Combining data collection from unmanned surface vehicles with geospatial analysis: Tools for improving surface water sampling, monitoring, and assessment

Tidal rivers and accompanying coastal environments represent critical links between the open estuary and the local tributary and watershed. In Florida, these coastal ecosystems are multi-use systems. They are often a primary source of water for agricultural, industrial, and human consumption all while functioning as commercial and recreational shipping thoroughfares and receiving storm water runoff and NPDES discharges. In addition to their importance for those direct human uses, their quality and characteristics directly affect the spawning, nursery, and juvenile habitats for numerous commercial and sport fisheries. Thus monitoring and assessment, especially identifying spatial patterns or trends in water chemistry (e.g. temperature, conductivity, salinity, turbidity, chlorophyll, dissolved organic matter and dissolved gasses), of these tidal environments can represent a complex sampling and analysis challenge. There is a perception that sampling and analyzing parameters at regularly spaced intervals over the surface area of a river system will be representative of general trends. However, standard sampling strategy assumes both that parameters will change in a consistent longitudinal and downstream manner and that the average of a parameter is the level where negative impacts occur. Using an innovative combination of unmanned surface vehicles (USV) and geospatial analytical techniques, we will show that this perception is not an entirely accurate or complete view.