柴达木盆地次生盐碱地工程治理技术研究

发布时间：2018-01-08 06:18

本文关键词：柴达木盆地次生盐碱地工程治理技术研究　出处：《青海大学》2016年硕士论文　论文类型：学位论文

【摘要】：在柴达木盆地分布着大范围的次生盐碱地,调研发现这是由于盆地各灌区灌排系统不健全,有灌无排,地下水抬升所导致,严重影响着农作物的正常生长。因此,通过开展新型暗管排水技术研究为有效降低地下水位,改良土壤为农作物的生长提供良好的土壤环境,提高土地利用率。本研究是通过采用新型暗管排水技术,在柴达木盆地的适应性研究,提出暗管间距、埋深及合理的冲洗定额。对实验中的混凝土集水管为增强其强度和耐腐性,给其加入一定量的纳米材料,研究其强度、密实度及耐腐性。试验结果显示,不同暗管埋深和间距下的暗管排水均能有效的降低土壤的含盐量。根据设定的灌溉制度,“灌—排”后的土壤含盐量均达到了0.5%以下,符合枸杞的正常生长。而且,在砂浆中加入一定量的纳米材料后,能有效的增加其强度和密实度,从而减少输水过程中的水分下渗量,防止土壤次生盐碱化的发生。最后通过对不同的暗管埋深和间距布置的分析,并结合非稳定流计算公式以及排盐和经济效益指标,提出了该试验区暗管排水布置的二维非线性规划数学模型,利用梯度投影法结合软件进行模型求解计算,确定适合该试验区的最优暗管布局。
[Abstract]:In Qaidam Basin, a large area of secondary saline-alkali land is distributed. It is found that this is caused by the imperfect irrigation and drainage system in each irrigation area of the basin, the irrigation without drainage, and the uplift of groundwater. Therefore, through the development of new underground drainage technology to effectively reduce the groundwater level, improve the soil for the growth of crops to provide a good soil environment. This study is based on the study of the adaptability of the new underground drainage technology in Qaidam Basin, and the distance between the hidden pipes is put forward. In order to enhance the strength and corrosion resistance of the concrete collector in the experiment, a certain amount of nano-material was added to study its strength, compactness and corrosion resistance. Under the different buried depth and spacing of the dark pipe drainage can effectively reduce the salt content of the soil. According to the irrigation system, the salt content of the soil after "irrigation and drainage" reached below 0.5%. In accordance with the normal growth of Lycium barbarum. Moreover, adding a certain amount of nano-materials to the mortar can effectively increase its strength and compactness, thus reducing the amount of water infiltration in the process of water transfer. Finally, through the analysis of different buried depth and spacing arrangement of dark pipe, combined with the calculation formula of unsteady flow and the index of salt discharge and economic benefit. A two-dimensional nonlinear programming mathematical model for the drainage arrangement of the underground pipe in the experimental area is presented. The optimal layout of the dark pipe is determined by using the gradient projection method combined with the software to solve the model.
【学位授予单位】：青海大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S156.4

【相似文献】