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Namaste!!!. Naba Raj Adhikari NEPAL. HydroMeteorological Activities in Nepal. Dept. of Hydrology Meteorology NEPAL. Nepal: Location. 26º 22' N - 30º 27' N Lat. 80º 4'E - 88º 12'E Long. Area: 147,181 km 2 Length: ~850 km EW Width: ~200 km NS Altitude:~ 60-8848 m.
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Namaste!!! Naba Raj Adhikari NEPAL
HydroMeteorological Activities in Nepal Dept. of Hydrology Meteorology NEPAL
Nepal: Location 26º 22' N - 30º 27' N Lat. 80º 4'E - 88º 12'E Long. Area: 147,181 km2 Length: ~850 km EW Width: ~200 km NS Altitude:~ 60-8848 m
Nepal:Physiographic • Terai Region (Gangetic Plain) • Siwaliks Region • Middle Mountain Region • High Mountain Region • Higher Himalayas
Nepal:Climate • Tropical Climate Terai • Cool temperate and alpine climateHimalayan ranges • Teraihottest part, summer temp. may rise as high as 40oc and is hot and humid, winter temp. 7o-23oc • Mountainsmild summer with temp. around 25-27oc, sub-zero to 12oc in winter • Himalayas frigid climate • Kathmandu valleypleasant climate with avg. summer temp. of 19-27oc & 2-12oc winter temp.
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 Mountainfew PTN zones exceeds 5000 mm • Himalayasdecreases up to 300 mm
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…
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
Disasters Scenario (1975-2001) Disaster Events Excluding Windstorm Source: http://www.southasianfloods.org
Top 10 Natural Disasters Source: http://www.cred.be/emdat/profiles/natural/nepal.htm#chronological table
Top 10 Natural Disasters (contd.) Source: http://www.cred.be/emdat/profiles/natural/nepal.htm#chronological table
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: http://www.southasianfloods.org
Nature of Floods in Nepal • Flash Flood • Inundation of Plain Area • Urban Flooding Source: http://www.southasianfloods.org
DHM towards Flood Forecasting • Wireless Data Transmission • Data Sharing with neighboring countries-India & Bangladesh • 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
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
Flood Forecasting System Long way to go !!!
Thank You !!! Dhanyabad !!!
A House almost under flood water 23 July 2002
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: 90-100 million cum