Back to top

New Project: Coupled Natural and Human Systems CNHS: Linking land-use decision making, water quality, and lake associations to understand human-natural feedbacks in lake catchments

Amy Hetherington and intern Iris Lin 

Kelly Cobourn, Cayelan Carey, Kevin Boyle, Amy Hetherington and others including Rudstam and Jackson: Funded by the National Science Foundation (2016-2019) Administrated through Virginia Tech. 

Freshwater lakes and their catchments present a rich and fascinating opportunity to examine the dynamics of coupled natural and human systems (CNHS). Humans derive great benefit from the irreplaceable services provided by lakes, such as drinking water, recreation, and fisheries, while at the same time contributing to the degradation of the very waters upon which they depend. However, degradation in the water quality attributes that people value can also serve as a catalyst for behavioral change through collective action, as evidenced by the increasing momentum of citizen-driven lake associations. To identify and quantify these feedbacks between lake water quality and human behavior, we propose to develop a novel, coupled modeling framework that captures how land-use decision making interacts with hydrological and limnological processes to transform nutrient loads into changes in lake water quality, and how altered water quality feeds back to human systems by affecting the amenities that people value. Our model will extend our interdisciplinary focus by examining how lake associations respond to changes in lake water quality and how their activities influence the behavior of citizens and policy makers to protect their freshwater resources. To construct the coupled model, we will augment our data and modeling resources with new information on the organizational capacity and effectiveness of three active and established lake associations. Our coupled modeling framework will integrate key human and natural systems in three focal lake catchments, allowing us to investigate human-natural feedbacks in those catchments and to build on our understanding of those linkages to generate insight into CNHS at a broad scale. 

Our interdisciplinary team of scientists and community partners seeks to comprehensively investigate the flows, nature, and extent of linkages among human and natural systems in lake catchments. To do so, we propose to first develop an in-depth understanding of the relationships, forcing agents, and feedbacks that drive CNHS dynamics in three contrasting focal lake catchments. Our approach to exploring these linkages involves deriving essential management variables, a concept used in hydrology and limnology but not yet extended to economics and social science, to describe the critical drivers of system dynamics and the structure of the relationships between those drivers. This analysis provides the mechanistic foundation necessary to statistically scale and extrapolate our understanding of the focal lake catchments to a diverse set of catchments representative of continental-scale gradients. To do so, we will use statistical approaches, such as Bayesian hierarchical and time series modeling, to test whether the essential management variables and their interrelationships explain CNHS dynamics across lake catchments spanning a 17-state region in the northeastern and midwestern U.S. We contend that these complementary activities are fundamentally necessary to develop a robust and generalizable understanding of the CNHS dynamics that drive the quality of freshwater, a critical and increasingly endangered natural resource essential for sustaining communities. 

We will fully partner with citizen-driven lake associations in our three focal catchments to support science-based monitoring, advocacy, and volunteerism. Our group has an established track record of collaborating with lake associations, which we will leverage to develop our study as well as to communicate the effects of lake associations on land use and water quality. We will use our study results to co-develop outreach and educational materials tailored to the needs of the communities in each catchment to assist lake associations in proactively and effectively protecting lake water quality. In addition, we will lead the integrated, interdisciplinary training of graduate students with the objective of building the human capital needed to support the next generation of CNHS research focusing on freshwater issues locally, nationally, and globally. We will bring together graduate student training and stakeholder outreach in three workshops that engage lake associations, the Global Lakes Ecological Observatory Network (GLEON), and the Lake multi-scaled GeOSpatial and temporal database (LAGOS) Macrosystems team to develop our analyses and to disseminate our results for our focal lake catchments and for CNHS at a sub-continental scale.