Anomaly Analysis Of Chemical Components Of Shallow Groundwater In Red Bed Area Of Quzhou

Quzhou is located at the headstream of Qiantang River,and surface water resources are the focus of local water ecological management.However,due to the abundance of surface water resources,the management of groundwater environment is relatively weak.At the same time,Quzhou City chemical industry structure is very obvious,and the degree of impact of chemical production on groundwater is not clear.Moreover,Quzhou City groundwater is mostly red pore fissure water,and its occurrence conditions are relatively complex,so the traceback and tracing of pollutants has always been a research difficulty.The identification of groundwater chemical component anomalies can effectively reflect the characteristics of groundwater environmental changes,and the magnitude of the changes will also be shown in the degree of anomalies.Traceability analysis of underground associations in red bed areas can effectively solve the problem of groundwater pollution source identification under complex occurrence conditions,and provide certain reference significance for local groundwater pollution control and prevention.Based on this,this article is based on five kinds of water chemical graph method,Durov diagram method and clustering analysis method combined with markov distance formula,the Quzhou City groundwater anomaly recognition research,and the abnormal degree of quantitative,got the degree of abnormal distribution in the study area,the degree of abnormal compared with groundwater quality partition,finally it is concluded that the size of the groundwater contamination risk in the study area.The results show that :(1)Among the three main methods,the combination of the five hydrochemical mapping methods and Mahalanobis distance method is the best for the identification of groundwater anomalies in the red bed area,and 17 groups of abnormal water samples are identified by consensus.Most of the abnormal points are concentrated in the areas where human activities are active,such as factories and towns.(2)The distribution of groundwater anomaly degree shows that the anomaly degree is the highest near the town of Yili.In addition,there are some regional anomalies in the northwest and northeast of the study area,which are in the state of second or third level,which is basically consistent with the population distribution density in this area.In addition,it is also greatly affected by factories and abandoned mines.(3)the degree of groundwater anomaly zoning and evaluation of groundwater quality partition comparison showed that the abnormal degree distribution and groundwater quality grade is similar distribution range,for ko Hang Bu town and city center,but no obvious groundwater quality problems of groundwater anomaly degree relatively high area should pay more attention to,such areas suffer the risk of groundwater pollution is relatively larger.According to the special characteristics of groundwater environment in the red bed area,the main pollution sources in the study area were identified and verified based on principal component analysis and Unmix model method,and the traceability analysis of the identified major pollution sources was carried out through numerical simulation method.The results showed that:(1)Among the three pollution sources obtained by principal component analysis,the contribution rate of industrial activity pollution sources is 27.56%,that of natural factors pollution sources is 17.42%,and that of atmospheric deposition pollution sources is 9.77.By comparison,the contribution rate of traffic sources identified by the UNMIX model is 34.2%,natural sources 25.3% and industrial pollution sources 40.5%.By combining and comparing the two sources,it can be found that the contribution rate of industrial activities is the largest among all pollution sources,indicating that industrial activities in the study area have the most serious pollution to groundwater in the red bed area.(2)Numerical simulation analysis was carried out on the industrial activity area,and a numerical model of underground water flow was established.For the area with high outlier value and serious pollution,particle source tracing analysis was carried out in four groups of time periods of 1 year,5 year,10 year and 15 year.Finally,the source of pollution was determined to be the chemical plant 1.5km east of Yilin town.The average transport rate of pollutants is calculated to be 158m/a,which provides a certain reference value for the prevention and control of groundwater pollution.