Based on the comprehensive analysis of hydrogeological data of the Dawu water source in Zibo city, the Modflow module in Groundwater Modeling System is used to carry out three-dimensional geological modeling of the Dawu water source, and the flow field model and solute transport model of the Dawu water source are established. Aiming at the problem of groundwater pollution in the key polluted area of the Hougao region-the Dawu water source-the pollutant transport model is established to explore the process of pollution transport. There are many types of groundwater pollutants in the Hougao area. Among them, ammonia nitrogen, chloride, petroleum, and benzene exceed the standard most seriously. In order to facilitate the research, we selected typical pollutants for in-depth study. The ammonia nitrogen is used as the control index of domestic and industrial waste water in the policy documents of pollution emission. It can show the specific situation of industrial waste water and domestic waste water pollution changing with time. Thus, the ammonia nitrogen with a higher exceeding standard is selected as the pollution factor in this simulation. Pollutant transport under the conditions of strong pumping and stop pumping is simulated. It is found that the pollutant is effectively controlled due to the pumping and discharging effects under the action of strong pumping, from 4 to 5 times exceeding the standard to slightly exceeding the standard. However, there is still a trend of migration to the eastern water supply area. After the pumping is stopped, the pollutant quickly migrates to the Xixia centralized water supply area, causing serious pollution to the water supply area. Finally, four other hydraulic interception wells are set up in the 500 m east of Hougao's four wells to further control the pollutant transport. When hydraulic interception wells and strong pumping wells are used together, the scope of ammonia nitrogen pollution is basically controlled near the interception wells, and it does not continue to spread to the eastern water supply area. The maximum monitoring value of pollution is 0.11 mg/L, which is controlled within the standard limit of three types of groundwater, and the pollutant control effect is the best, providing certain reference for similar pollution control work. scope of water source includes west of Zi river, east of Fengbei road, north of Liuzheng village and Xuwang village, and the closed area south of national highway 309. The total area of the water source is about 148 km 2 . Figure 1 shows the location of Dawu water source area.

An US-DBR was applied for simultaneous carbon tetrachloride (CT) and nitrate removal from groundwater.

Although the slippery boundary condition (BC) has been validated to enhance fracture permeability (k), the coupling effects of heterogeneous slippery BC and inertia on k remain less understood. We used computational fluid dynamics to investigate the competing roles of slippery BC and inertial forces in controlling k evolution with increasing pressure gradient by designing six cases with different slip length scenarios for a two-dimensional natural fracture. Our results suggest that pronounced inertial effects were directly related to and demonstrated by the growth of recirculation zone (RZ); this caused flow regimes transitioning from Darcy to non-Darcy and significantly reduced k, with an identical tailing slope for six cases, regardless of the variability in slip lengths. Moreover, the slippery BC dominantly determine the magnitude of k with orders depending on the slip length. Lastly, our study reveals that the specific k evolution path for the case with a varying slip length was significantly different from other cases with a homogeneous one, thus encouraging more efforts in determining the slip length for natural fractures via experiments.

The development of economy promotes the development of urbanization, and the power of urban space engineering, so the stability research of urban underground space engineering is very important. Although the existing evaluation models can consider a single form of underground space safety problems, they seldom consider the uncertainty of cross-blending of multiple information types within a certain interval, and cannot continuously express the quantitative results of the suitability assessment of urban underground space. This paper takes an underground tunnel in China as the research background, calculates the weight of the selected construction stability index through the analytic hierarchy process, and finally evaluates the stability of different sections of the project by TOPSIS method, and draws the corresponding conclusions.

In the observation wells installed along the Zihe River in the Dawu water source, the AquaVISION Colloidal Borescope produced by Geotech Company of the United States was used to measure the groundwater flow velocity along the Zihe River. We analyzed the measurement results based on the drilling information. The results showed that, (1)The groundwater flow velocity along the Zihe River in the Dawu water source area was between 56.798 and 122.599 m/d, and the average flow velocity was 95.380 m/d. The groundwater flow velocity of observation wells along the Zihe River was generally faster. The flow velocity of the SW447 well in the upstream of the Zihe River was the largest, and the average flow velocity was 122.599 m/d. The overall groundwater flow along the Weihe River flowed from south to north.(2)The control factors of groundwater flow velocity were mainly: large amount of water pumping, local geological structure, related hydrogeological conditions, etc.