03671nas a2200253 a 450000500170000000800410001703500150005810000250007324501020009826000680020030000230026849000270029150001450031850200580046352024850052165000550300665000490306170000380311070000500314870000490319870000450324781000590329285600660335120260817163550.0110511s2010    th uu|m rtt   0|  a1eng d  a.b120952301 aBhusal, Shyam Prasad10aAssessment of future climate and its impact on streamflow :ba case study of Bagmati Basin, Nepal  aPathum Thani, Thailand :bAsian Institute of Technology,c2010   a107 leaves :bill.1 aThesis ;vno. WM-09-05  aA thesis submitted in partial fulfillment of the requirements for the  degree of Master of Engineering in  Water Engineering and Management   aThesis (M.Eng.) - Asian Institute of Technology, 2009  aClimate Change is a global phenomenon but the trend and extent of its impact varies in spatial and  temporal  scale  demanding  local  scale  studies.  Bagmati  river  basin  in  Nepal  is  currently facing  the  problems  of  water  stress  and  floods  which  may  be  aggravated  due  to  climate change. This research is carried out to quantify the future changes in climate and its impact on streamflow  in  the  Bagmati  Basin.  The  research  methodology  includes  GCM  selection  and downscaling  of  GCM  data,  extreme  climate  indices  analysis  and  assessment  of  future  water availability under SRES scenarios A2 and B2.  Out  of  five  GCMs  (Hadcm3,  CSIRO,  CCSR/NIES,  CGCM3  and  ECHAM4)  analyzed, Hadcm3 provided statistically better results to represent present day precipitation while in case of  temperature  all  GCMs  show  statistically  reliable  performance.  Downscaling  with  SDSM model  has  well  estimated  both  mean  and  extreme  values  of  temperature  whereas  it  could  not estimate the extreme events of precipitation but the mean daily precipitation result is reliable. Scenario A2 indicates the diminish in precipitation amount during the dry period and increase during the wet period. However, scenario B2 shows increase during both periods. Maximum and minimum temperature extremes are increasing with higher rates during summer than  the  winter  indicating  more  severe  impact  of  warming  during  summer.  The  increase  in heavy precipitation events R20 (number of days with precipitation > 20mm), R35 (number of days  with  precipitation  >  35mm)  and  Rx5day  (maximum  5-day  precipitation)  will  lead  to increase  in  frequency  and  magnitude  of  floods  in  the  future.  Similarly,  the  increase  on  the trend of consecutive dry days (CDD) and decrease of consecutive wet days (CWD) reflects the occurrence  of  more  intense  droughts  in  the  future. The  hydrological  simulation  shows  that according  to  scenario  A2,  water  availability  will  be  decreased  during  pre-monsoon  period leading to increase in water stress during dry period while flow will increase during monsoon period  indicating  increase  in  flood  problems.  However,  scenario  B2  shows  increase  in  water availability  during  both  wet  and  dry  periods.  With these  expected  changes  on  future  climate and water availability in the basin, appropriate adaptation and management strategies are to be developed.     0aClimatic changesxEvaluationzNepalzBagmati Basin 0aStreamflowxEvaluationzNepalzBagmati Basin1 aBabel, Mukand Singh,eChairperson1 aPerret, Sylvain Roger,eExamination Committee1 aClemente, Roberto S.,eExamination Committee1 aGupta, Ashim Das,eExamination Committee2 aAsian Institute of Technology.tThesis ;vno. WM-09-05  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B04324