Models for estimating daily rainfall erosivity in China

Abstract

The rainfall erosivity factor (R) represents the multiplication of rainfall energy and maximum 30 minutes intensity by event (EI 30) and year. This rainfall erosivity index is widely used for empirical soil loss prediction. Its calculation, however, requires high temporal resolution rainfall data that are not readily available in many parts of the world. The purpose of this study was to parameterize models suitable for estimating erosivity from daily rainfall data, which are more widely available. One-minute resolution rainfall data recorded in sixteen stations over the eastern water erosion impacted regions of China were analyzed. The R-factor ranged from 781.9 to 8258.5 MJ mm ha-1 h-1 y-1. A total of 5942 erosive events from one-minute resolution rainfall data of ten stations were used to parameterize three models, and 4949 erosive events from the other six stations were used for validation. A threshold of daily rainfall between days classified as erosive and non-erosive was suggested to be 9.7 mm based on these data. Two of the models (I and II) used power law functions that required only daily rainfall totals. Model I used different model coefficients in the cool season (Oct.-Apr..) and warm season (May-Sept.), and Model II was fitted with a sinusoidal

Rainfall erosivity estimation based on rainfall data collected over a range of temporal resolutions

“…Two models used daily rainfall amount (Zhang et al, 2002b;Xie et al, 2015), two models used daily rainfall amount and daily maximum 10 min intensity (Xie et al, 2001 and Daily I), and one model used daily rainfall amount and daily maximum 60 min intensity (Xie et al, 2015). The model with daily rainfall amount as input in Xie et al (2015) performed better than that of Zhang et al (2002b) (Table 3). Daily I, which used daily rainfall amount and daily maximum 10 min intensity as inputs in this study, performed better than the model in Xie et al (2001).…”

“…Event models were simply models to predict individual event erosivities, regardless of whether they occurred in 1 or more days, and regardless of whether more than one event occurred in a day. For the daily model, rainfall erosivity for each day, R day , was calculated following the method by Xie et al (2015). When a day had only one erosive event and this event began and finished during the same day, then When more than one full rainfall event happened during 1 day, then…”

“…Yet there is a need for developing models for application in all areas of the world in order to produce erosivity maps that can be used for evaluating soil erosion rates (e.g., Sadeghi et al, 2011, Sadeghi andTavangar, 2015;Oliveira et al, 2012;Panagos et al, 2015;Zhang and Fu, 2003). For that reason many efforts have been undertaken to estimate rainfall erosivity by using daily (Richardson et al, 1983;Yu, 1998;Capolongo et al, 2008;Yin et al, 2007;Zhang et al, 2002a, b;Xie et al, 2001Xie et al, , 2015, monthly (Arnoldus, 1977;Renard and Freimund, 1994;Yu and Rosewell, 1996;Ferro et al, 1999;Wu, 1994;Zhou et al, 1995), or annual rainfall data (Lo et al, 1985;Renard and Freimund, 1994;Yu and Rosewell, 1996;Bonilla and Vidal, 2011;Zhang and Fu, 2003;Wang, 1987;Sun, 1990). Generally the technique has been to develop a simple empirical relationship between erosivity and coarse resolution rainfall based on limited finer resolution data and then to extend the analyses to wider areas and longer periods with coarser temporal resolution rainfall data (Angulo-Martinez and Begueria, 2012;Ma et al, 2014;Ramos and Duran, 2014;Sanchez-Moreno et al, 2014).…”

基于统计检验的降雨侵蚀力简易计算模型比较

“…降雨强度) [3][4][5] 。王万忠等 [6] 探究了不同降雨指标与 土壤侵蚀的相关性， 认为用 EI30 指标计算降雨侵蚀 力在中国同样适用， 目前， USLE 和 RUSLE 中 R 因子 广泛用于中国降雨侵蚀力相关研究 [7][8][9] 。 R 因子的计算需要较高时间分辨率的降雨过程 数据。Wischmeier 等认为 [4] ， 计算 R 因子时， 降雨资 料的时间分辨率应小于 15min， 且资料的时间序列 长度大于 20a [4] ) …”

Improving Rainfall Erosivity Estimates Using Merged TRMM and Gauge Data

“…However, continuous long-term rainfall data with high temporal resolutions are often unavailable in many areas of the world. For that reason, many efforts have been made to estimate rainfall erosivity by using daily rainfall data [42,43]. Zhang et al [44] developed a power function model to estimate rainfall erosivity based on daily rainfall data that is widely used in China, including in the First National Water Conservancy Survey [8,12,45,46].…”