Spatiotemporal Estimation of the Costs of

Agricultural beneficial management practices (BMPs) are popular strategies for mitigating non-point sources of pollution. There are economic costs for BMP placement on agricultural lands mainly because it affects profit margins of farm operations. Given the cost implication and biophysical heterogeneity of farm lands, 8 the spatial targeting of BMP placement is consequential to their cost-effectiveness. 9 Most BMPs are applied over several years, while farm production costs, crop yield and prices vary annually. Thus, BMP placement is fraught with complex spatiotemporal variabilities. Consequently, this study investigates spatiotemporal variability of BMP economic costs, to better target BMP placement and enhances their cost-effectiveness. A methodology based on rough sets has been developed to estimate BMP economic costs by accounting for the space-time variability of input variables. The method has been illustrated for three BMPs in Fairchild Creek watershed in southern Ontario, Canada. Validation of the output was undertaken by comparing its BMP cost against known costs. The results show 80% similarity between the estimate and known values. The findings demonstrate the rough sets approach as highly capable to effectively determine BMP economic costs, together with its flexibility to accommodate limited and extended time periods which make it suitable for use with practical data.