Evaluation Of Groundwater Vulnerability In Baotou City

Groundwater is an important resource for human living. With the development of industry and population expansion, water pollution is becoming more and more serious. Baotou is an important industrial city in our country, and its groundwater is facing severe pollution stress. Groundwater vulnerability assessment can be used to divide the antifouling capability of groundwater system and can provide theoretical basis for groundwater management.Based on survey of groundwater quality, the groundwater vulnerability in Baotou area was evaluated using DRASTIC modeling. However, the rating distribution is fragmented and the result does not match with the actual water quality conditions. So it needs a new evaluation method.The soil and vadose zone properties was studied by series test. The Cr (Ⅵ) adsorption isotherm static tests showed that adsorption is closely related to clay content in the soil, the higher clay content, the stronger adsorption. The soil of higher clay content match with the Langmuir adsorption equation and less clay content match with Freundlich adsorption equation. The soil saturated hydraulic conductivity and longitudinal dispersivity of laboratory test data are affected by the degree of dispersion of soil particles. The more dispersed of soil particles, the greater the parameters. For the study of contaminant migration law, the paper has simulated pollutants in the unsaturated soil transport by soil column experiments and HYDRUS-1D simulation separately, and obtained the curve of migration of Cr (Ⅵ) in the non-saturation.Finally, the process simulation method was used to assessment the groundwater vulnerability in Baotou Plain. Based on the simulated contaminant transport time using HYDRUS-1D, the evaluation results is proved reasonable.The assessment result shows that groundwater vulnerability in the northeastern part of the study area is lowest, contaminants entering the aquifer may takes a long time.The groundwater vulnerability is highest in the central and parts of the Yellow River alluvial plain, which is due to pollutants maybe into the shallow groundwater easily and the time from surface into aquifer is short.