Steps Towards the Simulation of Long-term Spatial-Temporal Soil Redistribution Patterns using QGEOWEPP

Keywords: Soil redistribution, soil loss, deposition, process-based model, GeoWEPP, WEPP
Session Type: Virtual Paper Abstract
Day: Monday
Session Start / End Time: 2/28/2022 03:40 PM (Eastern Time (US & Canada)) - 2/28/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 46

Abstract

Process-based, continuous models have demonstrated their advantage of representing event-based hydrological responses at smaller spatial and temporal scales for watershed outlets around the world. In this study, the process-based Geospatial Interface for the Water Erosion Prediction Project (GeoWEPP) was combined with open-source GIS software, QGIS. This new QGeoWEPP was then used to analyze the spatial and temporal changing patterns of soil redistribution and sediment yield in the time period from 1963 to 2001 at the Lucky Hills site of the Walnut Gulch Experimental Watershed (WGEW), Tombstone, Arizona (USA). For testing and validation purposes, a series of 39 QGeoWEPP simulations were performed in order to obtain the detailed spatial distribution of soil redistribution for each end of the year simulation. Single year, distributed annual soil redistribution rates were calculated using the simulation results of two adjacent years. Both the spatial distribution of soil loss and deposition were analyzed separately, corresponding with the changing patterns of accumulated event-based sediment yield. The spatial distribution of soil loss and deposition rates were classified into four types of patterns. Both the soil redistribution rates and the sediment yield are highly dependent on the number of significant rainfall events within each year. The detailed analysis of the spatial and temporal distribution of soil loss/deposition, as well as the event-based sediment yield accumulation can potentially provide an approach and guidance to the study of soil conservation within a relatively small watershed. QGeoWEPP is currently in the final stages of testing and should be released soon.