摘要：This paper presents an eutrophication diagnosis for the San Pedro-Mezquital basin at Mexico; procedure accounted to set up 10 sampling points distributed along the river pathway, sample collection was done at two extreme conditions: rainy season and dry season. Five parameters were analyzed in this work: pH, % Dissolved Oxygen, reactive phosphorus, and nitrogen species as nitrate and ammonia compounds. Obtained concentrations were statistically analyzed to establish if there were significant differences among sites and between seasons; being the dry season the one with higher nutrient content, ammonia can be considered statistical significance due to the total values found for each season. Calculation of the Karydis eutrophication index for each parameter showed that more damaged sites were those nearby the cities, and most of the sampled sites belonged to the eutrophic category.
关键词：Eutrophication; Pollutants; River Basin; River Watersheds
