Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05536201 THORN CREEK AT PARK FOREST, 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
1955 1 7 0 0.198 4.895 475 672 0.128
1957 1 7 0 0.212 2.540 1320 1710 0.006
1962 1 -- 0 0.247 0.215 116 197 0.911
1963 1 4B 0 0.255 0.215 60 116 0.980
1964 1 -- 0 0.262 1.249 134 217 0.883
1965 1 -- 0 0.269 1.102 215 315 0.689
1966 1 -- 0 0.276 2.985 502 662 0.135
1967 1 -- 0 0.284 1.463 369 497 0.305
1968 1 -- 0 0.291 3.505 1140 1410 0.012
1969 1 -- 0 0.298 0.692 139 213 0.888
1970 1 -- 0 0.306 1.521 400 523 0.265
1971 1 2 0 0.310 1.371 440 567 0.207
1972 1 -- 0 0.314 1.255 218 304 0.714
1973 1 -- 0 0.318 1.241 472 601 0.178
1974 1 -- 0 0.322 2.976 1460 1750 0.006
1975 1 -- 0 0.326 1.657 300 399 0.497
1976 1 -- 0 0.330 2.199 332 435 0.421
1977 1 -- 0 0.335 1.656 191 266 0.794
1978 1 -- 0 0.339 1.354 387 494 0.311