A Conceptual Nitrate Transport Model and Its Application at Different Scales

Groundwater and surface water pollution from nonpoint sources are problems of increasing concern. Nitrate transport is a crucial part in the whole process of nitrate loss. Previous methods for simulating the nitrate transport process usually involved solving complex advection–dispersion equations and required large amount of parameters and input data, which makes a model application expensive or invalid in terms of computation and data availability. The aim of this research is to develop a simple conceptual method to simulate the nitrate transport. In this paper, a simple conceptual method utilizing the distribution of nitrate loss against cumulative drainage to simulate the nitrate transport process is introduced. The concept and construction of this method are presented, and its applicability at different spatial scales is demonstrated. Results of model application at laboratory, pilot, and catchment scales show that this method has a good capability to simulate the transport of nitrate. Impact of spatial scales on parameters’ values is also discussed. Compared to conventional methods, this method requires fewer parameters, less computing time, and less input data.