General Information

Project area general description

The state of Connecticut

Are any areas excluded?

Flow statistics/basin characteristics not computed for the upper reaches of the Housatonic River and the mainstem of the Connecticut River due to extrapolating beyond the range of explanatory variables used in the study.

Types of flow statistics available

low flow, flow durations, and peak flows

ArcGIS version used for processing

9.3

Was TopoGrid used to process DEMs?

Yes

DEM and derivatives projection (general description)

NAD 1983 Connecticut State Plane Coordinate System FIPS 0600 Feet

DEM and derivatives (fdr, fac, etc.) resolution

30 m, resampled to 10 m

DEM source

U.S. Geological Survey, 2006, National Elevation Dataset

Hydrography source

USGS  NHD and centerline hydrography at 1:24,000 scale developed by CT DEP (Danenberg and Bogar, 1994)

Hydrologic unit "walls" source

USDA WBD and drainage subbasins at 1:24,000 scale (Connecticut Drainage Basin Boundaries)

Gage basin boundaries source

CT WSC digitized

Interactive map snapping tolerance

3 cells

 

Basin Characteristics Methods and Sources

Name

Description

Computation method

Data source

Report

Variable label in report

DRNAREA

Drainage area in square miles

polygon area

U.S. Geological Survey, 2006, National Elevation Dataset: accessed on June 25, 2009, at http://ned.usgs.gov.Watershed Boundary Dataset drainage boundaries (http://www.ncgc.nrcs.usda.gov/products/datasets/watershed/, accessed June 25, 2009

Ahearn (2010)

DRNAREA, DA

 

 

 

 

Ahearn (2004)

Drainage Area

ELEV

Mean Basin Elevation, in feet

area-weighted mean

U.S. Geological Survey, 2006, National Elevation Dataset: accessed on June 25, 2009, at http://ned.usgs.gov

Ahearn (2010)

ELEV, EL

 

 

 

 

Ahearn (2004)

Mean basin elevation

WETLAND

Wetlands, in percent

percent in area

U.S. Fish and Wildlife Service, 2009, National Wetlands Inventory: Branch of Resource and Mapping Support, accessed on August 5, 2009, at http://www.fws.gov/wetlands/

Ahearn (2010)

WETLAND

 

 

 

 

Wetlands

NOVAVPRE

Precipitation 1971-2000, November, mean monthly, in inches

Averaged over the basin surface area estimated using ArcInfo Grid

Prism Climate Group, 2009, Precipitation: Corvallis, Oreg., Oregon State University, accessed on August 5, 2009, at http://www.prism.oregonstate.edu/

Ahearn (2010)

PPTnov

 

 

 

 

 

Mean Monthly Precipitation (November)

PRCWINTER

Precipitation 1971-2000, December-February, mean monthly, in inches

Averaged over the basin surface area estimated using ArcInfo Grid as sum of monthly averages of December, January, and February divided by 3

Prism Climate Group, 2009, Precipitation: Corvallis, Oreg., Oregon State University, accessed on August 5, 2009, at http://www.prism.oregonstate.edu/

Ahearn (2010)

PPTow

 

 

 

 

 

Mean Monthly Precipitation (Dec-Feb)

CRSDFT

Coarse stratified deposits, in percent

Area of coarse stratified deposits /drainage area)*100; glacial meltwater deposits (stratified) consists of coarse deposits and stacked coarse deposits

Connecticut: Stone, J.R., Schafer, J.P., London, E.H., and Thompson, W.B., Compilation sheets at 1:24,000 scale for Stone, J.R., Schafer, J.P., London, E.H., and Thompson, W.B., 1992, Surficial materials map of Connecticut, at http://www.ct.gov/dep/cwp/view.asp?a=2698&q=322898&depNav_GID=1707#Geology. New York: New York State Geological Survey, Surficial Geology, New York State Museum Technology Center,U.S. Geological Survey Special Map, 2 sheets, scale 1:125,000, accessed on April 20, 2009, at  http://www.nysm.nysed.gov/gis.html, accessed on April 20, 2009.  Rhode Island: Glacial Deposits, Rhode Island Geographic Information System, http://www.edc.uri.edu/rigis/data/data.aspx?ISO=geoscientificInformation, accessed on April 20, 2009. Massachusetts: MassGIS, Surficial Geology (1:24,000), accessed on April 20, 2009.

Ahearn (2010)

CRSDFT

 

 

 

 

 

Coarse stratified deposits

I24H2Y

24-hour, 2-year precipitation

Averaged over the basin surface area estimated using ArcInfo Grid

24-hour precip values for 2 year frequency (B.N. Belcher, Northeast Regional Climatic Cneter, written commun., 2003)  estimated at 0.2-degree evenly spaced points (about every 12 mi) across the State using a Cress analysis and refined to 1,000 ft scale.

Ahearn (2004)

P2

 

 

 

 

 

24-hour, 2-year precipitation

I24H10Y

24-hour, 10-year precipitation

Averaged over the basin surface area estimated using ArcInfo Grid

24-hour precip values for 10 year frequency (B.N. Belcher, Northeast Regional Climatic Cneter, written commun., 2003)  estimated at 0.2-degree evenly spaced points (about every 12 mi) across the State using a Cress analysis and refined to 1,000 ft scale.

Ahearn (2004)

P10

 

 

 

 

 

24-hour, 2-year precipitation

I24H25Y

24-hour, 25-year precipitation

Averaged over the basin surface area estimated using ArcInfo Grid

24-hour precip values for 25 year frequency (B.N. Belcher, Northeast Regional Climatic Cneter, written commun., 2003)  estimated at 0.2-degree evenly spaced points (about every 12 mi) across the State using a Cress analysis and refined to 1,000 ft scale.

Ahearn (2004)

P25

 

 

 

 

 

24-hour, 2-year precipitation

I24H50Y

24-hour, 50-year precipitation

Averaged over the basin surface area estimated using ArcInfo Grid

24-hour precip values for 50 year frequency (B.N. Belcher, Northeast Regional Climatic Cneter, written commun., 2003)  estimated at 0.2-degree evenly spaced points (about every 12 mi) across the State using a Cress analysis and refined to 1,000 ft scale.

Ahearn (2004)

P50

 

 

 

 

 

24-hour, 2-year precipitation

I24H100Y

24-hour, 100-year precipitation

Averaged over the basin surface area estimated using ArcInfo Grid

24-hour precip values for 100 year frequency  (B.N. Belcher, Northeast Regional Climatic Cneter, written commun., 2003)  estimated at 0.2-degree evenly spaced points (about every 12 mi) across the State using a Cress analysis and refined to 1,000 ft scale.

Ahearn (2004)

P100

 

 

 

 

 

24-hour, 2-year precipitation

The Connecticut StreamStats introductory page here has additional information regarding the application, including links to reports, cooperators, and other explanatory information.