Abstract
We analyzed the monthly data of discharge, ammonium, total phosphorus, and potassium in the lower Mekong River to discuss the applicability of the rating curve function to estimate the nutrient concentration and to understand the inundation effects for nutrient expansion. The various sources of nutrient in the upstream directly affected the water quality in the downstream. Although the sedimentation amount depends on the discharge affecting deposition and erosion, ammonium and potassium directly reached the lower Mekong area because there was no correlation between discharge and these water quality parameters. Therefore, we cannot apply the rating curve function for nutrient water quality in the lower Mekong River.
