| Abstract: | Low-flow, base-flow, and mean-flow characteristics are an important part of assessing water resources in a watershed. These streamflow characteristics can be used by watershed planners and regulators to determine water availability, water-use allocations, assimilative capacities of streams, and aquatic-habitat needs. Streamflow characteristics are commonly predicted by use of regression equations when a nearby streamflow-gaging station is not available.
Regression equations for predicting low-flow, base-flow, and mean-flow characteristics for Pennsylvania streams were developed from data collected at 293 continuous- and partial-record streamflow-gaging stations with flow unaffected by upstream regulation, diversion, or mining. Continuous-record stations used in the regression analysis had 9 years or more of data, and partial-record stations used had seven or more measurements collected during base-flow conditions. The state was divided into five low-flow regions and regional regression equations were developed for the 7-day, 10-year; 7-day, 2-year; 30-day, 10-year; 30-day, 2-year; and 90-day, 10-year low flows using generalized least-squares regression. Statewide regression equations were developed for the 10-year, 25-year, and 50-year base flows using generalized least-squares regression. Statewide regression equations were developed for harmonic mean and mean annual flow using weighted least-squares regression.
Basin characteristics found to be significant explanatory variables at the 95-percent confidence level for one or more regression equations were drainage area, basin slope, thickness of soil, stream density, mean annual precipitation, mean elevation, and the percentage of glaciation, carbonate bedrock, forested area, and urban area within a basin. Standard errors of prediction ranged from 33 to 66 percent for the n-day, T-year low flows; 21 to 23 percent for the base flows; and 12 to 38 percent for the mean annual flow and harmonic mean, respectively. The regression equations are not valid in watersheds with upstream regulation, diversions, or mining activities. Watersheds with karst features need close examination as to the applicability of the regression-equation results. |
| Genre: | USGS Numbered Series |
| ProdID: | 77066 |
| Citation Author: | Stuckey, Marla H. |
| Citation Contributing Office: | Pennsylvania Water Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | - |
| Citation Editor: | |
| Citation End Page: | |
| Citation Issue: | |
| Citation Keywords: | |
| Citation Language: | ENGLISH |
| Citation Larger Work Title: | |
| Citation LatN: | 0425000 |
| Citation LatS: | 0390000 |
| Citation LonE: | -0780000 |
| Citation LonW: | -0800000 |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 88 |
| Citation Online Only Flag: | Y |
| Citation Phsyical Description: | iv, 84 p. |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | Scientific Investigations Report |
| Citation Series Code: | SIR |
| Citation Series Number: | 2006-5130 |
| Citation Search Results Text: | Low-flow, base-flow, and mean-flow regression equations for Pennsylvania streams; 2006; SIR; 2006-5130; Stuckey, Marla H. |
| Citation Start Page: | |
| Citation Volume: | |
| Citation Year: | 2006 |
| Type: | citation/reference |
| Text: | Low-flow, base-flow, and mean-flow regression equations for Pennsylvania streams; 2006; SIR; 2006-5130; Stuckey, Marla H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/sir/2006/5130/ |
| Date Other: | Thu, 20 Jul 2006 00:00 -0500 |
| Publisher: | |
