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| Spatial and temporal variations of rainfall erosivity in Henan Province |
| Wu Mingzuo1, He Ruizhen1, An Shuqing2, Yang Xitian1, Zhang Jun1 |
| 1. College of Forestry, Henan Agricultural University, 450002, Zhengzhou; 2. School of Life Science, Nanjing University, 210093, Nanjing: China |
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Abstract Rainfall is the main factor that causes soil erosion, and rainfall erosivity is the main dynamic index. So, accurately estimating the rainfall erosivity and analyzing its spatial and temporal variation is the key to predict soil erosion. Using the daily rainfall data of 119 meteorological sites in Henan Province from the year the site establishing to the year 2003, this paper calculated the rainfall erosivity of 119 sites in Henan Province, and analyzed its spatial and temporal variation. The results showed that: the yearly average rainfall erosivity in Henan Province generally increases from north to south, and the maximum value appears in Xinxian County, Jigongshan Mountain, Shangcheng County, Tongbai County and Pingyu County in the southern part of Henan Province, where erosivity are all above 7000MJ·mm/(hm2·h·a). According to yearly average rainfall erosivity, Henan Province can be classified 5 regional zones, which are consistent with rainfall erosivity isoline. The rainfall erosivity of all sites varies significantly with different years and has no yearly periodical principle by fast fourier transform (FFT). In one year period, the erosivity shows a mono-peak type, and mainly occurs in July to September with the concentration rate of 60% in the northern part. The erosivity has significant relationship with yearly erosion precipitation or the yearly erosion precipitation and daily erosion precipitation, and the correlation coefficient are 0.9672 and 0.9942, respectively.
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Received: 15 December 2011
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