| Cite this article: | 朱燕琴.基于降水特征的次降水侵蚀力估算模型 ―以黄土丘陵沟壑区典型小流域为例[J].灌溉排水学报,0,():-. |
| zhuyanqin.基于降水特征的次降水侵蚀力估算模型 ―以黄土丘陵沟壑区典型小流域为例[J].灌溉排水学报,0,():-. |
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| Estimation Model of Individual Rainfall Erosivity Based on Rainfall Characteristics ―Taking typical small watershed in the loess hilly and gully region in Gansu Province as a Case |
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zhuyanqin
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Gansu Agricultural University
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| Abstract: |
| 【Objective】Based on the analysis of individual erosive rainfall characteristics, to build the model of rainfall erosivity, the research results can provide reference for quantitative monitoring of regional water and soil loss and benefit evaluation of water and soil conservation.【Method】Erosive rainfall process data for five years were obtained from two typical runoff fields of Anjiagou small watershed and Longtan small watershed in the loess hilly and gully region in Gansu Province, the conversion relationship between the structure of rainfall (P) × rain intensity (I) and E×I30 were established.【Result】The results showed: rainfall erosivity above 50 MJ·mm/(hm2·h) were the main sources of rainfall erosivity in this area, accounting for 75% of the total erosivity. There was a linear function relationship between rainfall P and rainfall kinetic energy E, E=0.2057P-1.0671 (R2=0.763，n=48) . Rainfall single factors I30 (30-minute rainfall intensity), I60 (60-minute rainfall intensity) and E (rainfall kinetic energy) had a significant impact on soil loss (S) (P<0.01). The correlation coefficients (r) between P×I30, P×I60 and S were >0.616 (P<0.01), hence P×I30 and P×I60 were the main rainfall compound factors affecting the soil loss (S) on the slope. The relationship between P×I30, P×I60 and E×I30 conformed to the power equation, with the determination coefficient R2of 0.984 0, 0.9609. The effective coefficients of the two models were 98.9% and 98.1%, while the deviation coefficients were 2.0% and 3.2%, respectively. The rainfall was 50 mm>P>10 mm, the relative error of the predicted values of the two models was not more than 16%. The rainfall erosivity was above 50 MJ·mm/(hm2·h), the relative error of rainfall erosivity prediction values was less than 10%. 【Conclusion】The two models have good prediction effect. Therefore, rainfall is 50 mm>P>10 mm, P×I30, P×I60 can be used as index factors of individual rainfall erosivity in the region. |
| Key words: Loess hilly and gully region; Anjiagou small watershed; Water and soil loss; Rainfall erosivity; Erosive rainfall |
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