Development of The Navigator: A Lagrangian sensing system to characterize surface freshwater ecosystems

Aashish Khandelwal; Tzion Castillo; Ricardo González-Pinzón

doi:10.1016/j.watres.2023.120577

Development of The Navigator: A Lagrangian sensing system to characterize surface freshwater ecosystems

Water Res. 2023 Oct 15:245:120577. doi: 10.1016/j.watres.2023.120577. Epub 2023 Sep 4.

Authors

Aashish Khandelwal¹, Tzion Castillo², Ricardo González-Pinzón³

Affiliations

¹ Gerald May Department of Civil, Construction & Environmental Engineering, University of New Mexico, Albuquerque, NM, USA. Electronic address: ashkhandelwal@unm.edu.
² Gerald May Department of Civil, Construction & Environmental Engineering, University of New Mexico, Albuquerque, NM, USA; Electrical Engineering, University of New Mexico, Albuquerque, NM, USA.
³ Gerald May Department of Civil, Construction & Environmental Engineering, University of New Mexico, Albuquerque, NM, USA. Electronic address: gonzaric@unm.edu.

PMID: 37688858
DOI: 10.1016/j.watres.2023.120577

Abstract

Most freshwater aquatic studies rely on Eulerian monitoring, i.e., water quality and quantity are monitored using grab samples or semi-continuous sensors deployed at fixed cross-sections. While Eulerian monitoring is practical, it provides a limited understanding of spatial and temporal heterogeneity. We designed and built The Navigator, a Lagrangian (i.e., along a flow path) monitoring system that offers cost-effective solutions for in-situ, real-time data collection in surface freshwater ecosystems. The Navigator features a suite of technologies, including an autonomous surface vehicle with GPS and LTE connectivity, water quality sensors, a depth sonar, a camera, and a webpage dashboard to visualize real-time data. With these technologies, The Navigator provides insight into where, how, and why water quality and quantity change over time and space as it moves with the current or follows user-specified pathways. We tested The Navigator monitoring water quality parameters at high spatial-temporal resolution in multiple surface water bodies in New Mexico (USA) to: (1) identify water quality changes associated with land use changes along a 7th-order reach in the Rio Grande, (2) identify the fate of wildfire disturbances ∼175 km downstream of a burned watershed affected by the largest wildfire ever recorded in the state, (3) monitor the water quality of a recreational fishing pond in the City of Albuquerque. Our three successful tests confirm that The Navigator is an affordable (USD 5,101 in 2023) monitoring system that can be used to address questions involving mass and energy balances in surface waters.

Keywords: Autonomous; Ecosystems; Freshwater; Lagrangian; Monitoring; Surface; Water quantity and quality.