Critical review of water quality modeling and farm scale nutrient transport models widely used

Use of software engineering concepts in environmental modeling initiated many researchers to develop new models to predict the future scenario in water quality management. To understand the basics in numerical water quality modeling, a general differential equation involving advection, diffusion and source term is explained along with a modeling framework. We reviewed the present framework of farm-scale nutrient transport models that are used to simulate and predict the nutrient concentration in each water body. Each model addresses the loss of nitrogen and phosphorus from rural population and nutrient load and concentration in waterways. Some of the key farm scale nutrient transport models that are widely used at the present time are discussed.