A new R-SWAT Decision Making Framework for the Efficient Allocation of Best Management Practices

The work presents and illustrates the application of R-SWAT-DM, a new R framework designed for Decision Making (DM), related to the implementation of Best Management Practices (BMPs), for restoring and protecting the good ecological status of freshwater bodies. R-SWAT-DM combines the use of the SWAT watershed model, the spatial representation of BMPs and an economic component. The SWAT model served as the nonpoint source pollution estimator for current conditions (base line) as well as for scenarios with modified agricultural practices (fertilization and irrigation) and PS nutrient concentrations, after considering waste water treatment upgrading. R-SWAT-DM easily communicates with the SWAT and economic model through simple ASCII files and/or wrapper functions for exchanging information. It includes tools, to launch individual or iterative BMPs simulations or search for optimal strategies. The current version integrates the state of the art in mono and multi-objective optimization libraries that were already implemented in R. It also includes advanced plotting, mapping and statistical analysis functionalities to facilitate the interpretation and assessment of the results. We illustrate the application of R-SWAT-DM in one real-world case study for the Upper Danube Basin, for identifying optimal BMP allocation to achieve two objectives: minimize nutrient load exports and the net cost. The success of conservation programs depends to a great extent on the optimal identification of management solutions with respect to the envisaged environmental and economic objectives. This identification is a complex task, especially when considering that costs and efficiency of conservation strategies can change depending on their locations within a basin. The results shows that optimal spatial conservation practices could reduce the nutrients more than 50% while simultaneously provide more net economic value.JRC.H.1-Water Resource