The impact of different rainfall products on landscape modelling simulations

Skinner, Christopher J.; Peleg, Nadav; Quinn, Niall; Coulthard, Tom J.; Molnar, Peter; Freer, Jim

Abstract

Rainfall products can contain significantly different spatiotemporal estimates, depending on their underlying data and final constructed resolution. Commonly used products, such as rain gauges, rain gauge networks, and weather radar, differ in their information content regarding intensities, spatial variability, and natural climatic variability, therefore producing different estimates. Landscape evolution models (LEMs) simulate the geomorphic changes in landscapes, and current models can simulate timeframes from event level to millions of years and some use rainfall inputs to drive them. However, the impact of different rainfall products on LEM outputs has never been considered. This study uses the STREAP rainfall generator, calibrated using commonly used rainfall observation products, to produce longer rainfall records than the observations to drive the CAESAR‐Lisflood LEM to examine how differences in rainfall products affect simulated landscapes. The results show that the simulation of changes to basin geomorphology is sensitive to the differences between rainfall products, with these differences expressed linearly in discharges but non‐linearly in sediment yields. Furthermore, when applied over a 1500‐year period, large differences in the simulated long profiles were observed, with the simulations producing greater sediment yields showing erosion extending further downstream. This suggests that the choice of rainfall product to drive LEMs has a large impact on the final simulated landscapes. The combination of rainfall generator model and LEMs represents a potentially powerful method for assessing the impacts of rainfall product differences on landscapes and their short‐ and long‐term evolution.

Citation

Skinner, C. J., Peleg, N., Quinn, N., Coulthard, T. J., Molnar, P., & Freer, J. (in press). The impact of different rainfall products on landscape modelling simulations. Earth surface processes and landforms : the journal of the British Geomorphological Research Group, https://doi.org/10.1002/esp.4894

• Journal Article Type: Article
• Acceptance Date: May 14, 2020
• Online Publication Date: May 14, 2020
• Deposit Date: Jun 22, 2020
• Publicly Available Date: Jun 22, 2020
• Journal: Earth Surface Processes and Landforms
• Print ISSN: 0197-9337
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1002/esp.4894
• Keywords: Landscape evolution; Weather generator; Numerical modelling; Rainfall; Uncertainty
• Public URL: https://hull-repository.worktribe.com/output/3509300
• Publisher URL: https://onlinelibrary.wiley.com/doi/full/10.1002/esp.4894
• Additional Information: Received: 2019-06-21; Accepted: 2020-04-29; Published: 2020-05-14