Analysis of Future Changes of Geometric Range of Snake Lines and its Relation to Sediment Disasters in a Changing Climate

Abstract

This study aims to investigate the future changes of sediment disasters with a focus on investigating the patterns of snake line in a changing climate. Constituted by two parameters of hourly rainfall intensity and soil-water index, a snake line is a curve used for early-warning on rainfall-triggered sediment disasters. For reasonably projecting future climate, we adopted high-resolution future climate projections of 2-km and 5-km Non-Hydrostatic Regional Climate Models under the scenarios of RCP2.6 and RCP8.5. Snake lines obtained by climate projections were verified by the reanalyzed precipitation of Radar-AMeDAS. To quantify snake line pattern, we focused on analyzing the geometric range of snake line in terms of the maximal hourly rainfall and soil-water index. Obvious increasing trends for the two parameters and corresponding distributions are revealed on each mesh. Based on six stretching types of snake lines, we examined the spatial distributions and statistics of the future change of snake line patterns under the two scenarios as well as their relation to rainfall prone to sediment disasters. Based on the critical lines, we also demonstrate some statistical features of future hazardous rainfall.