Compound flood hazard and exposure in the Limpopo River Basin : A copula-based climate risk assessment for disaster risk reduction
Mathe, Marcio Fernando LU
and Persson, Andreas
LU
(2026)
In Journal of Hydrology: Regional Studies
66.
- Abstract
Study region: The Limpopo River Basin (LRB) is a transboundary catchment in Southern Africa spanning South Africa, Botswana, Zimbabwe, and Mozambique. The lower basin, particularly the Chókwè–Xai-Xai floodplain in Mozambique, is highly flood-prone due to flat topography, climate variability, and rapid agricultural and settlement expansion. Study focus: This study presents a climate-informed framework for assessing compound flood hazards in the LRB by coupling a process-based hydrological model with two-dimensional hydraulic simulations and copula-based multivariate statistics. Bias-corrected late-century (2065–2099) climate projections under RCP 4.5 and RCP 8.5 drive hydrological simulations that provide boundary conditions for 2D... (More)
Study region: The Limpopo River Basin (LRB) is a transboundary catchment in Southern Africa spanning South Africa, Botswana, Zimbabwe, and Mozambique. The lower basin, particularly the Chókwè–Xai-Xai floodplain in Mozambique, is highly flood-prone due to flat topography, climate variability, and rapid agricultural and settlement expansion. Study focus: This study presents a climate-informed framework for assessing compound flood hazards in the LRB by coupling a process-based hydrological model with two-dimensional hydraulic simulations and copula-based multivariate statistics. Bias-corrected late-century (2065–2099) climate projections under RCP 4.5 and RCP 8.5 drive hydrological simulations that provide boundary conditions for 2D hydraulic modelling of flood depth, velocity, and duration. Copula functions quantify dependencies among these variables and are used to derive probabilistic compound-hazard classes, which are intersected with land-cover data to assess exposure. New hydrological insights for the region: Results reveal moderate, symmetric dependence among flood depth, velocity, and duration, best captured by a Gaussian copula, indicating joint intensification without strong tail asymmetry. Compound hazards increase sharply with return period and emissions pathway, with the Chókwè–Xai-Xai corridor consistently identified as the primary hotspot. Under RCP 8.5, high compound-hazard areas expand non-linearly, approaching ∼48,000 ha for 100-year events, compared with ∼5500 ha under RCP 4.5. Agricultural land shows the greatest exposure, while urban exposure peaks at intermediate return periods. The framework provides decision-relevant evidence for climate-resilient floodplain zoning, infrastructure design, and early-warning prioritisation.
(Less)
- author
- Mathe, Marcio Fernando
LU
and Persson, Andreas
LU
- organization
- publishing date
- 2026-08
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Compound events, Flood Hazard Modelling, Hydrological extremes, Limpopo River Basin, Probabilistic hydrological modelling, Southern Africa
- in
- Journal of Hydrology: Regional Studies
- volume
- 66
- article number
- 103668
- publisher
- Elsevier
- external identifiers
-
- scopus:105042592287
- ISSN
- 2214-5818
- DOI
- 10.1016/j.ejrh.2026.103668
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license. http://creativecommons.org/licenses/by/4.0/
- id
- 7023ca14-cfba-48bb-b496-c10ff164e54b
- date added to LUP
- 2026-07-23 11:19:44
- date last changed
- 2026-07-23 11:19:44
@article{7023ca14-cfba-48bb-b496-c10ff164e54b,
abstract = {{<p>Study region: The Limpopo River Basin (LRB) is a transboundary catchment in Southern Africa spanning South Africa, Botswana, Zimbabwe, and Mozambique. The lower basin, particularly the Chókwè–Xai-Xai floodplain in Mozambique, is highly flood-prone due to flat topography, climate variability, and rapid agricultural and settlement expansion. Study focus: This study presents a climate-informed framework for assessing compound flood hazards in the LRB by coupling a process-based hydrological model with two-dimensional hydraulic simulations and copula-based multivariate statistics. Bias-corrected late-century (2065–2099) climate projections under RCP 4.5 and RCP 8.5 drive hydrological simulations that provide boundary conditions for 2D hydraulic modelling of flood depth, velocity, and duration. Copula functions quantify dependencies among these variables and are used to derive probabilistic compound-hazard classes, which are intersected with land-cover data to assess exposure. New hydrological insights for the region: Results reveal moderate, symmetric dependence among flood depth, velocity, and duration, best captured by a Gaussian copula, indicating joint intensification without strong tail asymmetry. Compound hazards increase sharply with return period and emissions pathway, with the Chókwè–Xai-Xai corridor consistently identified as the primary hotspot. Under RCP 8.5, high compound-hazard areas expand non-linearly, approaching ∼48,000 ha for 100-year events, compared with ∼5500 ha under RCP 4.5. Agricultural land shows the greatest exposure, while urban exposure peaks at intermediate return periods. The framework provides decision-relevant evidence for climate-resilient floodplain zoning, infrastructure design, and early-warning prioritisation.</p>}},
author = {{Mathe, Marcio Fernando and Persson, Andreas}},
issn = {{2214-5818}},
keywords = {{Compound events; Flood Hazard Modelling; Hydrological extremes; Limpopo River Basin; Probabilistic hydrological modelling; Southern Africa}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Journal of Hydrology: Regional Studies}},
title = {{Compound flood hazard and exposure in the Limpopo River Basin : A copula-based climate risk assessment for disaster risk reduction}},
url = {{http://dx.doi.org/10.1016/j.ejrh.2026.103668}},
doi = {{10.1016/j.ejrh.2026.103668}},
volume = {{66}},
year = {{2026}},
}