Lee et al. (2025) Introducing NLCD-Imp: A QGIS plugin to better replicate urban characteristics in land use/cover maps for SWAT

Identification

• Journal: Environmental Modelling & Software
• Year: 2025
• Date: 2025-11-25
• Authors: D. K. Lee, Ritesh Karki, Latif Kalin
• DOI: 10.1016/j.envsoft.2025.106798

Research Groups

• College of Forestry, Wildlife and Environment, Auburn University, Auburn, AL, USA
• College of Agriculture and Natural Resources, University of Maryland, College Park, MD, USA

Short Summary

This study developed NLCD-Imp, a QGIS plugin, to enhance National Land Cover Database (NLCD) maps with detailed urban characteristics for improved hydrological modeling. Applying NLCD-Imp to the Soil and Water Assessment Tool (SWAT) revealed increased surface runoff, reduced evapotranspiration, and a two-to fourfold increase in simulated nutrient loads in highly impervious urban areas, with a 2 % imperviousness threshold balancing model accuracy and complexity.

Objective

• To develop NLCD-Imp, a QGIS plugin, to enhance National Land Cover Database (NLCD) land use/land cover (LULC) maps by integrating detailed urban characteristics, thereby addressing the limitation of simplified urban classifications in watershed-scale hydrologic models.
• To apply NLCD-Imp to the Soil and Water Assessment Tool (SWAT) to assess its impact on hydrological and biochemical responses in an urban watershed.

Study Configuration

• Spatial Scale: Urban watershed scale.
• Temporal Scale: Not explicitly defined, but implies continuous hydrological and biochemical processes within a watershed.

Methodology and Data

• Models used: Soil and Water Assessment Tool (SWAT) for hydrological and biochemical simulations; NLCD-Imp QGIS plugin for enhancing LULC inputs.
• Data sources: National Land Cover Database (NLCD) land use/land cover (LULC) maps.

Main Results

• The NLCD-Imp inputs led to increased surface runoff and reduced evapotranspiration in the simulated urban watershed.
• Simulated nutrient loads in highly impervious urban areas showed a two-to fourfold increase when using NLCD-Imp enhanced LULC data.
• A threshold-based method identified a 2 % imperviousness threshold as optimal for balancing model accuracy and complexity.

Contributions

• Development of NLCD-Imp, a novel QGIS plugin, that significantly improves the representation of urban characteristics, particularly impervious surfaces, in LULC maps for hydrological models.
• Demonstrated the critical impact of detailed urban LULC representation on simulated hydrological and biochemical responses (runoff, evapotranspiration, nutrient loads) within an urban watershed using SWAT.
• Provided a practical imperviousness threshold (2 %) for balancing model accuracy and complexity in urban hydrological modeling.
• Enhanced the reliability of urban water management simulations and offered adaptability for integration with other hydrological models beyond SWAT.

Funding

Not specified in the provided text.

Citation

@article{Lee2025Introducing,
  author = {Lee, D. K. and Karki, Ritesh and Kalin, Latif},
  title = {Introducing NLCD-Imp: A QGIS plugin to better replicate urban characteristics in land use/cover maps for SWAT},
  journal = {Environmental Modelling & Software},
  year = {2025},
  doi = {10.1016/j.envsoft.2025.106798},
  url = {https://doi.org/10.1016/j.envsoft.2025.106798}
}