Appendix A 21

This appendix contains brief descriptions of how the data 

sets representing nutrient sources and land-to-water-delivery 

variables were compiled and how these data sets differed 

from those used in the RF1 SPARROW models. Detailed 

descriptions of the methods used to compile these data sets are 

contained in the data archives for each one.

Nutrient Sources

Natural Nutrient Sources

The nutrient source terms representing west-side and 

east-side forestland in the total nitrogen (TN) and total 

phosphorus (TP) models and scrubland and grassland in the TP 

model were used as surrogates for natural sources of nitrogen 

and phosphorus because direct estimates of these natural 

nutrient sources were not available for the Pacific Northwest 

(PNW). These natural nutrient sources result from complex 

biological and abiotic processes. In the TN model the natural 

source of nitrogen was fixation of atmospheric nitrogen in 

forests and in the TP model the natural source of phosphorus 

was the weathering of geologic material. These nutrient source 

terms were derived from the 2001 National Land Cover Data 

Base (NLCD) (Homer and others, 2004) (Michael Wieczorek, 

U.S. Geological Survey, written commun., June 11, 2011). 

The total areas of forestland (NLCD categories 41, 42, and 

43), scrubland (NLCD category 52), and grassland (NLCD 

category 71) were summarized for each incremental NHD 

catchment.

Point Sources

The nutrient source terms representing point sources 

included 785 facilities having a National Pollutant Discharge 

Elimination System (NPDES) permit. The discharge of TN 

and TP for 2002 from sewage treatment and food processing 

facilities were estimated using measured flow at plant outflows 

and either onsite measurements of TN and TP or a regional 

average for a specific industrial classification. The discharge of 

TN and TP were not estimated for facilities without adequate 

flow data. The discharges of TN and TP from fish farms and 

hatcheries for 2002 were estimated by using a mass balance 

of annual fish production and feed usage and an estimate 

of nitrogen and phosphorus content for fish and feed (Hal 

Michael, Washington Department of Fish and Wildlife, oral 

commun., December 2009). The discharge of TN and TP were 

not estimated for hatcheries and other aquaculture facilities 

without adequate production and feed data. The total amount 

of TN and TP discharged during 2002 from all point sources 

was estimated for each incremental NHD catchment (see 

Appendix A. Compilation of Model Input Data

GIS data #14 and #22). The data set of point sources used 

in the NHD SPARROW model included more facilities than 

the one used in the RF1 SPARROW model (785 versus 391) 

(Maupin and Ivahnenko, 2011) and the additional facilities 

were mostly non-major sewage treatment plants, fish farms 

and hatcheries, and food processing operations.

Developed Land

The nutrient source term representing developed land was 

used as surrogate for various nutrient sources originating from 

residential, commercial, and industrial land. The use of this 

source was intended to capture non-point sources of nutrients, 

including fertilizer, animal waste, and failing sewer systems 

from these settings. However, the atmospheric deposition 

of nitrogen or nutrients discharged from permitted point 

sources were not intended to be represented by this source. 

Developed land was equal to the summed areas of NLCD 

categories 21, 22, 23, and 24, minus areas representing roads. 

Areas representing roads were removed for three reasons: 

(1) forested catchments with extensive logging road networks 

would incorrectly exhibit a strong developed land signal, 

(2) an accurate representation of residential land use was 

needed to estimate the distribution of non-sewered population 

and non-farm fertilizer (see section Farm Fertilizer and NonFarm Fertilizer), and (3) the lack of nutrient use along most 

roadways. The total area of developed land was summarized 

for each incremental NHD catchment (GIS data #6 and #19). 

This approach was different from the approach used for the 

RF1 SPARROW models, which included NLCD categories 

22, 23, and 24, but did not explicitly eliminate roads. 

Non-Sewered Population

The nutrient source term representing non-sewered 

population (the number of people not served by a municipal 

wastewater-treatment plant) was used as a surrogate for 

nitrogen leaching from septic tanks. The extent of nonsewered population was computed by (1) overlaying census 

blocks polygons from the 2000 United States census on 

a grid of developed land (see section Developed Land); 

(2) distributing the population of each census block equally 

to each developed land grid cell within that census block; 

and (3) removing any of the grid cells that were within an 

area served by municipal sewers during 2002 (GIS data 

#15). The total non-sewered population was summarized 

for each incremental NHD catchment (GIS data #11 and 

#24). This approach was different from the one used in the 

RF1 SPARROW models, which used 1990 census tract 

data to estimate the population served by septic tanks (U.S. 

Geological Survey, 2011a). 
22 Application of the SPARROW Model to Assess Surface-Water Nutrient Conditions and Sources, Pacific Northwest

Atmospheric Nitrogen Deposition

The nutrient source term representing atmospheric 

nitrogen deposition was based on the results from the U.S. 

Environmental Protection Agency Community Multiscale Air 

Quality (CMAQ) model (R.L. Dennis, U.S. Environmental 

Protection Agency, written commun., June 2011). The CMAQ 

model provided spatially refined atmospheric deposition data, 

which reflected orographic barriers and nitrogen-islands, such 

as cities and farmland, and included estimates of wet and dry 

oxidized nitrogen deposition as well as wet and dry reduced 

nitrogen deposition. The CMAQ atmospheric nitrogen data 

were summarized for each incremental NHD catchment 

(GIS data #1 and #16). This data set was different from the 

atmospheric nitrogen deposition data set used in the RF1 

SPARROW TN model (Wieczorek and Lamotte, 2013), which 

was obtained from the National Atmospheric Deposition 

Program (NADP), because it represented total nitrogen 

deposition for 2002 (wet, dry, oxidized, and reduced), whereas 

the NADP data only represented wet deposition. 

Farm Fertilizer and Non-Farm Fertilizer

The nutrient source terms representing farm and non-farm 

fertilizer were based on county-level estimates of nitrogen 

and phosphorus from fertilizer use on farmland and non-farm 

land. The county-level estimates of 2002 farm and non-farm 

fertilizer use were compiled by the USGS based on statewide 

fertilizer sales and county-level expenditures (Gronberg and 

Spahr, 2012). The county-level USGS data for Idaho, Oregon, 

and Washington, however, were scaled to reflect differences 

between the statewide sales data compiled by the USGS and 

data compiled by those states. The statewide sales data were 

obtained from the Idaho State Department of Agriculture 

(Richard Killebrew, written commun., March 2011), the online 

archives of the Oregon State Library (Oregon Department 

of Agriculture, 2011), and the Washington State Department 

of Agriculture (Lizette Beckman, written commun., March 

2011). The county-level estimates of nitrogen and phosphorus 

from farm fertilizer were disaggregated equally to NLCD 

farmland in each county (NLCD categories 81 and 82) and 

the county-level estimates of nitrogen and phosphorus from 

non-farm fertilizer use were disaggregated equally to the 

developed land (see section Developed Land) in each county. 

The total amount of nitrogen and phosphorus from farm and 

non-farm fertilizer applied during 2002 was summarized for 

each incremental NHD catchment (GIS data #2–5 and #18). 

This approach was different from the approach used for the 

RF1 SPARROW models (Wieczorek and Lamotte, 2013), 

which did not account for differences between USGS and state 

estimates of sales data.

Livestock Manure

The nutrient source terms representing confined cattle 

and grazing livestock manure were based on the animal 

populations at registered dairies and feedlots, county-level 

livestock populations, and animal-specific nutrient

generation factors (nitrogen and phosphorus generated per 

animal per year). 

Confined Cattle Manure

The nutrient source term representing confined cattle 

manure was estimated by multiplying the number of cattle 

at each dairy or feedlot by the nitrogen and phosphorus 

generation factors for dairy cows and feedlot cattle, 

respectively. The location and population of each dairy 

and feedlot for 2002 were determined from permitting and 

inspection records obtained from the Idaho, Oregon, and 

Washington Departments of Agriculture (J.P. Bilderback, 

written commun., December 2009; Melissa Boschee, written 

commun., December 2009; and Virginia Prest, written 

commun., December 2009; respectively). The nitrogen 

and phosphorus generation factors were obtained from the 

USGS (D.K. Mueller, written commun., June 2010). All 

manure generated by a dairy or feedlot was assumed to be 

applied within the incremental NHD catchment containing 

that dairy or feedlot. This assumption was based on the 

facts that (1) most confined operations grow some or most 

of their own feed on nearby farmland and (2) manure is a 

low-cost alternative to commercial fertilizer for those crops 

if it is not trucked long distances (Araji and others, 2001, 

Sanford and others, 2009). The authors recognize that the 

assumption of applying all manure locally may over-represent 

manure applications in some areas because manure at some 

facilities is not applied locally, may be composted, or is used 

for energy production. The data needed to quantify these 

practices, however, does not exist on a regional basis and 

these practices are likely applied to a small fraction of the total 

manure generated in the PNW. The total amount of nitrogen 

and phosphorus generated at dairies and feedlots during 2002 

was summarized for each incremental NHD catchment (GIS 

data #13 and #21). The approach used to develop the nutrient 

source term representing manure from confined cattle for the 

NHD SPARROW models differed from the approach used 

for the RF1 SPARROW models (Wieczorek and Lamotte, 

2013). The data set for the RF1 model was based on livestock 

confinement factors for each county that were obtained from 

survey data from the 1980s (Kellog and others, 2000) rather 

than 2002 estimates of cattle populations at individual dairies 

and feedlots.
Appendix A 23

Grazing Livestock Manure

The nutrient source term representing grazing livestock 

manure included manure generated by rangeland cattle and 

the manure generated by all other non-cattle, non-poultry 

livestock. Each of these nutrient sources were compiled at the 

county level and disaggregated to the land based on assumed 

land use patterns. The manure generated by poultry operations 

was not included in this nutrient source term because poultry 

manure typically was not applied to farmland in the county 

where it was produced. Rather, poultry manure was most often 

sold statewide and regionally as fertilizer for farm and for 

nonfarm use (Julie Walker, Washington State Department of 

Agriculture, oral commun., January 2010), and could not be 

traced to a particular place of application.

The county-level estimates of nitrogen and phosphorus 

from rangeland cattle manure was estimated by subtracting 

the amount of nitrogen and phosphorus generated by dairy 

and feedlot cattle in each county from the total amount 

generated by all cattle. The county-level estimates of total 

of nitrogen and phosphorus generated by all cattle in each 

county were obtained from the USGS (D.K. Mueller, written 

commun., June 2010) and were based on 2002 animal counts 

compiled by the U.S. Department of Agriculture and annual 

nitrogen and phosphorus generation factors. The county-level 

estimates of nitrogen and phosphorus from non-cattle grazing 

livestock manure, which was generally a small percentage of 

the total grazing livestock manure, were also obtained from 

the USGS and based on 2002 animal counts compiled by 

the U.S. Department of Agriculture and annual nitrogen and 

phosphorus generation factors.

The county-level estimates of nitrogen and phosphorus 

from rangeland cattle manure were disaggregated equally to 

the potential grazing land in each county. A raster data set of 

potential rangeland was compiled using NLCD categories 

41 (deciduous forest), 42 (evergreen forest), 43 (mixed 

forest), 52 (shrub/scrub), 71 (grassland/herbaceous), and 

81 (pasture/hay). Potential rangeland was removed if it did 

not meet criteria for maximum slope, maximum canopy cover, 

minimum distance to perennial surface water or wells (David 

Ganskopp, U.S. Department of Agriculture, Agricultural 

Research Service, oral commun., January 2010), or if the land 

was managed by the Bureau of Land Management but was 

not part of a grazing allotment in 2002. The total amount of 

nitrogen and phosphorus from rangeland cattle manure during 

2002 was summarized for each incremental NHD catchment 

(GIS data #9, #10, and #20). The county-level estimates 

(2002) of nitrogen and phosphorus from non-cattle grazing 

livestock manure were disaggregated equally to grassland 

and pasture in each county (NLCD categories 70 and 81, 

respectively). The total amount of nitrogen and phosphorus 

from non-cattle grazing livestock manure during 2002 was 

summarized for each incremental NHD catchment (GIS data 

#7, #8, and #20).

The approach used to develop the nutrient source term 

representing manure from grazing livestock for the NHD 

SPARROW models differed from the method used for the RF1 

SPARROW models (Wieczorek and Lamotte, 2013) primarily 

in the way that the manure was disaggregated to the land. 

In the RF1 models, the land that received grazing livestock 

manure included cultivated crops even though very little 

of that land is used for livestock grazing in the PNW (U.S. 

Department of Agriculture, 2009). Additionally, the landscape 

types that received grazing livestock manure in the RF1 

models omitted much of the rangeland throughout the PNW 

by not including shrub/scrubland and forestland.

Nitrogen Leaching from Red Alder Trees

The nutrient source term representing the leaching 

of nitrogen from read alder trees (Alnus rubra) was based 

on a data set showing the distribution of this plant species 

throughout western Oregon and Washington. The same data 

set was used for the RF1 SPARROW models (U.S. Geological 

Survey, 2011b). The total basal area of red alder trees circa 

2002 was summarized for each incremental NHD catchment 

(GIS data #23).

Springs and Power Returns

A substantial proportion of the flow in some streams in 

the PNW is due to groundwater discharged from large spring 

complexes and a substantial proportion of the flow in some 

streams is due to the return of water that is diverted upstream 

for power generation. Because springs and power returns 

represent a routing of water that cannot be modeled within the 

SPARROW framework they were modeled as nutrient point 

sources. The nutrients in springs and power returns originate 

from some or all of the other natural and anthropogenic 

nutrient sources included in the models, but reach waterways 

in a concentrated manner similar to point sources. There 

were sufficient discharge and water-quality data to estimate 

mean annual TN and TP loads for three of the largest spring 

complexes—Opal Springs on the Crooked River in Oregon, 

Thousand Springs on the Snake River near Hagerman, Idaho, 

and Griffith and Waikiki Springs on the Little Spokane River 

in Washington. The nutrient loads from power returns were 

estimated in one of two ways. One approach was to use the 

fraction of streamflow received from an upstream reach (see 

section Surface-Water Drainage Network) at the point of 

diversion to estimate the percentage of load that was delivered 

to the receiving reach (an assumption was made that no 

nutrients were lost between the two reaches) and apply this 

percentage to the mean annual load estimated for a calibration 

station on or near the diversion reach. The other approach was 

used when no calibration station was on or near the diversion 
24 Application of the SPARROW Model to Assess Surface-Water Nutrient Conditions and Sources, Pacific Northwest

reach. In this case, measurements of discharge and nutrient 

concentrations for the diversion at the point where it entered a 

receiving reach were used to estimate mean annual TN and TP 

loads. The total amount of TN and TP discharged during 2002 

from the three spring complexes and the power returns was 

estimated for each incremental NHD catchment. This nutrient 

source was not included in the RF1 SPARROW models.

Land-to-Water Delivery

Solar Radiation

A data set of mean annual solar radiation was obtained 

for the PNW that represented the period between 1991 and 

2005 (National Renewable Energy Laboratory, 2011). The 

average mean annual solar radiation for each incremental 

NHD catchment was estimated (GIS data #12 and #25).

Arid Land Irrigated Agriculture

Arid land irrigated agriculture was defined as all 

agricultural land east of the Cascade Range to which irrigation 

water was applied. The extent of arid land irrigated agriculture 

was determined by (1) identifying areas of pasture/hay and 

cultivated crops (NLCD categories 81 and 82, respectively) 

that were east of the crest of the Cascade Range and 

(2) removing areas representing non-irrigated wheat from the 

areas identified in (1). Land containing non-irrigated wheat 

was identified based on professional understanding of major 

agricultural cropping patterns in the PNW, research done for 

this study, and evaluating the NLCD and aerial photography 

for obvious signs of irrigation such as center pivot circles or 

irrigation ditches. The percentage of each NHD incremental 

catchment containing arid land irrigation was estimated (GIS 

data #17). This data set was a refinement of the one used in the 

RF1 SPARROW models (Wise and Johnson, 2011).

Metadata Links to GIS Data

GIS Rasters

1. Total atmospheric deposition of oxidized and reduced 

nitrogen in the United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of wet and dry 

deposition of oxidized and reduced nitrogen in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_AtmosphericDeposition_td_tn

2. Application of fertilizer nitrogen to farm land in the 

United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of fertilizer nitrogen 

that was applied to farm land in the Pacific Northwest region 

of the United States (Hydro Region 17; MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_FertilizerDistribution_Farm_fert_n

3. Application of fertilizer phosphorus to farm land in the 

United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of fertilizer 

phosphorus that was applied to farm land in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_FertilizerDistribution_Farm_fert_p

4. Application of fertilizer nitrogen to nonfarm land in the 

United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of fertilizer nitrogen 

that was applied to nonfarm land in the Pacific Northwest 

region of the United States (Hydro Region 17; MRB7) during 

2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_FertilizerDistribution_Nonfarm_nfert_n

5. Application of fertilizer phosphorus to nonfarm land in 

the United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of fertilizer 

phosphorus that was applied to nonfarm land in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_FertilizerDistribution_Nonfarm_nfert_p

6. Nonroad developed land in the United States Pacific 

Northwest for 2001

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the extent of non-road developed 

land in the Pacific Northwest region of the United States 

(Hydro Region 17; MRB7) in 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LandUseDistribution_dev_nonroad
Appendix A 25

7. Application of nitrogen generated by non-cattle livestock 

to pasture land in the United States Pacific Northwest for 

2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of nitrogen generated 

by pastured, non-cattle livestock that was applied to pasture 

land in the Pacific Northwest region of the United States 

(Hydro Region 17; MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LivestockWasteDistribution_Pasture_past_n

8. Application of phosphorus generated by non-cattle 

livestock to pasture land in the United States Pacific 

Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of phosphorus 

generated by pastured, non-cattle livestock that was applied 

to pasture land in the Pacific Northwest region of the United 

States (Hydro Region 17; MRB7) during 2002. 

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LivestockWasteDistribution_Pasture_past_p

9. Application of nitrogen generated by grazing cattle to 

range land in the United States Pacific Northwest for 2002

Pischel, E.M.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of nitrogen generated 

by grazing cattle that was applied to range land in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LivestockWasteDistribution_Rangeland_range_n

10. Application of phosphorus generated by grazing cattle 

to range land in the United States Pacific Northwest for 

2002

Pischel, E.M.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of phosphorus 

generated by grazing cattle that was applied to range land 

in the Pacific Northwest region of the United States (Hydro 

Region 17; MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LivestockWasteDistribution_Rangeland_range_p

11. Nonsewered population in the United States Pacific 

Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent populations that did not have 

access to municipal sewer service in the Pacific Northwest 

region of the United States (Hydro Region 17; MRB7) in 

2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_SewageTreatment_NonSewered_nonsewered

12. Mean annual solar radiation in the United States Pacific 

Northwest (1991–2005)

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent mean annual solar radiation in the 

Pacific Northwest region of the United States (Hydro Region 

17; MRB7) for the period between 1991 and 2005.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_SolarRadiation_ghi_100

GIS Shapefiles

13. Nutrient generation at dairies and feedlots in the United 

States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of nitrogen and 

phosphorus generated by cattle at dairies and feedlots in the 

Pacific Northwest region of the United States (Hydro Region 

17; MRB7) during 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_PointSources_ConfinedCattle_CAFOs

14. Point source nutrient discharges to surface water in the 

United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of total nitrogen and 

total phosphorus discharged to surface waters in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002 from individual permitted wastewater 

facilities.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_PointSources_NHD
26 Application of the SPARROW Model to Assess Surface-Water Nutrient Conditions and Sources, Pacific Northwest

15. Areas with access to municipal sewer service in the 

United States Pacific Northwest for 2002

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent areas that had access to municipal 

sewer service in the Pacific Northwest region of the United 

States (Hydro Region 17; MRB7) in 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_SewageTreatment_Sewered_SeweredAreas

Summary Tables

16. Atmospheric deposition of nitrogen in the United States 

Pacific Northwest for 2002 summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of atmospheric 

nitrogen deposition in the Pacific Northwest region of the 

United States (Hydro Region 17; MRB7) during 2002 within 

each incremental watershed delineated in the NHDPlus v2 

dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_AtmosphericDeposition_summary

17. Arid land irrigation in the United States Pacific Northwest 

for 2001 summarized for NHDPlus v2 catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the area of arid land irrigation 

in the Pacific Northwest region of the United States (Hydro 

Region 17; MRB7) during 2001 within each incremental 

watershed delineated in the NHDPlus v2 dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_EastsideIrrigation_summary

18. Fertilizer nutrients applied to farm and nonfarm land in 

the United States Pacific Northwest for 2002 summarized 

for NHDPlus v2 catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of fertilizer nitrogen 

and phosphorus that was applied to farm and nonfarm land 

in the Pacific Northwest region of the United States (Hydro 

Region 17; MRB7) during 2002 within each incremental 

watershed delineated in the NHDPlus v2 dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_FertilizerDistribution_summary

19. Nonroad developed land in the United States Pacific 

Northwest for 2001 summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the area of non-road developed 

land within each incremental watershed delineated in the 

NHDPlus v2 dataset in the Pacific Northwest region of the 

United States (Hydro Region 17; MRB7) in 2001.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LandUseDistribution_DevelopedNonRoad_

summary

20. Nutrients generated by livestock applied to farm land, 

pasture land, and range land in the United States 

Pacific Northwest for 2002 summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of nitrogen and 

phosphorus that was generated by livestock and applied 

to land in the Pacific Northwest region of the United 

States (Hydro Region 17; MRB7) during 2002 within each 

incremental watershed delineated in the NHDPlus v2 dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_LivestockWasteDistribution_summary

21. Nutrient generation at dairies and feedlots in the United 

States Pacific Northwest for 2002 summarized for 

NHDPlus v2 catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of nitrogen and 

phosphorus generated by cattle at dairies and feedlots in the 

Pacific Northwest region of the United States (Hydro Region 

17; MRB7) during 2002 within each incremental watershed 

delineated in the NHDPlus v2 dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_PointSources_ConfinedCattle_CAFO_summary

22. Point source nutrient discharges to surface water in the 

United States Pacific Northwest for 2002 summarized for 

NHDPlus v2 catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the amount of total nitrogen and 

total phosphorus discharged to surface waters in the Pacific 

Northwest region of the United States (Hydro Region 17; 

MRB7) during 2002 from all permitted wastewater facilities 

located within each incremental watershed delineated in the 

NHDPlus v2 dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_PointSources_NHD_summary
Appendix A 27

23. Red alder trees distribution in the United States Pacific 

Northwest for 2002 summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the basal area of red alder trees 

within each incremental watershed delineated in the NHDPlus 

v2 dataset in the Pacific Northwest region of the United States 

(Hydro Region 17; MRB7) in 2001.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_RedAlder_summary

24. Nonsewered population in the United States Pacific 

Northwest for 2002 summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent the population within each 

incremental watershed delineated in the NHDPlus v2 dataset 

in the Pacific Northwest region of the United States (Hydro 

Region 17; MRB7) that did not have access to municipal 

sewer service in 2002.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_SewageTreatment_NonSewered_summary

25. Mean annual solar radiation in the United States Pacific 

Northwest (1991–2005) summarized for NHDPlus v2 

catchments

Wise, D.R.

This spatial data set was created by the U.S. Geological 

Survey (USGS) to represent mean annual solar radiation in the 

Pacific Northwest region of the United States (Hydro Region 

17; MRB7) for the period between 1991 and 2005 within 

each incremental watershed delineated in the NNHDPlus v2 

dataset.

http://water.usgs.gov/lookup/getspatial?sir2013-5103_PNW_

SPARROW_SolarRadiation_summary

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