Observed and urbanization-adjusted annual maximum peak discharge and associated urban fraction and precipitation values at USGS streamgage:
04087400 KELLOGG RAVINE AT ZION, 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
1962 1 -- 0 0.306 0.628 121 315 0.850
1963 1 -- 0 0.319 0.360 125 318 0.845
1964 1 -- 0 0.332 1.830 122 310 0.861
1965 1 -- 0 0.346 0.555 206 428 0.599
1966 1 -- 0 0.359 0.468 288 545 0.345
1967 1 -- 0 0.372 1.291 265 510 0.420
1968 1 -- 0 0.385 0.991 119 294 0.892
1969 1 -- 0 0.398 1.083 937 1430 0.012
1970 1 -- 0 0.411 1.040 224 430 0.593
1971 1 -- 0 0.425 0.428 388 646 0.189
1972 1 -- 0 0.439 1.159 601 943 0.048
1973 1 -- 0 0.453 1.408 114 272 0.927
1974 1 -- 0 0.467 1.072 285 497 0.446
1975 1 -- 0 0.481 0.319 136 292 0.897
1976 1 -- 0 0.495 1.264 471 729 0.132