1 Namaste!!! Naba Raj Adhikari NEPAL

2 HydroMeteorological Activities in Nepal Dept. of Hydrology Meteorology NEPAL

3 Nepal: Location Area: 147,181 km 2 Length: ~850 km EW Width: ~200 km NS Altitude:~ m Area: 147,181 km 2 Length: ~850 km EW Width: ~200 km NS Altitude:~ m 26º 22' N - 30º 27' N Lat. 80º 4'E - 88º 12'E Long.

4 Nepal: Topographic

5 Nepal: Physiographic

6 Terai Region (Gangetic Plain) Siwaliks Region Middle Mountain Region High Mountain Region Higher Himalayas

7 Nepal: Climate Tropical Climate  Terai Cool temperate and alpine climate  Himalayan ranges Terai  hottest part, summer temp. may rise as high as 40 o c and is hot and humid, winter temp. 7 o -23 o c Mountains  mild summer with temp. around o c, sub-zero to 12 o c in winter Himalayas  frigid climate Kathmandu valley  pleasant climate with avg. summer temp. of o c & 2-12 o c winter temp.

8 Nepal: Climate (contd.) Rainfall is extensive (~80% of the annual) during the south-west monsoon period (June to August) with eastern part receiving max. In the winter, the western part receives a larger portion of rainfall Annual Precipitation Plain area  1500 mm or less Foot of the Siwaliks  >2000 mm Northern side of Mahabharat  1000 mm Middle/High Mountain  few PTN zones exceeds 5000 mm Himalayas  decreases up to 300 mm

9 DHM (Dept. of Hydrology & Meteorology) Government Organization under Ministry of Science and Technology Has mandate from HMG/N to monitor all hydrological and meteorological activities in Nepal No agency is entitled to carry out such activities without a proper liaison with DHM Member of WMO Actively participates in the program relevant international organizations such as UNESCO’s IHP and WMO’s OHP etc…

10 DHM: Activities Hydrological and Meteorological activities were started in an organized manner in 1962 DHM has been upgraded to department status in 1988 Current Projects under DHM –River Hydrology –Meteorology –Weather forecasting –Flood Forecasting –Snow & Glacier Hydrology –Tsho-Rolpa GLOF Risk Reduction Project

11 DHM: Station Network Station TypeNo. Precipitation Climate Agro-met Synoptic Aero-Synoptic Total Met.282 Hydrometric154

12 DHM: Station Network

13 Disasters Scenario ( ) Source: Disaster Events Excluding Windstorm

14 Top 10 Natural Disasters DisasterDateKilled Earthquake15-Jan-19349,040 Epidemic15-Jun-19911,334 Flood23-Aug-19931,048 EpidemicNov-19631,000 Flood12-Jul Earthquake20-Aug Flood29-Sep EpidemicApr SlideJul Flood15-Aug Source: table

15 Top 10 Natural Disasters (contd.) DisasterDateAffected Drought19-May-19803,500,000 Drought ,000 Flood23-Aug ,268 FloodAug ,000 Earthquake20-Aug ,016 Earthquake29-Jul ,600 SlideJul ,865 FloodSep ,050 Flood12-Jul ,382 SlideAug ,000 Source: table

16 Disasters: Facts & Figures Types of Hazards: Drought/famines, Earthquakes, Epidemics, Floods and Wind Storms Largest killer: Wind Storms (88.36%, as % of people killed due to disasters) Most occurring disaster: Wind Storms (48.02%, as a % of all disasters) Largest affecter: Floods (79.59%, as % of all affected) Annual frequency of all disasters: 6.56 Annual frequency of wind storms: 3.15 Annual frequency of floods: 1.78 Source:

17 Nature of Floods in Nepal Flash Flood Inundation of Plain Area Urban Flooding Source:

18 DHM towards Flood Forecasting Wireless Data Transmission Data Sharing with neighboring countries-India & Bangladesh Tsho Rolpa Risk Reduction and Early Warning System Tsho Rolpa Risk Reduction and Early Warning System Initiated to calibrate easily available R-R models HFAM TOP, Tank, Xinanjinag, ANN, ADM etc. Results are not encouraging for flood peaks

19 Problems No real time data transmission system Flood with landslides: Difficult to predict landslide Scouring and siltation of river beds: difficult to operate automatic recorder

20 Flood Forecasting System Long way to go !!!

21 Thank You !!! Dhanyabad !!!

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25 A House almost under flood water 23 July 2002

26 Urban Flooding-23 July 2002

27 Urban Flooding-23 July 2002

28 Inundation in Plain Area

29 Floods & Landslides-2002

30 Floods & Landslides-2003

31 Slope Failures: Sources of debris

32 Landscape:High Himalayas

33 Landscape: High Mountains

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35 Tsho Rolpa Glacier Lake

36 Tsho Rolpa Glacier Lake Length: 3.3 km Width: 0.5 km Max. Depth: 122 m Avg. Depth: 55m Area: 1.65 sqkm Dam Height: 150 m Volume: million cum

37 Tsho Rolpa Early Warning System: Siren in 19 Villages

38 Station network for flood forecasting