### Abstract

Original language | English |
---|---|

Pages (from-to) | 39-48 |

Number of pages | 10 |

Journal | Journal of Hydrology |

Volume | 329 |

Publication status | Published - 2006 |

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### All Science Journal Classification (ASJC) codes

- Soil Science
- Earth-Surface Processes

### Cite this

Research output: Contribution to journal › Article

*Journal of Hydrology*, vol. 329, pp. 39-48.

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TY - JOUR

T1 - Influence of the rainfall measurement interval on the erosivity determinations in the Mediterranean area

AU - Agnese, Carmelo

AU - D'Asaro, Francesco

AU - D'Agostino, Lucia

PY - 2006

Y1 - 2006

N2 - The single-storm erosion index, EI, of the USLE and RUSLE models may vary appreciably with the rainfall measurement interval, Dt. However, the effect of Dt on EI has not been investigated in the Mediterranean area. Approximately 700 erosive events and 1.5 years of rainfall energies measured by a rainfall impact measurement device were used to evaluate the effect of the rainfall measurement interval (5 min 6 Dt 6 60 min) on the erosivity determinations in the Mediterranean semi-arid area of Sicily. According to both literature and practical considerations, a reference time interval equal to 15 min was used in this investigation. Hourly rainfall data led to an appreciable underestimation of the mean value of EI (i.e., by also a factor of two, depending on the location). In the range 5 min 6 Dt 6 15 min, the effect of the rainfall measurement interval on the predicted erosivity was negligible (i.e., mean values differing by a maximum factor of 1.10) as compared with the uncertainties in the soil loss predictions. Two methods were developed for estimating the reference single-storm erosion index, (EI)15, from hourly rainfall data in Sicily. Method 1 converts the erosion index calculated on a 60- min measurement interval basis to (EI)15. Method 2 estimates (EI)15 by using the storm rainfall depth and the maximum rainfall intensity. Testing the two methods against two independent data sets produced a maximum difference between the estimated and the calculated mean values of (EI)15 equal to 7% for method 1 and 11% for method 2. Both methods may be applied in practice, depending on the available rainfall data. For a given rainfall intensity, the specific power, P, measured at eight time intervals (5 min 6 Dt 6 60 min) was in the range ±10% of the mean of the eight P values.

AB - The single-storm erosion index, EI, of the USLE and RUSLE models may vary appreciably with the rainfall measurement interval, Dt. However, the effect of Dt on EI has not been investigated in the Mediterranean area. Approximately 700 erosive events and 1.5 years of rainfall energies measured by a rainfall impact measurement device were used to evaluate the effect of the rainfall measurement interval (5 min 6 Dt 6 60 min) on the erosivity determinations in the Mediterranean semi-arid area of Sicily. According to both literature and practical considerations, a reference time interval equal to 15 min was used in this investigation. Hourly rainfall data led to an appreciable underestimation of the mean value of EI (i.e., by also a factor of two, depending on the location). In the range 5 min 6 Dt 6 15 min, the effect of the rainfall measurement interval on the predicted erosivity was negligible (i.e., mean values differing by a maximum factor of 1.10) as compared with the uncertainties in the soil loss predictions. Two methods were developed for estimating the reference single-storm erosion index, (EI)15, from hourly rainfall data in Sicily. Method 1 converts the erosion index calculated on a 60- min measurement interval basis to (EI)15. Method 2 estimates (EI)15 by using the storm rainfall depth and the maximum rainfall intensity. Testing the two methods against two independent data sets produced a maximum difference between the estimated and the calculated mean values of (EI)15 equal to 7% for method 1 and 11% for method 2. Both methods may be applied in practice, depending on the available rainfall data. For a given rainfall intensity, the specific power, P, measured at eight time intervals (5 min 6 Dt 6 60 min) was in the range ±10% of the mean of the eight P values.

UR - http://hdl.handle.net/10447/12299

M3 - Article

VL - 329

SP - 39

EP - 48

JO - Journal of Hydrology

JF - Journal of Hydrology

SN - 0022-1694

ER -