Land use influencing the pesticides concentration in Ma river and its tributaries in Thanh Hoa province

Surface water frequently contains pesticide residues, which could be a hazard to freshwater ecosystems and biodiversity. Pesticides can enter waters through a number of different pathways, but oncentrations is runoff from irrigation or precipitation. This study presents an investigation of banned pesticides used across the range of land use in catchments of the Ma river and its tributaries in Thanh Hoa province, Vietnam in period of time 2011-2015. Applying principal component analysis (PCA), we investigated the relationship between specific pesticides and land use. Besides, the method of aggregating monitoring locations known as cluster analysis (CA) has also been applied in this study. All ten banned pesticides including eight insecticides (aldrin/dierin, BHC, chlordane, endrin, heptachlor, lindan, malathion, and parathion) and two herbicides (2,4D and paraquat) studied still occur in surface water due to their persistence and remobilization during floods, runoff and not presumably influenced by the fraction of land uses area in the catchments. Clustering results revealed banned pesticides still occurs in some areas.