Rainfall erosivity is crucial to be considered at a monthly. The rainfall erosivity is defined as the product of the total event ke and the 30minute maximum rainfall intensity, as rainfall ke alone may not provide the best estimation of erosivity 10. The r factor is a multiannual average index that measures rainfall s kinetic energy and intensity to describe the effect of rainfall on sheet and rill erosion. Estimation of rainfall erosivity using 5 to 60minute. An official website of the united states government.
Wanga a school of geography, beijing normal university, key laboratory of environmental change and natural disaster, ministry of education, beijing, china b usdaars, southwest watershed research center, united states. Pdf improving rainfall erosivity estimates using merged trmm. Empirical estimation of the spatial sediment transport. The r factor in this study was calculated based on merged daily rainfall data with rigorous quality control. The sum of the ei30 values corresponds to rainfall erosivity, also called the r factor of. Estimation of rainfall erosivity using 5 to 60minute fixedinterval rainfall data from china s. Rainfall erosivity is the kinetic energy of raindrops impact and the rate of associated runoff. The assessment of climate change on rainfallrunoff. Sum of ei30 of each month, was the annual rainfall erosivity.
The aim of this study is to assess the improvement of the estimation of daily rainfall by merging trmm 3b42 and rain gauge data using the colcok technique and thereby estimate rainfall erosivity in china at a. Combining the relatively high rfactor values with the relatively high kfactor values 0. Estimating the rainfall erosivity factor from monthly precipitation data in the. This article is a simplified guide on how to calculate rainfall erosivity factor using qgis. Improving rainfall erosivity estimates using merged trmm and gauge data hongfen teng 1, ziqiang ma 1, adrian chappell 2, zhou shi 1, zongzheng liang 1 and wu yu 3. This coefficient is based on the product of the rainfall. Rainfall erosivity r factor is one of the 5 factors for estimating soil erosion using rusle model and is the only seasonally varying besides crops, but crop are manmade spatiotemporal resolution is critical for evaluating. The importance of assessing past and future climate differences plays an important role in future planning in relation to climate change. Pdf the need for continuous recording rain gauges makes it difficult to. Pdf estimating the rainfall erosivity factor from monthly.
Changes in the frequency or intensity of rainfall due to climate always affect the conservation of soil resources, which leads to land degradation. Rainfall erosivity estimation based on rainfall data collected over a. These models have in common a rainfall erosivity factor. The rainfall erosivity factor r was calculated using the method shown in section 2. Global vulnerability of soil ecosystems to erosion.
Rainfall erosivity in europe esdac european commission. Improving rainfall erosivity estimates using merged trmm. Pdf improving rainfall erosivity estimates using merged. Finally, the anual average rainfall erosivity was obtained for the period evaluated performing the sum of annual rainfall erosivity divided by number of years. Pdf soil erosion is a global issue that threatens food security and causes. Seasonal variation and climate change impact in rainfall. Regressionkriging was used to interpolate the rainfall erosivity values of sin.
Estimating the rainfall erosivity factor from monthly precipitation data. The rain erosivity factor r factor of the revised universal soil loss equation. Spatial and temporal variability of rainfall erosivity factor for. Before we proceed, its important for us to mention a few points about rainfall erosivity factor. R the rainfall erosivity factor, is the number of rainfall erosion index units for a particular location k the soil erodibility factor, is the soil loss rate per erosion index unit for a specified soil as measured on a unit plot, which is defined as 22. More details about the mannkendall test are available in kendall 1975 or. Thus, in the universal soil loss equation usle, the coefficient of rainfall erosivity, r, was introduced. Rainfall erosivity as a dynamic factor of soil loss by water erosion is modelled. How to calculate rainfall erosivity factor using qgis. Agropedology 2001,11,4552 soil erodibility of jorhat and. Scatter plot between the rain gauge calculated annual r factor and the. The rainfall erosivity factor calculator can be used to help determine if your small construction site qualifies for stormwater discharge waivers. The spatiotemporal variability of erosivity depending on precipitation using the rainfall erosivity r of.1065 429 113 142 753 1461 492 588 1228 719 1039 1249 93 1073 1140 1246 917 1117 685 118 123 176 951 319 245 431 1524 1233 338 736 11 417 1377 1304 1017 15 419 1122 832 744 1019 205 1337 124