Analysis on the Hydrochemistry Characteristics and the Formation Reason of Groundwater in Wadi Bay Area of Libya

SONG Xiao-ming et al (College of Environment and Resources in Jilin University,Changchun,Jilin 130026)

Hydrochemistry characteristics of groundwater;Seawater invasion;Libya;Arid area;Wadi Bay

[Objective] The research aimed to analyze the formation reason of groundwater hydrochemistry characteristics in the dry valley region of Wadi Bay area of Libya and provide the scientific basis for the reasonable development utilization and the environmental protection of groundwater.[Method] Took Wadi Bay area(dry valley) of Libya as the example,Piper trilinear graphic representation method,the descriptive statistics,the ion ratio coefficient method and the isotope evidence were used to systematically study the special hydrochemistry characteristics of shallow groundwater in the arid climate condition in Wadi Bay area of Libya.[Result] The salt content of groundwater in the area was very high,and TDS was during 3.2-8.4 g/L.The main groundwater type was Cl·SO4-Na·Ca,then was Cl·SO4-Na·Ca·Mg.The concentrations of Cl-,Na+ and SO42-etc.in the groundwater in 70 km from the sea had the remarkable variation,but the concentrations of Mn2+,Ba2+,Si2+,NH4+ and NO3-didn't have the same mutation phenomenon.[Conclusion] The hydrochemistry characteristics of shallow groundwater didn't relate to the lixiviation,the evaporation concentration effect and human activities.The major cause was the mixing effect of seawater and freshwater in the invasion process of seawater.