EGU21-13140
https://doi.org/10.5194/egusphere-egu21-13140
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Fire-induced catchment erosion on a depleted soil system from GeoWEPP and RUSLE models, Santa Olga, Chile

Violeta Tolorza1, Dagoberto Poblete2, Virginia I. González3, Mauricio Zambrano-Bigiarini1,4, Julián Cabezas2, and Mauricio Galleguillos2,4
Violeta Tolorza et al.
  • 1Universidad de La Frontera, Temuco, Chile (violle@gmail.com)
  • 2Departamento de Ciencias Ambientales y Recursos Naturales Renovables, Universidad de Chile
  • 3Universidad del Norte, Barranquilla, Colombia
  • 4Center for Climate and Resilience Research (CR)2, Santiago, Chile

The recent increase in frequency and extent of severe wildfires in South-Central Chile is degrading the already eroded soils of the Coastal Cordillera. Spatially explicit quantification of erosion triggered by that disturbances may reveal useful information for soil conservation and land planning purposes, which is especially relevant in drinking-water catchments. We compared estimations of water erosion using a process-based and an empirical modeling approaches in a small (173 ha) burned drinking water catchment. To this end, we implemented the GeoWEPP process-based model and the RUSLE empirical approach for different scenarios of wildfire severity using remote sensing, in situ soil and hydro-meteorological data (2001-2019). Individual Hydrologic Response Units resulted in very low erosion rates in GeoWEPP respect to RUSLE, while both simulations represent low erosion rates respect to observations reported for other latitudes of the Coastal Cordillera. Those low erosion rates could be explained by low rainfall erosivity and high critical shear stress, which in turn is a consequence of soil compaction.  The spatial variations of the modeled sediment yields (2001-2019) were associated both to the wildfire and to the land management at hillslopes, which involves clear cut timber harvest at most forest plantations areas. A better quantification of those erosion processes is necessary to improve the understanding of the evolution of Chilean forestry landscape, in order to prioritize efforts for soil conservation and ecosystem restoration.

How to cite: Tolorza, V., Poblete, D., González, V. I., Zambrano-Bigiarini, M., Cabezas, J., and Galleguillos, M.: Fire-induced catchment erosion on a depleted soil system from GeoWEPP and RUSLE models, Santa Olga, Chile, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13140, https://doi.org/10.5194/egusphere-egu21-13140, 2021.