This data layer presents the results of a modeling of net anthropogenic inputs of nitrogen and phosphorus (NANI/NAPI) carried out by Professor Roxane Maranger and Stéphanie Shousha from the University of Montreal as part of a partnership with the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP). The modeling was carried out using the Net Anthropogenic Nitrogen/Phosphorus Input method applied for the first time in Quebec by ([Goyette et al., 2016]) (https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fagupubs.onlinelibrary.wiley.com%2Fdoi%2F10.1002%2F2016GB005384&data=05%7C02%7CAntoine.Prince%40environnement.gouv.qc.ca%7Ce9a3e849691c4a3f9bc008de4e23f624%7C4262d4ec5a674957abb6bf78aca6a6f5%7C0%7C0%7C639034113587157844%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C 0% 7C%7C%7C&sdata=a7ktxc6ea9u4thdsbor9ojrkspdjgwno%2Fbaizkkkuaq%3D&reserved=0)) then refined in ([Shousha & Maranger, 2024] (https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbesjournals.onlinelibrary.wiley.com%2Fdoi%2Ffull%2F10.1111%2F1365-2664.14733&data=05%7C02%7CAntoine.Prince%40environnement.gouv.qc.ca%7Ce9a3e849691c4a3f9bc008de4e23f624%7C4262d4ec5a674957abb6bf78aca6a6f5%7C0%7C0%7C639034113587193473%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=AdT31R8 IHMEEYRZZ1HGMTRTUAEE8XMRMAQBRNAUJDN 4% 3D&reserved=0)). The model is based on the premise that a region imports nitrogen and phosphorus to support its population and agricultural activities.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**

This dataset presents the physicochemical and bacteriological evolution of water in rivers in southern Quebec and the St. Lawrence River. The 10-year (2015-2024) temporal trends on the rivers and in the river present the evolution of the ambient concentrations of physicochemical and bacteriological parameters, while the 20-year (2004-2023) time trends on the rivers present the evolution of loads and concentrations adjusted for the flows of physicochemical and bacteriological parameters. *Note that the temporal trends in total phosphorus have been invalidated due to an underestimation of concentrations caused by analytical biases that affect the majority of the data targeted for calculations. Therefore, they are not broadcast.**This third party metadata element was translated using an automated translation tool (Amazon Translate).**