Abstract:
Hydrological   and   related  meteorological   data   are needed   for   proper  planning  in   development,   management   and optimal  utilization  of water  resources  of  the  country  and   its water  related  environment.  Advances  in  hydrology are  dependent on	good, reliable   and   continuous   measurements	of	the hydrological	variables.	The   data   collected	by	various agencies   in our country  is  generally  in  raw  form.   The   first important   task  in  the whole  gambit  of  hydrologic  analysis   is the   collection  true,  accurate  and  regular data.  This  needs   a through   understanding  of  methods  of measurement,  on  the   part 
of	the   people   responsible   to   collect   such	data.	The conventional   and   responsible   to   collect   such   data.	The conventional   and modern methods  need  to  be  imbibed  into,   not only   observers,   technicians   but   also   in   water   resources engineer   & managers.  The  second  concern  is  the  processing   of such   raw  data.  Data processing  classified  as  preliminary   and secondary  data processing  is  essential  before putting  the  data for   further use  in  analysis.  Processing  of  hydrological   data has   two  major objectives : One  to  evaluate  the  data   for   its accuracy   and   the  other  to prepare  the data  in   a   form   most valuable   to  the  users.  The  measurements  of  hydrological   data are   recorded  and  processed by  a wide  range  of   methods,   from the   manual   writing   down  and   processing   to   the   invisible marking   and  processing  of  electronic  impulses  on   a   magnetic  tape.  Automated  data processing  using  high  speed computers has immense potential  for  handling  large volume of hydrologic data in   a quick  and  economic  way.  The  third  step  in this   link   is the  analysis  of  hydrologic  data  by existing methods and use of new  and modern methods  like  hydrologic  modelling etc. 
In   the   study  reported herein   various   aspects   of hydrologic  data collection,  processing  and analysis have   been dealt  in  detail.  In  the  present  study  an attempt  has been made to  cover  in depth one  of  the  most  important,  crucial  and   need of   the   day   i.e. collection, processing   and   analysis   of hydrologic   data.  The  report  opens  with  a basic  discussion   on data   processing  including  important  definitions  and   concepts after   this   a   section  has  been devoted   to   hydrologic   data collection/estimation,  existing  system  of  data collection   in India	and   the   various   organisations   involved   in	these activities.	Though	more   stress   has	been	focused on precipitation   and   discharge  data however,   other   data   like ground	water,	water quality,	sediment,	and	other meteorological   data have  also  been covered.  The next part   of the   report  deals  with  the  processing  of  various   hydrological parameters. The  stress  has  been made  en  the use  of   computers and  electronic  data processing.  This  is  followed  by  the  recent developments   in   hydrology  i.e.  mathematical   modelling.   The chapter   cover  the  basic  definition,  classes   of   mathematical models   and   provides  a brief  review of   available   hydrologic models. Finally  the  conclusions  brings  out  the  importance   of data  processing  and  usefulness  of  automated data processing  in present 	context. 	It  has  also  been  concluded  from   the   study that  the  automated  data processing  and  persons  trained  in this field  are  needed  to  maintain  the  pace with the  development   in hydrological  data  analysis  and modelling.