This study aims at proposing a modelling of flows and overflows of structures at fine resolution (5 m) for rainfall intensities of different return periods. The overflow points of the network are identified by the difference between the maximum flow and the capacity of the network to evacuate floods. The results of the simulations show that the drainage network appears to be overflowing for rare frequency rainfall events (100 years). The method seems adaptable to different contexts.

Rainfall-induced landslides cause significant damage and fatality worldwide, but we have few datasets constraining the impact of individual storms. We present and analyze 8 landslide inventories, with >150 to >150 00 landslides, comprehensively representing the landslide population caused by 8 storms from Asia and the Americas. We found that the total storm rainfall is a major control on total landsliding, landslide size, and that storms trigger landslides on less steep slopes than earthquakes.

Since 1950, the Niger River basin has overcome drastic changes. In Niamey city, the highest river levels and the longest flooded period ever recorded occurred in 2003, 2010, 2012 and 2013, with heavy casualties and property damage. The reasons for these changes, and the relative role of climate versus Land Use Land Cover changes are still debated and are investigated in this paper using observations and modelling. We conclude on the successive role of cover and then rainfall variability.

A dramatic increase in the frequency and intensity of floods due to the Niger River has been observed in the last decade in Niamey. This paper analyses how changes in rainfall may explain this flood intensification, based on a 30 year long series of satellite rainfall and a hydrological model. We show that the salient changes in the mean decadal hydrograph between 1983 and 2013 are well mimicked by the simulations. This implyes that rainfall is the first driver to the observed changes.