DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR ECO-FRIENDLY MANAGEMENT OF WATER RESOURCES AND AGROCHEMICALS

摘要

Agriculture is listed as a major contributor of NPS pollution, which causes degradation of surface and ground water resources through soil erosion, chemical runoff, and leaching. Quantification and control of NPS pollutants is a real challenge. However, this can be achieved if the processes of transport (on surface and downward) of pollutants can be properly understood and modeled. Hardly any of the existing models accurately simulates both the surface transport and leaching of NPS pollutants. The processes of transport of agrochemicals being related to surface and subsurface hydrology, watershed should be taken as the unit for this type of study. Keeping these facts in mind, the current study was taken up with the major goal of developing a Decision Support System (DSS) for eco-friendly management of water resources and agrochemicals. The DSS takes into account both surface transport and leaching of pollutants. It uses modified curve number method, suitable for the region, to simulate the runoff volume. The modified Universal Soil Loss Equation is used to simulate the sediment yield. Modified Richards's equation and diffusion dispersion equations are used to simulate the downward movement of water and solutes through the soil respectively. Multiple-objective linear programming technique was used for optimization. The developed DSS was calibrated with the observed data from a 951 ha monitored watershed and controlled field experiments conducted under a sponsored research project undertaken by the authors. The DSS is to be tested in other larger watersheds so that it could be generalized and used as an effective tool for decision making related to eco-friendly management of agrochemicals, without sacrificing the agro-production.