Research On Groundwater System Vulnerability Responding On Anthropic Activity Based On Hufu Plain Of North China

It is important base to environmental protection and groundwater feasibleexploitation and protection that groundwater system vulnearability assessment. Thispaper discussed the important significance that the research on groundwater systemvulnerability responding to human activities based on four aspects:the necessary demandto comprehended more inherent attribute of groundwater system vulnerability, the inevitableresult to research the affect between groundwater and human activities each other, therequirement of groundwater resources proper utilization and protection,the final need tokeep economic sustainable development. Finally, determining the research purporses ofthe paper are to research how groundwater system vulnerability responded to humanactivities and how anthropic activity impacted on groundwater system vulnerability, andguides to groundwater resource sustainable development.The paper clarified that human activities impacted on groundwater based on the change ofgroundwater dynamical field and chemic field and dividing into three stage based on groundwaterexploitation density, water table change and groundwater quality deteriorate recent fifty years. Theresults are①that the groundwater recharge,runoff and drainage have been changedbecause of overexploitation long-term and making water table change.②that there hasbeen groundwater pumping cone③The TDS and chemic ingredient have been changedbecause human activities disturbed groundwater natural chemic field.The paper foused on the assessment of groundwater aquifer snesitivity andgroundwater resources vulnerability.The former assessment factors are groundwaterdepth, thickness of aquifer send body, hydraulic conductity of the aquifer, vadose zonelithology and recharge of precipitation.The latter assessment factors are groundwaterrecharge, groundwater specific yield, groundwater exploitation intensity, groundwaterTDS, aquifef effective porosity, groundwater feasible exploitation and aquiferthickness.The paper computed the weight of aquifer snesitivity and groundwaterresources vulnerability by grey theory and BP network and proved their reasonable eachother,and assessed aquifer snesitivity and groundwater resources vulnerability andformed their map respectively, the aquifer snesitivity in middle of the Hufu plain isbatter than west and west is better than east; fresh water area is better than salty waterarea.Based on above studies,①the groundwater aquifer snesitivity is invisible whenwater table falling extent is less than 7m; it is probable that groundwater aquifer snesitivity enhanced one level when water table falling extent is 7～25m and aquifersnesitivity enhanced two level when water table falling extent is more than 25m.②Infresh groundwater area, the groundwater resourcrs vulnerability change is unobviouswhen water table falling extent is less than 12m; it is probable that groundwaterresources vulnerability strongthed one level when water table falling extent is 12～24mand groundwater resources vulnerability enhanced two level when water table fallingextent is more than 24m. In salty groundwater area, the groundwater resourcrsvulnerability change is unobvious when water table falling extent is 4～10m; it isprobable that groundwater resources vulnerability strongthed one level when water tablefalling extent is 14～18m and groundwater resources vulnerability enhanced two levelwhen water table falling extent is more than 22m.③The water table deepened is firstfactor to enhanced groundwater aquifer snesitivity,which reduced the chance ofcontamination penetrated into aquifer because groundwater exploitation thickenedvadose zone and reduced precipitation recharge coefficient.The groundwater resourcesvulnerability depend on groundwater system natural conditions and human activities aredominant factor when it impacted intensively on groundwater.The paper analysed comprehensively groundwater system vulnerability and divideHufu plain into 4 area and subdivided into 13 subarea Based on the law of change ofgroundwater aquifer snesitivity and groundwater resources vulnerability with watertable falling extent, optimal water table is 27～30m in fresh groundwater area and 15～19m in salty groundwater area.Finally, the paper divided groundwater exploitation into 4area and subdivided into 11 subarea in Hufu plain based on actuality and current ofgroundwater system vulnerability, groundwateroptimal water table and actuality ofgroundwater depth.The paper overcomed the short of DRASTIC method by mathematics simulationthe assessment factors, assessed comprehensively assessed groundwater systemvulnerability and put forward measures of groundwater proper utilization andprotection,which were innovation of groundwater system vulnerability and offeringreference of groundwater exploitation and protection.