Study On Water Quality Risk Control Of Rural Water Supply Groundwater Sources In Shandong Province

In recent years,the CPC Central Committee and the State Council attach great importance to the safety of rural drinking water.With the successful ending of the two-year action for rural drinking water security and the 13 th Five-Year Plan for the consolidation and improvement of rural drinking water security,China ’ s rural water supply has developed rapidly,and has entered a new stage of water supply security after four stages of natural development,drinking water starting,drinking water solving difficulties and drinking water security.In the new stage,ensuring the water quality safety of groundwater sources is still the core content of rural water supply security,but the ability of Shandong Province to protect the water quality of groundwater sources and control pollution remains to be improved.This paper mainly analyzes and summarizes the current situation and regional characteristics of rural water supply and groundwater sources in Shandong Province through investigation and work data.Then,AHP is used to reasonably select and optimize the evaluation index of groundwater sources,and a risk assessment system for rural water supply and groundwater sources is established to quickly and comprehensively evaluate the water sources.Then,principal component analysis is used to determine the influencing factors that characterize the groundwater quality in the study area,and Gaussian function is used to fit to determine the potential characteristic pollutants that affect the water sources in the study area.The pollution load of the main pollutants in the study area is estimated,and the pollution control methods of groundwater sources are proposed.The main results of this paper are as follows :(1)According to the relevant statistical data of rural drinking water safety,among the rural drinking water indicators in Shandong Province,the compliance rate of water quality by population is only 63.7 %,which is the lowest compared with other indicators;According to the statistics of the number of projects,the proportion of groundwater as the source of water in the pipe network extension project,ten thousand tons of water supply project,ten thousand people water supply project,ten thousand people and less than ten thousand people water supply projects is 63.91 %,68.73 %,97.72 % and 94.27 %,respectively.It can be seen that there are water quality problems in rural water supply in Shandong Province,and groundwater is the main source of water supply.It is of great significance to protect the water quality safety of groundwater sources for rural water supply.(2)According to the current situation of water source and water supply in Shandong Province,combined with administrative divisions,Shandong Province is divided into three partitions : eastern Shandong and peninsula hilly area,central Shandong and southern Shandong mountainous area,and northwest Shandong southwest plain area.The regional characteristics of rural water supply and water source are comprehensively analyzed.In terms of water supply mode,the single village water supply mode in eastern Shandong and peninsula hilly area,central Shandong and southern Shandong mountainous area is relatively high,and the joint village water supply mode in northwest Shandong southwest plain area is relatively high;In terms of water sources,the proportions of groundwater sources in the three zones were 89.2 %,97.3 % and 95.9 %,respectively.With the expansion of water supply scale,the proportion of groundwater sources in water supply projects showed a downward trend.In terms of water quality,the water quality of water source is basically good,but there is a widespread phenomenon of excessive microbial indicators.High-fluorine groundwater mostly exists in plains and valley basins.Brackish water exists in the coastal area of Jiaodong Peninsula.The water quality of Linyi and Liaocheng has the problem of excessive iron and manganese.(3)According to the characteristics of rural water supply groundwater source in Shandong Province and the relevant standards and norms,the risk assessment indexes are selected and optimized.The analytic hierarchy process is used to assign the weights of the system layer and the index layer,and the risk assessment system of rural water supply groundwater source is established,which consists of 1 target layer,5 system layers and 21 index layers.(4)The principal component analysis was used to determine the first principal components of the influencing factors of water quality in the study area as PH,total hardness,total dissolved solids and nitrate nitrogen.The Gaussian function was used to fit the data point set to draw the water quality change trend.It was determined that the characteristic pollutants in the study area were mainly nitrate.The source of pollutants in the study area was identified by nitrogen isotope method.The nitrate pollution load in the study area was estimated,and the pollution degree of characteristic pollutants was quantitatively evaluated.The pollution control technologies for protecting the water quality of groundwater sources were proposed.