Model Library

Geomorphology-Based Nonpoint Source Pollution (GBNP)

Model name: Geomorphology-Based Nonpoint Source Pollution (GBNP)

Developed by: researchers at University of Tokyo, led by Dr. Yang (Last update: 2002)

Model type: Grid-based, distributed, process-based, hydrological watershed model

Computational requirements: N/A

Software requirements: GIS: optional.

Link to download model: Not open-source.

Capabilities and Limitations:

Capabilities

  • It discretizes a watershed into ‘hillslope–river network’ and describes the dynamics of pollutant transport and relevant hydrology and hydraulics (Wang et al., 2020);
  • It uses geomorphological features to accurately represent watershed physical characteristics (Wang et al., 2014).

Limitations

  • Not open-source;
  • It does not simulate the biogeochemical interactions between the atmosphere and the land surface (Abdolghafoorian & Dirmeyer, 2021; Wang et al., 2023);
  • It lacks the ability to simulate farmland fertilization, manure application, and urban air pollution (Wang et al., 2023);
  • It cannot simulate changes in aquatic ecosystem dynamics, such as shifts in nutrient limitation and their impact on nitrate uptake and TN retention, highlighting a limitation in addressing nutrient thresholds and self-purification processes (Wang et al., 2015).

Model Inputs and Outputs:

Inputs

Topography, Soil type, LULC, Vegetation, Hydrological data, Water quality data

Outputs

The model simulates processes of rainfall–runoff, soil erosion, sediment routing, and pollutant transport.

Examples:

References

Wang, A., Yang, D., & Tang, L. (2020). Spatiotemporal variation in nitrogen loads and their impacts on river water quality in the upper Yangtze River basin. Journal of Hydrology, 590, 125487. https://doi.org/10.1016/j.jhydrol.2020.125487

Wang, S., Wang, A., Yang, D., Gu, Y., Tang, L., & Sun, X. (2023). Understanding the spatiotemporal variability in nonpoint source nutrient loads and its effect on water quality in the upper Xin’an river basin, Eastern China. Journal of Hydrology, 621, 129582. https://doi.org/10.1016/j.jhydrol.2023.129582

Objectives

The aim of this study was to (1) estimate the spatial and temporal variation in N loads from the landscape; (2) understand the spatial and temporal variability in the export coefficient and riverine N retention; and (3) clarify the influences on river N concentration.

The objectives of the study are: (1) to understand the spatiotemporal variations in N and P loads over the past 40 years in the XRB; (2) to investigate the influences of pollution change on river water quality; (3) to clarify the contribution of atmospheric deposition to river water quality in the study area.