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| Titel |
Estimation of the mean annual erosivity in the region Easthern Andalusia (Spain) through the maximum annual precipitation values of 24 hours and daily duration. |
| VerfasserIn |
Patricia Ayuso-Ruiz, Jose Luis Ayuso, Encarnación Taguas, Amanda García-Marín, Rafael Ayuso-Muñoz |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250051300
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| Zusammenfassung |
| Soil loss is commonly predicted using an empirical model such as the Universal Soil Loss
Equation (USLE), because of its simple structure and easy application. Among the empirical
coefficients used to calculate potential erosion, rainfall erosivity represents a natural
environmental constraint on soil erosion that limits and conditions land use and management.
Long term records of the erosivity values are not common since they require rainfall data at
intervals of at least 30 minutes and the weather records are usually given on a daily or
monthly basis.
In this work, the relationships between the mean annual erosivity (EI30)y and the
maximum annual precipitation values of 24 hours (P24) and daily duration (Pd) from the
four provinces in the region Easthern Andalusia (Spain) are explored.
Using hourly data of precipitation corresponding to the period 1981-2007 from Jaén,
Málaga, Granada and Almería, the values of annual erosivities (EI60) were calculated for
different minimum times between events (MTE; 1, 2, 3, 4, 5 and 6 h). Only the events with a
larger accumulated rainfall depth than 10 mm were considered. A data series of time step
equal to 10 min corresponding to the period 1999-2002 allowed to adjust the relationships
EI60-EI30. Then, the parameters a and b as well as the determination coefficient were
calculated for the potential equations (EI30)y = a.P24b and (EI30)y = a.Pdb in the four
considered gauges, where (EI30)y is the mean annual erosivity and P24 and Pd are the
averages of the anual máximum rainfall in 24 h and anual máximum daily precipitation,
respectively.
The results show how the longer MTEs are considered, the largest determination
coefficients are obtained. In addition, the best adjusting –with a determination coeffcient
equal to 0.9992- was obtained for MTE of 6 hours and the duration of 24 h. This simple
approach for calculating the mean annual erosivity could be applied in other areas in
order to study and to calculate the erosion risk through daily/24 h data records. |
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