Model Library

INtegrated CAtchment (INCA)

Model name: INtegrated CAtchment (INCA)

Developed by: Dr. Paul Whitehead and Dr. Dan Butterfield (Last update: 2021)

Model type: Semi-distributed, daily-time step, dynamic, process-based, hydrological, ecological, and water quality watershed model

Model family: Each member simulates specific type of water quality addressed by the suffix (e.g., INCA-N, INCA-P, INCA-C), hydrology (PERSiST), pathogens (INCA Pathogens), and microplastics (INCA Micro-Plastics). However, this project only accounts for the water quality and hydrological models of INCA.

Computational requirements: Windows.

Software requirements: GIS: optional

Link to download model: Not open-source

Capabilities and Limitations:

Capabilities

  • The Integrated Catchments (INCA) model has been extensively used in Europe, particularly in England (Zeckoski et al., 2009);
  • INCA-P models water delivery to watercourses via quick flow, which accounts for overland flow and other rapid flow pathways, soil water flow and groundwater flow (Jackson-Blake et al., 2017);
  • The model accounts for sediment deposition and re-entrainment, supporting both transport-limited and supply-limited sediment transport (Bussi et al., 2021).

Limitations

  • Not open-source;
  • Soil phosphorus (P) dynamics in INCA-P remain relatively simple (Tong et al., 2022);
  • Current catchment-scale water quality models, including INCA, are considered overly complex (Jackson-Blake et al., 2017);
  • INCA-PEco simulates total phytoplankton concentration but lacks species-specific modeling, limiting its long-term applicability, such as under climate simulations (Crossman et al., 2021);
  • INCA does not account for long-term river channel morphological changes beyond sediment deposition or depletion (Bussi et al., 2021);
  • It is not fully distributed (Bussi et al., 2021).

 Model Inputs and Outputs:

Inputs

Topography data, River network topology, Reach characteristics, Channel width and slope, LULC data, Soil data, Meteorological data, Hydrological data, Water quality data, Point-source effluents (if any).

Outputs

  • INCA simulates stream flow rates, concentrations of nutrients such as nitrogen (nitrate, ammonium) and phosphorus, sediment loads, pathogen levels, phytoplankton concentrations, and other water quality indicators.
  • The INCA model has been successfully applied to address various environmental issues in catchments, including changing pollution environments, Eutrophication assessments, Environmental impact assessment, Catchment management strategies, Land use and population change, Climate change.

Examples:

References

Hansen, A. M., Díaz-Valencia, S., & Sandoval-Chacón, D. A. (2022). Natural attenuation and its impact on reactive carbon loads to a eutrophic reservoir located in a mountain temperate zone. Applied Geochemistry, 146, 105466. https://doi.org/10.1016/j.apgeochem.2022.105466


Bussi, G., Darby, S. E., Whitehead, P. G., Jin, L., Dadson, S. J., Voepel, H. E., Vasilopoulos, G., Hackney, C. R., Hutton, C., Berchoux, T., Parsons, D. R., & Nicholas, A. (2021). Impact of dams and climate change on suspended sediment flux to the Mekong delta. Science of The Total Environment, 755(1), 142468. https://doi.org/10.1016/j.scitotenv.2020.142468

Objectives

The objectives of the study are to evaluate reactive carbon loads from hydrological basins to lakes and reservoirs, specifically the Valle de Bravo reservoir, and to determine and propose emission reduction scenarios to decrease these loads. The study also aims to highlight the importance of evaluating both diffuse and point source emissions, as well as natural attenuations, in understanding carbon transport to water bodies.

This study applied the INCA hydrological and sediment model to the Mekong River catchment in South East Asia to assess the impact of several large dams (both existing and planned) on the suspended sediment fluxes of the river.