Throughout history, humans have instinctively observed temperature. Scientific progress in the earth sciences has leaped forward so that now improvements in the resolution of such observations can be made on spatial and temporal scales, as well as in multiple dimensions. This presentation will discuss advances in temperature observation based on several studies using a fiber-optic distributed temperature sensing (FO-DTS) system at the Guarani aquifer system and a thermal response test for geothermal exchange in Urbana as an example on Water-Energy nexus study.
The Guarani aquifer system is one of the most important transboundary aquifers in the world. Located in parts of four South American countries (Argentina, Brazil, Paraguay, and Uruguay), it covers an estimated area of 1.2 million km². Despite the importance of the aquifer, only a few studies have quantified its recharge and discharge. For more than 10 years, our colleagues at the University of São Paulo (USP at São Carlos) have monitored the groundwater level, stream flow rate, stream stage, and weather parameters within the Guarani aquifer recharge zone encompassed by the Ribeirão da Onça watershed. This 65.0 km2 watershed is dominated by agricultural activities, which include sugar cane, citrus, and eucalyptus farming. The FO-DTS equipment from the University of Illinois at Urbana-Champaign (UIUC) was applied in Brazil to measure synoptic high-resolution temperature distributions at fine spatial and temporal scales and to identify stretches with gaining behavior. The collected data and research findings provide important background measurements and evaluations relevant to long-term monitoring needs within the Guarani aquifer system. In Urbana, FO-DTS has been used for a number of research projects funded by the National Science Foundation, U.S. Geological Survey, U.S. Department of Energy, U.S. Department of Defense, and UIUC to determine the influence of near-surface temperature changes and the Earth’s geothermal heat flux from below, including groundwater flow advection. The future investigations could be the thermal regime impact on microbiome ecosystem in subsurface as one of the research priorities on climate change impact and adaption which was identified by Illinois Water Resources Center and Illinois-Indiana Sea Grant College Program. The discussion on research opportunities for both federal programs are also welcome during this presentation.