There is an increasing appreciation that food–energy–water (FEW) nexus problems are approaching criticality in both the developing and developed world. As researchers and managers attempt to address these complex resource management issues, the concept of the FEW nexus has generated a rapidly growing footprint in global sustainability discourse. However, this momentum in the FEW nexus space could be better guided if researchers could more clearly identify what is and is not a FEW problem. Without this conceptual clarity, it can be difficult to defend the position that FEW innovations will produce desired outcomes and avoid unintended consequences. Here we examine the growing FEW nexus scholarship to critically evaluate what features are necessary to define a FEW nexus. This analysis suggests that the FEW nexus differs from sector-focused natural resource or sustainability problems in both complexity and stakes. It also motivates two new foci for research: the identification of low-dimension indexes of FEW system status and approaches for identifying boundaries of specific FEW nexuses.

The theoretical concept and initial test results of a Passive Surface Water Fluxmeter (PSFM) to directly and simultaneously measure cumulative water and solute mass fluxes in surface water flow systems are presented. The PSFM consists of a symmetric hydrofoil that is vertically installed in a stream and one or more sorbent columns that are connected to the nonuniform flow field around the hydrofoil. Depending on the ambient flow velocity, a flow occurs through each column, which elutes portions of initially present “resident” tracers in the column, while, at the same time, solutes in the water (e.g., contaminants or nutrients) are retained in the sorbent column. Quantification of the resident tracer mass remaining and the mass of solutes sorbed in the column enables determination of the local cumulative or time-averaged water and solute mass fluxes. Laboratory flume experiments show good agreement with independent measurements (R² ≥ 0.96) for instantaneous water fluxes (tested range: 0.3−0.7 m/s), cumulative water fluxes (50−600 L/cm²), and cumulative nitrate fluxes (0.4−5.1 g/cm²). Future work is required to validate the PSFM performance under a larger range of flow velocities, transient flow, and transport conditions and for different hydrofoil shapes.

Given climatic uncertainty and human population growth, tracking the world's freshwater availability is essential. Fortunately, data necessary to identify surface water patterns are abundant. Wrangling these data into an analytically friendly format, however, can be difficult for researchers not experienced in data manipulation and high‐performance computing. To increase data accessibility, we developed the Global Lake area, Climate, and Population (GLCP) dataset. The GLCP offers annually aggregated surface area, temperature, precipitation, and human population estimates for over 1.42 million lakes globally between 1995 and 2015. Our dataset is peer‐reviewed and publicly available in a tabular format, enabling researchers with a range of skill levels to effectively work with the data. All aggregation procedures were performed within Google Earth Engine and R, empowering future users to replicate and modify scripts. Three case studies are presented to highlight concrete applications of the GLCP with emphasis on natural resource management at local, regional, and national scales.