Land use and nutrient patterns in upstream watersheds of St. Martin

River

Kris Beckert, Thomas Fisher,

Roman Jesien, Ben Fertig, Judy O’Neil,

Tim Carruthers, Bill Dennison

Methods

• Monthly nutrient data obtained for 6 streams in St. Martin River watershed July 2006-Jan 2008

• Aerial photography used to re-draw land use polygons in GIS

• Land use calculation for stream sub-watersheds in St. Martin River region

• USGS average monthly discharge data for Birch Branch at Showell July 2006- Sept 2007

• Total Nitrogen and Total Phosphorus yearly loading• Regression analysis of land use vs. Dec-March nutrient

concentrations

St. Martin River 2005 Aerial Photography

St. Martin River 2005 Aerial Photography

Correction of Land Use Polygons• 2002 land use files

obtained from Maryland Department of Planning

• Overestimation of land use, especially feeding operations

• Polygons re-drawn closer to aerial imagery

Initial Feeding

Operations Polygon

Correction of Land Use Polygons• 2002 land use files

obtained from Maryland Department of Planning

• Overestimation of land use, especially feeding operations

• Polygons re-drawn closer to aerial imagery

New Feeding

Operations

Polygon

Forest

Stream Sites

B8

B6

B5

B3B2

B1

USGS

gage

B1: Dam

Watershed area (ha)

3056

N load (y-1) 30,970

Average TNha-1yr-1 10.14

P load (y-1) 1,325

Average TPha-1yr-1 0.43

B2: Slab Bridge at Hotel Rd.

Watershed area (ha)

131

N load (y-1) 1,455

Average TNha-1yr-1 12.79

P load (y-1) 47

Average TPha-1yr-1 0.36

B3: Carey Branch at Hotel Rd

Watershed area (ha)

1,593

N load (y-1) 14,643

Average TNha-1yr-1 9.20

P load (y-1) 601

Average TPha-1yr-1 0.38

B5: Bunting Branch at Rt. 54

Watershed area (ha)

907

N load (y-1) 11,537

Average TNha-1yr-1 12.71

P load (y-1) 316

Average TPha-1yr-1 0.35

B6: Unnamed Tributary

Watershed area (ha)

133

N load (y-1) 2,623

Average TNha-1yr-1 19.67***

P load (y-1) 46

Average TPha-1yr-1 0.35*

*Lowest observed value***Highest observed value

B8: Church Branch

Watershed area (ha)

1284

N load (y-1) 11,585

Average TNha-1yr-1 9.02*

P load (y-1) 588

Average TPha-1yr-1 0.46***

*Lowest observed value***Highest observed value

Regressions: Nitrogen vs. Anthropogenic land use

Regressions: Phosphorus vs. Anthropogenic land

use

Regressions: Nitrogen vs. Feeding Operations

Regressions: Phosphorus vs. Feeding Operations

Regressions: Nitrogen vs. Natural

Regressions: Phosphorus vs. Natural