RESUMEN
Hydrobiogeochemical processes governing water quantity and quality are highly variable in space and time. Focusing on thirty river locations in Québec, Canada, three water quality hotness indices were used to classify watersheds as contaminant transport hotspots. Concentration and load data for suspended solids (SS), total nitrogen (TN), and total phosphorous (TP) were used to identify transport hotspots, and results were compared across hotness indices with different data requirements. The role of hydroclimatic and physiographic characteristics on the occurrence and temporal persistence of transport hotspots was examined. Results show that the identification of transport hotspots was dependent on both the type of data and the hotness index used. Relationships between temporal and spatial predictors, however, were generally consistent. Annual transport hotspot occurrence was found to be related to temporal characteristics such as the number of dry days, potential evapotranspiration, and snow water equivalent, while hotspot temporal persistence was correlated to landcover characteristics. Stark differences in the identification of SS, TN, and TP transport hotspots were attributed to differences in mobilization processes and provided insights into dominant water and nutrient flowpaths in the studied watersheds. This study highlighted the importance of comparing contaminant dynamics across watersheds even when high-frequency water quality data or discharge data are not available. Characterizing hotspot occurrence and persistence, among hotness indices and water quality parameters, could be useful for watershed managers when identifying problematic watersheds, exploring legacy effects, and establishing a prioritization framework for areas that would benefit from enhanced routine monitoring or targeted mitigation strategies.
Asunto(s)
Monitoreo del Ambiente , Nitrógeno , Fósforo , Ríos , Contaminantes Químicos del Agua , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Fósforo/análisis , Ríos/química , Quebec , Nitrógeno/análisis , Calidad del Agua , Movimientos del Agua , Contaminación Química del Agua/estadística & datos numéricosRESUMEN
OBJECTIVE: To test the effect of a behavioural economics intervention in two food pantries on the nutritional quality of foods available at the pantries and the foods selected by adults visiting food pantries. DESIGN: An intervention (SuperShelf) was implemented in two food pantries (Sites A and B), with two other pantries (Sites C and D) serving as a control for pantry outcomes. The intervention aimed to increase the amount and variety of healthy foods (supply), as well as the appeal of healthy foods (demand) using behavioural economics strategies. Assessments included baseline and 4-month follow-up client surveys, client cart inventories, pantry inventories and environmental assessments. A fidelity score (range 0-100) was assigned to each intervention pantry to measure the degree of implementation. A Healthy Eating Index-2010 (HEI-2010) score (range 0-100) was generated for each client cart and pantry. SETTING: Four Minnesota food pantries, USA.ParticipantsClients visiting intervention pantries before (n 71) and after (n 70) the intervention. RESULTS: Fidelity scores differed by intervention site (Site A=82, Site B=51). At Site A, in adjusted models, client cart HEI-2010 scores increased on average by 11·8 points (P<0·0001), whereas there was no change at Site B. HEI-2010 pantry environment scores increased in intervention pantries (Site A=8 points, Site B=19 points) and decreased slightly in control pantries (Site C=-4 points, Site D=-3 points). CONCLUSIONS: When implemented as intended, SuperShelf has the potential to improve the nutritional quality of foods available to and selected by pantry clients.