[目的]分析九寨沟2017年"8·8"地震后崩坡积碎石土和当地沉积黏性土不同比例混合体的土壤水分特性,选出适宜研究区植物生长的最佳改良碎石土,为九寨沟地区灾后生态环境修复提供科学依据.[方法]将九寨沟当地黏性土与九寨沟地区碎石土以不同体积比进行混合,通过土水特征曲线试验、水分常数试验、土柱试验来探究不同比例下土壤水分特性,挑选适宜于植物生长的混合土比例.[结果]①van Genuchten模型能够很好地拟合改良碎石土的土水特征曲线,土壤进气值随着黏性土比例的增加而增加,参数a在一定程度上能够表征进气值的状态.②改良后的碎石土使吸湿系数、凋萎系数、田间持水量、饱和含水量等都随着黏性土比例的增加而增加.相较于碎石土,添加黏性土的改良碎石土可用水量增大22.26％～50.00％,最大有效水量增大70.96％～131.46％,更加有利于植物生长.③3种模型对比下,Philip模型对土壤水分入渗模拟效果最好,吸渗率S大小能够在一定程度上代表初始入渗速率的变化趋势.[结论]综合对比不同比例改良碎石土水分特性可见,当下覆土层为储水层,可选择碎石土与黏性土比例为7∶3作为改良碎石土最佳配比;当下覆土层为非储水层,无法储存水分时,可选择碎石土与黏性土比例为3∶7作为改良碎石土最佳配比.
[Objective]The soil water characteristics of the mixture of landslide gravel soil and local sedimentary cohesive soil in different proportions in Jiuzhai Valley after the"8·8"earthquake in 2017,were analyzed,and the best improved gravel soil suitable for plant growth in the study area was selected in order to provide scientific basis for ecological environment restoration after earthquake in Jiuzhai Valley region.[Methods]A local clay soil from Jiuzhai Valley and gravel soil from the Jiuzhai Valley region were mixed at different volume ratios,and soil water characteristics were investigated by soil water characteristic curve test,water constant test,and soil column test to investigate the soil water characteristics under the different mixing ratios in order to select soil mixing ratios suitable for plant growth.[Results]① The van Genuchten model was able to fit the soil-water characteristic curve of the improved gravel soil well,and the soil air-entry value increased as the proportion of clay soil increased.The parameter α characterized the state of the air-entry value to a certain extent.② The improved gravel soil increased the water absorption coefficient,wilting coefficient,field water-holding capacity and saturated water content as the proportion of clay soil increased.The water availability and maximum effective water volume of the gravel soil increased by 22.26％～50.00％with the addition of clay soil(compared with the gravel soil),and the maximum effective water volume similarly increased by 70.96％～131.46％.③ Of the three models evaluated,the Philip model simulated soil water infiltration the best,and the size of the uptake rate(S)can represent the change trend of the initial infiltration rate to a certain extent.[Conclusion]Comprehensive comparisons of the water characteristics of different ratios of improved gravel soil showed that,when the overlying soil layer is a water storage layer,a gravel soil to clay soil ratio of 7∶3 can be selected as the optimal ratio for improved gravel soil.When the overlying soil layer is a non-storage layer that is not capable of storing water,a gravel soil to clay soil ratio of 3∶7 can be selected as the optimal ratio for improved gravel soil.
朱锦宇;裴向军;肖维阳;张晓超;张文翔;王益
成都理工大学环境与土木工程学院,四川成都 610059||成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都 610059成都理工大学生态环境学院,四川成都 610059||成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都 610059九寨沟风景名胜区管理局,四川阿坝藏族羌族自治州 623402
农业科学
改良碎石土;水分特性;黏性土含量;九寨沟
improved gravel soil;water characteristics;cohesive soil content;Jiuzhai Valley
《水土保持通报》 2024 (001)
40-49,85 / 11
九寨沟风景名胜区管理局采购项目"九沟湖泊沼泽化及河道生态恢复研究项目"(N5132112022000246);四川省自然科学基金(2023NSFSC0378)
10.13961/j.cnki.stbctb.2024.01.005
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