3.2 Modeling Technology
There is no question that modeling technology is already one of the most important and widely used tools for solving long-term environmental problems and will become even more so in the future. Modeling allows to formalize scientific understanding and to integrate the various components and processes involved in the surface/subsurface water system. It also acts as a bridge for knowledge transfer between scientists and policy makers (or the public), as a basis for testing different scenarios and allows to integrate sound planning and management strategies with economic development by means of cost-benefit analyses and finding optimal solutions. Moreover, without modeling technology it would be difficult, if not impossible, to predict the anticipated impacts of any proposed plan and management policy. In the main, the planning, design, management and operation of complex water resource systems depend on modeling technology and its continual development and improvement. Generally, these technologies include simulation and/or optimization models. Since the models embody physical parameters for describing hydrologic systems, bounds on decision and state variables to account for management goals, their reliability depends on the quantity and quality of available data.
3.2.1 Simulation models
Simulation models are essential for analyzing complex processes of surface and subsurface flow and transport, because they provide a quantitative framework for synthesizing and handling the large set of characteristics that describe the variability of