04377nas|a2200457 a 4500 20260817162826.0 070212s2006 th uu|m rtt 0| a1eng d .b12006579 AIT Thesis no.WM-05-9 Choden, Thinley Application of a local area model for rainfall forecasting in Bhutan Pathum Thani, Thailand : Asian Institute of Technology, 2006 87 leaves : ill. Thesis ; no. WM-05-9 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Thesis (M.Eng.) - Asian Institute of Technology, 2006 Landslide, flash floods etc. are inevitable problems in Bhutan, especially during the rainy season. Even though the rainfall is useful for providing water, it creates havoc when it exceeds certain amount. Hence, the prediction of rainfall is very necessary to avoid natural disasters. The aim of this study is to forecast rainfall for Bhutan using a limited area model. The study results will be useful in providing warning to avoid adverse consequences of floods and landslides. The Weather Research and Forecasting (WRF) model is used for forecasting the rainfall. The intial and boundary conditions for the model are provided by the gridded meteorological output from the Global Forecast System (GFS) model of National Centers for Environmental Prediction (NCEP). Considering the restrictions and requirements imposed by computing power and the simulation time, a three level nested grid structure of 75, 15 and 5km grid sizes are used. The vertical space is divided into 31 unequally spaced layers. The model results are compared with the observed rainfall data using the Thiessen Polygon method. The field data is collected from meteorological stations in Bhutan and basic analyses are carried out to understand the rainfall patterns. Even though Bhutan is a very small country, the variations in rainfall are extremes. The southern part of Bhutan receives more rainfall than the other parts due to the monsoon wind from the Bay of Bengal which is laden with moisture. The regional and local differences in rainfall are due to the altitude, the incoming wind directions, aspects, rain shadow effects and the elevation. The visual comparison of the observed and the computed rainfall distribution shows that the model underestimates the rainfall in the wet periods in most of the stations. It, however, provides good results when the rainfall is very less or when there are no rains. During the dry periods, the model predicts the rainfall well except for a small area within Bhutan. There is a potential for improvement in the forecast results if the hourly instead of daily data is used and also if the local terrestrial data is used instead of the global data Rain and rainfall Bhutan Forecasting Babel, Mukand Singh, Chairperson Gupta, Ashim Das, Chairperson Sutat Weesakul, Examination committee Honda, Kiyoshi, Examination Committee Herath, Srikantha, Examination committee Government of Austria, Scholarship Donor Asian Institute of Technology. Thesis ; no. WM-05-9 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B10694 .b12006579 mnait u 240611 0 070212 m a u 0 mnait mnait mnarc mnarc 20 40 Barcode : 30050120550685 CREATED : 2005-09-15 RECORD # : i12516922 LPATRON : 1022244 LCHKIN : 2012-08-17 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 8 TOT RENEW : 13 Barcode : 30050120550768 CREATED : 2005-09-15 RECORD # : i12516934 LPATRON : 1023408 LCHKIN : 2012-08-19 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 3 TOT RENEW : 0 Barcode : 30050120233605 CREATED : 2016-01-04 RECORD # : i12920708 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050121018047 CREATED : 2020-10-07 RECORD # : i13281434 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 6434 6434 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Thesis no.WM-05-9 30050120550685 2026-08-17 16:28:26 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT Thesis no.WM-05-9 30050120550768 2026-08-17 16:28:26 2 2026-08-17 20 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no.WM-05-9 30050120233605 2026-08-17 16:28:26 2026-08-17 40 0 0 0 0 MAIN MAIN mnarc 2026-08-17 0 AIT Thesis no.WM-05-9 30050121018047 2026-08-17 16:28:26 3 2026-08-17 20