Table 5. Median incremental yields of total nitrogen and total phosphorus for six-digit Hydrologic Unit Code (HUC6) watersheds in the United States Pacific Northwest (2002 conditions).


[HUC6 locations are shown in figures 1–3. Values are based on the results obtained from then National Hydrography Dataset (NHD) total nitrogen and total phosphorus SPARROW models developed for the United States Pacific Northwest. Incremental yield: is equal to the local load divided by the NHD catchment area, where the local load is the load generated exclusively within an NHD catchment. Abbreviation: kg/ha-yr, kilogram per hectare per year]


Region	HUC6 abbreviation	Total nitrogen			Total phosphorus
		Median incremental yield (kg/ha-yr)	Rank		Median incremental yield (kg/ha-yr)	Rank
Pacific Coast	WACR	6.25	2		0.745	1
	NOCR	10.87	1		0.630	2
	SOCR	2.22	6		0.403	6
West Side Basins	PUGT	3.88	5		0.540	3
	LCOL	4.05	4		0.508	5
	WILL	4.55	3		0.517	4
Columbia River Basin	KOOT	0.51	16		0.098	11
	PDOR	0.63	13		0.128	10
	SPOK	0.87	11		0.140	8
	UCOL	0.42	17		0.063	19
	YAKI	0.93	10		0.070	13
	JDAY	0.41	18		0.066	16
	DESC	0.28	20		0.068	14
	MCOL	1.10	8		0.066	17
Snake River Basin	SNKH	0.57	14		0.065	18
	USNK	0.33	19		0.050	20
	MSBS	0.10	21		0.026	22
	MSPW	0.55	15		0.130	9
	SALM	0.69	12		0.068	15
	CLRW	1.13	7		0.141	7
	LSNK	0.94	9		0.097	12
Oregon Closed Basins	ORCB	0.10	22		0.040	21

First posted July 17, 2013