Geomática e hidrofobicidad postincendio a escala de parcela: capturando la repelencia al agua del suelo a microescala/Geomatics and Post-Fire Soil Water Repellency at the Plot Scale: Capturing Soil Water Repellency at the Microscale

Los incendios forestales pueden modificar de forma importante las propiedades hidrológicas del suelo. Entre estos cambios se encuentra la repelencia al agua del suelo (soil water repellency, SWR), que puede reducir la infiltración y favorecer la escorrentía y la erosión. Sin embargo, su distribución no es uniforme: incluso dentro de una misma parcela pueden coexistir zonas hidrófilas y áreas con elevada repelencia.

Esta variabilidad convierte a la escala de parcela en un nivel de observación especialmente interesante para la geomática. Frente a la resolución espacial de los sensores satelitales, los UAV permiten obtener imágenes RGB, multiespectrales o térmicas con resolución centimétrica. Estas observaciones pueden complementarse con fotogrametría Structure-from-Motion (SfM) y escáner láser terrestre (TLS) para caracterizar la microtopografía, la rugosidad y la evolución de pequeños regueros.

La clave está en integrar estas observaciones con mediciones directas de campo, como el Water Drop Penetration Time (WDPT). Los datos de campo permiten calibrar y validar modelos capaces de estimar espacialmente la repelencia, mientras que la teledetección hiperespectral ha demostrado su potencial para relacionar determinadas características de la superficie quemada con la SWR.

Esta integración permite pasar de mediciones puntuales a mapas espaciales de vulnerabilidad hidrológica, útiles para analizar dónde puede concentrarse la escorrentía y dónde pueden desarrollarse procesos erosivos después de las primeras lluvias. Así, la geomática se convierte en un puente entre la observación detallada del suelo y la modelización hidrológica de áreas quemada.

     Fuente/Source: Pradhan & Floyd (2024)

Geomatics and Post-Fire Soil Water Repellency at the Plot Scale: Capturing Soil Water Repellency at the Microscale

Wildfires can substantially modify the hydrological properties of soil. Among these changes is soil water repellency (SWR), which can reduce infiltration and promote runoff and erosion. However, its spatial distribution is far from uniform: even within a single plot, hydrophilic areas may coexist with zones showing high levels of water repellency.

This variability makes the plot scale particularly relevant for geomatics. Compared with the spatial resolution of satellite sensors, UAVs can provide RGB, multispectral, or thermal imagery at centimetre-level resolution. These observations can be combined with Structure-from-Motion (SfM) photogrammetry and terrestrial laser scanning (TLS) to characterize microtopography, surface roughness, and the development of small rills.

The key is to integrate these observations with direct field measurements, such as the Water Drop Penetration Time (WDPT) test. Field measurements make it possible to calibrate and validate models capable of spatially estimating soil water repellency, while hyperspectral remote sensing has shown potential for relating specific characteristics of burned surfaces to SWR.

This integration makes it possible to move from point measurements to spatial maps of hydrological vulnerability, helping to identify areas where runoff may become concentrated and where erosion processes may develop following the first rainfall events. In this way, geomatics becomes a bridge between detailed soil observation and hydrological modelling of burned areas.

Bibliografía/References

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Arcenegui, V., Mataix-Solera, J., Guerrero, C., Zornoza, R., Mayoral, A. M., & Morales, J. (2007). Factors controlling the water repellency induced by fire in calcareous Mediterranean forest soils. European Journal of Soil Science, 58, 1254–1259. https://doi.org/10.1111/j.1365-2389.2007.00917.x

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Pradhan, N. R., & Floyd, I. (2024). Examining the effect of moisture thresholds on post-fire water-repellent soil: A large-scale modelling approach applied to the Upper Arroyo Seco watershed, California, USA. International Journal of Wildland Fire, 33, WF22083. https://doi.org/10.1071/WF22083

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