A multi-tier approach for agricultural watershed management

A multi-tier approach for agricultural watershed management has been propos ed. The approach involves identification of a watershed management issue/pr oblem, selection or development of simple conceptual model suitable for the exploration of the issue/problem identified and appropriate to the databas e available, and application of the model to address the identified issue/p roblem. The procedure is repeated by increasing the complexity in the conce ptual model until the identified issue/problem has been addressed satisfact orily. An application of the procedure to an example watershed in southern Ontario conditions is shown. The application example has revealed that for identification of temporal pattern of runoff and sediment loads a simple co nceptual model is adequate. For identification of spatial location of the s ediment source areas and for the development of a monitoring program for th e evaluation of remedial strategies a more complex distributed agricultural watershed model is necessary.