2nd Asian Water Cycle Symposium (AWCS) Country Report Myanmar Htay Htay Than Dept. of Meteorology and Hydrology Myanmar 9 January 2007 N N India Hkamti n Myitkyina i w d n i Homalin h China C Bhamo y d Katha a w r a Mawlaik y e n i y Kalewa A w l n Monywa Hsipaw a h Sagaing Mandalay T Myitnge Laos Nyaung U Chauk Minbu Magway Aunglan Pyay Ta ung o o g n Thailand ou Madauk t Shwegyin t o i Henzada g S a Zaungtu B Bago Hpa-an ANDARMAN SEA ANDARMAN SEA 100 50 0 50 100 100 50 0 50 100 Rivers in Myanmar River forecasting stations in Myanmar WATERSHED MANAGEMENT ACTIVITIES Only about 6% of the total water resources of 870 million acre feet per annum are being utilized annually Numerous irrigation facilities have been implemented After 1988, the government put forward continuous efforts in the constructions of dams and reservoirs throughout the country by utilizing large capital investment Completed between 1988-1989 to 2006 numbered 193 new dams Establishment of 298 river pump stations and 999 of village dams were made for rural water supply and agricultural use Natural disasters -Meteorological -Hydrological -Geological River floods Flash floods Inundations Very low River water levels Very low ground water levels Heavy rain spells Droughts River Basin Description Location : 17º 30’ to 18º 30’ (North latitude) 96º 45’ to 97º 10’ (East Longitude) Catchment outlet: 17º 48’ ( N. Lat) , 96º 48’(E. Long) Catchment Area : 1747 km2 MOLTS Point 1 : 17º 52’, 96º 52’ MOLTS Pt. 1 eln : 12 m (above mean sea level) Available Data at Shwegyin Basin 42 miles long from North to South 19 miles wide from east to west only one Met. And Hydro. Station Rainfall, water level, water temperature, discharge, sediment discharge, evaporation, wind direction, wind speed, humidity Monthly Distribution of Flood in Shwegyin Percentage of Flood Station Frequency Period June July Aug Sep Oct Shwegyin 3 21 74 3 0 34 1966-2005 Needs related to water resources management in the basin To install two telemetering stations and one receiving station in Shwegyin river basin, in order to get early warning system To develop forecasting technique for flash flood To display the hydrological behavior of watersheds after estimation the geomorphologic parameters from digital elevation model To develop accurate flood inundation maps based on flows the hydrologic model using all available data including GIS data sources Impact of Geomorphologic Parameters on Watershed Hydrology Geomorphologic Governing Hydrological Parameters behavior Relief ratio, relative relief, Affect the time of concentration elongation ratio and average of the watershed, runoff rate slope and sediment loss Stream length ratios, bifurcation Governs the peak runoff rate ratio, drainage density and and the sediment loss drainage factor Shape factor Defines the basin elongation, affects the time of concentration and the peak runoff rate and translation time of runoff reaching the outlet Severe Flood Record (Since 1966) Years Flood Peak (cm) Flood Duration Record above DL 1997 927 4 days 12 hours 1st Max. 1999 902 11 days 12 hours 2nd Max. 1996 827 5 days 12 hours 3rd Max. Rainfall (mm) 1000 100 200 300 400 500 600 700 800 900 0 Monthly Average Rainfall in Shwegyin Station Shwegyin in Average Rainfall Monthly Jan Feb Mar Apr (1967-2005) May Months Annual Rainfall (mm) Jun 1000 1500 2000 2500 3000 3500 4000 4500 5000 500 0 Jul 1967 Comparison of Annual of RainfallComparison ShwegyinStation of Aug 1969 Sep 1971 1973 Oct 1975 Nov 1977 Dec 1979 1981 Years 1983 1985 Percentage(%) 1987 10 15 20 25 30 1989 0 5 Monthly Distributionof Rainfall Shwegyin in Station 1991 0 1993 Jan 1995 Feb 1997 1999 Mar 00 1% 2001 Apr 2003 8 % 2005 May 20% Months Jun 24 % 24 Jul 27 % Aug 13 % 13 Sep 6% Oct 1% Nov Dec 0 Monthly Mean Discharge of Shwegyin Station (1967-2005) 1200 1000 /s) 800 3 600 400 Discharge (m Discharge 200 0 J an Feb Mar Apr May J un J ul Aug S ep Oct Nov Dec Month Danger Level (cm) Level Danger Below and Above Above and Below -150 -100 100 150 200 250 -50 50 Yearly Below and Above Danger Level of Shwegyin Station LevelShwegyin of Danger Above and Below Yearly 0 1967 1970 1973 1976 below DL Days 1979 DL above 10 12 14 0 2 4 6 8 1982 700 cm Level Danger 1967 Flood DurationinShw 1985 1969 1971 1988 1973 1991 1975 1994 1977 1979 1997 1981 2000 1983 egyin Station(1967-2005) 2003 1985 2006 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 Flash Flood in Shwegyin River on July 2006 800 0 750 100 Danger Level 700 cm 700 200 650 300 600 550 400 500 500 Rainfall (mm) Rainfall Water(cm) Level 450 600 400 700 350 300 800 2-Jul-06 5-Jul-06 8-Jul-06 11-Jul-06 14-Jul-06 17-Jul-06 20-Jul-06 23-Jul-06 26-Jul-06 29-Jul-06 20-Jun-06 23-Jun-06 26-Jun-06 29-Jun-06 Water Level Change within 12 hours : 239 cm Flash Flood in Shwegyin River on Aug 1997 1000 0 100 900 200 800 300 Danger Level 700 cm 700 400 500 600 (mm) Rainfall Water Level (cm) Level Water 600 500 700 400 800 1-Aug-97 4-Aug-97 7-Aug-97 20-Jul-97 23-Jul-97 26-Jul-97 29-Jul-97 10-Aug-97 13-Aug-97 16-Aug-97 19-Aug-97 22-Aug-97 25-Aug-97 28-Aug-97 Water Level Change within 24 hours : 174 cm Damage cause by flash flood at Shwegyin in 1997 The flood water cover 6 wards out of 8 wards in Shwegyin 4/5 of the areas which inundated 504 houses washed away 6336 acres of paddy field were affected Data Analysis For Pre-phase Preparation Statistical Characteristics of Original Series Parameters Mean SD Cv Cs Ck R1 Annual Max. 2085 717.3 0.34 1.01 4.68 0.16 Discharge (m3/s) Annual Max. 151 56.0 0.37 3.16 17.43 -0.11 Rainfall (mm) Outlier Test Computed Observed Remark Annual Peak QH QL QH QL Flow (m3/s) 4816 809 4388 952 Annual Max 317 66 424 80 High Rainfall(mm) Outlier The Result of Randomness and Trend Analysis Turning Kendal’s Mann Spear Auto Parameters Point Rank Kendal Rho correlation Test Correlation Test Test Annual Max. -1.43 0.21 0.21 0.53 1.18 Discharge Annual Max. 0.91 0.54 0.58 0.60 -0.52 Rainfall Median Run Ran Run WW above Von Von Rank Hurt Parameters Crossin Test Test and Neuma Neuman Difference Coeff: g Test below n Annual Max. -2.27 -2.63 1.22 -0.004 -1.71 -1.06 -2.56 0.82 Discharge Annual Max. 0.65 0.33 -0.68 0.0004 1.33 0.63 1.22 0.59 Rainfall Most of tests gave the identical results Draft Implementation Plan To develop forecasting technique for flash flood To develop the design flood and design rainfall for difference return periods and probable maximum precipitation (PMP) of one to three days To compare the estimated design flood by unit hydrograph approach with the flood frequency analysis To display the hydrological behavior of watersheds after estimation the geomorphologic parameters from digital elevation model To develop accurate flood inundation maps based on flows the hydrologic model using all available data including GIS data sources Shwegyin Station North latitude : 17º 30’ to 18º 30’ East Longitude : 96º 45’ to 97º 10’.