This title presents mathematical models of pesticide degradation in the environment based on various abiotic and biotic factors such as temperature, humidity, water transport, soil properties, and microorganisms. These simulation programs provide the tools needed to calculate the fate of organic chemicals in the environment. The book combines different aspects of environmental modeling and describes a totally new approach to the regionalization of pesticide transport in soils. By applying these methods, the use of pesticides can be optimized with regard to timing and quantities.