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黄土高塬沟壑区沟坡道路侵蚀特征及植物路 防蚀机理研究
王浩
Subtype硕士
2010-05
Degree Grantor中国科学院研究生院
Place of Conferral北京
Keyword黄土高塬沟壑区 剥蚀率 临界水动力条件 放水冲刷试验 土质路 植物路
Abstract

沟坡道路侵蚀是黄土高塬沟壑区普遍存在、侵蚀程度较高的一种侵蚀类型。它切断
了原来的水流路线,汇集了塬面、农田、村庄、农舍产生的大量径流,加之道路路面产
流效率极高,径流冲刷异常严重,常常使土质路面变得沟蚀交错、泥泞不堪,甚至被冲
毁冲断,其水土流失明显高于非道路区。目前把广大沟坡生产型土质道路变成柏油路面
或煤渣石子路面是不现实的。实践证明,植物路是解决这一问题最经济、最有效的途径。
因此,本研究以黄土高塬沟壑区植物路和土质路为研究对象,采用野外放水试验研究方
法,研究黄土高塬沟壑区道路侵蚀产沙过程、水动力学特性及侵蚀输沙规律,揭示地形
坡度、流量、下垫面类型等因素与侵蚀产沙及水动力参数之间的关系,对比分析植物路
和土质路的水动力学差异特征,揭示道路侵蚀的植物防蚀机理,为建立高塬沟壑区道路
植物防蚀体系提供定量评价参数和科学依据,为该地区农业生产、水保规划和生态建设
服务。得出以下主要结论:
(1) 植物路和土质路产沙率与水流含沙量随时间变化均为试验初期数值最大,之后
迅速下降,在10min 左右趋于平缓。产沙率和水流含沙量均随道路坡度及放水流量增大
而增大。同一坡度不同放水流量下,植物路和土质路的产沙率均随时间变化呈负对数关
系。不同放水流量下土质路产沙率与坡度呈对数关系,植物路产沙率与坡度呈指数关系。
(2) 植物路和土质路水流流速大约在5min 时增大至最高值,10min 后流速降低,逐
渐趋于平缓。土质道路相同流量下,径流流速随坡度呈一直线状,而植物路增大趋势较
缓,表明植被的存在能够很好地限制坡度增大对径流流速的影响。
(3) 植物路和土质路水流雷诺数分别在938.7-8049.4、1205.3-15277.4 之间变化。在
一定坡度不同流量条件下,道路坡面径流弗汝德数随径流历时增长而减小。土质路坡面
水流弗汝德数值在0.54-2.44 之间,平均值为1.09。植物路坡面水流弗汝德数值在
0.58-1.12 之间,平均值为0.75。
(4) 在同坡度同流量条件下植物路较土质路,输沙量减少率为48.35%-85.31%, 9°
坡度时,减沙率最大;植物路径流含沙量减少率在33.09%-83.08%之间。
(5) 植物路和土质路水流剪切力、水流功率、单宽能耗随时间均呈增大趋势。同坡
度与流量下,植物路水流剪切力和水流功率比土质路要小,植物路单宽能耗比土质路大,
从水动力学角度揭示了植物路有效防蚀的机制。(6) 植物路和土质路土壤剥蚀率与各水动力学参数均呈线性关系,且存在侵蚀临界
值。植物路和土质路的侵蚀临界剪切力、临界水流功率、临界单宽能耗分别为:2.44Pa、
3.36Pa;0.26 N/(m·s)、0.45 N/(m·s);2.99 g/(m2·s)、3.48 g/(m2·s)。

Other Abstract

The road erosion of slope-gully was a typical type of erosion with ubiquity and intensity on the loess
plateau. It cut off the original water line and collected most runoff of the part of the loess plateau, farmland,
village and farmhouse, earth road often became staggered gully erosion, muddy and even was destroyed
due to producing extremely high runoff efficiency and scouring serious of which water and soil loss was
obvious higher than that of non-road area. At present, it is not realistic to change the majority production
road of slope of gully into asphalt road or cinder gravel road. Practice had proved that plant-covered road
was the most economical and effective way to solve this problem. Therefore, in this paper, taking
plant-covered road and earth road on the loess plateau-gully region as research object, the process of
erosion and sediment yield, characteristic of hydrodynamic and law of erosion sediment transport of road
were studied by using field water discharge scouring experiments, and the relationships between the factors
of terrain slope, discharge, type of different surface conditions and so on and erosion and sediment yield,
hydrodynamic parameters were revealed. By analyzing the difference characteristics of hydrodynamic of
plant-covered road and earth road, the mechanism of plant protecting of road erosion was revealed, which
provided quantitative evaluation parameters and scientific basis for establishing system of plant protecting
erosion on the loess plateau-gully region, planning services for agricultural production, water conservation
and ecological construction in this region. Main conclusions showed as follow:
(1) Sediment yield rate and flow sand concentration were the greatest at the beginning of the
experiment with the time changed, then decreased significantly and tended to stable about 10min. They
increased as the slope of road and flow discharge increased. Sediment yield rate has a negative logarithmic
relationship with the time under the same slope and different flow discharges. There was a logarithmic
relationship between sediment yield rate of earth road and slope under the different flow discharges, while
an exponential relationship between sediment yield rate of plant-covered road and slope was identified.
(2) Flow velocity increased to the highest value about 5min, then decreased and tended to stable about
10min. In the condition of the same flow discharge, runoff rate of earth road have been in line with change
of the slope, while a parabolic shape was described for plant-covered road, which indicated that the effect
of slope increased on runoff velocity was well restricted by recovering vegetation.
(3) Reynolds number of earth road changed between 1205.3 and 15277.4, while it was
938.7-8049.4 for plant-covered road. Froude number of slope runoff of road decreased with runoff  duration under a certain slope and the different flow discharges. Fr of slope flow of earth road was 0.54 to
2.44 and average value was 1.09, while it was 0.58 to 1.12 and average value was 1.09 for plant-covered
road.
(4) The effect of plant-covered road reducing water was only 0.63% to 6.15%, which was not obvious;
under the same slope and flow discharge, the decrement rate of sediment yield rate was 35.00% to 83.77%
and reached the highest for 9°; The decrement rate of runoff sand concentration of plant-covered road was
33.09% to 81.42%.
(5) Flow shear stress, stream power, energy consumption of unit width increased with time. Under the
same slope and flow discharge, flow shear stress and stream power of plant-covered road were smaller than
that of earth road, and energy consumption of unit width was greater than that of earth road, which
indicated that plant-covered road had an effective action of preventing soil erosion.
(6) There was a linear relationship between soil detachment rate and variation hydrodynamic
parameters, and erosion critical value existed. The critical shear stress, critical stream power and critical
energy consumption of unit width of plant-covered road and earth road were 2.44Pa,3.36Pa; 0.36 N/(m·s),
0.45 N/(m·s); 2.99 g/(m2·s), 3.48 g/(m2·s) respectively.

MOST Discipline Catalogue土壤学
Language中文
Document Type学位论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8852
Collection水保所知识产出(1956---)
Recommended Citation
GB/T 7714
王浩. 黄土高塬沟壑区沟坡道路侵蚀特征及植物路 防蚀机理研究[D]. 北京. 中国科学院研究生院,2010.
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