Simulation of Pesticide Percolation in the Soil Based on Cellular Automata

In the last decades, the use of pesticides has increased exponentially agricultural production. However, it is a well known fact that excessive use of pesticides can be hazardous both for the environment and human health. It is thus essential to assess thoroughly the impact on the environment of a given pesticide before its application. When they are sprayed on crops, pesticides are absorbed by the soil. Then, when water flows through the soil because of rain or floods, chemical substances can be released into it. The amount of pesticide released into water mainly depends on the chemical properties of the pesticide itself and the physical and morphological properties of the soil. Finally, water carries the pesticides to the groundwater layer, polluting it. Simulation models provide a useful tool for the evaluation of the pollutive potential of a pesticide, and in the absence of experimental data are often the only option available. The model we present is based on Cellular Automata. It permits to reproduce explicitly the flow of water, and the chemical reactions taking place between water and soil. Moreover, with Cellular Automata is possible to generate artificial percolation beds, reproducing in detail the morphological features of real types of soil, thus reducing the need to collect experimental data. The results obtained from simulations are consistent with real case studies.