水利学报Issue(6)：728-734,7.DOI:10.13243/j.cnki.slxb.2014.06.012
黄土中降雨入渗规律的现场监测研究
In-situ observation on rainfall infiltration in loess
摘要
Abstract
By many artificial rainfall tests, the depth of rainfall infiltration in loess area was 4 meters at most. So, it is considered that the rainfall is hard to reach groundwater through the normal leaking way, but through vertical fissures,sinkholes or some other water paths to recharge groundwater. However,accord⁃ing to our investigation, these water paths only occur in unloading areas which always in the edge of loess tableland, but rare in the center. In order to make clear surface water recharge groundwater in loess area, a monitoring site was set up in Zhengning county, Gansu Province. By using the soil moisture meters which inserted into the wall of a 10-meter-deep exploratory well, the changes of volumetric moisture con⁃tent of soil layers with different depth were observed continuously for one year under the condition of natu⁃ral rainfall, the daily precipitation during the monitoring period was also recorded by rain gauge. The re⁃sults show that the moisture content of the shallow layers within 2 meters changed in annual cycle, and the trend is consistent with the change of evaporation. When the precipitation is less than 18 mm/d,the cir⁃culation of soil moisture occurs mainly in surface layers, and has little effect on the moisture content be⁃low 20 centimeters. But when the precipitation is more than 18 mm/d, the moisture content may have a sudden increase. The greater the rainfall, the higher the growth of moisture content and the deeper the af⁃fected range will be. With the increasing depth, the growth decreases and the change of moisture content lags behind the depth. The infiltration zone of the loess is about 2 meters. In the unsaturated soil below 2 meters, water moves mainly in the form of unsaturated seepage or vapor form, the motion of vapor is very small but cannot be ignored, the water would gather on the surface as encountering paleosol layer with low permeability,weak zone will be formed after long-term accumulation,inducing loess landslides eventually.关键词
水分迁移/入渗深度/体积含水率/非饱和黄土/降雨Key words
water infiltration/infiltration depth/volumetric water content/unsaturated loess/rainfall分类
建筑与水利引用本文复制引用
张常亮,李萍,李同录,张茂省..黄土中降雨入渗规律的现场监测研究[J].水利学报,2014,(6):728-734,7.基金项目
国家自然科学基金资助项目 （）
