通过对陕西洛川凤栖镇剖面黄土与红色古土壤8个层位的入渗实验及孔隙度与CaCO3含量测定,研究了黄土与古土壤入渗特征和地下水富集条件。结果表明,陕西洛川西沟L4、L5、L6和L7黄土的稳定入渗率较大,4个层位的平均值为0.65mm min^-1;S4、S5、S6和S7古土壤稳定入渗率较小,4个层位的平均值为0.37mm min^-1;黄土层达到稳定入渗的时间较短,一般为60~90min,红色古土壤达到稳定入渗的时间较长,一般为90—120min。黄土层含水空间发育好、渗透性强和利于成为含水层,这是冷干的气候动力条件决定的。红褐色古土壤层含水空间发育较差、渗透性弱和利于成为隔水层,这是温湿的气候动力条件决定的。将洛川西沟剖面渗水实验数据用三种人渗公式分别进行拟合得出,通常采用的三个经验公式均适用于描述40万~70万a间发育的黄土和红色古土壤层的入渗规律。本文的研究拓宽了第四纪气候变化理论应用的新领域,表明更新世气候变化在黄土地层土壤水和地下水资源富集条件、富集规律和水资源开发利用研究中有重要应用价值。
A water infiltration experiment,soil porosity and CaCO3 content determination was conducted at Fengqi in Luochuan of Shaanxi Province on soil profiles of loess and palesol to explore infiltration characteristics and the conditions for groundwater enrichment. Results show that stable infiltration rate of Horizon L4 , L5 , L6and L7 of Loess profile in Xigou, Luochuan, was higher, averaging 0.65 mm min^-1 and the stable infiltration rate of Horizon S4 , S5, S6 and S7 was lower, averaging 0.37 mm min^-1. In the loess profile infiltration rate leveled off quickly, generally within 60 - 90 minutes, while in the palesol it did slower, usually within 90 - 120 minutes. With higher porosity and higher infiltration rate, the loess had a well-developed aquifer, which is attributed to the dynamics of cold-dry climate. Low in porosity and weak in permeability, paleosol tended to form an impermeable layer, which is attributed to the dynamics of warm and hu- mid climate. Attempts were made to fit the three infiltration equations with the data obtained from the infiltration experiment. The three empirical formula commonly used are all applicable to describe infiltration law of loess and paleosol 400 ka -700 ka BP old. The findings of the study have opened up a new field for application of the theory of climatic change in the Quaternary. It is quite clear that the information of climate change in the Pleistocene is of high application value in the study on conditions of enrichment of soil water groundwater and rules of the enrichment, and exploitation of the water resources.