination (R 2 ) Nash-Sutcliffe Index (NSI) 14

15 Results Monthly stream flow calibration ( ) Statistics Monthly stream flow (m 3 /s) Measured SWAT Calib ratio n Mean Max Min Range Standard deviation Correlation coefficient 0.65

16 Daily stream flow validation Statistics 2002 daily stream flow (m 3 /s) Measure d SWAT Valid ation Mean Max Min Range Standard deviation Correlation coefficient 0.66

17 Monthly water discharge at Phuoc Long ( ) Observed Simulated R 2 : 0,769 NSI: 0,720 Flow (cms) Time (months) 17

18 Monthly water discharge at Phuoc Hoa ( ) Observed Simulated R 2 : 0,822 NSI: 0,794 Flow (cms) Time (months) 18

19 The variations of rainfall and water discharge at Phuoc Long and Phuoc Hoa ( )

20 The study simulated the water discharge of Be river basin in the period from by SWAT model. The model gives good results for the monthly time step (R² and NSI > 0.7). The preliminary results show that SWAT can be used in Be river basin to simulate the flow and especially for the monthly time step. 20

21 Data improvements and more calibration must be done to use the model for the daily time step. Assessing the impact of land management practices and climate change on water discharge. 21

22 Southeast Asian Regional Center for Graduate Study and Research in Agriculture (SEARCA) Nong Lam University (NLU), Ho Chi Minh City

23 8/10/2012 Nguyen Kim Loi 23

24 8/10/2012 Nguyen Kim Loi 24

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26 The volume of water moving past a crosssection of a stream over a set period of time (unit: m 3 /s). Water discharge = area x velocity 26

27 Water discharge defines shape, size and course of the stream. Water discharge modeling provides useful information for flood forecasting, predicting sediment loads and assessing the impact of climate change to water resource. 27

28 Hydrologic Balance Evaporation and Transpiration Precipitation Root Zone Vadose (unsaturated) Zone Shallow (unconfined) Aquifer Revap from shallow aquifer Infiltration/plant uptake/ Soil moisture redistribution Percolation to shallow aquifer Lateral Flow Surface Runoff Return Flow Water Discharge Confining Layer Deep (confined) Aquifer Flow out of watershed Recharge to deep aquifer 28