Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05551930 WELCH CREEK NEAR BIG ROCK, IL

Observed annual peak-flood magnitudes were adjusted to 2010 land-use conditions on the basis of panel data regression model with fixed effect analysis. The symbols presented in the figure are: "observed annual peaks", "adjusted annual peaks", and "fraction of urbanization in the watershed"

Legend for Graph

Water year Segment Discharge code Cumulative reservoir storage (acre-feet) Urban fraction Precipitation (inches) Observed peak discharge (ft3/s) Adjusted peak discharge (ft3/s) Exceedance probability
1965 1 -- 0 0.044 0.069 334 366 0.503
1966 1 -- 0 0.044 0.477 398 434 0.381
1967 1 -- 0 0.044 1.113 306 336 0.571
1968 1 -- 0 0.045 1.337 155 175 0.874
1969 1 -- 0 0.045 0.109 314 344 0.551
1970 1 -- 0 0.045 1.444 354 387 0.462
1971 1 -- 0 0.046 0.374 297 326 0.595
1972 1 -- 0 0.047 1.071 563 606 0.179
1973 1 -- 0 0.048 1.467 334 365 0.507
1974 1 -- 0 0.049 1.320 694 744 0.096
1975 1 -- 0 0.050 0.855 187 208 0.820
1976 1 -- 0 0.051 1.089 291 318 0.611
1977 1 -- 0 0.052 0.834 141 158 0.897
1978 1 -- 0 0.053 1.390 525 562 0.214
1979 1 -- 0 0.054 0.354 402 434 0.381
1980 1 -- 0 0.055 0.913 180 199 0.834