水保所知识产出(1956---)知识库

研究黑土区坡面侵蚀影响因素将为黑土区侵蚀防治和黑土资源保护提供重要的
科学依据。本文以吉林省榆树市典型黑土区坡面土壤为研究对象，以降雨和汇流两种
侵蚀动力为切入点，采用模拟降雨和上方汇流试验相结合的研究方法，阐明侵蚀动力
条件（降雨能量、降雨强度和上方汇流）和地表条件（坡度、坡长、土壤结皮和翻耕
深度）对黑土区坡面侵蚀过程的影响，揭示黑土区坡面侵蚀的水动力学机理。主要研
究结论如下：
（1）分析了降雨能量、降雨强度和汇流强度对黑土区坡面土壤侵蚀的影响。与
消除降雨能量的试验条件相比，有降雨能量试验条件下的坡面径流量仅增加了
12.8%~39.7%，而坡面侵蚀量则增加了 1.7~1.9 倍。降雨强度由 50 mm h −1 增加到 100
mm h −1 时，坡面径流量和侵蚀量分别增加了 1.4~12.4 和 4.2~6.1 倍。汇流强度对坡面
侵蚀过程的影响受坡面侵蚀方式的影响。当坡面以片蚀为主时，汇流强度由 50 L min −1
增加到 150 L min −1 ，坡面侵蚀量无显著性变化，而当汇流强度由 150 L min −1 增加到
300 L min −1 ，坡面侵蚀量呈明显增加趋势。而当坡面以细沟侵蚀为主时，坡面侵蚀量
随汇流强度的增加而呈明显的增加趋势；与汇流强度 50 L min −1 相比，汇流强由 100 L
min −1 增加到 300 L min −1 时，坡面侵蚀量增加了 6.2~61.7 倍。
（2）剖析了降雨和汇流两种侵蚀动力条件下地形因子和地表条件对坡面侵蚀特
征的影响。降雨侵蚀动力条件下，坡长由 5 m 增加到 10 m 时，在相同降雨强度和坡
度试验条件下，坡面径流量和侵蚀量分别增加了 0.1~3.1 和 2.1~2.9 倍；坡度由 5°增
加到 10°时，在相同降雨强度和坡长试验条件下，坡面侵蚀量增加了 0.4~0.9 倍。汇
流侵蚀动力条件下，汇流强度由 50 L min −1 增加到 300 L min −1 时，坡度由 5°增加到
10°引起坡面侵蚀量增加了 2.6~201.0 倍。地表结皮对坡面侵蚀的影响受降雨强度、坡
度和坡长的综合影响。翻耕深度由 5 cm 增加到 20 cm 时，坡面侵蚀量变化受降雨强
度和坡度的综合影响；而汇流侵蚀动力条件下坡面侵蚀量变化随翻耕深度的变化受坡
面侵蚀方式的影响。
（3）分析了降雨和汇流两种侵蚀动力条件下影响黑土区坡面侵蚀的主要因素。
降雨侵蚀动力条件下影响坡面侵蚀的主要因素是坡长；并建立了坡面侵蚀量与坡长、
降雨强度—坡长交互作用的经验关系式。汇流侵蚀动力条件下影响坡面侵蚀的主要因
素是汇流强度—坡度交互作用；建立了坡面侵蚀量与汇流强度—坡度交互作用的经验
关系式；汇流侵蚀动力条件下坡面侵蚀量与径流量相关关系受侵蚀方式的影响较为明显。
（4）探究了降雨侵蚀动力条件下的坡面侵蚀的水动力学机理。随降雨强度、坡
度和坡长的增加，径流流速、雷诺数和弗汝德数均呈增加趋势，而 Darcy-Weisbach
阻力系数则呈减少趋势。土壤结皮的存在使得坡面 Darcy-Weisbach 阻力系数降低了
25.6%~40.3%。翻耕深度由 5 cm 增加到 20 cm 时，坡面平均流速降低了 36.8%~40.2%，
Darcy-Weisbach 阻力系数则分别增加了 1.5~1.8 倍。降雨侵蚀动力条件下坡面侵蚀量
与径流剪切力、径流功率以及单位径流功率间无显著的线性关系；而坡面侵蚀量与径
流流速和弗汝德数呈极显著正相关关系，与 Darcy-Weisbach 阻力系数呈显著负相关
关系。
（5）探讨了上方汇流侵蚀动力条件下的坡面侵蚀水动力学机理。随汇流强度和
坡度的增大，径流平均流速、雷诺数和弗汝德数均有所增加；Darcy-Weisbach 阻力系
数则逐渐降低。翻耕深度对坡面水力学参数的影响受坡度和汇流强度的综合影响。分
别建立了坡面侵蚀侵蚀量与径流剪切力、径流功率和单位径流功率的关系式。径流流
速和单位水流功率是表征坡面侵蚀的最佳水力学和水动力学参数。
关键词：降雨和汇流；地表条件；侵蚀方式；翻耕深度；典型黑土区

The study of affecting factors of hillslope soil erosion processes in the Mollisol region
is an urgent demand to prevent soil erosion and protect black soil resources. This study
took the erosivity dynamics (rainfall and confluence) in the water erosion process as the
key point, selected eroded croplands of Yushu City in Jilin Province as research site, and a
method of laboratory rainfall simulation and inflow experiments was conducted to
investigate soil erosion process and mechanism. The study evaluated the effects of erosive
agents (raindrop impact, rainfall intensity and inflow water) and soil surface conditions
(slope gradient, slope length, soil crust and till depth) on soil erosion processes and flow
hydraulic and hydrodynamic mechanism. Main conclusions of this study were as follows:
(1) Effects of rainfall energy, rainfall intensity and inflow rate on runoff and soil loss of
the Mollisol hillslope were analyzed. Runoff and soil loss with rainfall energy were
increased 12.8%~39.7% and 1.7~1.9 times compared with those eliminating rainfall energy
treatments, respectively. When rainfall intensity increased from 50 to 100 mm h −1 , runoff
and soil loss increased 1.4~12.4 and 4.2~6.1 times, respectively. Inflow water from
upslope had a significant influence on runoff and soil loss in the inflow experiment, and
the effects were affected by the dominant erosion pattern. When sheet erosion dominant,
soil loss did not have significant differences among the 50, 100, and 150 L min −1 inflow rates, but soil
loss at 200 and 300 L min −1 inflow rates was significantly different; while  an increase of inflow rate
from 50 to 300 L min −1 casued soil loss to increase 6.2~61.7 times at rill dominant erosion
pattern.
(2) Soil surface conditions under both rainfall and inflow experiments had significant
effects on soil erosion process in the Mollisol hillslope. The result showed that runoff and
soil loss increased 0.1~3.1 and 2.1~2.9 times when slope length was increased from 5 to 10
m under the same rainfall intensity and slope gradient, respectively. When slope gradient  increased from 5 to 10°，soil loss increased 0.4~0.9 times under the same rainfall intensity
and slope length; while soil loss increased 2.6~201.0 times for slope gradient increased
from 5 to 10° when inflow rate increased from 50 to 300 L min –1 . Effect of soil crust on
soil erosion processes was affected by rainfall intensity, slope gradient and slope length
conditions. With the increase of till depth, the change trends of soil loss were complex and
affected by rainfall intensity and slope gradient under rainfall experiment. Dominant
erosion pattern had obviously impact on effects of till depths on soil loss under inflow
experiment.
(3) The main impact factors of soil loss under both rainfall and inflow experiments at
the Mollisol hillslope were quantified. For rainfall experiment, soil loss had the strongest
correlation with slope length, and established empirical equations of soil loss with slope
length and coupling effects of rainfall intensity—slope length. For inflow experiment, soil
loss had the strongest correlation with coupling effects of inflow rate—slope gradient. The
empirical equations for predicting soil loss by coupling effects of inflow rate—slope
gradient were also established.
(4) The effects of different impact factors on flow hydraulic characteristics and dynamic
mechanisms of soil erosion under rainfall experiment were explored. Flow velocity,
Reynolds number and Froude number were increased with the increase of rainfall intensity,
slope gradient and slope length, while Darcy-Weisbach resistance coefficient showed an
opposite trend. For treatments with soil crust, Darcy-Weisbach resistance coefficient
decreased 25.6%~40.3% compared with those without soil crust treatments. Increasing of
till depth from 5 to 20 cm induced flow velocity decreasing by 36.8%~40.2%, while
Darcy-Weisbach resistance coefficient increasing by 1.5~1.8 times, respectively. However,
no significant linear relationships between soil erosion with flow shear stress, stream
power and unit stream power were found. Furthermore, soil erosion at the Mollisol
hillslope was sensitive to flow velocity, Froude number and Darcy-Weisbach resistance
coefficient.
(5) Relationships between soil loss and hydrodynamic parameters for different impact
factors and dominant erosion patterns under inflow experiment were discussed. Flow
velocity, Reynolds number and Froude number were increased with the increase of inflow
rate and slope gradient, while Darcy-Weisbach resistance coefficient decreased. Effects of  till depth on flow hydrodynamic characteristic were complex, and which also affected by
the impacts of inflow rate and slope gradient. The relational expressions between soil
erosion and shear stress, stream power, and unit stream power were respectively
established. The key hydraulic and hydrodynamic parameters which influenced soil loss
were flow velocity and unit stream power.
KEY WORDS: rainfall and inflow experiments; soil surface condition; domiant erosion
pattern; till depth; the Mollisol region