Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
05550450 POPLAR CREEK NEAR ONTARIOVILLE, 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
1961 1 -- 633 0.133 1.282 200 292 0.452
1962 1 -- 633 0.146 0.270 275 373 0.247
1963 1 -- 633 0.159 1.738 118 185 0.792
1964 1 -- 633 0.172 3.149 146 216 0.700
1965 1 -- 633 0.185 0.579 200 277 0.495
1966 1 -- 633 0.198 0.533 263 345 0.309
1967 1 -- 633 0.211 1.215 410 510 0.093
1968 1 2 633 0.224 3.270 217 287 0.467
1969 0 -- 1154 0.237 2.081 137 200 0.750
1970 2 -- 1154 0.250 2.400 190 273 0.510
1971 2 -- 1154 0.270 0.235 179 253 0.576
1972 2 -- 1154 0.289 0.662 290 380 0.234
1973 2 -- 1154 0.309 1.830 374 475 0.122
1974 2 -- 1154 0.329 0.957 254 327 0.354
1975 2 -- 1154 0.348 0.643 128 174 0.822
1976 2 -- 1154 0.368 1.640 297 362 0.268
1977 2 -- 1154 0.388 1.350 111 147 0.890