10 



NEW YORK STATE MUSEUM 



PAGE 



The relation of rainfall to runoff (cont'd) 

 Runoff (cont'd) 



Danger of using percentages 118 



Runoff coefficient misleading . . 119 



Relation between total runoff and runoff of storage period 119 



Effect of low ground water 120 



Vermeule's formulas 121 



Russell's formulas 125 



Relation between catchment area and maximum, minimum and 



mean runoff .*. . 125 



The extreme low-water period 127 



Rainfall, runoff, evaporation and variation from the mean on 



Hudson and Genesee rivers 130 



Hudson river 130 



Genesee river , 130 



Comparison of rainfalls, Hudson and Genesee rivers 131 



Comparison of runoffs, Hudson and Genesee rivers 131 



Comparison of evaporations, Hudson and Genesee rivers 132 



Variation in weir measurements 132 



Genesee and Hudson gagings reduced to sharp-crested weir meas- 

 urements 133 



Evaporation 134 



Fitz Gerald's formula for evaporation 134 



Evaporation relations 135 



Effect of wind and other meteorological elements 136 



Persistency of evaporation 137 



Negative evaporation 138 



Evaporation at Ogdensburg \ 140 



Croton Water Department's evaporation records 141 



Evaporation at Rochester 144 



Drain gages at Geneva 144 



Hight of w r ater in wells 158 



The relation of geologic structure to runoff 162 



Forests , 172 



Do forests increase rainfall? ( 172 



Relation of forests to stream flow 173 



The Forest preserve t 174 



The Adirondack park 175 



Area of the Forest preserve 176 



The Catskill park 177 



Effect of forests 178 



Forestation of the Croton catchment area 186 



Details concerning tables and diagrams 188 



Topographic relations of the catchment areas of some of the main 



streams tabulated 188 



Family resemblance of streams 189 



Description of Muskingum, Genesee, Croton and Hudson rivers. .. . 190 



Description of diagrams 192 



Exponential formula 197 



Runoff diagrams 197 



