东北半干旱区不同耕作方式下的侵蚀性降雨标准比较

[目的]侵蚀性降雨标准是计算土壤流失的关键指标,侵蚀性降雨标准的拟定与耕作方式密切相关,比较同一地区不同耕作方式下的侵蚀性降雨标准差异,对于提高区域土壤侵蚀预报精度具有重要意义.[方法]根据东北半干旱区径流小区2013～2019年共7年的降雨径流观测资料,采用频率分析法,拟定几种典型耕作方式下的侵蚀性降雨雨量标准,并进...

Comparison of Erosive Rainfall Standards under Different Tillage Methods in the Semi-arid Region of Northeast China

  Objective  The erosive rainfall standard is a key indicator for calculating soil loss. The formulation of the erosive rainfall standard is closely related to the tillage method. Comparing the difference of the erosive rainfall standards under different tillage methods in the same area is of great significance for improving the accuracy of regional soil erosion forecasting.  Method  Based on the rainfall-runoff observation data of runoff plots in semi-arid region of Northeast China from 2013 to 2019, the erosive rainfall standards under several typical tillage patterns were formulated by using frequency analysis method.  Result  (1) compared with bare land plot (4.45 mm), the average value of seven-year erosive rainfall standard of horizontal ridge plot ( 9.6 mm), along ridge plot (11.65 mm) and ridge plant zone plot (21.15 mm) increased by 2.16, 2.62 and 4.75 times, respectively. (2) With the increase of years, the relative error of erosive rainfall standard decreased, the coefficient of variation decreased and the qualified rate increased. The qualified rate of erosive rainfall standard reached 100% when selecting 5-year data series of bare land plot, horizontal ridge plot, along ridge plot and ridge plant zone plot. (3) The larger the runoff coefficient was, the more the runoff production times were, and the smaller the erosive rainfall standard was.  Conclusion  The comparison of different tillage patterns showed that horizontal ridge plot, along ridge plot and ridge plant zone plot could effectively improve the erosive rainfall standard, of which the ridge plant zone plot is the most significant one. Five-year rainfall data could meet the determination conditions of the erosive rainfall standard. The benefit of sediment and flow reduction is the best in the ridge plant zone plot, followed by the horizontal ridge plot and along ridge plot. The results could provide a certain reference basis for the comprehensive management of soil and water conservation in the semi-arid area of Northeast China.