人工模拟降雨下汶川震区滑坡堆积体产沙规律  

Sediment characteristic of landslide accumulation body in earthquake zone of Wenchuan under artificial rainfall simulation condition

作　　者：甘凤玲 何丙辉[1] 王涛[2] 

机构地区：[1]西南大学资源环境学院/三峡库区生态环境教育部重点实验室,重庆400715 [2]中国电力工程顾问集团中南电力设计院有限公司,武汉430071

出　　处：《农业工程学报》2016年第12期158-164,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(41271291)

摘　　要：为明确震区滑坡堆积体坡面产沙的特点,该文采用室内人工模拟降雨试验,对不同土石比(质量比为1:1、1:2、1:4)的滑坡堆积体侵蚀产沙规律进行研究。结果表明,同一土石比不同降雨强度与同一雨强不同土石比条件下,震区滑坡堆积体产沙随时间的变化形式,为波动型和平缓型。土石比和雨强对滑坡堆积体径流含沙量有显著影响,即当滑坡堆积体土石比为1:1时,稳定产沙率随着雨强增大而增大,即2.80 g/min(1.0 mm/min)<7.76 g/min(1.5 mm/min)<10.84 g/min(2.0 mm/min);在土石比为1:2雨强1.0 mm/min时没有产流产沙,1.5 mm/min雨强条件下的产沙率小于雨强2.0 mm/min的产沙率;土石比为1:4的滑坡堆积体在整个试验过程中没有产流产沙。土石比与平均产沙率、累积产沙量的偏相关系数相比于雨强更大,累积径流量和累积产沙量为极显著线性关系。研究为汶川震区滑坡堆积体的水土流失预测和治理提供理论依据。Scientific management of soil and water loss on landslide deposits is meaningful and important in Wenchuan earthquake area. This study aimed to investigate the sediment characteristics of landslide accumulation body in earthquake zone of Wenchuan under artificial rainfall simulation condition. On the basis of field surveying, the soil-rock ratio was designed as 1：1, 1：2 and 1：4. The rainfall intensities of 1.0, 1.5 and 2.0 mm/min simulated the precipitation often occurring in Wenchuan landslide deposit. Under the combination of different rainfall intensity and soil-rock ratio, the sediment yield and sediment concentration in runoff were measured. The results showed that： 1） the soil-rock ratio and rainfall intensity were the influence factors of the sediment yield and the sediment concentration of landslide deposit. The correlation between mean sediment yield rate and soil-rock ratio was higher than that with rain intensities. Runoff was not found in the treatment of soil-rock ratio of 1：4 under all the conditions and in the soil-rock ratio of 1：2 under the rain intensity of 1.0 mm/min. It indicated that a critical value might be between the soil-rock ratio of 1：2 and 1：4. Above the critical value, rainfall infiltration was large and runoff could not be yielded; 2） The sediment rate presented a upward-to-stable trend during the erosion. The mean sediment yield rate, the values under the stable condition, and cumulative sediment amount increased with increasing rainfall intensity. The fluctuation of soil-rock ratio 1：1 was higher than that with soil-rock ratio of 1：2. The latter change was more stable; 3） Sediment in runoff increased with increasing soil-rock ratios and also with increasing rainfall intensity; and 4） Cumulative sediment amount increased with cumulative runoff but the sediment yield happed after the runoff. The sediment characteristic of landslide deposit with different soil-rock ratio under different rainfall intensity in earthquake zone was quite different. In the land

关 键 词：沙 径流 滑坡 堆积体 汶川震区 人工降雨 

分 类 号：S157.1[农业科学—土壤学]