Households as ecological agents:

1
Households as ecological agents

• Integrating household survey information in a
  spatially-explicit, dynamic urban watershed model.

Neely L. Law, UNC-CH Morgan Grove, USDA Forest
Service
2
Purpose

• Describe a survey and model that integrate
  social, physical and ecological data to
  understand the drivers/factors of hydroecologic
  change in an urban watershed

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Introduction

• Urban watersheds
• hybrid systems in which engineered systems
  superimposed on the natural system
• ecosystems in which human actions exert direct or
  indirect control on ecosystem processes through
  the use and disposition of environmental resources

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Change in flowpaths forested to urban
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Do people and place make a difference?

• Social differentiation affects distribution of
  capital and use of resources
• Link physical, ecological and social data to
  understand the drivers of ecological change in
  urban watersheds

6
Social area index for the Gwynns Falls watershed
(Grove 1996).
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Background

• Land use based simulation models
• aspatial
• human activity not considered
• Variation in lawn characteristics (scale at which
  they are run too coarse)
• stratified by socioeconomic conditions?
• Social patterns and processes part of urban
  hydroecologic mosaic

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Method of Integration

• Survey
• data collection capturing social behavior and
  physical data
• Urban watershed model RHESSys
• analysis of integrated data

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Survey Goals

• Global
• Analysis and modeling that integrates
  physical, ecological and sociocultural patterns
  and processes
• Specific
• Estimate nutrient and water flux from
  residential lawn care practices
• variation in practices
• model parameterization using RHESSys

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Scale of research

• At what scale is the integration approached
• patch
• subdivision or parcel
• Regional Hydro-Ecologic Simulation System model
• spatially explicit hierarchical structure
• spatial data processing and simulation model for
  water, carbon and nutrient flux

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RHESSys Object Hierarchy
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Aspatial Strata
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Methods Survey

• Household survey to link physical, ecological and
  social data
• questionnaire and soil samples
• Survey focus on nutrient and water flux in urban
  watershed from lawn care maintenance practices
• parameterize model
• variation in lawn care practices

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Survey Description

• 2 part survey design
• Questionnaire
• lawn care practices
• lawn characteristics (grass species, area)
• Soil Samples
• soil sample analysis
• bulk density, organic matter, chemistry
• Enroll participation of Master Gardeners

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Survey Sample

• Geographic area of study
• socioeconomic and hydrologic processes
• subdivision
• Analytical unit household
• stratified random sample of 2 study sites
• Glyndon (0.8 km2, n 100)
• Baisman Run (3.66 km2, n50)

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Data

• Digital elevation model
• Parcel data (Maryland Property View)
• High resolution aerial photography
• Input to RHESSys Regional Hydro-Ecologic
  Simulation System

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Lessons to be Learned for Integrated Research

• Data
• Scale to capture variability
• social and ecological variables
• patch redefined for urban watersheds
• Availability
• require survey
• scale and limited research area on fertilizer
  application
• Tool(s) for spatial integration and scaling
• RHESSys