slope_fdc

postprocessinglib.evaluation.metrics.slope_fdc(df: DataFrame, percentiles: tuple[float, float] = [33, 66], stations: list[int] = []) → list[float]

Calculates the slope of the Flow Duration Curve (FDC).

Parameters:

  • df (pd.DataFrame) – Streamflow values for calculating the FDC slope. Each column corresponds to a station.

  • percentiles (tuple[float, float]) – Percentiles used for slope calculation (e.g., (33, 66) for 33rd and 66th percentiles).

  • stations (list[int]) – List of station indices (1-indexed) for which to calculate the slope. If empty, all stations are processed.

Returns:

DataFrame with the slope of the FDC for each station.

Return type:

pd.DataFrame

Example

>>> import pandas as pd
>>> from postprocessinglib.evaluation import metrics
>>> from metrics import slope_fdc
>>> data = pd.DataFrame({
>>>     "Station1": [1.2, 0.8, 0.6, 0.4, 0.2],
>>>     "Station2": [2.0, 1.5, 1.0, 0.5, 0.2]
>>> })
>>> slope_fdc(df=data, percentiles=(33, 66))
                fdc_Slope
    Station 1      3.1566
    Station 2      2.3474