U Mekong River Commission Regional Flood Management and Mitigation Centre Weekly Flood Situation Report for the Mekong River Basin Prepared at: /7/7, covering the week from the 7 th th July 7 General Behaviour of the Mekong River and Flood Situation Over weather situation During last week, there was rainfall happened in many parts of the LMB, most of heavy rainfalls happened in the upper and middle reaches of LMB. The first three maximum accumulated rainfalls were at Paksane (. mm.), Stung Treng ( mm.) and Koh Khel (. mm.), see Figure and Table A for more details. Accumulated Rainfall in LMB Jinghong Chiang Saen Luang Prabang Rainfall - mm Chiang Khan Vientiane Nongkhai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet Khong Chiam Pakse Stung Treng Kratie Kompong Cham Phnom Penh (Bassac) Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Figure : Accumulated Rainfall Distribution over the LMB from 7 th th July 7 MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Figure : Weekly Rainfall Distribution over the LMB from 7 th th July 7 MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 General behaviour of the Mekong River Compared the Long Term Average (LTA), during the last week, the water levels at most stations in LMB were fluctuated about or above the LTA, except Chiang Saen that was below the LTA. For stations from Chiang Saen and Luang Prabang During the last week, the water levels at Chiang Saen and Luang Prabang were fluctuated below or about the LTA. For stations from Chiang Khan, Vientiane and Nong Khai and Paksane During the last week, the water levels at these stations were fluctuated about or above the LTA. For stations from Thakhet/Nakhon Phanom to Pakse During the last week, the water levels at these stations were fluctuated above the LTA. For stations from Stung Treng to Kampong Cham During the last week, the water levels at these stations were fluctuated above the LTA. For stations from Phnom Penh to Koh Khel/Neak Luong During the last week, the water levels at these stations were fluctuated above the LTA. Tan Chau and Chau Doc During the last week, the water levels at these stations were fluctuated above the LTA. Note: For areas between forecast stations, please refer to the nearest forecast station. Flood Situation Flood stage or alarm stage: No alarm stage (where the forecast is expected to reach flood level within three days) was reported anywhere on the mainstream of the Mekong River during the last week. Water levels were still significantly below flood levels (as defined by the national agency) at all forecast stations. Damage or victims: No damage or loss of life due to river flooding was recorded anywhere along the Mekong River during the last week. For more details see the following annexes: - tables and graphs for water level and rainfall for the last week in Annex A - a graph for accuracy in Annex B - a table of forecast achievement in Annex B - tables and graphs for performance in Annex B - the water level graphs showing the observed water level for the season in Annex C MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Annex A: Graphs and Tables Table A: observed water levels Unit in m Jinghong Chiang Saen Luang Prabang Chiang Khan Vientiane Nongkhai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet 7 7/7.7. 9. 9...9..9....99 7.7 7.9........7.9 /7.7.7 9. 9... 9. 7.9.99 7.9 7. 9... 7........9.7 9/7.7.7 9...9 7.. 9...7. 9.9.. 7.9...7.9.7... /7.7. 9.. 7...9 9.9. 9...7....9.9.9.9.9.7.. /7.7.. 9..9 7.. 9.. 9..9. 9..9.7. 7..7...9..9 /7.. 9. 9.. 7..7 9.. 9. 9.. 9...7. 7.9.9...7.. /7... 9.9. 7.. 9..7 9. 9.. 9...7. 7....... /7.7..7. 7. 7.7. 9.. 9. 9..7 9..7..7 7..9...7.. Khong Chiam Pakse Stung Treng Kratie Kompong Cham Phnom Penh (Bassac) Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Table A: observed rainfall Unit in mm Jinghong Chiang Saen Luang Prabang Chiang Khan Vientiane Nongkhai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet 7 7/7..7..7.... 79.7 7..9.. 9.. nr nr -.. nr.. /7.. 9. 9... 77.... 7..7.. nr.. -. nr 7... 9/7.... nr..9...7.7.. 9. 9...7 -.. nr. 7. /7.. 9.......7. nr..... 7. - 7. 7.... /7.. 9.... 7.. 7.7.... 9.... -..... /7.......7. 7.. nr.9. nr nr. nr - nr nr nr nr. /7 7.. 9.. nr.. 7..9. nr 9.7 9.... nr -.. nr nr nr /7. 9... nr. nr... -.7. 7. nr nr nr -.9. nr nr - Sum R.. 7. 9.7. 7..... 7.. 9.. 97...7.. 99. 7. 9. 97. Khong Chiam Pakse Stung Treng Kratie Kompong Cham Phnom Penh (Bassac) Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Page MRC Weekly Flood Situation Report Week 7 th th July 7
Monday, th July 7 Figure A: Observed water level and rainfall for Jinghong, Chiang Saen, and Luang Prabang MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Figure A: Observed water level and rainfall for Chiang Khan, Vientiane, Nongkhai, and Paksane Vientiane Nongkhai 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 Vientiane 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) /7 /7 /7 Nongkhai Page MRC Weekly Flood Situation Report Week 7 th th July 7 Paksane 7/7 /7 9/7 /7 /7 hour rainfall at 7am (mm) /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 Paksane hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 Chiang Khan Chiang Khan........ hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7
Monday, th July 7 Figure A: Observed water level and rainfall for Nakhon Phanom, Thakhek, Mukdahan and Savannakhet Thakhek Mukdahan 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 Thakhek 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) /7 Mukdahan MRC Weekly Flood Situation Report Week 7 th th July 7 Page 7 Savannakhet 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 Savannakhet hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 Nakhon Phanom Nakhon Phanom hour rainfall at 7am (mm)
Monday, th July 7 Figure A: Observed water level and rainfall for Khong Chiam, Pakse, Stung Treng, and Kratie Khong Chiam Pakse Stung Treng 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 Pakse 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) /7 /7 /7 Stung Treng Page MRC Weekly Flood Situation Report Week 7 th th July 7 Kratie 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 Kratie hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 Khong Chiam hour rainfall at 7am (mm)
Monday, th July 7 Figure A: Water level and rainfall for Kompong Cham, Phnom Penh (Bassac and Port), and Koh Khel Kompong Cham Phnom Penh (Bassac) Phnom Penh Port 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 Phnom Penh (Bassac) hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 /7 Phnom Penh Port MRC Weekly Flood Situation Report Week 7 th th July 7 Page 9 9 7 Koh Khel 9 7 hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 Koh Khel hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 Kompong Cham hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7
Monday, th July 7 Figure A: Water level and rainfall for Neak Luong, Prek Kdam, Tan Chau and Chau Doc Neak Luong Prek Kdam Tan Chau 9 9 7 7-7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7 Neak Luong Prek Kdam 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7 Tan Chau.... Page MRC Weekly Flood Situation Report Week 7 th th July 7 - Chau Doc 7/7 /7 9/7 /7 /7 /7 /7 /7 7/7 /7 9/7 /7 /7 /7 /7 /7..... Chau Doc hour rainfall at 7am (mm) 7/7 /7 9/7 /7 /7 /7 /7 /7
Monday, th July 7 Annex B: Accuracy and performance Accuracy Accuracy describes the accuracy of the adjusted and published forecast, based on the results of the MRC Mekong Flood Forecasting System, which are then adjusted by the Flood Forecaster in Charge taking into consideration known biases in input data and his/her knowledge of the response of the model system and the hydrology of the Mekong River Basin. The information is presented as a graph below, showing the average flood forecasting accuracy along the Mekong mainstream. In general, the overall accuracy is fair for -day to -day forecast lead time at all stations in the LMB. However, the accuracies at Chiang Saen, Vientiane to Thakhek for -day and - day forecast; Tan Chau and Chau Doc for - day to -day forecast were less than expected. The above differences due to two main factors: () internal model functionality in forecasting; for which the parameter adjustment in the model is not possible especially at stations in the upper part and in the Mekong delta where are affected by tidal; () the adjustment by utilizing the practical knowledge and experience of flood forecaster-in-charge; () the heavy rainfall happened in many tributaries inside the LMB. See the Figure B and table B for more detail. Flood Forecasted Performance Mean Absolute Differences (cm) -DAY -DAY -DAY -DAY -DAY Chiang Saen Luang Prabang Chiang Khan Vientiane Nong Khai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet Khong Chiam Pakse Stung Treng Kratie Kompong Cham Bassac Chaktomuk Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Figure B: Average flood forecast accuracy along the Mekong mainstream (from 7 th th July 7) MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Forecast Achievement The forecast achievement indicates the % of days that the forecast at a particular station for a lead-time is successful against a respective benchmark (Table B). Table B: Achievement of daily forecast against benchmarks Unit in % Chiang Saen Luang Prabang Chiang Khan Vientiane Nongkhai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet Khong Chiam -day.9 7. 7.....9.9 7. 7...9 7..9.7...7.7. 7. 7. 7. -day..7.7..7....7.7.7..7.....7...7.. -day....................... -day 7...... 7. 7. 7....... 7... 7.....7 -day.7...7.7...7.7.........7...7.. Pakse Stung Treng Kratie Kompong Cham Phnom Penh (Bassac) Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Average Table B: Benchmarks of success (Indicator of accuracy in mean absolute error) Unit in cm Chiang Saen Luang Prabang Chiang Khan Vientiane Nongkhai Paksane Nakhon Phanom Thakhek Mukdahan Savannakhet Note: An indication of the accuracy given in the Table B is based on the performance of the forecast made in from the new flood forecasting system and the configuration for the 9 flood season and is published on the website of MRC (http://ffw.mrcmekong.org/accuracy.htm). Khong Chiam -day -day -day -day 7 7 -day 7 7 A new set of performance indicators that is established by combining international standards and the specific circumstances in the Mekong River Basin, is applied officially for the flood season of onward. Pakse Stung Treng Kratie Kompong Cham Phnom Penh (Bassac) Phnom Penh Port Koh Khel Neak Luong Prek Kdam Tan Chau Chau Doc Page MRC Weekly Flood Situation Report Week 7 th th July 7
Monday, th July 7 Performance Performance is assessed by evaluating a number of performance indicators, see table and graphs below: Table B: Overview of performance indicators for the past days including the current report date Flood Forecast: time sent Arrival time of input data (average) Missing data (number) FF completed and sent (time) stations without forecast FF completed and sent (time) Weather informaition available (number) NOAA data China Cambodia - DHRW Cambodia - DOM 7 week : - : 7: 7:9 : : 7: :7 7 month : - - : 7: 7:9 : : 7: 7: season : - : 7: 7: 7:9 : 7: 7:7 7 9 9 Week is the week for which this report is made; Month is actually the last days (or less if the flood season has just begun); Season is the current flood season up to the date of this report. Lao PDR - DMH Thailand - DWR Viet Nam - NCHMF NOAA data China Cambodia - DHRW Cambodia - DOM Lao PDR - DMH Thailand - DWR Viet Nam - NCHMF Time : 9: : 7: Data Delivery - Delivery Times 7/7 /7 9/7 /7 /7 /7 /7 /7 Date Figure B: Data delivery times for the past days including the current report date NOAA China CAM DHRW CAM DOM LAO DMH THAI DWR VN NCHMF MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Number Data Delivery - Missing Data 7/7 /7 9/7 /7 /7 /7 /7 /7 Date NOAA China CAM DHRW CAM DOM LAO DMH THAI DWR VN NCHMF Figure B: Missing data for the past days including the current report date Time : Flood Forecast - Completion Time Flood Forecast - Stations without Forecast Time Flood Forecast - Second Forecast Needed : : : : : : : 9: Date 7/7 /7 9/7 /7 /7 /7 /7 /7 Date 7/7 /7 9/7 /7 /7 /7 /7 /7 9: Date 7/7 /7 9/7 /7 /7 /7 /7 /7 Figure B: Flood forecast completion time Figure B: Flood forecast stations without forecast Figure B: Second forecast needed Page MRC Weekly Flood Situation Report Week 7 th th July 7
Monday, th July 7 Annex C: Season Water Level Graphs This Annex has the water level graphs of the report date. These graphs are distributed daily by email together with the Flood Bulletins. HYDROGRAPHS OF THE MEKONG AT MAINSTREAM STATIONS IN FLOOD SEASON FROM JUNE TO OCTOBER Water Level at 7am of Mekong at Jing Hong -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Av9-99 Time in days 7 Water Level at 7am of Mekong at Chiang Saen -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 Time in days 7 Water Level at 7am of Mekong at Luang Prabang -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 Time in days 7 MRC Weekly Flood Situation Report Week 7 th th July 7 Page
Monday, th July 7 Water Level at 7am of Mekong at Chiang Khan Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Vientiane Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Nong Khai Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Paksane Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Page MRC Weekly Flood Situation Report Week 7 th th July 7
Monday, th July 7 Water Level at 7am of Mekong at Nakhon Phanom Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 Time in days 99 7 Water Level at 7am of Mekong at Thakhek Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Savannakhet Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Mukdahan Gaugeheight inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 MRC Weekly Flood Situation Report Week 7 th th July 7 Page 7
Monday, th July 7 Water Level at 7am of Mekong at Khong Chiam -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Pakse -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Stung Treng -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Kratie -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Page MRC Weekly Flood Situation Report Week 7 th th July 7
Monday, th July 7 Water Level at 7am of Mekong at Kampong Cham -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Phnom Penh Chaktomuk -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Tonle Sap at Phnom Penh Port -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 9 Water Level at 7am of Bassac at Koh Khel 7 -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 MRC Weekly Flood Situation Report Week 7 th th July 7 Page 9
Monday, th July 7 9 Water Level at 7am of Mekong at Neak Luong Gaugeheight in metres 7 -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Tonle Sap at Prek Kdam Gauge height inmetres -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Mekong at Tan Chau Gaugeheight in metres - -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Water Level at 7am of Bassac at Chau Doc Gaugeheight in metres - -Jun -Jun -Jul -Jul -Jul -Aug -Aug -Sep 9-Sep -Oct 9-Oct -Nov Alarm Flood Av- 99 99 7 Page MRC Weekly Flood Situation Report Week 7 th th July 7