Research On Water And Soil Environment Quality And Health Evaluation Of Hengshui Water Source Protection Area

Water is the source of life.Building a healthy groundwater environment system is part of our country’s economic and social sustainable development strategy,and it is also the foundation of ecosystem health.In recent years,the industry and economy of Hengshui area have developed rapidly,but the problem of environmental pollution caused by the development has become increasingly severe.For instance,the impact of human production activities,transportation and sewage irrigation on the soil and water environment,and the long-term overexploitation of groundwater has caused the dropping of groundwater level and the deteriorating of water quality to a large extent.Therefore,it is of great significance to evaluate the water and soil environmental quality of groundwater sources in Hengshui City,which can provide reference for the protection,response and prediction of environmental health issues of groundwater sources.Previously,the research on the soil and water environment in Hengshui City was relatively scattered.This paper takes Taocheng District,Hengshui City as the main research focus,and conducts the following studies by collecting surface water and groundwater samples,as well as shallow soil samples and deep soil samples:1.The content and distribution characteristics of 10 heavy metals including Vanadium,Chromium,Cobalt,Copper,Zinc,Arsenic,Nickel,Cadmium,Antimony,and Lead in the soil samples were detected and analyzed.The coefficient of variation of Pb content has reached a high degree of variation,which has the characteristics of point source pollution.In deep soil,the accumulation of heavy metals in the silt layer and silty clay layer is obvious,and the variation trends of different elements are similar at the same depth.The distributions of Sb and Cd are uniform which indicate the same migration and enrichment properties.2.The land-use pollution risk assessment and heavy metal pollution assessment were made for the shallow soil samples and the deep soil samples respectively.According to the evaluation results,the pollution risk of surface construction land mainly caused by Co,Pb and As.The pollution risk of surface agricultural land mostly contributed by Cd,As and Cu.The pollution risk of deep construction land mainly comes from Co.The Nemerow index method was employed to evaluate the heavy metal pollution in the topsoil.The conclusion indicated the topsoil was heavily polluted by Co,Cd and Sb.Under the potential ecological evaluation method,the heavy metal pollution in the deep soil is at low potential ecological risk which mainly benefit from Cd and Sb.3.The background values of 10 heavy metal elements(V,Cr,Co,Cu,Zn,As,Ni,Cd,Sb,Pb)in two strata(Holocene and Pleistocene)were calculated,and compared with the background values of soil elements in the national soil C layer and Hebei Province.In general,the soil background values of V,Cr,Co,Cu,Ni,Cd,and Sb in the two layers are higher than the national soil background values,whereas the average content of Zn,As and Pb were lower.4.5 conventional chemical indicators(p H,temperature,conductivity,dissolved oxygen,redox potential)and 4 characteristic chemical indicators(fluoride ion,chloride ion,sulfate ion,sodium ion)in the water sample)content and distribution characteristics were self-tested and analyzed.According to these 9 indicators,differences between surface water,shallow groundwater,and deep groundwater were compared.The result indicated the variability of deep groundwater is lower than shallow groundwater and surface water.Based on the above results,typical sample points were selected for resampling,and 67 of the surface water samples were selected according to the "Environmental Quality Standard for Surface Water"(GB3838-2002)and "Environmental Quality Standard for Groundwater"(GB/T14848-2017).93 indicators in groundwater samples were detected and analyzed,and the water quality of surface water and groundwater was evaluated by multi-indicator method.The evaluation results show that most indicators do not exceed the surface water or groundwater Class III water limit,except for the oxygen consumption slightly exceeding the Class III water standard.87.5% of the shallow groundwater in the whole area is Class V,poor water quality,with the major indicators,sodium,chloride and sulfate,exceeding the standard.75% of the deep groundwater in the region of Class III,indicated the overall water quality is good.5.Using fuzzy analytic hierarchy process to evaluate the health of water source,the index system is divided into 1 target layer,5 aspect layers and 14 base layers,involving 14 evaluation indicators such as water quality,water quantity,and potential pollution sources.The soil environment is included in the evaluation index system,which makes the evaluation results more accurate and credible.The evaluation results reveal that the basic environmental conditions of groundwater drinking water sources and protected areas in Hengshui City are generally good.Among them,the level of investigation and research is excellent,the management status is good,the soil environment status is qualified,however the water quality status and water quantity status are poor.