Rainfall characteristics such as intensity, duration, and frequency are key determinants of the hydrogeomorphic response of a catchment. The presence of non-linear and threshold effects makes the relationship between rainfall variability and geomorphological dynamics difficult to quantify. Yet, this is particularly relevant under predicted exacerbated erosion induced by an intensification of hydroclimatic extremes and ensuing erosional processes. In this study, we evaluate the effects of rainfall temporal variability on catchment morphology and sediment erosion, transport, and deposition across diverse grain sizes, catchment shapes, and climates. Specifically, we simulate multiple rainfall realizations using the modified Bartlett-Lewis rectangular pulse model and assess catchment geomorphic response through the CAESAR-Lisflood landscape evolution model. Virtual catchments are used in the numerical experiments and simulations are conducted over centennial timescales. Simulation results show that higher rainfall temporal variability increases net sediment discharge, domain erosion, and deposition volumes. Particularly, more arid regions respond more actively to rainfall variations and coarser grain size configurations amplify the hydrogeomorphic response. We derive a power-law function linking standardized changes in catchment net sediment discharge and fluctuations in rainfall temporal variability, with a consistent exponent across simulations and supported by long-term observational data. Such quantification of the effects of predicted changes in rainfall patterns on catchment hydromorphological response is crucial to forecasting the implications of expected changes in rainfall patterns for downstream sediment delivery. Results further highlight the need to explicitly account for local variability in rainfall intensification when estimating potential changes in soil erosion fluxes. Plain Language Summary Climate change is expected to cause an increase in soil erosion, with notable effects on multiple ecosystem services. One important factor in regulating soil erosion processes is how rainfall occurs-not just its annual quantity but also how often storms take place and how intense they are. In this study, we generated different rainfall scenarios and used a landscape evolution model to see how different rainfall temporal patterns modulate soil erosion through catchments characterized by different soil and topographic conditions. We found that, as rainfall events become less frequent but more intense, more soil is eroded and deposited downstream. This effect is stronger in drier climates and when the soil is made of coarser particles. We further derived a predictive relation to quantify the changes in soil erosion due to rainfall variation over time, which is confirmed by both long-term observational data and numerical simulations from previous studies.