Hydrological modelling of flood risk and watershed response to land use change: A case study of the Anambra Watershed, Nigeria
DOI:
https://doi.org/10.63373/3047-8014/55Keywords:
Land use change, Land cover change, Flood risk assessment, Hydrological modelling, HEC-HMSAbstract
Land use and land cover (LULC) changes significantly influence watershed hydrological processes and flood risk. This study assessed the effects of long-term LULC change on the hydrological response of the Anambra Watershed between 1995 and 2025 using Remote Sensing (RS), Geographic Information Systems (GIS), and HEC-HMS hydrological modelling. Satellite imagery was analyzed to quantify historical land cover changes, while HEC-HMS was employed to simulate rainfall–runoff responses under varying land use conditions. The results revealed a 184.2% increase in built-up areas and substantial declines in forest cover (34.1%) and wetlands (34.0%) over the study period. Hydrological simulations showed that these changes reduced infiltration by 45.4%, increased surface runoff by 36.0%, and increased peak discharge by 38.6% under a 100-year rainfall event. The time-to-peak also decreased from 14.2 to 11.8 hours, indicating a faster watershed response to storm events. Flood susceptibility mapping further revealed that approximately 73% of the watershed falls within medium to very high flood-risk categories, with the highest vulnerability concentrated in the southern floodplain regions. The findings demonstrate that long-term land use change has significantly altered the hydrological behaviour of the watershed and increased flood vulnerability. The study highlights the importance of riparian restoration, wetland conservation, and sustainable urban drainage strategies for effective flood-risk management within the watershed.
References
Balarabe, A., Iguisi, E. O., Mukhtar, I., Lawal, Z. R., Ahmed, A., Umar, J. H., Salihu, S. A., Hassan, A. W., Haliru, Y., Aliyu, M. H., & Khalid, U. S. (2025). Impact of Land Use and Land Cover (LULC) Changes on flood risk in the downstream communities of the Tiga Dam, Kano River, Nigeria. Fudma Journal of Sciences, 9(11), 167-177.
Chow, V. T., Maidment, D. R., & Mays, L. W. (1988). Applied hydrology. McGraw-Hill.
Chukwuma, E. C., et al. (2021). Integrated GIS and multi-criteria decision analysis for flood vulnerability assessment in south-eastern Nigeria. Journal of Hydrology and Spatial Sciences, 14(2), 89–104.
Enem, E. S., Enemuo, C. J., & Okafor, T. U. (2025). Effect of technological gamification on upper basic education students’achievement and interest in computer studies in Awka education zone. South Eastern Journal of Research and Sustainable Development (SEJRSD), 18(1), 67-83.
Esri. (2023). ArcGIS Pro documentation. Esri Inc.
Ezeanyagu, N. D., Opara, F. M., & Okafor, T. U. (2023). Motivation and self-esteem as predictors of secondary school students’ achievement in biology in Awka educational zone of Anambra state. UNIZIK Journal of Educational Research and Policy Studies, 16(2), 219-228.
HEC. (2022). Hydrologic Modelling System HEC-HMS user’s manual (Version 4.11). Hydrologic Engineering Centre, U.S. Army Corps of Engineers.
Herold, M., Goldstein, N. C., & Clarke, K. C. (2003). The spatiotemporal form of urban growth: Measurement, analysis and modelling. Remote Sensing of Environment, 86(3), 286–302. DOI: https://doi.org/10.1016/S0034-4257(03)00075-0
Jensen, J. R. (2005). Introductory digital image processing: A remote sensing perspective (3rd ed.). Prentice Hall.
Lillesand, T. M., Kiefer, R. W., & Chipman, J. W. (2015). Remote sensing and image interpretation (7th ed.). Wiley.
Muogbo, U. F., Okafor, T. U., & Umezulike, F. M. (2026). Teachers’ readiness and competence in integrating ai-based educational tools in computer studies classrooms in Nnewi education zone, Anambra state, Nigeria. STEM journal of Anambra STAN, 6(2), 72-81.
Muogbo, U. F., Okafor, U. T., & Okafor, C. F. (2025). Impact of experiential learning strategy on secondary school students’ academic achievement in computer studies in Nnewi Education Zone, Anambra State.
NASA. (2023). Landsat science mission overview. National Aeronautics and Space Administration.
Nkwunonwo, U. C., Whitworth, M., & Baily, B. (2020). A review of flood risk analysis and management in Nigeria. International Journal of Environmental Research and Public Health, 17(3), 1–24.
Nneka, R. N., & Okafor, T. U. (2013). Assessment of Science Teachers’ Level of Computer Literacy and Usage in Colleges of Education: Implication for Global Competitiveness. African Journal of Education, Science and Technology (AJEST), 1(1), 250-258.
Okafor, G. C., & Agunwamba, J. C. (2024). Comprehensive GIS-based flood risk assessment of vulnerable areas in Anambra State, Nigeria. West African Journal of Infrastructure and Moisture Management, 8(4), 1–23.
Okafor, T. U. (2017). Physics process skills and its acquisition on secondary school physics students in Aguata and Nnewi Education Zones of Anambra state. American Academic & Scholarly Research Journal, 9(3), 159–181.
Okafor, T. U. (2018). A way forward in enhancing the participation of the girl-child in physics education. International Journal of Advanced and Innovative Research, 7(7), 1–5.
Okafor, T. U. (2019). Effect of Polya's Problem Solving Technique on the Academic Achievement of Senior Secondary School Student in Physics. European Journal of Physics Education, 10(1), 38-48.
Saaty, T. L. (1980). The analytic hierarchy process. McGraw-Hill. DOI: https://doi.org/10.21236/ADA214804
SCS-USDA. (1986). Urban hydrology for small watersheds (Technical Release 55). Soil Conservation Service, United States Department of Agriculture.
Shrestha, S., Lohpaisankrit, W., & Ninsawat, S. (2021). Flood hazard assessment using GIS and multi-criteria decision analysis. Hydrological Sciences Journal, 66(4), 567–582.
Smith, K., & Ward, R. (2015). Floods: Physical processes and human impacts (2nd ed.). Wiley-Blackwell.
Tella, A., & Balogun, I. A. (2020). A GIS-based flood vulnerability modelling of Anambra State using an integrated IVFRN-DEMATEL-ANP model. Heliyon, 6(9), e04929.
Ugonwa O, T. (2015). Difficulties Encountered by Secondary School Physics Students in Answering Mathematical Related Physics Questions. American Academic & Scholarly Research Journal, 7(5), 111–10.
United States Geological Survey (USGS). (2023). Earth Explorer user guide and geospatial data portal. U.S. Department of the Interior.
Ward, P. J., & Shukla, S. (2017). Flood risk and climate change in developing regions. Hydrology and Earth System Sciences, 21(1), 1–18.
Weng, Q. (2012). Remote sensing of impervious surfaces in the urban areas: Requirements, methods, and trends. Remote Sensing of Environment, 117, 34–49. DOI: https://doi.org/10.1016/j.rse.2011.02.030
Youssef, A. M., Pradhan, B., Gaber, A. F. D., & Buchroithner, M. F. (2011). Geomorphological hazard analysis using GIS and remote sensing techniques. Natural Hazards and Earth System Sciences, 11(3), 1173–1185.
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