Disproportionality as a Framework for Linking Social and Biophysical Systems

ABSTRACT

Interdisciplinary research is capable of investigating questions that no single or independent collection of disciplines can address. This interdisciplinary approach was used to investigate why nonpoint source pollution to a lake had not changed even though the often cited social drivers of this situation had changed significantly. The concept of disproportionality was adapted to examine social and biophysical interactions at different spatial and temporal scales to address this situation. Rather than using social and biophysical variable as contextual or additive relative to each other, we examined their interactive or multiplicative effects at coarse and fine spatial and temporal scales. Limited occurrence of inappropriate behaviors in vulnerable biophysical settings resulted in disproportionate environmental impacts. The concept of disproportionality implies that the environmental meaning placed on any social behavior requires accounting for where and when it occurs in a biophysical setting, and that a few outliers can determine system performance and outcomes.

Keywords:

• agriculture
• cross-scale
• development
• disproportionality
• eutrophication
• interdisciplinary
• nonpoint source pollution
• space and time

The publication of this article was supported by Water and Watersheds grant R-82801001 from the U.S. Environmental Protection Agency's Science to Achieve Results (STAR) program and grant 2001–04610 from the USDA-CSREES-IFAFS program. We also received partial support from the NSF–Long Term Ecological Research, Northern Temperate Lakes program. Heartfelt thanks to the anonymous reviewers who provided thoughtful suggestions to an earlier version of this article.

Notes

^a Historically, 1.22 mi² of the drainage area does not contribute to surface runoff.

The term load refers to the mass of phosphorus being delivered during a fixed time period, typically 1 day. This is distinguished from concentration, which refers to the mass of phosphorus being delivered within a fixed runoff volume.

Independent in the sense that the social processes, development, do not consider that there is a “location” to the biophysical characteristics (P levels) that will influence the outcome of this process. See Goodchild and Janelle (2004) for a complete explanation of this concept.