Environmental Data Analysis BC ENV 3017


Exercise: Hudson River Discharge and Climate Change

Global climate change most likely will have an effect on the hydrologic cycle and this affect river discharge rates. We want to find out if the discharge rate of the  Hudson River is affected by this.
  1.  Download the Hudson River flow data from the web site of the class:  The data have been measured for the later years and reconstructed from other measurements for the earlier years for the Green Island Station of the Hudson River. See below for the sources of the data.
  2. Calculate the basic statistics of the discharge rate (mean, median, SD). Make a histogarm of the discharge data, do they appear to be normally distributed?
  3. Plot the discharge rate as a time series (line plot).
  4. Add a linear trend line curve to the data and display equation and r2 on the plot. Is the discharge rate increasing or decreasing with time?
  5. Perform a t-test (use the LINEST function, calculate the t-statistic and use TDIST to calculate the P-value. USe the help files in EXCEL to help yourself if you have any problems). Is there a significant trend in the discharge rate of the Hudson as a function of time?
  6. Determine the significance of the correlation also by using the REGRESSION function. Make sure that the P-value is the same as the one obtained above.

Source of data:

USGS: New York NWIS-W Data Retrieval
Hudson River At Green Island Ny (01358000)
EPA: Watershed Information Middle Hudson