工程堆积体陡坡坡面土壤侵蚀水动力学过程  

Hydrodynamic process of soil erosion in steep slope of engineering accumulation

作　　者：张乐涛[1,2] 高照良[1,3] 田红卫[4] 

机构地区：[1]中国科学院水利部水土保持研究所 [2]中国科学院大学 [3]西北农林科技大学水土保持研究所 [4]西北农林科技大学资源环境学院

出　　处：《农业工程学报》2013年第24期94-102,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十二五"农村领域国家科技计划课题:农田水土保持关键技术研究与示范(2011BAD31B01)

摘　　要：工程堆积体产生的新增水土流失严重威胁工程建设区及其附近区域的生态安全。该文采用野外放水冲刷试验的方法,对神木—府谷高速公路沿线典型工程堆积体陡坡坡面土壤侵蚀水动力过程进行了研究,结果表明,1)水流剪切力、水流功率及径流动能对薄层水流侵蚀土壤剥蚀率的影响皆可用线性方程描述,单位水流功率、过水断面单位能量的影响不显著;2)水流剪切力、水流功率、过水断面单位能量对细沟侵蚀土壤剥蚀率的影响皆可用线性方程描述,单位水流功率的影响可用幂函数方程描述,径流动能的影响可用对数线性方程描述;3)水流功率是与土壤剥蚀率关系最好的水动力学参数,是坡面侵蚀的动力根源;4)发生细沟侵蚀的临界水流功率为3 N/(m·s),细沟可蚀性参数为8×10-3s2/m2。该结果可为工程堆积体陡坡坡面土壤侵蚀模型的建立奠定基础,为生产建设项目区新增水土流失治理提供科学依据。Soil erosion newly derived from engineering accumulation severely threatens ecological safety of construction sites and surrounding areas. It is of great necessity to carry out researches on hydrodynamic process of soil erosion originated from engineering soil deposits, and develop prediction model of soil erosion in production and construction areas. A set of field pouring water scouring experiments were conducted on the experimental plot with 72.7%gradient and 12-meter length, which lies in a steep slope of a typical spoil ground along the line of Shenfu freeway, to investigate the hydrodynamic process of soil erosion of the engineering accumulation. At the upper slope of runoff plot, a watering system consisting of submersible pump, water segregator, valves, flowmeter,overflow tank and impermeable fabric was set up achieve desired discharges. Inflow discharges were designed according to calculated unit discharge occurred on experimental plot under a certain rainstorm frequency and determined by pre-experiment. During the whole experimental process, 4 evenly spaced observation sections were down slope arranged to conduct soil sampling, flow velocity measurement and water-crossing section observations. At the bottom of experimental plot, a bucket was designed to collect all the runoff and sediment, and take samples during different intervals at different stages of experimental process. The process of runoff producing and sediment yielding can be deduced and calculated from the water level recording in the bucket and samples. A single trial persisted 40-50 minutes. Preliminary result reveals that： 1） relationships between flow shear stress, stream power, flow kinetic energy and soil detachment rate under sheet flow erosion all can be expressed by linear equation, except that effects of unit stream power and unit energy of water-carrying section on sheet flow erosion rates are not significant;2） soil detachment rate under rill erosion conditions can be described with log-linear equation of runoff kinetic ene

关 键 词：土壤 侵蚀 径流 工程堆积体 陡坡 水动力过程 水流功率 

分 类 号：S157.1[农业科学—土壤学]