Why do we need to use numerical models? Field observations and data collection are of primary importance in understanding the environment. However, time and cost often prohibits our ability to fully understand the dynamic effects that the environment has on our study area. Once field observations are measured and recorded, we can use that information to estimate how variation in the environment will affect our project. For example, what effect does an increase in the mean water level have on sediment transport? What velocities can we expect in an estuary if we dredge it to a new depth? Will an intended structure have an effect on water quality?
Numerical models based on sound physical principles and validated with field observations can explain dynamic processes that we may miss with just field data and help forecast changes in our physical and biological environments.