应用遥感与地理信息系统评价公路地质背景的方法

在公路的预设计阶段 ,需要快速、廉价的公路地质背景信息 ,遥感与GIS技术正能满足这种要求。本文认为利用遥感与GIS评价公路地质背景应包括地理因素、地质条件、水文地质与工程地质等因素 ,空间评价应从公路分段评价、重点工程评价、地质灾害分布三方面进行。本文介绍了应用这种方法对贵州省镇兴公路关岭至兴仁段的地质背景评价     

华北山区大气气溶胶浓度及其尺度谱分布的研究

1980年3月,我们在北京北部山区,用光学粒子计数器观测了“干净”地区近地层大气气溶胶浓度与尺度谱分布。发现“有霾”大气气溶胶的浓度及其尺度谱分布的变化特征具有特殊性。计算表明,三参数谱模式的拟合效果较好。     

Effects of source size,monitoring distance and aquifer heterogeneity on contaminant mass discharge and plume spread uncertainty

Estimating the movement of dissolved contaminants in heterogeneous aquifers is very important for the monitoring design, risk assessment, and remediation of contaminated aquifers. This work explored the influence of source size, monitoring distance, and aquifer heterogeneity on the accuracy of contaminant mass discharge (CMD) estimation using leaching surface approach as well as on the plume spread uncertainty in a 2-D heterogeneous aquifer. The interaction among source size, monitoring distance, and aquifer heterogeneity regarding the accuracy of CMD estimation and the plume spread uncertainty at downstream of the contaminated aquifer was extensively investigated. The transient leaking of a contaminated aquifer in a saturated heterogeneous aquifer under steady-state flow conditions was simulated. The effect of aquifer heterogeneity on the CMD uncertainty was evaluated through the expected values and variance. The results showed that the CMD estimation error varied from underestimation in the mildly heterogeneous aquifer, over accurate estimation in the medium heterogeneous aquifer to overestimation in the highly heterogeneous aquifer. Additionally, the results illustrated that the mean and variance of the transverse spatial extent of the peak concentrations for the plume at the control plane were very sensitive to the aquifer heterogeneity and detectable concentrations of contaminants.     

Experimental and numerical investigations of the effect of imbricated gravel structures on flow and solute transport in a highly heterogeneous alluvial-proluvial fan aquifer,SW China

Environmental Fluid Mechanics - An alluvial-proluvial fan (APF) has heterogeneous characteristics, which result in the development of imbricated gravel channel networks formed by flow erosion. In...     

层状非均质各向异性含水层中抽水井对污染物迁移影响数值模拟研究

为研究层状非均质含水层中渗流与污染物迁移问题,本文以大理冲洪积扇盆地典型层状非均质各向异性含水层为例,建立垂向剖面二维层状非均质各向异性含水层水文地质数值模型,利用MT3DMS溶质迁移模拟程序模拟分析抽水井抽水率、深度、位置不同条件下污染物迁移特征。结果表明,抽水率大小对污染物运移速率影响较大,深层抽水井对污染物运移影响较明显,透镜体的存在使污染物出现拖尾现象,弱透水层厚度使污染物运移时间延迟,且降低污染物浓度。