Flood analysis of the Limpopo River basin through past evolution reconstruction and a geomorphological approach

Abstract

Abstract. This research reconstructs the past evolution of the Limpopo River, a transboundary system located in southeastern Africa, and describes its geomorphological settings through a literature review and field work activities, with the aim of analysing flood hazard in the basin. Major changes have occurred since the late Jurassic-early Cretaceous period due to successive tectonic events. The paper demonstrates that the apparently abandoned drainage conformation of the palaeo-Limpopo in the upper and middle stretches of the river today constitutes preferential flood-prone areas in the case of major rainfall events. An important palaeo-delta is identified in the lower Limpopo, which imposes a particular drainage pattern onto the floodplain in Mozambique and influences the flood dynamics at present. The adopted method is helpful in determining flood hazard in a data-scarce area showing complex fluvial dynamics, and allows for the identification of unsuitable locations for human settlements.

A paleo‐hydro‐geomorphological perspective on urban flood risk assessment

“…An important shortcoming of the aforementioned complex modelling approaches is the high amount of input data needed for setting up, calibration, and verification of the models, and the high computational cost associated with the simulation of different probable scenarios. The historical and hydro‐geomorphological approach (Spaliviero, ) appears as a simple but efficient framework for a better long‐term territorial planning (e.g., Forte, Pennetta, & Strobl, ; Nirupama & Simonovic, ; Spaliviero, De Dapper, & Maló, ). In this context, fluvial geomorphology provides a framework for flood‐risk assessment, especially through (a) delineation of flood prone areas in broad alluvial valleys by mapping flood‐related landforms and deposits, soil and plant associations, and flood observations (Benito & Hudson, ; Bodoque et al, ) and (b) paleohydrology reconstructions of the evolution of rivers (Isla et al, ) and lakes (Guerra, Piovano, Córdoba, Sylvestre, & Damatto, ).…”

Strengthening the capacity of irrigation schemes to cope with flood through improved maintenance: a collaborative approach to analySe the case of Chókwè, Mozambique

“…The map and discussions highlighted that the primary flow did not surge from the Limpopo River or dyke leakage as expected but from the north‐western part of the scheme as the old waterways of the Elephant River were reactivated (Spaliviero et al ., ). In a second phase dyke failure (through leakage or local overtopping) accentuated the process.…”

“…Mozambique is the third most exposed country to extreme events on the African continent (Global Facility for Disaster Reduction and Recovery, ). The area of the Chókwè Irrigation Scheme, which lies in the inundation plain of the Limpopo River (Figure ), is particularly vulnerable (Asante et al ., ) due to the influence of a huge palaeo‐delta in the flood dynamics (Spaliviero et al ., ). There was no discernible pattern of rain changes in the south of Mozambique between 1960 and 2008 because of the high interannual variability, but the proportion of total rainfall that falls in heavy events is projected to increase during December to February in projections from all models and all scenarios, by up to 18%.…”

Geological development of the Limpopo Shelf (southern Mozambique) during the last sealevel cycle

“…3A, D and 6). The modern Limpopo shows a width of around 100 m close to its termination with a flood plain of several kilometers width including numerous meander loops (Spaliviero et al 2014;Sitoe et al 2015). Thus, these fluvial channels probably represent the course of the Limpopo River during shelf exposure (Figs.…”