Abstract:
The  availability  of water  resources  is  highly   variable   both in  space  and  time   in   India.   Assessment   of   river   fibw   during non-monsoon months  along  with  its  time  distribution   is   essential for  planning   and   development   of   water   resources   and   related schemes for meeting  the  growing   requirements   of   our   developing society.  Low flow modelling  is also   necessary   far   dealing   with problems of  stream pollution.  The analysis of  low flows  is equally important for municipal  and  industrial  water supply  schemes,   both from view points  of quantity  and quality. 
The quantum of  flows  in  the   river   in   the   lean   season   is 
generally  very  low	-  varying  from about	15%	in	l*rder   snow   fed
rivers  to  less than	1%  in  some of  the   smaller   river   systems   in
coastal   areas.   Although   the   availability	of	water	during
non-monsoon season  is very  low,  it   plays   a   vital   role   on   the dk,velopment and activities   of   the   region.   Reasonably   accurate estimation  of  the water  resources available during  lean period and also  its  possible  forecast   will   go   a   long   way   in   systematic developmental  planning and utilization  of  the water  resources. 
The  importance of  low  flow  forecasting  is  being   increasingly felt for efficient management   of   the   existing   water   resources projects  as well  as for optimal  planning of  the future  projects. 
A  number  of models have  been suggested  by  various  authors   in the  recent  times  for the flow flow forecasting  but the statistical 
approach   is   still   relevant   and   unavoidable	under	specific
circumstances.  In  this  report,  a suitable   statistical   model   for the  low  flow  forecasting  has  been described. 
This  report  is a  part of  work  programme of Hydrologic   Design Division  and  the study  has been carried out by Shri  M.E.  Hague and Rakesh  Kumar,  Scientists of  the  Institute.