Authors : Haja Nirina Raveloalison; Rakotoson Andriatiana Tolontsoa; Tovonirina Mamiharizo Jackie; Razafiarisera Ralay Tiana

Volume/Issue : Volume 11 - 2026, Issue 7 - July

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Google Scholar : https://tinyurl.com/4py2yvja

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DOI : https://doi.org/10.38124/ijisrt/26jul383

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Abstract : Rainfall distribution shows strong seasonality, with monthly peaks reaching 307–323 mm at Mahitsy Kely and Anosizato, and 315–321 mm at Ambohimanambola. Observed discharges indicate major wet-season peaks, reaching approximately 330 m³/s at Mahitsy Kely and 270–280 m³/s at Anosizato. The spatial correlation matrix confirms that flood risk is strongly associated with altitude score and distance score, both at 0.76, and with overall pressure at 0.77. These results show that flood vulnerability results from the combined effects of low altitude, hydrographic convergence, seasonal discharge peaks and spatial pressure.

Keywords : Ikopa Basin; Flood Vulnerability; Hydrospatial Modelling; Rainfall–Discharge Dynamics; Spatial Risk Correlation.

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