URBAN REFO

RESTATI

ON AS A

STORMW

ATER

MANAGEMENT

TOOL

GEOG591 Final ProjectBy: Sophie Wilderotter, Tyler Tran, Casey Stern,

Sarah Rhodes and Kaitlin Finan

INTRODUCTION

• Negative Impacts of Urbanization and Impervious Cover:

Physical impacts: Increased velocity /volume of runoff, Flooding, Erosion of Stream Banks, Decline in Infiltration and Groundwater Recharge, Degradation of Riparian Zones

Ecological Impacts: Contamination of water bodies by non-point source pollution can cause stress for aquatic organisms such as: hypoxia by nutrients (N &P), pathogen contamination of shellfish beds, physiological effects by toxic chemicals

(Arnold and Gibbons, 1996)

A STORM-WATER MANAGEMENT TOOL: REFORESTATION

• Increased evapotranspiration• Reduced runoff• Potential tool for Carbon

sequestration

STUDY OBJECTIVES

(1)Quantify and characterize the tree cover, including the life form, extent of trees and LAI, in Chapel Hill and Carrboro, NC

(2)Determine suitable regions for reforestation in Chapel Hill and Carrboro alongside roadways and sidewalks and areas of low LAI

(3)Estimate the water balance change that would result from increasing tree cover in this region.

FLOW CHART

Current Tree Extent (Sophie, Casey, Kaitlin)

• LAI• Tree Type

Potential for Reforestation (Sarah, Tyler)

• Land Cover• Buffer• Interception

Water Balance Change (Everyone)

• Evapotranspiration

• 50 vs 100% of potential

STUDY SITE

• Municipalities of Chapel Hill and Carrboro combined

• 77.2 square kilometers• Created a shape file of the outline of our

study area

METHODS: LAI AND TREE EXTENT

LAI from EVI and Dr. Song, Forests from NLCDRaster Calculator

•BL_LAI = (NLCD==41)*LAI •CN_LAI = (NLCD==42)*LAI•MX_LAI = (NLCD==43)*LAI

CONTINUED

Weighted Average LAI by tree type in Excel

Reclassification to find extent of Trees

TREE COVER EXTENT BY LAI

Average LAI Results:

Conifer: 6.06Deciduous: 8.32Mixed: 6.64

RESULTS: TREE COVER EXTENT BY TREE TYPE

Conifer=

6.3 km2, 8.2% Deciduous=

11.9 km2, 15.4% Mixed=

1.3 km2, 1.7%

IMPERVIOUS, GRASS AND BARREN IN CHAPEL HILL/CARRBORO

Cover Type Area (m2)

Trees 43,454,039

Water 533,369

Impervious 10,778,014

Buildings 4,874,686

Grass 7,743,444

Barren 284,467

•Potential for Tree Cover Expansion (Tyler and Sarah)•Grass/barren land, parking lots, alongside streams, sidewalks not surrounded by impervious •Using CH/Carrboro mask of South Orange Classification, we determined areas of barren land, impervious surface, and grass. Calculate proportion of these areas that would be appropriate for reforestation

POTENTIAL FOR REFORESTATION ALONGSIDE ROADS/SIDEWALKS

• Buffer Information: We created a 2m buffer surrounding impervious surfaces in CH/Carrboro, here is the area of the buffer covered by grass and barren:

Grass: 2,120,780m2

Barren: 28,914m2

1. Area of impervious covered if broadleaved were to be planted in suitable areas around roads/sidewalks=

(4.09m)*(1,074,847m)= 4,396,124.23m2 interference area

2. Area of impervious covered if loblolly pines were to be planted in suitable areas around roads/sidewalks=

(3.175)*( 1,074,847m)=3,412,639.23m2

interference area

 

LAI DISCUSSION

http://26.media.tumblr.com/tumblr_l7lcjyuJiX1qdstgoo1_500.jpg: Algal blooms

http://media.treehugger.com/assets/images/2011/10/peru-national-reforestation-campaign.jpg: planting woman

REFERENCES