A decision-oriented model to evaluate the effect of land use and agricultural management on herbicide contamination in stream water

• Published in: Environmental modelling & software : with environment data news 2009-12, Vol.24 (12), p.1433-1446
• Main Authors: Gascuel-Odoux, Chantal, Aurousseau, Pierre, Cordier, Marie-Odile, Durand, Patrick, Garcia, Frederick, Masson, Véronique, Salmon-Monviola, Jordy, Tortrat, Florent, Trepos, Ronan
• Format: Article
• Language: English
• Subjects: Agricultural management; Agriculture; Artificial Intelligence; Catchment; Catchments; Computer Science; Contamination; Decision oriented; Freshwater; Herbicide; Herbicides; Land use; Modeling and Simulation; Modelling; Pesticide; Stream water quality; Streams; Subsurface flow; Surface flow; Zea mays
• ISSN: 1364-8152
• DOI: 10.1016/j.envsoft.2009.06.002

Modelling stream water pollution by herbicides in agricultural areas is a critical issue since numerous and incompletely known processes are involved. A decision-oriented model, SACADEAU-Transf, which represents water and pesticide transfer in medium-sized catchments (10–50 km 2) is presented. This model aims at evaluating the effect of land use, agricultural practice and landscape on the contamination of stream water in rural catchments. The processes are represented in an easily understandable way with a moderate amount of information, producing semi-quantitative and spatialized outputs. Modelling focuses on the first few months after herbicide application when high levels of contamination are generally observed, by considering transfer through the catchment area via surface and subsurface flow. The surface flow, based on a tree plot network representation of the catchment, is controlled by soil-surface properties and saturated conditions. The subsurface flow based on Topmodel concepts is controlled by the topography. Herbicide transfer is coupled to water transfer by taking into account the main characteristics of the chemicals. The model simulates the daily water and herbicide outflow at the outlets of the farmers' fields as well as from the catchment. Preliminary results on maize herbicide transfer are presented for an agricultural catchment with an area of 17 km 2 located in north-western France. The relevance of SACADEAU-Transf model is discussed in view of the qualities required for the decision-oriented models developed for improving agro-environmental management.