﻿HYDROLOGY 
  OF 
  NEW 
  YORK 
  189 
  

  

  Family 
  resemblance 
  of 
  streams. 
  In 
  tables 
  Nos. 
  42, 
  43, 
  61 
  and 
  

   66 
  we 
  have 
  the 
  mean 
  rainfall, 
  runoff 
  and 
  evaporation 
  of 
  the 
  

   storage, 
  growing 
  and 
  replenishing 
  periods 
  for 
  Muskingum, 
  Gen- 
  

   esee, 
  Croton 
  and 
  Hudson 
  rivers. 
  Those 
  tables 
  show 
  what 
  may 
  

   be 
  termed 
  the 
  family 
  resemblance 
  between 
  streams. 
  For 
  instance, 
  

   for 
  the 
  Muskingum 
  and 
  Genesee 
  rivers 
  the 
  mean 
  rainfall 
  of 
  the 
  

   storage 
  period 
  is 
  about 
  19 
  inches, 
  with 
  a 
  runoff 
  of 
  about 
  10 
  inches 
  

   and 
  an 
  evaporation 
  of 
  about 
  9 
  inches. 
  For 
  the 
  growing 
  period 
  

   the 
  mean 
  rainfall 
  of 
  each 
  of 
  these 
  two 
  streams 
  is 
  about 
  12 
  inches, 
  

   with 
  runoff 
  1.7 
  inches 
  and 
  evaporation 
  10 
  inches. 
  For 
  the 
  replen^ 
  

   ishing 
  period 
  the 
  mean 
  rainfall 
  of 
  each 
  is 
  about 
  9 
  inches, 
  with 
  

   runoff 
  about 
  2 
  inches 
  and 
  evaporation 
  7.5 
  inches. 
  The 
  total 
  rain- 
  

   fall 
  of 
  the 
  whole 
  year 
  is 
  40 
  inches 
  for 
  each 
  stream 
  — 
  runoff 
  13.5 
  

   inches 
  and 
  evaporation 
  26.5 
  inches. 
  

  

  The 
  Croton 
  river 
  has 
  a 
  much 
  higher 
  rainfall. 
  Twenty-four 
  

   inches 
  in 
  the 
  storage 
  period 
  produces 
  17 
  inches 
  of 
  runoff, 
  with 
  an 
  

   evaporation 
  of 
  7 
  inches. 
  From 
  13.6 
  inches 
  of 
  rain 
  in 
  the 
  summer 
  

   we 
  have 
  2.6 
  inches 
  of 
  runoff, 
  with 
  11 
  inches 
  of 
  evaporation. 
  The 
  

   rainfall 
  for 
  the 
  year 
  is 
  49.4 
  inches, 
  or, 
  say, 
  9 
  inches 
  more 
  than 
  for 
  

   Muskingum 
  and 
  Genesee 
  rivers. 
  The 
  runoff 
  is 
  also 
  about 
  9 
  inches 
  

   in 
  excess 
  of 
  that 
  of 
  these 
  two 
  streams. 
  The 
  evaporation 
  is, 
  how- 
  

   ever, 
  the 
  same, 
  pointing 
  very 
  strongly 
  to 
  a 
  similar 
  cause. 
  

  

  The 
  Hudson 
  river 
  shows 
  apparently 
  the 
  effect 
  of 
  an 
  impermeable 
  

   catchment, 
  combined 
  with 
  a 
  large 
  forest 
  area. 
  It 
  has 
  a 
  mean 
  

   annual 
  rainfall 
  of 
  44.2 
  inches, 
  yielding 
  23.3 
  inches 
  runoff, 
  with 
  

   20.9 
  inches 
  evaporation. 
  For 
  the 
  storage 
  period 
  20.6 
  inches 
  rain- 
  

   fall 
  yields 
  16.1 
  inches 
  runoff, 
  with 
  4.5 
  inches 
  evaporation. 
  For 
  

   the 
  growing 
  period 
  12.7 
  inches 
  rainfall 
  yields 
  3.5 
  inches 
  runoff, 
  

   with 
  9.3 
  inches 
  evaporation. 
  For 
  the 
  replenishing 
  period 
  10.9 
  

   inches 
  rainfall 
  yields 
  3.7 
  inches 
  runoff 
  and 
  7.1 
  inches 
  evaporation. 
  

  

  The 
  classification 
  here 
  given 
  is 
  experimental 
  merely, 
  and 
  is 
  

   subject 
  to 
  modification 
  with 
  the 
  gathering 
  of 
  more 
  complete 
  

   data. 
  1 
  

  

  In 
  the 
  foregoing 
  the 
  classification 
  is, 
  with 
  the 
  exception 
  of 
  

   Muskingum 
  river, 
  not 
  only 
  limited 
  to 
  the 
  State 
  of 
  New 
  York 
  but 
  

  

  lFor 
  more 
  extended 
  discussion 
  of 
  classification 
  of 
  streams 
  see 
  paper 
  on 
  

   Relation 
  of 
  Rainfall 
  to 
  Runoff. 
  

  

  