About

The Wisconsin Wetland Wireless Observatory is a long term project to monitor the effects of global warming on water resources of the Northern Highland Lake District in northcentral Wisconsin (NHLD; 46°N, 89°W). This region contains hundreds of undeveloped and nearly pristine glacial lakes, many of which have direct hydrological connection to wetlands. The specific objective is to better constrain the impact of climate change on fluxes of water and carbon. To do this, networks of small, radio-controlled sensors are being embedded in remote environments. Predicted changes in Wisconsin’s climate have several implications for these valuable water resources. More intense summer storms and longer periods of evaporation are expected to alter water budgets and thereby impact hydrochemical exchanges between lakes, their adjacent wetlands and the atmosphere. One potential consequence is the mobilization of organic carbon currently sequestered in wetland peat. The mobilization of this vast carbon reservoir could release additional CO2 and CH4 into the atmosphere and thereby exacerbate the global warming problem. The technical challenge of this project is to develop a network of low-cost, energy-efficient sensors that can monitor change in wetland-dominated catchments over coming decades. Sensor nodes would be distributed across the catchments to measure water levels, water chemistry, rainfall and evaporation. The goal is an automated array of sensors that can function unattended for months at a time and transmit data in near-real time to a distant base station via low power radios. A prototype sensor network was deployed in summer 2007. The results of that deployment were promising, but power consumption was higher than expected and data reporting was erratic. Subsequent design changes have improved the performance and reliability of the sensor nodes. During summer 2009, data on wetland porewaters, lake waters, rainfall and evaporation were successfully transmitted from one catchment at 15 minute intervals for a period of several months. Further improvements in network design are anticipated. This environmental monitoring project is a collaborative effort involving partners from the Wisconsin Department of Natural Resources, the Department of Electrical and Computer Engineering, University of Wisconsin-Madison, and the Center for Limnology, University of Wisconsin-Madison. The field base for research is the Trout Lake Research Station operated by UW-Madison. Funding is provided by the Wisconsin DNR and the Wisconsin Focus on Energy EERD program