Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area Guilin University of Technology, Guilin, 541004, China.
Key Lab of Subtropical Agriculture and Environment of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China.
Environ Sci Pollut Res Int. 2018 Apr;25(10):9474-9484. doi: 10.1007/s11356-018-1198-9. Epub 2018 Jan 20.
Changes in natural rainfall regimes have taken place and are expected to become more pronounced in future decades. These changes are also likely to be accompanied by changes in crop management practices. The main purpose of this study was to analyze runoff and soil loss in relation to rainfall regimes and terracing in the Three Gorges area, China. Based on 10 years of field observation and k-mean clusters, 101 rainfall events were grouped into three rainfall regimes. Rainfall regime I was the group of events with strong rainfall intensity, high frequency, and short duration. Rainfall regime III consisted of events with low intensity, long duration, and high rainfall amount. Rainfall regime II was the aggregation of events of high intensity and amount, and less frequent occurrence. The results showed that event runoff coefficients were not significantly different among rainfall regimes. However, the average soil erosion rates in rainfall regimes I and II were significantly higher than that in regime III. The average erosion rates under rainfall regimes I, II, and III were 21.6, 39.7, and 9.8 g m, respectively. The effect of rainfall regime on soil erosion also was changed by terracing. On unterraced cropland, soil erosion rate in rainfall regime I is significantly higher than that in regime III. However, the situation did not exist in unterraced orchard. Terracing significantly reduced runoff and soil erosion, and compensated the effects of rainfall regime on soil erosion, which indicated that runoff and erosion in terraced system may be little influenced by climate change. Based on these results, it was suggested more attention should be paid to the timing of rainfall events in relation to crop development and the high erosion on unterraced citrus orchard to control soil erosion in this area.
自然降雨模式已经发生变化，并预计在未来几十年变得更加明显。这些变化也可能伴随着作物管理实践的变化。本研究的主要目的是分析三峡地区降雨模式和梯田与径流量和土壤流失的关系。基于 10 年的野外观测和 k-均值聚类，将 101 场降雨事件分为三种降雨模式。降雨模式 I 是指降雨强度大、频率高、历时短的事件组。降雨模式 III 由强度低、持续时间长、降雨量高的事件组成。降雨模式 II 是高强度和高降雨量事件的聚合，发生频率较低。结果表明，事件径流系数在降雨模式之间没有显著差异。然而，降雨模式 I 和 II 的平均土壤侵蚀率明显高于模式 III。降雨模式 I、II 和 III 下的平均侵蚀率分别为 21.6、39.7 和 9.8 g m。降雨模式对土壤侵蚀的影响也因梯田而改变。在未开垦的农田中，降雨模式 I 的土壤侵蚀率明显高于模式 III。然而，在未开垦的果园中则不存在这种情况。梯田显著减少了径流量和土壤侵蚀，并补偿了降雨模式对土壤侵蚀的影响，这表明梯田系统中的径流量和侵蚀可能受气候变化的影响较小。基于这些结果，建议在作物发育和未开垦柑橘果园的高侵蚀方面更加关注降雨事件的时间，以控制该地区的土壤侵蚀。
