Ronny Berndtsson
Professor, Dep Director, MECW Dep Scientific Coordinator
Water Erosion Modelling using Fractal Rainfall Disaggregation, a Study in Semiarid Tunisia
Author
Summary, in English
To investigate rainfall disaggregation possibilities, a regionalization of fine time-scale and daily rainfall was undertaken. The results showed that the spatial properties are typically non-isotropic. Clustering showed that two different homogeneous rainfall subgroups are closely related to the predominant convective and frontal rainfall types. The comparison illustrated important similarities between the maximum 15-min and the daily rainfall data.
The above findings were an incentive to explore the multiplicative properties of a 4-year rainfall time series. The time series showed scaling behavior for time scales up to 100 min that coincides with the most active erosion process time scale. Moreover, the temporal structure of rainfall was reproduced using a disaggregation model (Olsson, 1998). The observed and generated rainfall time series displayed several similar characteristics. This allowed the reproduction of erosivity for erosive rainfall events longer than 45 minutes. The erosion modeling was performed using the USLE/GIS approach. Maps of observed and generated spatial erosion distribution were combined with the Masson’s and Wischmeier-Smith’s erosion limit intervals. According to the above, the potential of rainfall scaling-based approaches to predict water erosion levels in semiarid areas seems promising. Using this approach may help soil and water authorities in semiarid areas to better manage soil erosion problems.
Department/s
- Division of Water Resources Engineering
Publishing year
2009
Language
English
Full text
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Document type
Dissertation
Topic
- Water Engineering
Keywords
- Soil erosion
- semiarid
- Tunisia
- rainfall
- fractal
- diaggregation
Status
Published
Supervisor
- Ronny Berndtsson
Defence date
12 June 2009
Defence time
13:15
Defence place
Room V:B, V-building, John Ericssons väg 1, Lund University Faculty of Engineering
Opponent
- Robin Clarke (Prof)