层状土壤水分运动特征及植物生长适宜性

发布时间：2018-03-02 05:19

  本文关键词： 层状土 毛管障碍 群体光合速率 HYDRUS-1D 晋陕蒙接壤区 水分运动　出处：《西北农林科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：晋陕蒙接壤地区矿产资源十分丰富,但在煤炭的开采过程中,土地遭到严重破坏,生态恶化。按土地法规定,排土场大部分区段的最终利用方向是农耕地,然而目前排土场土壤随意堆砌,加之,矿区降水较少,植被恢复困难。本文利用质地差异明显的土壤人为构造层状结构,以期利于植物生长。设置沙土、砒砂岩、黄绵土和红粘土四种均质土体和黄-沙-红(黄绵土-沙土-红粘土)、黄-红-沙(黄绵土-红粘土-沙土)、沙-黄-砒(沙土-黄绵土-砒砂岩)、黄-砒-沙(黄绵土-砒砂岩-沙土)四种层状土体,借助室内土柱自动观测系统测定四种均质土体和四种层状土体的入渗及蒸发过程,并利用HYDRUS-1D模拟入渗与蒸发过程,从理论上描述层状土水分运动特征。并在层状土柱上种植紫花苜蓿,测量不同结构层状土上苜蓿群体光合速率的变化,分析不同结构层状土对植物生长的适宜性。得到以下主要结论:(1)不同质地均质土壤入渗性能、蒸发性能差异较大,入渗性能从大到小排序为:沙土、砒砂岩、黄绵土、红粘土,蒸发性能从大到小排序为:黄绵土、红粘土、沙土、砒砂岩。统计分析表明,四种土壤入渗过程模拟结果的Re(相对误差)绝对值都在11.0%以下,R2在0.90以上,利用HYDRUS-1D结合入渗、蒸发过程剖面含水量变化反演土壤水力参数具有较高的精度。(2)黄-红-沙型层状土入渗速率慢,在强降雨条件下不能使水分迅速入渗。黄-砒-沙型层状土湿润锋到达第三层土体后运移速率仍很快,阻水效果差,水分容易渗漏到更深层土壤。黄-沙-红、沙-黄-砒型层状土在短时间内能贮存大量水分,且第三层土体阻水作用强,黄-沙-红型层状土下层红粘土阻水效果尤其明显。统计分析表明,实测和模拟入渗速率和剖面含水量的R2在0.86到0.97之间,入渗速率的平均误差(MEP)和标准偏差(SDP)分别在-0.0004和-0.0097,0.025和0.039之间,剖面含水量的平均误差(MEP)和标准偏差(SDP)分别在-0.0222和0.0057,0.034和0.092之间。说明HYDRUS-1D利用连续监测的入渗过程土壤剖面含水量反解水力参数,经优化后,可以准确模拟层状土入渗过程。四种层状土壤持水性能及蒸发性能差异较大,黄-沙-红和黄-红-沙型层状土整体田间持水量大于沙-黄-砒和黄-砒-沙型层状土的田间持水量,沙-黄-砒型层状土的保水性能最好,另外三种层状土的保水性能差异不显著。黄-红-沙和黄-砒-沙持水量虽高,但水分易蒸发散失,可供植物蒸腾利用的水分少。沙-黄-砒型层状土持水量低,因存在毛管障碍,有效抑制下层水分向上运动减少蒸发,可供植物利用的水分较多。(3)同一时刻,黄-沙-红和沙-黄-砒型层状土苜蓿群体光合速率大于黄-红-沙和黄-砒-沙型层状土苜蓿的群体光合速率。用群体光合速率评价层状土对植物生长的适宜性,黄-沙-红和沙-黄-砒型层状土比黄-红-沙和黄-砒-沙型层状土更适宜植物生长。本研究利用自动化测量系统监测层状土水分运动特征,并利用群体光合速率评价不同结构层状土对植物生长的适宜性,结果表明黄-沙-红、沙-黄-砒型层状土适合应用到晋陕蒙矿区排土场建设中。
[Abstract]:The contiguous area is rich in mineral resources, but in the process of mining coal, land destruction, ecological deterioration. According to the provisions of the law of the land, dump parts of end use direction is agricultural, however, dump soil randompacking, in addition, in less precipitation, vegetation in this paper. The use of artificial soil layer structure texture difference, in order to help the plant. Setting sand, sandstone, loessial soil and red clay of four kinds of homogeneous soil and yellow sand (red yellow loamy soil and red clay and sand), yellow red sand (loessial soil and red clay and sand), sand yellow (soft sand - Loess - sandstone), yellow sand (in loessial soil - sandstone - sand) four layered soil, the infiltration and evaporation process of the automatic observation system for determination of four kinds of homogeneous soil and four layered soil soil column, and use HYDRUS-1D to simulate the infiltration and The evaporation process, describe the layered soil water movement characteristics in theory. And planting alfalfa in layered soil column, measured in different structure of layered soil on the photosynthetic rate of Alfalfa population changes, analysis of different structure of layered soil suitable for the growth of plants. The main conclusions are as follows: (1) different texture homogeneous soil infiltration different properties, evaporation, infiltration from large to small order: sand, sandstone, Huang Miantu, red clay, evaporation from large to small order: Huang Miantu, red clay, sand and sandstone. Statistical analysis showed that the four kinds of soil infiltration process simulation results of the Re (absolute relative error) the values are below 11%, more than 0.90 in R2, HYDRUS-1D with the use of infiltration, evaporation of moisture profile inversion of soil hydraulic parameters with high accuracy. (2) - red - yellow sand layered soil infiltration rate is slow, can't keep the water in the condition of strong rainfall Fast infiltration. The soft yellow sand layered soil wetting front reached third layer soil after the migration rate is still very fast, water blocking effect, water is easy to seep into the deeper soil. Yellow sand - red, yellow sand in layered soil in a short time can store large amounts of water, and the third layer the soil with strong water resistance, especially yellow - red sand - layered soil layer of red clay type water blocking effect. Statistical analysis showed that the measured and simulated infiltration rate and soil water content of R2 between 0.86 to 0.97, the average error of infiltration rate (MEP) and standard deviation (SDP) respectively in -0.0004 and between -0.0097,0.025 and 0.039, the average error of section water content (MEP) and standard deviation (SDP) respectively in -0.0222 and 0.0057,0.034 between 0.092 and HYDRUS-1D. The continuous monitoring of the infiltration process of soil moisture profile inverse hydraulic parameters, after optimization, can accurately simulate the layered soil infiltration process. 鍥涚�嶅眰鐘跺湡澹ゆ寔姘存�ц兘鍙婅捀鍙戞，

本文编号：1555180