| Abstract: | Impervious surfaces such as paved roads, parking lots, and building roofs can affect the natural streamflow patterns and ecosystems of nearby streams. This dataset summarizes the percentage of impervious area for watersheds across Massachusetts by using a newly available statewide 1-m binary raster dataset of impervious surface for 2005. In order to accurately capture the wide spatial variability of impervious surface, it was necessary to delineate a new set of finely discretized basin boundaries for Massachusetts. This new set of basins was delineated at a scale finer than that of the existing 12-digit Hydrologic Unit Code basins (HUC-12s) of the national Watershed Boundary Dataset. The dataset consists of three GIS shapefiles. The Massachusetts nested subbasins and the hydrologic units data layers consist of topographically delineated boundaries and their associated percentage of impervious cover for all of Massachusetts except Cape Cod, the Islands, and the Plymouth-Carver region. The Massachusetts groundwater-contributing areas data layer consists of groundwater contributing-area boundaries for streams and coastal areas of Cape Cod and the Plymouth-Carver region. These boundaries were delineated by using groundwater-flow models previously published by the U.S. Geological Survey.
Subbasin and hydrologic unit boundaries were delineated statewide with the exception of Cape Cod and the Plymouth-Carver Region. For the purpose of this study, a subbasin is defined as the entire drainage area upstream of an outlet point. Subbasins draining to multiple outlet points on the same stream are nested. That is, a large downstream subbasin polygon comprises all of the smaller upstream subbasin polygons. A hydrologic unit is the intervening drainage area between a given outlet point and the outlet point of the next upstream unit (Fig. 1). Hydrologic units divide subbasins into discrete, nonoverlapping areas. Each hydrologic unit corresponds to a subbasin delineated from the same outlet point; the hydrologic unit and the subbasin share the same unique identifier attribute. Because the same set of outlet points was used for the delineation of subbasins and hydrologic units, the linework for both data layers is identical; however, polygon attributes differ because for a given outlet point, the subbasin polygon area is the sum of all the upstream hydrologic units. Impervious surface summarized for a subbasin represents the percentage of impervious surface area of the entire upstream watershed, whereas the impervious surface for a hydrologic unit represents the percentage of impervious surface area for the intervening drainage area between two outlet points. |
| Genre: | USGS Numbered Series |
| ProdID: | 97610 |
| Citation Author: | Brandt, Sara L.; Steeves, Peter A. |
| Citation Contributing Office: | U.S. Geological Survey |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | - |
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| Citation End Page: | |
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| Citation Keywords: | |
| Citation Language: | ENGLISH |
| Citation Larger Work Title: | |
| Citation LatN: | 045.302523 |
| Citation LatS: | 041.463959 |
| Citation LonE: | -069.91795 |
| Citation LonW: | -073.66684 |
| Citation Month: | |
| Citation No Pagination: | Y |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | Y |
| Citation Phsyical Description: | Available online only |
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| Citation Public Comments: | Prepared in cooperation with the U.S. Environmental Protection Agency |
| Citation Publisher: | U.S. Geological Survey |
| Citation Series: | Data Series |
| Citation Series Code: | DS |
| Citation Series Number: | 451 |
| Citation Search Results Text: | Local and Cumulative Impervious Cover of Massachusetts Stream Basins; 2009; DS; 451; Brandt, Sara L.; Steeves, Peter A. |
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| Citation Volume: | |
| Citation Year: | 2009 |
| Type: | citation/reference |
| Text: | Local and Cumulative Impervious Cover of Massachusetts Stream Basins; 2009; DS; 451; Brandt, Sara L.; Steeves, Peter A. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/ds/451/ |
| Date Other: | Wed, 17 Jun 2009 00:00 -0500 |
| Publisher: | U.S. Geological Survey |
