Appendix 2. The Intermittent and Perennial Status of Stream Reaches Estimated for the Shawsheen River Basin by Using a Logistic Regression Equation and Automated Mapping Procedure 2. Locations of field-visited stream sites designated as perennial streams used in development of the logistic regression equation for estimating the probability of a stream flowing perennially, late July through early September 2001 ...............12 3. Locations of field-visited stream sites designated as intermittent streams used in development of the logistic regression equation for estimating the probability of a stream flowing perennially in, late July through early September 2001 ...........14 4. Histograms showing the distribution of the estimated flow durations on the dates of field visits at the A, 351 stream sites throughout Massachusetts; B, 285 stream sites with drainage areas less than 2.00 square miles throughout Massachusetts; C, 28 stream sites in the Shawsheen River Basin, northeastern Massachusetts; and D, 84 stream sites in the South Coastal Basin, southeastern Massachusetts.