Spatial and temporal variability in rainfall erosivity under Alpine climate : a Slovenian case study using optical disdrometer data

Bezak, Nejc (author), Petan, Sašo (author), Mikoš, Matjaž (author)

Rainfall erosivity is one of the most important parameters that influence soil erosion rates. It is characterized by a large spatial and temporal variability. For example, in Slovenia, which covers around 20,000 km$^2$, the annual rainfall erosivity ranges from less than 1,000 MJ mm ha$^{–1}$ h$^{–1}$ to more than 10,000 MJ mm ha$^{–1}$ h$^{–1}$. Drop size distribution (DSD) data are needed to investigate rainfall erosivity characteristics. More than 2 years of DSD measurements using optical disdrometers located at six stations in Slovenia were used to investigate the spatial and temporal variability in rainfall erosivity in Slovenia. Experimental results have indicated that elevation is a poor predictor of rainfall erosivity and that erosivity is more strongly correlated to the mean annual precipitation. Approximately 90% of the total kinetic energy (KE) was accounted for in about 35% of 1 min disdrometer data. The highest 1 min intensities (I) and consequently also KE values were measured in summer followed by autumn and spring. The local KE-I equation yielded an acceptable fit to the measured data in case of all six stations. The relatively large percentage of 1 min rainfall intensities above 5 mm/h can at least partially explain some very high annual rainfall erosivity values (i.e., near or above 10,000 MJ mm ha$^{–1}$ h$^{–1}$). Convective and large-scale precipitation events also result in various rainfall erosivity characteristics. The station microlocation and wind impacts in case of some stations yielded relatively large differences between the data measured using the optical disdrometer and the pluviograph. Preliminary conclusions have been gathered, but further measurements are needed to get even better insight into spatial and temporal variability in rainfall erosivity under Alpine climate in Slovenia.

• Language: English
• Keywords: rainfall erosivity, kinetic energy, disdrometer, altitude, climate, hydrology, Slovenia
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 16 str.
• Numbering: Vol. 9, art. 735492
• PID: 20.500.12556/RUL-132161
• UDC: 556(497.4)
• ISSN on article: 2296-665X
• DOI: 10.3389/fenvs.2021.735492
• COBISS.SI-ID: 80414467
• Publication date in RUL: 14.10.2021

Record is a part of a journal

• Title: Frontiers in environmental science
• Shortened title: Front. environ. sci.
• Publisher: Frontiers Media
• ISSN: 2296-665X
• COBISS.SI-ID: 523094297

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: erozivnost padavin, kinetična energija, disdrometer, nadmorska višina, klima, hidrologija, Slovenija

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0180
• Name: Vodarstvo in geotehnika - orodja in metode za analize in simulacije procesov ter razvoj tehnologij

• Funder: University of Ljubljana, UNESCO Chair on Water-Related Disaster Risk Reduction