CLIMATES REPORT OF NP N 1961 EPAL AND 2012 WWF was founded in 1961 T +100 HEIR WWF is in over 100 countries, on 5 continents I M PLICATION S +5M +5,000 WWF has over 5,000 WWF has over 5 million staff worldwide supporters CLIMATES OF NEPAL NP AND THEIR IMPLICATIONS... W WW.WWFNEPAL.ORG Why we are here To stop the degradation of the planet’s natural environment and to build a future in which humans live in harmony with nature. www.wwfnepal.org © 1986 Panda Symbol WWF-World Wide Fund For Nature (also known as World Wildlife Fund) ® “WWF” is a WWF Registered Trademark - Janak Lal Nayava Shrestha WWF Nepal, P. O. Box: 7660, Baluwatar, Kathmandu, Nepal T: +977 1 4434820, F: +977 1 4438458, E: [email protected] Collected Published Papers on Climates of Nepal and their implications ........ Table of Contents Pages Forword I Preface II About the book and author IV Acknowledgements VI . Acronyms VII 1. Heavy monsoon rainfall in Nepal, Weather, 1974 1 2. Climates of Nepal, The Himalayan review, 1975 9 3. Topoclimatology of the Kathmandu Valley, Proceedings ANZAAS, 49th Congress, New Zealand, 1979 13 4. A Topoclimatological investigation of solar radiation in the Kathmandu valley, Nepal, Australian Meteorologic al Magazine, 1980 24 5. Estimation of Temperature over Nepal, The Himalayan Review, 1980 37 6. Areal rainfall in the Kathmandu valley, Mausam, 1981 44 7. Rainfall in Nepal, The Himalayan review, 1982 51 8. Environmental impacts on agricultural development, Collected papers, Nepal's Nature Paradise By T.C.Majupuria, 1984/85 61 9. Monitoring and evaluation of crop yield and production in Nepal, Proceedings, RONAST, 3rd Congress, 1999 70 10. Probable maximum precipitation, Proceeding of the 2nd Intl symposium on control Beijing 2002 82 11. Temporal variation of rainfall in Nepal since 1971-2000, Journal of Hydrology and Meteorology, 2004 91 12. The estimation of potential evapo-transpiration by climate model for Western Nepal, Journal of Hydrology and Meteorology, 2005 102 13. The analysis of wind for Western Nepal, Journal of Hydrology and Meteorology, 2006 112 14. Variations of rice yield with rainfall in Nepal during 1971-2000, Journal of Hydrology and Meteorology, 2008 121 15. Impact of climate, climate change and modern technology on Wheat production in Nepal: a case study at Bhairahawa, Journal of Hydrology and Meteorology, 2009 131 16. Impact of climate change on production and productivity in Nepal: a case study of maize research and development in Nepal, Journal of Agriculture and Environment, 2010 145 17. SOHAM - Nepal’s Chairman Dr. Janak Lal Nayava’s speech on WMO day-2005 156 18. Further wor ks and references on Climates of Nepal 161 19. Dendrogram 164 II Preface: This preface is especially for general readers: the defi nation given here under may help them to understand better. It is understood that the climatic parameters, such as global solar radiation, maximum temperature, minimum temperature, precipitation, wind and potential evapo-transpiration are integral parts of climate, understanding of which in relation of this country’s climate are very essential. Radiation: The ultimate source of energy and the solar radiation received at the earth’s surface consists of two parts: direct solar radiation and diffused sky radiation. The sum of these two radiation components is known as the global radiation. It is understood that the intensity of solar radiation reaching the earth’s surface at different slopes and aspects has enormous impact on crop production and management: such as engineering design, natural resource management, cold storage, building, road, canal, alternate energy and air conditioning. The duration and intensity of radiation are important for photosynthesis, which plays a vital role in plant growth. The global solar radiation on different aspects with cloudless sky as well as average conditions of sky at Kathmandu have been presented with fi gures. Please refer paper no. 3. Temperature: Temperature is important in all biological processes and it is hazardous in extreme temperature. When temperature is below 00C, frost might occur and as a result, plants are damaged due to freezing. The unexpected occurrence of frost in agricultural is serious. The study of climatology and topographic data can help to predict the zone of frost free area. At high temperature, above 400C, serious damage might occur in plants and crops due to thermal stress. Below 150C, crops productivity will be decreased and tropical crops usually cease to grow at 150C, between these two extremes, there is an optimum temperature, say 200C to 300C which favors rapid growth. Development of models on temperature and the temperature patterns of the hottest and coldest week have been presented in paper no. 7 and the 30 year trends of temperature at a few places have also been presented in paper no. 14, 15 and 16. Precipitation: Water plays very important role in aspects such as town planning, agriculture, natural resource management and industry. Intensity of rainfall should be well understood in constructing roads, bridges, fl ood forecasting and sewerage installations. The seasonal rainfall plays a vital role in water conservation. The intensity of the summer monsoon rains in Nepal and the date of the onset of the monsoon are both important factors in the country’s economy, because it is the main season for the country’s major crop. A case study of post monsoon rainfall on paper no.1, the general feature of the atmospheric circulation over Nepal, mean and annual monsoon rainfall over Nepal on paper no. 5, areal rainfall in the Kathmandu valley on paper no. 6, temporal variations of rainfall in Nepal in paper no. 10 and fi nally probable maximum temperature were dealt on paper no. 11. Wind: wind plays crucial role in the development of various projects, such as wind speed direction being useful factors for transmission lines, construction of bridges and it is a crucial factor in choosing the site of a runway. Wind is one the main factors in the study of air pollution and in locating new sites for industry and town planning. Knowledge of wind profi le is necessary for the construction of tall buildings and television towers. The choice of best sites and best design of wind power installation is to a large extent a climatological question. Wind breaks and shelter belts can be made to reduce the serious damage of wind. The transpiration and carbon dioxide assimilation of plants depend upon the wind velocity. Wind is also a crucial factor for success in mountaineering expeditions in Nepal Himalayas. Mean wind speed values III the Western Nepal have been studied and the spatial variations of wind at each month have been tested. These mean maps of wind speeds will give the general pattern of wind at the study area. Refer to paper no. 13 Humidity: Humidity will indicate whether climate is dry or moist which will help to suitable to suitable crops according to humidity index. Humidity is used to measure the comfort of the human index and humidity is measured in many sophisticated factories to avoid the corrosion and damping effect. Evaporation: Evaporation from soil and plant surface is a phenomenon of cance in agrometeorology. As a matter of fact, evapo-transpiration is one of the main parameters in water balance and energy balance studies. These studies are very necessary for irrigation planning and practices, water conservation, water supply and agricultural planning. The estimation of evapo-transpiration by climate models for western Nepal is presented in paper no. 12. Others: Certain extreme meteorological co nditions bring severe hazards such as drought, cold waves, heat waves, storms and hurricanes, which directly affect our daily lives and loss of property and lives. Timing of occurrence and duration of fog are both important factors to aviation for better planning of their schedule. The best location and routing of motorways can be determined from climatological data on the frequency of fog, frost, high winds and drifting snow. Climatological investigations can provide information on their likely frequency, magnitude and duration. Thus topoclimatology, monitoring and evaluation of crop yield and production and climate change and its impact on economic perspective are also dealt. Now the study of applied climatology is related to many (refer paper no. 3, 8, 9, 14, 15 and 16). These types of studies involving close cooperation between climatologists, engineers, agronomists, economists and planners help to obtain the maximum from the weather and climatic factors related to their projects. These studies are of course tips of the iceberg. To out the information of work accomplished is very important for researcher to begin their work. Any comments and suggestions are most welcome for the further development. Thank you. Janak Lal Nayava Shrestha [email protected] IV About the book and author: In early 1960’s Nepal felt to initiate to establish the meteorological service in Nepal, due caused by necessity of aviation route forecast for International and meteorological facilities needed at International Airport at Kathmandu as per International Civil Aviation Organization (ICAO) rule. In 1964, Mr. M. Gilead, Director of Israel Meteorological Service (IMS) was deputed to Government of Nepal as an advisor by World Meteorological Organization (WMO) to advice for the establishment of Meteorological Service in Nepal. Under this venture, Department of Hydrology and Meteorology (DHM) was established in 1966 and the same year DHM became the member of WMO. During his tenure in Nepal, I was awarded WMO fellowship and went to Israel in 1966 and I had a very individual, intensive operational course covering basic foundations of meteorology. I still feel indebted and thankful to Mr. Gilead and the Israel Meteorological Service. 1967-1971: Meteorologist, DHM, Kathmandu 19 71-1972: Acting Deputy Director, DHM, Kathmandu 1972-1974: On study leave at Birmingham University, England for M.Sc.